Slashdot Mirror
Living Without a Pulse
SteamyMobile writes "Can you live without a pulse? Yes, now you can. The reason why we have a pulse is because it's hard for evolution to result in turbines or continuously spinning things. The next generation of artificial hearts may have no pulse. They also have no bearings, so they should last much longer than previous attempts. In fact, engineers don't give a predicted lifespan on these models. How would your life be different without a pulse?"
How would your life be different without a pulse?
I would have had much more in common with my ex-wife.
Trolling is a art,
FTA: "The pump also has a curious side effect: people implanted with the device have no pulse."
/dies
They had better put an obvious port on it so paramedics know it's there before sending voltage through.
I can see the first really drunk guy with one of these taking a nap on the beach:
"ZZzzzzzzZZZZzzzzzZZ"
"Sir!"
"Oh my GOD! He's Dead, Jim!!!"
"He's got no pulse! Call an ambulance!"
(ambulance arrives, 10min later)
"This man has no pulse! I've been giving him CPR since I called you guys and I can't get a signal!"
"CLEAR!!!!!!!!!!!" "ZZZZAPP!!!!"
The dangers of knowledge trigger emotional distress in human beings.
I couldn't listen to pulse pumping techno, that is for sure, though that is probably not a bad thing....
We can't be sure what the pulse controls, plus I would like to be able to tell if I'm still alive.
... at the Doctors office without being able to take our pulse while they stall until there is a doctor available to see us?
having visited the SteamyMobile site, perhaps you're more interested in "throb"?
... waking up in a coffin because someone thought you were dead :(
I hate sigs
I wouldn't be able to tell how hard I'm exercising. Which brings up the point that these turbines are going to have to be variable speed if they're going to accommodate humans' varying oxygen needs.
http://alternatives.rzero.com/
I wouldn't have to take the two different high-blood pressure meds that I do now. That would save me about $35/month and the random side effects that go with taking these medicines (shortness of breath when exercising, dizziness when getting up to fast, etc).
I already live without a pulse...you insensitive clod...
"Facts are meaningless. You could use facts to prove anything that's even remotely true." - Homer Simpson
I heard that people without pulse get a sense of disorientation and un-equilibrium. Especially those with screw drive hearts. Since the body has operated on a pulse for so many years, I have talked to people that have these screw drive heart devices, and they initially they couldn't even sleep at night because they didn't have the pulse in their ear.
I wonder how many goth vampire wannabes will elect to have these implanted, just to improve their authenticity?
If you're living, but have no pulse, I think the real question is: Can you see yourself in a mirror?
~Warning!~ The above is encrypted using rot676!
I wonder what it would do to people should they start to exercise again. I know its not a heart replacemnt but if the blood needs to flow through faster because you are using the oxygen in it at a higher rate would it respond to that? If not rehab is going to be quite a pain in the arse.
Either way this is pretty cool its a step in the right direction for modern medicine and in search of the heart replacement. I dont know if I could live with my chest sounding like a washing machine all the time though that may drive me a little nuts.
Geez, with no Pulse, I guess I'd have to learn how to live with WinAmp. Nah, Deliplayer, for sure.
There are certain advantages to having a "pulse". Examples are: The alternating low and high pressures may allow the bodies baroreceptors to better control blood pressure and there are other important feedback mechanisms associated with having alternating high and low pressures in response to the heart contracting. I would worry that some of the new pumps could undermine those mechanisms.....
Visit Jonesblog and say hello.
Will this artificial heart have an automatic flow regulator, or will there be a nob on the pacemaker allowing the recipient to regulate the flow?
Basically, the body needs to pump varying amounts of oxygen through the body at different times (i.e. running) and would need some method of varying the flow rate.
Or would they perhaps replace one of the patient's nipples with a regulator dial?
You may treat all information submitted above as wild speculation.
is there any way you can confine your wierdness to k5?
11*43+456^2
...they tried that. Complications aroze because the circulatory system wasn't built for continuous flow.
tasks(723) drafts(105) languages(484) examples(29106)
I wonder what kind of effect this has on the body. Think about it, it's a pretty constant stream of blood flowing, as opposed to a stop/start of a pulse. Sure, there's several (I'd say at least... 5 or 6)* pulses per minute, but if I remember seeing video of a cellular level for vessels, it looked more like a semi-congested LA highway rather than a smooth flow. My guess is you'd probably need some sort of batteryless implant that would measure blood pressure as well.
* Very technical here.
Small potatoes make the steak look bigger.
from the article:
"LVADs are not designed to replace the heart but are implanted alongside it under the rib cage."
Therefore your heart is still there beating. This is just a supplement to it.
I can't believe that the body has no problem with living without a pulse! I would have expected complicated side effects (the lack of rythm disturbing some other micro or macro cycles). Any biologists in the house care to explain how far back in evolutionary terms it is since we last had no pulse? Does nothing depend on it or do we really have the diversity in our dna to adapt to the situation?
Never underestimate the dark side of the Source
Then I'd not only lack rhythm, I'd have no beat, either!
Semi-seriously, though, would this eliminate the possibility of things, uh, throbbing?
Ceci n'est pas un post.
A few months back I did a first-aid course at work. One of the interesting things I found out was the technique they use for checking to see if someone's heart is beating:
Basically, you pinch their earlobe. This forces the blood out of the lobe, and then you let go. If colour returns to the lobe, then the heart is beating and blood has been pumped back in. If it does not then blood is no longer moving around the body.
This technique would probably also work for those with no pulse.
I understand that these completely replace the heart, how do they cope with things that make your heart beat faster? like stress, etc.
With no pulse, I'd be afraid to take a nap in the park. "God damn it! I'm in the morgue again!"
What would be worse though...I imagine most of the people getting these will be rather up in years. And, as old people and dads do, they will inevitably fall asleep in front of the TV.
The first 6 or 7 times they do this, their family will think they're dead and will start going through his pockets. But then it becomes a "boy who cried wolf" scenario, and they think he's just sleeping when he's actually dead. Next thing you know, ol' grandpa has funked up the Lazy Boy, and they have to take him out in a bucket.
- First they ignore you, then they laugh at you, then ???, then profit.
He has no pulse sir.
He's the undead! SHOOT IT! SHOOT IT!!!!!!
Wouldn't that constant vortex sucking sound be annoying after a while?
My mom always said, "Jim, you're 1 in a million." Given the current population, there are 7000 of me. God help us all!
I'm sure someone will be adding their favorite politician to this thread but seriously - I'd put money that there will be some consequences to not having a pulse. Valves will not get the exercise they need or something. N million years of evolution (or 7 days of design if that is what you buy into) means that there are probably lots of subtle interdepenancies of a pulsating blood supply. Of course some of the consequences might well be good...
90% of the wealth is in 2% of the pockets. Bummer to be in the majority.
I think this has happened before (someone living without a pulse). There was some old man in Kentucky in the last year or so who was hooked up to an external blood pumping device. He was on the news because he lived for a few months, setting a record for the person who lived the longest without a heart. He was asked by a television reporter what it was like to not have a heart, and the guy said not having a pulse was the strangest thing he'd ever experienced. He said it was really really eerily quiet. Gross.
World's tallest building rises in the desert
Considering our veins are outfitted with nice valves that prevent the backflow of blood in between pumps of the heart, what would happen to them when they are no longer needed? One would think that they just wouldn't close, which I suppose is fine, but it just seems that they might create an unwanted side-effect.
Also, it is possible that our organs aren't capabale of handling blood in a constant stream and they need those precious milliseconds of rest in between beats.
Perhaps I should've stayed in medicine and then I'd know these answers, but since I didn't, anyone know or have a better theoretical idea?
"Time is long and life is short, so begin to live while you still can." -EV
"Must have a pulse" is no longer a requirement. :-)
dinner: it's what's for beer
Too bad this came in too late for Slashdot's previous poll regarding putting yourself on a robot body. Having these means we're one sep closer to becoming Borgs.
Take-off every
Many more torches, pitch forks and steaks.
Like I don't have enough of THOSE in my life already...
You can't take the sky from me...
Rock on caterpillar drive, I say. I'm thinking Hunt for Red October here.
Stem
I would totally mess with people. I'd hang around in busy public areas claiming to be undead (or dead, not sure which is creepier) and then when people questioned me i'd be able to prove, by traditional metrics that i am dead (no pulse). then i would try to avoid the police, because, c'mon, people get creeped out pretty easily.
sigSEGV - doy!
My sex life would be worse. I mean - today I only get those that would "do anyone with a pulse". Once I fall out of that category, my only sex life would be when my pocket is picked.
Underholdning.info
The golf course hasn't put in WiFi yet.
Stephen
"Don't write down to your readers, the only people less intelligent than you can't read" - Sign on Newspaper Office Wall
These things have been on TV here in Australia more than once in the last year or so, they're very cool devices. And indeed, there is no measurable pulse, despite being installed along-side the existing (sick) heart.
The neat thing technologically is the completely frictionless impeller which is suspended by magentic fields and the lubricated by the flow of blood. Without damanging the blood because it is far enough away from the pump walls and moves slowly enough.
Because there is no friction the pump itself should last effectively indefinitely, assuming the wiring doesn't burn itself out.
_
\\/ are accustomed' - First Lensman
I had a class in school that discussed implants in the larger veins, for instance the legs, that would boost blood flow back up to the heart in high-G situations. The idea was to use a low RPM turbine, driven through an inductive loop in the flight suit, to increase blood pressure. The other idea was to use a magneto-hydrodynamic "Red October" style of assist, but there was debate about running that much electrical field through the body/conductive liquid (blood).
I for one, would welcome our new Turbocharged Circulatory Overlords.
I want to delete my account but Slashdot doesn't allow it.
Man, I bet food tastes good through that mouth. And waddaya know, this isn't "trolling"... Well you have a nice day, too. (and no, I'm not going to suggest you have a nice weekend.)
This space intentionally left (almost) blank.
... oh wait... that's common already.
I'm still curious about sex.
Well yeah, but this is for when natures's solution fails. Kidneys and bone marrow solve the blood cell damage problem. :-)
I'm wondering about the little one-way valves throughout the body which aid the pulse. Does such a system damage or suffocate those valves?
Aren't there other systems in the body which depend on the pulse? Could the move to a pulseless heart make a later transplant less likely to be successful?
.... I would fake death more easily !! ;) .. every kids dream ... huh .. wait a minute, i'm no longer a kid !! damn it ...
I fuse with Mercer every single day...
The VentrAssist has two tubes, one drawing blood in from the left ventricle and the other sending it out to the aorta, the body's main artery. A cord emerges from the abdomen, where patients connect it to a rechargeable battery.
Could be a bummer to go on holiday and forget to bring your charger, then.
Matthew @ Bytemark Hosting
Lawyers have been working without a pulse for years!
Slashdot's rate-of-post filter: Preventing you from posting too many great ideas at once.
...could you live with a power cord sticking out of your stomach to recharge the thing? Heh. Interesting.
-- Liberalism is a mental disorder.
I believe it was several several years ago that they had "improved" on the heart by creating a device that worked without a conventional pulse.. everything hooked to it died.. It seems some of our body systems require a pulse for regulation??? I am remembering this from quite a number of years back, but it seems that I recall that this is why they can't keep people on the external artificial heart/kidney too long, because it is a constant flow, and doesn't replicate a pulse. I know I remember this, but I don't know if and/or how we got around it to make it work now.
I've already sold my soul to Milhouse, I'd guess living without a pulse shouldn't be too different.
If someone says he and his monkey have nothing to hide, they almost certainly do.
Hmm, this could be bad for any male porn star that needs a replacement heart. Aren't the male porn stars supposed to be able to hold a throbbing erection? Now it's gonna have the distinct hum of a turbine.
Could be good, could be bad. Hmm.
Presently here, but not there.
Well, that and the guy you just checked screaming "OW! You just pinched me fucking ear!" will probably help as well.
Just look at the *BSD projects ;)
I'm sure "SlashdotMedia" will improve on all the wonders that Dice Holdings blessed us all with
There are some pretty hypothetical models of water flow in the brain that rely on vascular pulatile variations to help slosh things around. If the water (CSF) in the brain acts in part as a cleaning fluid to help dispose of biochemical junk then taking away the pulse may be a very bad thing. Imagine the ineffectiveness of our clothes washer if only spun round and round with no agitation.
For some reason this reminds me of a rotary engine. Lets hope they run a little better than those used in the RX-7s, no one wants their heart burning oil (although the added HP is nice).
On a serious note, I've always wondered how artificial hearts adjust pulse (or in this case flow). If I had one of these and went running --probably not a first choice of activities for someone with an artificial heart -- would the flow increase?
That's because it's too easy for the manufacturer to go back on that lifetime warranty.
There was once an article about one of the first patient to receive a mechanical heart valve, who was travelling by air. Apparently, the security staff wouldn't let him onto the plane due to the ticking noise they heard emanating from his chest cavity. The patient had to call up the hospital and get confirmation from the doctor. On later flights he had to carry a certificate in his passport explaining the source of the noise.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
>Man, I bet food tastes good through that mouth
are you trying to make fun of disabled people? fuck you, prick.
Until slashdot has a section on mythology it'd be wise to keep your superstitious beliefs to yourself.
In fact, engineers don't give a predicted lifespan on these models.
I'm not sure that fact would comfort me were I to need one of these things.
Similarly, I recall seeing a documentary on this, which mentioned that the pulse may in fact be necessary to control and stimulate the growth of vessel walls. Anyone know if the opinion on this has changed?
Parent is on topic, especially the validity of so many elective surgeries now days and the fact that the world is obsessed with making themselves different than who they truly are.
If we can flag comments funny because they make a point of the uses of these devices, we can mod this guy insightful for thinking of potentially valid uses of the product in discussion here.
All i can tell you is that you define it really well, with all you existencial problems! Only humans do that ..
I fuse with Mercer every single day...
Not a reliable indication. You'd be amazed how much peripheral circulation shuts down in patients in shock as the body attempts to maintain blood pressure in the core. At best, refill at the lobe will give you a general idea that the patient may be perfusing well, but lack of refill is certainly not an indication of pulselessness. Circulation out at the skin layer is one of the first things the body cuts back on in an attempt to combat shock.
(IMHO - however I speak from many years of experience as a Paramedic.)
Interestingly enough, there was a sci-fi book years ago that had this concept as an important detail. The book is called Superluminal and the author is Vonda K. McIntyre.
The book is about faster than light travel through other dimensions beyond the 4th. The pilots of the ships had their hearts removed and replaced with pumps that the pilot could control through biofeedback to allow them to control their bodies more closely through the stresses of superluminal travel.
"Sometimes the truth is stupid." - Lawrence, creator of Prime Intellect
Maybe these things will make artificial "Thump, Thump" sounds, just like some digicams that do an audible but synthetic "click" when triggered.
How long does this thing last on battery power? It seems to have an infinite lifespan due to no physical contact of moving surfaces but I expect it still needs a battery.
Reviews with a twist! http://www.sardonicbastard.com
...you could have at parties, meetings, and so on. Just sit/lie/lean there, not moving, wait til someone takes your pulse, and watch everyone go nuts.
Of course, with my luck, the person who knows CPR won't be Hello Nurse...
The human body is wonderfully designed and mainted in equilibrium. It is not designed for changes such as these. The end organ systems require high enough blood pressure to perfuse the capillary beds, delivering oxygen at a fast, predictable rate. This pressure is delivered with the contraction of the left ventricle as the blood then courses through the aorta and to the rest of the body.
HOWEVER, the arterial system NEEDS a period of relaxation, diastolsis. The arterial system will develop atherosclerosis, or hardening of the arteries, calcium deposition, aneurysm formation with possible dissection etc unless the pressure is allowed to relax. It can cause end organ damage if there is not this pressure release. Particularly at risk are the kidney. Chronic renal failure may develop as the kidneys lose function because of the constantly high pressure. It is difficult to improve upon what we currently have.
And yeah, I did just get modpoints... so if you post on this topic, I guess you're safe.
No friction, eh? I guess, then, they only need to give the impeller a push and it'll keep going for ever. Mind you,the impeller is coming into contact with the blood, so I think their would be at least some friction, which means that the blades should eventually wear down... A long time from now.
When you are excited or nervous, others complain they hear a faint whirring sound...
Live free or die
Like, a few years ago. I also remember seeing it on TV in Britain. IIRC there were problems keeping the thing from getting clagged up, because the body tries to coat foreign objects with tissue, but IANA physician.
When I am king, you will be first against the wall.
to do some overclocking tests on it to create "The Doom3 Utlimate Body Guide"
"Look Lois, the two symbols of the Republican Party: an elephant, and a fat white guy who is threatened by change."
My mind keeps thinking of that old adage, "It's not nice to fool with mother nature."
When you get to my age, the present is a very alien place...
Using HTML in email is like putting sound effects on your phone calls. Just say <strong>no</strong>.
This reminds me the way airplanes evoluted... For nature is easier to make the birds move up and down their wings. Man at the beggining tried to copycat the nature and tried to make planes with moving wings. But as we all now it is much easier for humans to fly using turbines. Maybe this is the case with hearts too. Instead of trying to mimic the 4 chambers way that natural heart uses, we should use our good old knows turbine pumps...
http://www.imdb.com/title/tt0083197/
It's called "Threshold" and it's about a non-beating (turbine) artificial heart.
What do you know? Art actually beat Life to the punch!
there are alot of factors that require the pulsing of a heart. for instance you have the various valves in your veins that prevent backflow. these valves provide some resistance, and are essentially calibrated to perfectly open up for maximum flow at the peak of the hearts pulse. now unless these constant flow pumps are running at the peak pressure that a heart makes (which cant be good for the body either).. then i see bad circulation for the fingers and toes (and more) as this is where the most resistance is.
... my original model, thanks.
Seriously though, as long as you're still breathing I doubt it's an issue. I don't think most people would bother checking for a pulse (something that requires physical contact) if they can see you breathing.
You are not alone. This is not normal. None of this is normal.
Well, for one thing, that weird, blue fish guy (w/the voice of Niles Crane) in Hellboy wouldn't be able to sense me behind walls!
(Sorry... Just saw the movie last night & it's on my mind)
Seriously, wouldn't this result in a whole new line of doctors if this becomes common place?
There's so much to specialize in regarding the circulatory system now, that it seems no pulse would warrant an entire new line of doctors prepared to diagnose and treat ailments to those who don't fit the normal modus operandi of pulse/heart related diagnosis.
It also begs the question of whether or not other body organs and/or functions rely on a pulse to syncronize their operation. Anyone know?
It's actually sad that they're teaching this. It's not reliable in all cases. I suspect they've fallen back on this method because too many people either panic in a real emergency, or just can't seem to be bothered to learn to do it right.
"Scanners Live in Vain"
Also see Vonda McIntyre's story "Aztecs".
Both involve the removal of hearts for purposes of
space travel.
When I took my freshmen chemistry courses in college, we had electronic stirs - you'd drop this plastic coated magnetic "plug" in a beaker, and then set the beaker on the machine. An alternating magnetic field would cause the plug to spin, stirring the fluid.
And now, 15 years later, someone finally figured out that you could apply the same principle to moving blood. Amazing.
I've always wondered why people bleed to death on the operating room table from trauma. When I worked as a mechanic, I had a supply of various diameter tubings readily available so I could plug a vacuum leak when diagnosing a carburetor malfunction. I've never understood why surgeons can't do the same with blood vessels - the patient is bleeding from a major artery, and it never occurs to them that the could slice the artery in half and connect the ends with surgical tubing?
I had always thought that there must be some really scientific reason for this, but now it occurs to me that it might just be ignorance. It took medical science 15 years to figure out that a lab stir would work better than bearings? I knew that as a freshmen! Ask the hubble designers - it uses frictionless magnetic bearings - maybe they could have clued someone in?
The society for a thought-free internet welcomes you.
I had a very similar reaction, IANAHS (I am not a Heart Surgeon) but in the article it says...
it only has one moving part, a spinning impeller that drives a continuous stream of blood.
Surely the human body is not designed for a continuous stream of blood ?.
Saying that I am sure that this has all been researched thorougly to get to this stage and my limited medical knowledge probably isn't very useful.
You are absolutely correct. If you look at the internal surface of a major vein you will notice that it it is uneven. It does not allow blood to flow back and this works properly only with a pulse flow. It will not work properly with a constant flow. So people who rely entirely on a device like this will be prone to various vein problems - varicose veins, cirrose like vena portalis deformities, etc. So devices like this cannot replace a heart 100%. At the same time they may be enough to provide assistance for a week or failing heart (this is what these guys are claiming to do anyway).
While on the subject, continuous exposure of blood to a strong magnetic field is not something that has been investigated and there may be some long term problems associated with it.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
..it's time to throw out your organ donar card.
UNIX/Linux Consulting
There would still be a need for the valves in the veins for stopping backflow. The venous pressure is very low. If i remember right (my last physiology course was a long time ago), most of the return flow is added by movement (muscles squeezing the veins pushing blood through the valves and the breathing cycle which causes the large veins to expand and collapse which pulls blood back to the thorax and towards the heart.
This is a very simplistic explanation as I remember it, and I haven't had much coffee yet so the old gray matter is not ticking at full speed yet.
The two values in a blood pressure reading represent pressure during contraction of the heart (the top or systolic value) and during relaxation (the bottom or diastolic). If the pump maintains constant pressure, there would be no diastolic value.
Also, current methods of taking BP rely on the presence pulse noise (that's what they are listening for with the stethoscope when they release the air from the cuff). A new method would have to be devised.
The scale wouldn't tremble when you go to weight yourself, for one.
Also, if you had an unrelated accident that caused you to go unconscious, I assume you would have to have a Medic Alert bracelet that says you don't have a pulse so that rescue efforts wouldn't be prematurely terminated.
i'm amazed that i survived - an airbag saved my life.
the procedure is actually to assess them first... something along the line of shaking them and asking "Annie! Annie! Are you OK?"
If they answer "yes," you're done.
I realize you were only joking, but the entire clinical picture needs to be taken into account.
My favorite EMS call is the patient with a minor head injury who is rushed in with a "blown pupil." When you go see the patient, they're awake and alert, not vomiting, not somnolent, etc. It's usually someone who's new, and doesn't understand the pathophysiology behind Uncal Herniation and 3rd nerve compression.
Back to the topic at hand... I wonder if the lack (or blunting) of the systolic peak and diastolic trough in the blood pressure would lead to any physiologic problems? According to the article, the device is actually a Left Ventricular Assist Device (the ole' intra-aortic balloon pump is the classic example of such a device). It steals blood from the left ventricle and steadily pumps it into the aorta... but I wonder if it has any effect on the coronary arteries?
The coronary arteries mainly fill during diastole, when the aortic valve closes and blood floods the coronary sinuses on the aortic side of said valve... since this device essentially "steals" blood from the left ventricle and injects it somewhere downstream, I wonder if the coronaries get the same filling? (I suppose it's a question of where you place the downstream catheter.) It might not make a difference if you have clean coronaries, but if you've got a Left-main stenosis, it could be bad to drop that filling pressure...
In a perfect hydraulic system, it wouldn't matter, since pressure injected in one location would increase pressure in all locations... but arteries have compliance, and they can flex.
Interesting device... it'd be nice to know some more details.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Lol. As a former nuclear/plasma physics graduate student, it makes me laugh even more. Do you know how that caterpiller drive actually works? The field of study is called magnetohydrodynamics and is one of the most @*#%$!* involved things I've studied...
Basically, you have an electric field of some sort or readily available ions (think, salts in the ocean water), apply some strong magnetic fields of differing strength, and cause a forceful ion drift in the direction perpendicular. I just call it Evil Fluid Dynamics With 50 Other Variables.
As an aside, since there are relatively fewer dissolved salts, the Red October's caterpiller drive wouldn't work in fresh water. Neat eh? Not that there are terribly many huge bodies of fresh water where you'd worry about silent submaries.
At any rate, there are dissolved salts in blood, aren't there? So you could theoretically do this for a heart pump. But who knows what the heck it'd do to the patient and I'm guessing you'd need a whole lot of auxiliary equipment.
A preposition is a terrible thing to end a sentence with.
Darl McBride is living proof you can survive with no pulse.
Linux with kernel panic...
MadPenguin.org
If you couldn't dance before, you'd be doubly screwed.
It seems odd that you'd think such a macroscale impeller would "slice" such tiny objects.
BTW: I think the difference between propeller and impeller is that propeller is intended to move an object in a medium (boat in water) and impeller is intended to move the medium through a system (water pump for plumbing). Both use spinning blades to perform the task.
I'm wondering about the little one-way valves throughout the body which aid the pulse. Does such a system damage or suffocate those valves?
Also, the heart isn't the only pump in the body - the muscles in your legs help return blood to the heart when you run. That why if you run then stop abruptly you feel faint, because suddenly the load on your heart has suddenly increased and it needs to ramp up to pump blood all the way up to your head at a usable pressure (which is one reason you should warm down properly after exercising). How would the impeller interact with "pulses" from the legs?
Would this new heart increase/decrease blood flow as the body requires? How do you check for an elevated heart rate? Is this even possible with an artificial heart?
It'd be kind of weird for EMTs and first responders. Our training tells us that the first thing we do for a victim is check the pulse...if 'not having one' could be considered normal, it'd throw a wrench into the works. Imagine having to wear a bracelet asserting that yes, you're not supposed to have a pulse.
Also, arterial bleeding could be harder to identify, and therefore more dangerous. There are other ways to tell if it's an artery bleeding, but the spurting is what people tend to look for.
Would it not be simple to have the turbine increase and decrease blood flow in order to mimic a normal pulse?
I would think that this, if implemented properly, would prevent those health problems associated with constant blood flow through the veins and arteries.
"When God kisses Satan and the Incarnations applaud." "Death is dead. Long live Death!"
On arteries? and so, less chance of a stroke, or a blood vessel tearing?
Blood pressure monitors would not work as you would not have the two readings?
Would your bodys sense of rhythm be altered? no internal metronome?
Even if they do check you might end up with a wooden stake through your fancy pulseless heart tho.
As someone who has worked with impeller pumps for the last decade, there is going to be a significant difference in the amount of damage done to the cells. I have seen live sea-life on the output side of impeller based pumps, where a propeller style pump does as you say, chop every thing up.
IIRC, blood vessels contain a number of one way valves which open and close in response to a pulse, so I'm surprised that these don't fail and have problems in the absence of one.
Maybe the pulse is not totally absent, from the article, this only replaces half of the heart, presumably leaving the other half to pulse along as before.....
I presume that they can't really pulse the pump to truly simulate a heart operation, as that may have effects on its power consumption and reliability.
On another subject, is blood affected by magnetic fields? I just wonder if any problems are caused by the magnetic coil drive system of this thing.
Donte Alistair Anderson Roberts - hi son!
Karma: Chameleon
There's a movie called Threshold with Donald Sutherland as a doctor that implants an artificial heart which does not produce a pulse. I recall it being quite good, although it was a long time ago.
I would think that a continuous flow of oxygenated blood would provide greater efficiency than a pulsed flow. That is, unless you need the pause to give time for the oxygen transfer.
I'm in the hole of the broadband donut.
---------------
Well, it would definately help tighten the groupings up at the shooting range. This could be a big boon to snipers :)
I wonder how long before someone who gets one of these constant-flow style of artificial hearts, decides to tweak others by putting forth the claim that they're a vampire?
;-)
"Here, look, feel my wrist, see? No pulse. Put your ear to my chest, no heartbeat."
And I wonder if the artificial heart's warranty covers wooden stake damage.
He's Dead Jim. No wait wait he's alive.
This
... to judge where I am at my training / during racing.
If you want to e-mail me, use my PGP Key.
No pulse:
Vampires have no pulse.
Dead:
You are living on borrowed time.
Need blood:
These artificail pump tend to damge blood cells. You need some kind of replacement for this.
Long livetime:
form the article: " There is no predicted lifespan for VentrAssist because there are no wearing parts"
SMG: more work for you!
Actually, I read a Reader's Digest article about a similar pump a couple years ago. Some young girl in England had a viral heart infection and would have required a transplant. Instead, they stopped her heartbeat and implanted a constant pump like this. The doctors were all concerned about the effects of not having a pulse, not having 2 bounces for blood pressure measurements.
She lived quite well with the device and the stopping of her heart actually let the heart muscle repair itself. It turned out that resting the muscle was very good for it. She was eventually taken off the device and her heart restarted.
So no, there are not the adverse effects doctors had theorized about.
Do really dense people warp space more than others?
mdiarmspafpothama (My dad is a retired medical school professor and former president of the heart association midwest affiliate) and he agrees with you.
I told him about a woman in england that had an earlier version of one of these for several days while waiting for a real (human) heart (this was a few years ago). His imediate reaction was that pulsitile flow probably slows the build up of plaques in the arteries, and that people without a pulse would, IHNSHO (in his not so humble opinion), be more likely to experience blockages.
Of coarse that was just his gut reaction and he has not researched the topic...
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
Well, im pretty certain its important. Stresses tell cells how to grow - without gravity providing feedback bones decalcify. Im sure there are growth processes that are pulse dependant that direct the proper functioning of blood vessle walls. Pulses also have a pumping effect, where blockages down at the capillary level would be cleared by the pressure peaks whereas with a static pressure the blockage would not clear.
So basically most Americans effectively have no pulse already? I swear, we're always ahead of the curve.
You better watch out, there may be dogs about . .
If you look at the internal surface of a major vein you will notice that it it is uneven. It does not allow blood to flow back and this works properly only with a pulse flow. It will not work properly with a constant flow.
But a flowback prevention device is only needed because of the pulsed flow. Without flowback prevention, blood could never reach the head as it would keep running back down the arteries as the heart cycled. As long as a continuous flow is of sufficient pressure, this problem is eliminated, and the need for flowback prevention is removed.
I remember reading about a condition in a heart-lung patient called "pumphead", and found a partial article online. So there may be something useful to the body that a pulse provides. Some capillaries may have come to mechanically rely on the high and low pressures provided by a pulse. I'm reminded of how tides are useful to life on ocean shores like certain sea anenamies, or gremlins or turtles that deposit their eggs during the highest tide of the month.
I spit coffee all over my desk.
Nah, not politician.
I think getting one of these is a requirement for all management positions.
Generally speaking, however, if you have a medical condition that necessitates a heart transplant(!) chances are the doctors aren't going to be cool with extreme physical activity
In fact, they may forbid you any sort of strenuous activity including (*Gasp*) sex.
You better watch out, there may be dogs about . .
.....will the Corazon 440BX model allow me to overclock?
Apparently the reason they now teach this method is because it's more reliable for those who haven't had a great deal of training - i.e. most First Aiders.
Obviously the pulse check is only used after you've already checked for breathing.
Exactly what I was thinking. The law of unintended consequences may come into effect here.
The lack of a pulse may not seem like a big deal, but the physiology of human blood pressure is based on pulsatile flow. The loss of that "pulse" may cause real problems... would small emboli or damaged red cells will get stuck in the microcirculation without that pulsatile flow to dislodge them?.
Where it would cause problems for me clinically is when placing arterial lines, drawing blood gasses, or assessing for arterial insufficiency. For example, every elderly patient who comes in with a broken hip gets a pulse check in their leg... if it's not present, they have a much more urgent problem than simply getting their hip fixed with a gamma nail... the same would apply if they were in an accident and broke their femoral shaft. Also, anatomic variations are common... how do you find the artery if there's no pulse?
The ability to assess for a pulse is very important in clinical medicine... I'm sure there are many more examples.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
What if a person with one of these suddenly passes out? I can already see the horror stories about EMTs using a defibrilator(sp?) on someone simply because they couldn't find a pulse.
ASCII pr0n. Coming to a Lunar Lander near you!
So, what invariably causes death is that something happens to the body that places it under stress. When the body realizes it can't go on, the heart fails and the body dies...
So what happens to people suffering from disease that won't be able to die? The heart will just keep going and going, keeping them alive unless maybe their lungs fill up with fluid... I don't know that this would actually happen, but if someone lives so long on one of these things that their quality of life is shit, what do you do then?
I suppose they could commit suicide, but many religions forbid it, and it is even against the law in some states.
Just a thought..
Blood just squirting is woefully inefficient. Now when you cut a major artery, you'll die much more quickly.
If I understand it correctly the reason they teach this method to First Aiders is that it's generally easier and more accurate for those who've not had a great deal of training or experience in detecting pulses.
Basically, you pinch their earlobe. This forces the blood out of the lobe, and then you let go. If colour returns to the lobe, then the heart is beating and blood has been pumped back in. If it does not then blood is no longer moving around the body.
Often called distal capillary response, it's more a measure of your blood pressure than a beating heart. Granted you won't have one long before you loose the other, but it's possible for people to have very low blood pressure and not have an immediate response, causing you to think they have no heartbeat. Also, small children sometimes have weird responses, especially with nail beds, no idea why.
Incidentally, the AHA has recently switched from checking for a pulse to checking for "signs of circulation" (coughing, breathing, movements) in all class levels except their highest (designed for healthcare providers) as laypeople were screwing it up a huge percentage of the time.
But but but ... removing the pulse would be like removing the clock signal from a motherboard. I'm all for overclocking the heart/brain with a little caffeine ... but removing the clock signal altogether is a little too 'way out' for me. I never did believe in those analogue computers ...
The thing about a pulse is the blood vessel valves need only open at the peak pressure of the pulse. The rest of the time the blood pressure can be quite low. On average the blood will still flow the right way.
:).
Whereas for a pulseless heart the blood pressure has to be at the peak continuously.
There are also other issues to do with general plumbing - I read somewhere that heart surgeons have found putting a slight twist in a bypass vein makes it less likely to clog up. Theory is that it causes the blood to swirl and that could help keep the vessels clear and healthy. I can't find the original article (New Scientist) but you can read about it here.
Quote: "They discovered that the smooth shear stress caused three genes to become more active (New Scientist, Science, 5 October 1996, p 17). Two of these code for enzymes that reduce blood clotting and protect cells from damage. The third gene produces a protein vital for the synthesis of nitric oxide, which inhibits the development of thrombi--blood clots--and prevents the surrounding layer of smooth muscle cells from overgrowing the endothelial layer. But the activities of these genes were barely detectable in cells that felt turbulent shear stress or no stress at all. Some stress, it seems, is a good thing. "
So without a pulse it is likely that the cells may not behave correctly.
Well at least you might have some fun with the old-style lie detector tests
Or maybe because so many people are too fucking fat to find a pulse?
No, put you'll have to pay for fresh batteries (even rechargables loose their potency after a while) and electricity costs for recharging them.
Except maybe since its a mechanical heart, it will just tell you that the pump is still working. The person may be somewhat dead by then with the pump still circulating the blood and keeping the person at least seem moderately alive.
http://imdb.com/title/tt0083197/
He's not a doctor, but he played one in the moovies.
--- Ban humanity.
A couple of years ago there was an artificial heart installation in Rochester, NY that gave a "pulseless" heart to an old man. He lived for a little more than a year, then died of something else I think.
Old news?
-Jem
> Maybe the pulse is not totally absent, from the
> article, this only replaces half of the heart
Yup, but it's the part that pumps the blood from the lungs into the body. So the majority of the body would have no pulse.
The valves are there so that during the inactive part of the heart's cycle, the blood doesn't rush in the wrong direction due to gravity - otherwise, for example, your legs would basically inflate with blood.
If that's it (and IANAD), that means the valves exist precisely because the heart cannot sustain a constant pressure, but pulses. No pulse - no valves needed.
However, the valves also regulate the distribution of the blood in the body. I have no idea whether tht function would be affected.
I can see it now - A pressure gauge implanted among your chest hairs.
:p
If they wanted to make this technology useful, give me a way to "tune" my pressure. It'll ruin the market for viagra!
Mod me troll, if you must, I can't help it.
Without a pulse you would be legally dead in most countries
it only has one moving part, a spinning impeller that drives a continuous stream of blood.
IANAHS, but I think that heart-lung machines don't use spinning blades because they would fold the red cells. They use a rubber pipe which is squeezed from outside, achieving a similar effect to the way in which the heart changes shape to move blood.
# cat
Damn, my RAM is full of llamas.
Anyone with a current artificial heart, or even a pacemaker, has a constant pulse. A pulse is selected to allow a little excess capacity, so that gettting of the couch doesn't get you winded.
Breathing is variable as someone else mentioned though... this provides for some variation in oxigen delivery to muscle tissue. Anyway, people who have artificial hearts should be taking it fairly easy.
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
So... it appears we'll have to come up with a new way to measure blood pressure, particularly. Presumably, the best way to do this is to fit the turbine with inlet and discharge pressure sensors, and a flow meter. Step 2 is to establish some sort of numbers for what is "normal" for turbine heart patients.
This ups the ante for health care professionals by a bit. Not only do you need to know normal ranges, consequences, and treatments for standard BP and pulse ranges, you would need to be familiar with turbine pressure and flow ranges as well.
This thing is powered by battery power. You could conceivably have blood flow and pressure after death. What happens the body dies, but the heart doesn't get the message?
Sometimes I worry that I'll develop Alzheimer's disease, but no one will notice.
I'm sure the doctors doing the research know much more about this than I do, and have done sufficient animal testing to prove the device's safety in humans, but I still have to wonder, like you said, that we may not know all of what we're messing with.
That said, it'd probably be great fun at parties. "Man, I think I smoked too much, I can't feel my pulse!"
I feel fantastic, and I'm still alive.
We could always test the theory on some of those stray cats people like to use for target practice. ;-)
I'm curious if they could push the constant flow from the turbine into an elastic, valved chamber. If the valve worked like a pressure relief valve in an air tank, the pressure would build until the valve opened, releasing a rush of blood until the pressure dropped back down to a much lower level, at which point the valve would close again and the cycle would repeat.
How would your life be different without a pulse?
Well, for one thing, I wouldn't be able to have throbbing, pulsing erections"There is no predicted lifespan for VentrAssist because there are no wearing parts," says co-inventor of the device and company founder John Woodard. "It could be a hundred years, we don't know."
Sorry, but if you can't even offer an intelligent analysis of the lifespan issue, then you don't know enough about your device.
Makes it sound amateurish.
Memorable Quotes from
Day at the Races, A (1937)
[Taking a pulse]
Dr. Hackenbush: Either he's dead or my watch has stopped.
http://www.imdb.com/title/tt0028772/quotes
"This? I can make a hat, I can make a brooch, I can make a pterodactyl..."
Only arteries have a pulse. The blood flow is as follows: heart -> arteries -> capillaries -> veins -> heart. By the time the blood gets thru the capillaries to the veins the blood pressure is vastly reduced and the pulsatile flow generated by the heart is not felt in the veins. Hence veins do not have a pulse. The valves in the veins have nothing to do with the pulsatile flow of the heart and hence a constant flow heart will not affect the functioning of the veins in any way. Venous problems like varicose veins, cirrose like vena portalis deformities are not related to how the heart pumps.
capilliary flow, where most oxygen exchange takes place, is pretty much constant flow anyway.
The funny thing about a pulse is the fact that it keeps putting stress on the arteries, keeping their flexibility up and helps removing miniscule amounts of sediment.
It will be quite funny to watch people with artificial hearts die of arterisklerosis way before their time because some eager engineer thought that a smooth pump would be a good idea.
I just got a nifty heart monitor for running. Guess I should just go eBay it now...
I have a low LVEF (Left Ventricular Ejection Fraction). A couple years ago while jogging I suffered a tachycardia (extremely rapid heart rate) that had me at around 300 beats a minute for 45 minutes. They gave me a defibrillator, but said that it was possible that the drugs might not be able to stop the decline of my LVEF and would require a heart transplant. Heart transplants are extremely hard to get, btw. Basically, if you need one, you're screwed.
So to me, this device looks pretty darn cool. The cloned hearts grown from your own cells method is also pretty darn neat. The prospect of being an actual Borg is enticing, but the reservations about secondary effects of not having a pulse do give one pause. Yet if going with a cloned heart encourages the cloning of other organs, then perhaps that would be a better way to go. Decisions, decisions...
Do what you can, with what you have, where you are.
- Now, let's say that they determine that the guy with one of these hearts dies. If the heart just continues to operate, things could get
- messy when he gets to the morgue! And the mortician may have some psychological problems after cutting open a dead person have having blood flow out of its body instead of just leak out since the artifical heart is still operating.
Before I go any further, I'll stop.I have a bumber sticker in my cubicle that says
What if you faint?
Isn't it bad to have CPR done to you if your heart still functions.
Thanks to the internet, we can now all die alone together! -SomeWoman
consult with/trust in yOUR creators.... keeping things flowing 'smoothly' since/until forever. see you there?
tell 'em robbIE? or knot? as for the fauxking PostBlock censorship devise: phewww
I seem to recal this type of artificial heart in a movie that came out sometime in the early 80's. I don't remember much about it mainly because I was 13 or so but I think it had Donald Sutherland in it.
Any ideas?
that's besides waking up in the middle of the night, feeling no pulse and screaming...
Science as a way of life.
I'm personally not into elective/cosmetic body modifications (or, frankly, even into things like getting a haircut, me damn hippie), but I have talked with some people that are, and they say the purpose of their modifications is to bring their bodies in line with who they really are.
Such would also be the case with, say, sex-change operations. Or even people that get surgery because they think they have ugly noses (when they think the nose is ugly, it's not even so much their nose anymore as just a nose they can get replaced).
Most people do things intentionally to change who they are. I, for example, run. I wasn't naturally able to run fast, but I practice it so I can. People often change themselves by learning things (i.e., someone who isn't a programmer wants to be a programmer and thus learns to program, turning self into programmer). Sometimes body modification is a way they do that.
Mod parent up.
This is correct, valves in venous sysmte do block back flow, but they do not rely on your heart pumping, rather they need the muscle arround them to compress them.
Soldiers standing at attention for long periods of time are prone to fainting because they are not moving their leg muscles and the blood is pooling in their legs.
When your leg muscles contract they also compress any veins near by, the vein valves cause the blood to move primarly toward the heart....
(IMAD) I am a doctor.
DJMD - The fourth man - Planetary
I wouldn't know; In high school, my BP tended in the uncomfortably low 80/50 range... which caused at least one school nurse much consternation, as she couldn't find my pulse in wrist or throat. "Dear, are you sure you're breathing?" Since getting out from my mother's obsessively healthy "low salt/low fat" cooking, I've achieved a more normal 100/70 normal BP.... but I still don't hear my heartbeat.
//Information does not want to be free; it wants to breed.
Alas, some poor soul might not meet the primary requirement for our nation's great vocational colleges.
The angel in the oatmeal.
I'm black you insensitive clod
I'm no medical proffessional, but isn't blood pressure measured by listening for the pulse while constricting the flow with a sphygmometer.
How would blood pressure be measured without this reference. Like air pressure in tires?
Thanks to the internet, we can now all die alone together! -SomeWoman
The reason why we have a pulse is because it's hard for evolution to result in turbines or continuously spinning things.
:-)
That's a loaded sentence
It's also hard for evolution to result in something as complex as an eye; In fact, if you look at how many seperate pieces must 'evolve' for an eye to function, you'll realize that a turbine would be much easier to 'evolve' than an eye.
This is not flamebait... lol... In fact, run over to your library (bookshelf?) and grab a copy of Darwin's book "On the Origin of Species..." and turn to page 162. Read the section about the mousetrap. Darwin concludes that "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." (i.e., an irreducibly complex system). A mousetrap has five essential pieces - and if any one of them is missing (i.e., the spring, the hammer, the catch, the platform or the holding bar), the trap will not function.
But back to a turbine, which you say is impossible for to evolve on its own...
I'll take your challenge one step further and show you something that does exist in nature: the flagella on a bacterium.
A flagellum looks kinda like a hair that's attached to the surface of the bacterium. It acts like a propeller & allows the bacterium to swim. The flagellum is attached to and rotated by a small electrical motor made up of several different proteins.
The flagellum contains a rod (i.e., a drive shaft), a hook (i.e., a universal joint), L and P rings (i.e., bushings), S and M rings (i.e., the rotor), and a C ring & stud (stator). The electrical power for driving the motor is supplied by the voltage difference developed across the cell membrane.
Anyway, what was that about evolution not being able to cause a turbine to be created? I definitely agree with you on that point!
Can anyone offer a plausible explanation for how any one of the pieces of a bacterial flagellum would offer that bacterium some sort of advantage?
That said, it would be really weird to not feel my own heartbeat!
I can't believe the number comments that were posted before Politburo pointed out the obvious...
The heart can not stop, and lungs might work for a long time under these conditions, even if you are brain dead. I can see a big problem with these people just failling into a coma, that doctors can not guarantee is permanent.
When I cut my arm off, I will be able to bleed out just like the Black Knight in Monty Python and the Holy Grail.
Picture include for the visualizationally challenged.
"I went on a diet, swore off drinking and heavy eating. And in fourteen days, I had lost exactly two weeks. Joe E. Lewis
I'd be dead.
I am waiting for the artifical lung that uses my computer fan.
No more pumping my chest muscle just to get air in and out.
I can't wait...
Breathing with your own lungs is for suckers, anyway!
I live the greatest adventure anyone could hope for. -- Tosk the hunted
- I live the greatest adventure anyone could possibly desire. - Tosk the Hunted
Well that might be nice. Instead of arbitrary numbers that don't mean things to people, you could just tell them they are at $x PSI =P
When you place the heart at rest, you remove the load it sees, and use an artificial pump to do the work.
You don't stop the heart. Even today, with cardioplegic solutions significantly advanced, supplemented with NAD-compounds and amino acids, stopping the heart bears the significant risk that you can't get it restarted again.
Cardioplegia for cardiac surgery involves infusing a potassium-rich solution into the coronary arteries, which stops the heart in diastole. Further, the solution is cold, and the heart is bathed in an iced saline slush to cool it further and diminish its metabolic requirements. At this point, the heart is *NOT* getting a blood rich perfusion (barring the use of blood-based cadioplegia, which I'm still not sure is as good an idea as some others think) medium.
If you were to start reperfusing the arrested heart with blood, with a normal electrolyte composition, the extra potassium would be washed out, the heart would rewarm, and if it has sufficient energy stores, and a sufficiently normal physiology, it would begin to contract again.
So: To put the heart at rest, you unload it, keep the blood chemistry as normal as possible, maintain good nutrition status (parenteral alementation), and see if the heart muscle recovers.
Never ascribe to malice that which can adequately be explained by tenure.
What about the affects on the mind? A beating heart can be like a clock ticking and giving us a sense of time.
Not only that but it might be like someone having heard static in the background all his life and then suddenly the static stops. This could be a good thing but it could also seem very weird.
Al Gore's been doing it (living withut a pulse) for years, so we know that the side effects are too terrible to contemplate.
that is the exact purpose of the aorta - it's elastic walls enable it to mitigate the pressure differences and provide a continuous bood stream /more or less/ to the rest of the body.
The problem is that that was a short term replacement. It could be that problems don't show up till you've had a beatless heart for years, so we can't rule out difficulties yet.
But OTOH there may be no problems at all, so if it's more reliable than existing artificial hearts I'd probably take it over the old design, if I needed a new heart. (I'm planning to keep my current one for a while yet though)
"The price good men pay for indifference to public affairs is to be ruled by evil men." -Plato
Without a pulse, you might have a sexual response but it just wouldn't be exciting. Pulse puts the throb in the knob.
Now their snipers won't have to worry about firing in between heartbeats. Anybody want to bet on how long it'll be before we have black-ops cyborg snipers with no pulse?
Could it be becuase they're busy doing real work?
Also, the heart isn't the only pump in the body - the muscles in your legs help return blood to the heart when you run. That why if you run then stop abruptly you feel faint, because suddenly the load on your heart has suddenly increased and it needs to ramp up to pump blood all the way up to your head at a usable pressure (which is one reason you should warm down properly after exercising). How would the impeller interact with "pulses" from the legs?
If someone is in such bad shape that they need an impellor blood pump installed, then I seriously doubt that running or any other strenuous exercise will be on their agenda.
Restarted her heart ?!? That's frickin' crazy ! Do you have any linkage to back this up ?
The only thing close I could find was the story of Peter Houghton. He's been living with a 'no pulse' artificial heart for four years now. Seems to be doing pretty well. Especially since his other alternative was dead. No mention of them restarting his heart. Nor any crazy vein problems from not having a pulse.
--LordPixie
Cardiac bypass, used commonly during a CABG (coronoary artery bypass graft) operation, involves an external pump, pumping blood around the body after gas exchange has occured outside the body (ie. carbon dioxide removed and oxygen added, plus some other bits'n'pieces). (Bypass is required during CABG because the operations are commonly performed with the heart 'stopped' for 30-60 minutes while the surgeon attaches the grafts. 'Off-pump' CABGs are sometimes performed where the surgeon operates on the beating heart, avoiding the need for bypass).
Anyway - the bypass pump commonly delivers continuous (ie. non-pulsatile) flow, even though most modern machines have the capability to deliver pulsatile flow. Research is somewhat inconclusive as to whether there is any disadvantage in delivering non-pulsatile flow in this setting, although in most situations where someone has poor kidney function the machine will be set to deliver a pseudo-pulsatile flow, in an attempt to mimic the normal physiology.
The rationale here is that some (inconclusive) research suggests that the kidney's may be damaged by non-pulsatile flow. As the kidney's receive such a large proportion of cardiac output (25% !), it;s wouldn't be surprising.
I would be surprised if a non-pulsatile flow didn't throw up some unexpected problem - but also, my time as an anaesthetist (or anaesthesiologist in the US) continually demonstrates the impressive adaptability of the human body!
(and regardless, being on bypass does all sorts of unpleasant things to the body, independent of the presence/absence of pulsatile pressures.)
From the ventracor website:
"The VentrAssist(TM) LVAS has the potential to become as commonplace and reliable as pacemakers."
That seems to be a pretty bold statement considering that implanting one of these is a pretty invasive procedure and that the implant leaves you with wires penetrating the skin leaving a path for infection. This technology combined with the AbioCor (did I get that right) transdermal battery would be pretty cool.
I also do not see any valve in the design, so if the battery were to fail, the heart would not be able to pump.
There are pacemaker / defibrillator (CRT) devices on the market today that offer, long term, effective treatment for several types of heart failure (see the new england journal of medicine), they require a minimally invasive procedure, are completely implanted - no external wires, and the heart maintains some pumping ability in the event of a device failure. Also, the patient regains a quality of life and independence that you could not have with worrying about keeping your batteries charged and wires protruding from your abdomen.
The design of the device is novel and very interesting and , without a doubt, will benefit a small population of patients. I am waiting, however, for the next generations of treatments that target the tissue and biology repsonsible for the pathology. Gene therapy, stem cells, etc. offer greater hope and better long term outcomes for patients. Pumps are only for sustaining until something better can be found.
> (IMAD) I am a doctor.
;-)
Good thing your patients' lives don't depend on your ability to create acronyms.
Linky linky.
Basically, this man was implanted with a similar 'no pulse' device back in 2000. He has yet to suffer any unintended consequences. No veins collapsing, head exploding, reversed bloodflow causing time to go backwards, etc, etc. Of course, four years isn't a terribly long time compred to a whole human life, but it's a very good start.
--LordPixie
The difference being that those million years still doesn't mean there aren't occasional problems with the original. This is why people get their biological unit replaced with a mechanical one.
It may take a while to determine the unintended consequences, but unless someone tries. We'll never know unless it is tried. I don't really see this as dangerous, I think stuff like this gets tried on lower mammals before going on to humans.
...to being in such close contact with strong magnetic fields since it will be repeatedly passing over the permanent magnet impellor blades and thru the magnetic fields generated by the motor's stationary coils.
There has been a lot of quack "patent medicine" over the years about treating the body with magnetism, but does anyone know the truth about how constant (and in this case VERY close proximity) exposure to strong magnetic fields might affect the hemoglobin?
isnt' the lack of a pulse, (assuming the device works as intended)
It is carrying around the power supply for this thing, with wires sticking out of your body. Worldheart http://www.worldheart.com/ has been testing an artificial heart that can be powered without a physical connection, but you still have to carry the charger around.
My rights don't need management.
I saw this technology in a documentary on PBS at least fifteen years ago, but it was for a full heart replacement. They were reviewing artificial heart research after the Jarvik-7 was implanted. The odd thing was that the show went into a bit of detail about a centrifugal pump and its power supply, but I haven't seen anything about it since then.
Apparently a small nuclear pellet was used in the battery, which was in a lead-lined container about the size of half a D-size battery. The battery could be implanted completely, unlike the Jarvik, which requires a dangerous (susceptible to infection) tube running through the skin to a suitcase sized pneumatic pump. The issue they focused on was the danger of the radioactive pellet. Apparently concern had been raised about the possibility of an artificial heart recipient being in a plane crash. The fear was that the radioactive battery would leak. So they went to great pains to test it, including shooting it out of a gun, to show it was safe.
IIRC, the concept of being without a pulse, and the need for more research about this, was mentioned almost as an afterthought. But I've wondered ever since then what happened to this type of artificial heart. A completely self-contained apparatus would seem to be a godsend. But I always assumed that lack of pulse was the gotcha.
I even discovered that Marilyn Vos Savant, whose Q&A column appears each week in the national Parade insert to many Sunday newspapers. is married to Robert Jarvik, and consdered writing him in care of her about this device. But I never got a round tuit.
Xesdeeni
You're probably thinking of perfusion, often checked by pinching the finger and toe nails along with the ears to see how long it takes the color to return. It is used to test how well their blood is circulating rather then for a heart beat.
Did you know that many clocks depend on your outlet current being exactly 60 (or 50) Hz? In the US, I believe federal regulations dictate that over some specified period of time, your wall outlet has to count to the right total number of oscillations. When load is high, causing the generators to spin slowly, the cycle count can get off by minutes, and the electric company has to make up for in off-peak periods by running the generators faster.
In biological systems, we often see unusual dependencies. I think I read somewhere that certain birds can't swallow without gravity. And why not? It's there! Make use of it! That's the way evolution works. Nothing is more redundant than it needs to be (well, we can talk about transposons later). In humans, bone density is dependent on load, which is why our bones atrophe in weightlessness.
So, given that we HAVE a pulse, I would be surprised if some part of your body didn't take advantage of it.
Just ask senator Hatch, he should know.
Snowden and Manning are heroes.
No pulse, huh? Being an EMT, if I got called to a scene where this guy was a patient, I would find no pulse and start to defribillate him, then ZAP!, the artifical heart is toasted and the guy is really in trouble. I hope these people wear some kind of ID bracelet or necklace.
This is not as much about flowback prevention as it is about auxilary blood pumps. Such one-way valves are common in veins, esp in extremities, where the blood pressure is low and the stream is continuous. The pressure exerted along the walls of the vein by the contractions of skeletal muscles is enough to drive the blood forward. Standing still for long periods of time therefore numbs your legs and puts extra burden on your heart.
Don't they use the pulse to identify blood vessels when giving injections and drawing blood? My veins are deep, and I feel like a pincushion after giving blood. How would they go if there wasn't a pulse to guide them? Trial and error? Ouch.
Umm... that's strange. When both my girlfriend and I took (independent) first aid courses, we were specifically told to check for a pulse regardless of a lack of or minimal breathing activity before starting CPR, as the heart may very well still be working, and all that's needed is mouth-to-mouth (or unblocking of their throat, etc.) to keep their oxygen supply going, especially as, I believe, in many cases breathing stops before cardiac activity. Given that performing CPR on someone whose heart is still beating can (a) stop it beating and (b) damage the heart by pushing it out of the rhythm it's already beating in, I have to say that unless our instructors really screwed up with what they told us, I'm a bit worried that you were taught this.
While I mostly agree with you, I have one nit-pick/addition. As a former meat wagon operator (oh, sorry...I mean paramedic), checking for blood flow in extremities can be done by checking capillary refill as well.
Huh? Yeah...push on your fingernail. The nailbed turns white. The time it takes to go back to pink/red is your capillary refill time. Should be 1-2 seconds max, or you've got problems....not necessarily low bp....dehydration and low o2 saturation will do it too.
That being said, no pulse....how the hell do I get a BP? I'm guessing my pulseox won't work either. Do they have an LCD control panel mounted on their chest so I can check and adjust their BP with a little screwdriver? I can see this type of thing really compilcating/confusing emergency medicine.
Do not fold, spindle or mutilate.
I would appreciate the improved ability to snap sharp pictures at slower shutter speeds.
And perhaps my cardiologist could get one of these newfangled hearts first, so he could perform the operation on me with greater precision.
I develped a pump for extracorporeal circulation of blood back in the mid 1970's and had to take a lot of these problems into account. My pump was pulsitile and had a very physiologic wave form including dichrotic notch. It also had 2 orders of magnitude less damage to red blood cells than the best pumps on the market at the time. (at least with the cow blood I experimented with) (Read on for an explanation of this) After spending a lot of money on patent lawyers, the device got shelved when I couldn't get a clear patent on it. I think people here on slashdot are missing the point of continuous (non-pulsitile) flow. The elasticity of the arteries especially the aorta actually adds to the pulsitile nature of blood flow. There is an artifact seen in blood pressure measurements called the dichrotic notch that is a direct result of this. If it is absent it is an indication that hardening of the arteries has taken place. The main purpose of circulation is to get blood to tissues and organs. Once there, it has to infiltrate the organs deeply in order to properly transfer oxygen and nutrients and carry away wastes. We were evolved with pulsitile flow and as a result the perfusion of organs and tissues is better with this type of fluid dynamic. That doesn't mean it won't work with constant flow, only that it won't be as efficient. It may take several years before these inefficencies result in some kind of problems. An increase in plaque deposition comes to mind because the tissues arent stretching and contracting. The other problem with turbines and impellers is the "waring blender effect" where the blood cells are "chopped up" by the spinning blades. This leads to hemolysis (release of hemoglobin into the blood form broken red blood cells) which puts a strain on the kidneys which aren't beilng perfused properly because of the non pulsitile flow, etc. etc. you get the picture. Anyway, it's interesting but not a permanent solution.
I can see it all now. Two lovers holding each other close. One says to the other: "I love to listen to the whirring of your heart!"
"Gentlemen, you can't fight in here! This is the War Room!" -- Dr. Strangelove
I remember seeing a documentary about this a few years ago and yes, the fact that prop/impellers chop stuff to bits was a big problem for the doctors working on the project. However, they used very sophisticated modelling and milling techniques (I think the term "developed for the space industry" was banded about) and managed to produce a design that didn't mulch the red blood cells.
I'm with the other posters who point out that adverse side effects aren't all that likely -- but the truth is, even if there are long-term effects, the fact of the matter is, the people who are getting these devices are folks who are unlikely to live a whole lot longer anyway. If it's a choice between certain death in a few months, or possible death a few years down the road from unknown complications, which option are you going to take?
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Humans drive cars and cars are driven by humans. Without a car, humans can't drive. Without a human, cars cannot be driven. Since we have such an irreducibly complex system, we must therefore conclude that humans and cars were created at the same time.
What are you talking about? Do you have any idea what an irreducibly complex system is? How about Natural Selection? (The basis of the theory of evolution.)
I'm sure you were trying to make a point with that statement, but I'm not sure what that point might be as your analogy is neither self consistent nor relevant to my post...
I googled, and all I could find were prototypes...
Also, I know for a fact that my grandfather's pacemaker is constant speed, and he had that put in only 3-4 years ago...
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
It may be that for a typical over weight person who happens to just got a kick in the primordial brain's fight or flight system might have enough adrelinin in their system that they would feel a pulse on a brick.
I agree with what you said, but considering the MOD's post I was mainly thinking of the modifications people do to become who they aren't. No matter how much a vamp tries, he/she will never be what the mythical person is. As canines are replaced, hearts changed to a lack of pulse, there is so much more than needs to happen that is beyond todays science.
But with that being said, I can completely agree that what a person becomes out of work, fun, or living their life sometimes don't mirror who they feel they are in the inside.
I was thinking more of the "Why can't people love themselves for themselves" without taking into consideration your views on that they are, and shaping their outward appearance can mirror their inward appearance.
Thanks Al
I can't find the patent number (not 5,588,812, but sounds similar), but this has already been done with a bladeless turbine. The blood enters the chamber near the center of a smooth disk, and as the fluid contacts the spinning surface, it is accelerated to the periphery where the output is.
Since a bladeless turbine does not slice through the fluid/blood, I imagine that the damage to cells would be less compared to intermittent seals crushing cells or traditional turbine blades slicing through them.
The last time I checked my pulse was about 4 months ago. It's not that it isn't important, but I would probably miss the beating of my heart, and all of the 'special' side effects from that. I think that most people would dismiss the pulse as something we 'take' when we press our finger on our wrist. But what about the body rhythms that may affect our everyday life.
Examples:
Being 'lulled' to sleep by a constant heartbeat. This is a basic to mammals, starting before childbirth.
Realizing stress level (throbbing ears, thumping neck). Taking steps to temporarily alleviate the stress.
The corrolated emotions that have to do with heartbeats may be affected, like anger and love.
I might suggest to a company that builds one of these coronary-turbines to add an simulated heartbeat to it.
If your heart is still contracting and it is not connected to the bloodstream, does it make a sound?
err the pressure/flow on teh venous side of the system has very little correlation in terms of quality with the arterial side as it has passed through the *MASSIVE* volume that is the capillary system. Indeed venous blood return from your legs relies more on muscle action than anything else. That's why the valves are their to keep the flow one way. These folk 'll just die without some form of pump and the blood flows in arteries constantly anyway, it's rate of flow pulsates but should never drop below positve to zero, unless your dead of course
A way to prevent those unsightly varicose veins! Dr. Nick should be installing these in no time.
..He could not get his sleep rhythms right for about a year, which the doctor who operated on him said was common, so no pulse may mess up your sleep cycles.
This was when they used a blood circulation device when his heart had to be worked on
http://www.geocities.com/sethseekstruth/great_out
You said: Can anyone offer a plausible explanation for how any one of the pieces of a bacterial flagellum would offer that bacterium some sort of advantage?
Why yes, I think we can!
A nice quote from the conclusion: ...the very fact that a step-by-step Darwinian model can be constructed that is plausible and testable significantly weakens the suggestion that extraordinary explanations might be required.
Nice try though...
No sense of humor as well as no brain, eh, bozo?
Thats some kinky bacteria.
+5 to Archery
However, they used very sophisticated modelling and milling techniques (I think the term "developed for the space industry" was banded about)
Heh. Developed for manufacturing silent propellors for nuclear submarines, more likely.
-- Alastair
The blood is also full of ions, the NaCl percentage content is roughly 1/3 that of seawater.
A major problem with continous flow would seem to be the diastolic part of the cardiac cycle (when the heart is refilling) is critical for back-flow from the body (arteries do not have valves) into the coronary artieres (the arteries that feed the heart). The aorta (main artery from the heart to the body) is elastic, so a large bolus (fluid surge) of blood is ejected into the aorta, stretching the aorta during systole (contraction of the heart). When the heart then relaxes (diastole) the stretched aorta recoils, and squeezes blood both forward and backwards. The heart has an output check valve at the aorta (aortic valve) which prevents it from completely flowing back; however a small takeoff (the sinus of valsalva) allows the blood to surge into the coronary arteries, and since the heart is relaxed, flow all the way to the muscle of the heart. I don't know if someone has looked into coronary blood flow during these continous pumps, but it might be useful to see, since these hearts are in bad enough shape without becoming ischemic (oxygen starved)
Now that would be quite shocking indeed!
I'd like to know what the experience would be going through airport security with a rechargable battery taped to your chest... I can just see the guard demanding the battery be disconnected and run through the security scanner while the prospective passenger collapses...
could the impeller be continuously throttled to provide some pulse action?
Have GNU . . . Will Travel
Well, this is a well-deserved flame.
Darwin doesn't even mention mousetraps in the chapter from which the individual whose propaganda you are parroting lifted this passage.
It's pretty clear that calebb is just another not-so-honest creationist who has taken (probably nth-hand) out-of-context a passage from a book he's possibly never even seen. Even if he has seen it, he certainly hasn't read it for comprehension.
Now, let's look at the rest of that passage, shall we? (emphasis added)
If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case. No doubt many organs exist of which we do not know the transitional grades, more especially if we look to much-isolated species, round which, according to my theory, there has been much extinction. Or again, if we look to an organ common to all the members of a large class, for in this latter case the organ must have been first formed at an extremely remote period, since which all the many members of the class have been developed; and in order to discover the early transitional grades through which the organ has passed, we should have to look to very ancient ancestral forms, long since become extinct.
We should be extremely cautious in concluding that an organ could not have been formed by transitional gradations of some kind. Numerous cases could be given amongst the lower animals of the same organ performing at the same time wholly distinct functions; thus the alimentary canal respires, digests, and excretes in the larva of the dragon-fly and in the fish Cobites. In the Hydra, the animal may be turned inside out, and the exterior surface will then digest and the stomach respire
It's absolutely appalling to see such worthless rubbish like calebb's post here modded up to a score greater than -1.
BTW, "On the Origin of Species..." can be found in its entirety on-line at http://www.talkorigins.org/faqs/origin.html.
Heart rate monitors have become essential for training in endurance atheletic events, as the pulse rate tells almost exactly how hard the heart and the rest of the body are working. Does this turbine have a tachometer?
Seriously, I wonder how this thing varies blood flow with varying body activity. After R'ingTFA, I see that it's meant to assist a weak heart, not replace it, so now I wonder why there's no pulse unless the weak heart is virtually dead.
Obviously (if you RTFA) these are meant for people who are expected to die soon from heart failure and have little or no other hope. But I still wonder if it varies blood flow speed with varying activity, and this would appear to be a concern with any artificial heart or similar device. Just standing takes more energy than sitting. The article says nothing about that.
Tag lost or not installed.
First of all get your mind out of the gutter, that's not what I meant.
I'm talking about a long (three or four complete turns in length) cylindrical-shaped screw rotor encased in a tube, that rotates in one direction, pulling the fluid thru thru the tube. It wouldn't have to rotate very fast, and could be powered by magnets imbedded in the rotor, stationary coils in the case fed properly timed alternating current, and the rotor could be bearing-less, suspended in the tube via combination of magnetism and fluid cushion suspension. Think that would work, and not damage the cells?
Since this uses magneitic levitation (sp) as a repacement for bearing and magnetic force to spin the blades...what happens if the patient becomes senile (sp) and does not remember having the unit implanted while having an MRI scan...?
So, who do you think will be the first to overclock one of these. I can see it now:
Yeah my heart runs at 100 RPMs, but you see this button. If i'm ever in danger I just push this button, and wham up to 7200 for 20 seconds.
And then they armed me with moderator points and the world mourned.
just don't go shooting people over your lameo god.
You are correct... cap refill can be a useful tool in the field, but it's hard to quantify based on its numbers; 2 secs, 3 secs, 4 secs? The sensitivity and specificity of cap refill isn't really what it should be to be considered a reliable test by itself (don't misunderstand; cap refill is clinically useful, and I use it all the time... but only as part of the bigger picture).
Cyanosis (or even methemoglobinemia) won't necessarily decrease your cap refill. It may make your nailbeds blue, but they will probably pink-up (or blue-up) at the same rate, provided you're not hypoperfusing. Dehydration, low BP, cold, Reynauds phenomenon, peripheral vasoconstriction of whatever cause, etc will all affect cap refill.
In its heyday, cap refill was actually part of the Trauma Score during most of the 1980s (put out by the American College of Surgeons to help stratify trauma patients). Interestingly, it was given significantly less clinical importance about ten years later when the Revised Trauma Score was developed (there had been some studies that seriously questioned its reliability).
Getting back to the main point: I find standard blood pressure measurements to be very useful. There are so many nuances involved between the systolic and diastolic measurements for various disease processes, like the narrowing of the pulse pressure in hemorrhagic shock... loss of pulsatile flow, and a single pressure measurement could seriously affect clinicians' ability to interpret normal/abnormal physiologic parameters.
It might not make a big practical difference, but still...
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Uh, isn't the entire point of these pumps to REPLACE the damaged heart? I mean if you have a low maintenance pump with little chance of failure why are you relying at all on the failing/failed natural heart?
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
I think the organic heart is removed to implant the artificial heart, so coronary blood flow is non-existant! This is not about temporary bypass with an artificial heart/lung machine, this is permanent stuff, heart replacement.
From the quoted article:
(3) Only one major system-level change of function, and four minor shifts of function, need be invoked to explain the origin of the flagellum; this involves five subsystem-level cooption events.
Only four minor shifts of function - all in the correct order, and only after all the requisite pieces have been evolved into place. Doesn't that sound statistically implausible? Doesn't that sound at all like constructing a remotely possible chain of events after the fact to fit the observed end state?
I call on Occam's Razor, and deduce that it's much more likely that the flagellum was created in place, rather than evolved through a bizarre sequence of highly improbable random events.
You are free to draw your own conclusions as to the nature of the creator.
The cure for cancer is coming: Reovirus
Darwin doesn't even mention mousetraps in the chapter
You are absolutely correct! My apologies for being misleading (and completely incorrect!) in my wording.
The fact that Darwin says that "he can find no such case" is irrelevant to my post... But thank you for adding more context to the passage I mentioned.
From reading the article, it appears that this will be an artificial heart, not a temporary bypass system. The value is that the mean time to failure should be greatly increased. That is a serious issue for something you have to cut a person open to repair or replace, much less so for an external system used (by any given individual) for very short periods of time.
nuff said.
Well, as long as you get him to Miracle Max while he's still only mostly dead you should be ok.
-Peter
In its heyday, cap refill was actually part of the Trauma Score during most of the 1980s
;)
My cert has been out since about 1996. Which probably explains why the first thing I think of is cap refill
Do not fold, spindle or mutilate.
Watch out for those crazies, they always seem to have plenty of time to verbally masturbate and reproduce, but not much time for common sense or understanding when it comes to their logical fallacies.
This is not flamebait... lol...
"No blood, no decay. Just a few stitches."
Maybe the Monster's problem wasn't his abnormal brain, or his early torture by a sadistic hunchback in a mad aristocrat's storm-tossed mountain keep. Maybe it just lacked the steady rhythm of its own pulse, reminding it that it marched to the beat of its own drummer, just like everyone else.
--
make install -not war
Evolution came up with these clever things. Imagine a whip mounted on a panel-mounted electric motor. The whip is on the outside of the cell, the motor coils and so on are on the inside of the cell and the panel in the cell wall.
Theis makes a rotor which give bacteria the ability to swim. Sort of.
Re articial hearts, something like an archimedes screw has been around for quite a few years, again powered by externally worn magnetic inductors. Researchers found that simply giving the heart muscle a rest for a few weeks in many cases restored function. The screw caused much less shear to the delicate blood cells.
I wish at was Friday, but I dont want to wish my life away. So I wish it was last Friday.
How would your life be different without a pulse?
I'd end up on some medical bloopers show after an accident renders me unconscious and the paramedics try to ressucitate me when they feel no pulse.
That could be ugly, though it might wake me up pretty fast.
I believe that continuously throttling would add more moving parts to wear out. *shrug* Maybe pulses aren't necessary. After all, we don't see propellors (other than hippopotami with their excrement...) or wheels in nature, yet it's much easier for us to design those than planes with flapping wings or vehicles with legs.
This sig has absolutely no significance and serves only to take up screen space and waste the time of the reader.
I guy falls asleep on a plane with one of these things and wakes up in a body bag.
a withut? Is that like the Gilligan's Island version of a house of Knowlage?
Paying taxes to buy civilization is like paying a hooker to buy love.
I'd appreciate a link to that... I've been doing this for a long time, and I've never thought that belief was widely held. I've heard of theoretical links between C. pneumoniae, but that's about it (of course, C. pneumoniae has been theoretically linked to all kinds of things, including Chronic Fatigue Syndrome, among others).
I'd say the classical risk factors for heart disease still hold; smoking, hypertension, diabetes, the bad gene (usually a triglyceride or cholesterol metabolism problem), etc. This really isn't a flat-earth-round-earth debate... Any new theory had better be pretty compelling, particularly with the mountain of research backing up the standard risk factors.
The "bacterial infection" guys may turn out to be right... but they're going to have to prove it.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Blood will always flow if there's pressure behind it (doh). I'd expect, based more on physics than any experience in cardiology, that a continuous flow at maybe 100mm (well below common systole) would work just fine without overstressing any part of the system.
But if future studies were to show that a pulsing system really does something useful, it shouldn't be too hard to put a controller chip that has the impeller spin up and spin down at some reasonable rate.
BTW, just because it's different from nature doesn't mean it's harmful. For example, it may have taken 50 years (largely due to politics) but it's now considered medically safe for women to take continuous contraceptives and go without menstrual cycles for all or most of the year.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
Blood pressure can be measured in PSI in any event. It just customarily isn't.
1 PSI = approx 52 mm Hg.
Just because it CAN be done, doesn't mean it should!
I recall an old science show that said that the pulsating pressure was actually important for the human body. As I recall (and it's been nearly 20 years), the pulse helps the blood travel down certain pathways it couldn't reach under a steady push, and that it gives the body more time to transfer the goods, so to speak, intra-pulse. The discovery was made because the old dialysis machines delivered steady stream and they learned that not all the blood was circulated (some pooled).
Not that I'm 100 percent sure about this. I like my ticker. I mean, with a non-pulse heart, if I were to pass out, they'd think I was dead.
What those who want activist courts fear is rule by the people.
What about atmospheres?
Thanks to the internet, we can now all die alone together! -SomeWoman
doesnt the pulsing blood flow "encourage" flexibility/elasticity of arterial walls? it seems that with a constant pressure the walls of the blood vessels may not be able stretch as well and perhaps be more prone to damage from pressure changes or perhaps rapid movement and whatnot. at the same time i dont see why this device cant provide a pulsing blood flow, why not have it accellerate and decellerate at regular intervals roughly mimicking the behavior of a human heart. furthermore maybe you could connect a few nerves which would normally trigger heartbeats to accelerate the pump when needed.
or Adenocard (trade name in the US).
It can induce asystole for a few seconds... I've never seen it last for 30 seconds.
Patient reports of the adenosine experience vary greatly. Some don't mind it... others would rather have you cut their heart out than get adenosine. I'll never forget a biker guy I saw a couple of times for recurrent SVT (SuperVentricular Tachycardia). He hated adenosine (though it always worked); said it made him feel like he was dying. He was a great big muscular tattoo-covered man, and would cry like a little baby when you brought out the drug, literally weeping in terror.
To see a grown man reduced to that... my heart really went out to the poor guy.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
this will allow for a greater volume of circulation. since regular bloodflow is not continuous, there is dynamic force delivered to your arteries everytime your heart beats.
in the short run a continuous blood flow would allow for higher speeds, and would only deliver constant, not dynamic load. much easier on the arteries. things like athletic ability, muscular regeneration, even mental improvement are all possible effects of this. sex (for males) might also be radically different (perhaps even dangerous with effects like priapism),or even total impotence. the hardest thing to predict would be arterial break down due to the lack of dynamic force a normal heart delivers? and if this breakdown occurs would it ever reach a point where it would need to be treated?
Maybe, to encourage the use of these things, they could, like, treat them like hybrid cars and let people cut in (go to the head of the) line at the grocery store, like an HOV lane. Put an extra no-pulse heart in your chest, and only use the real one for, say, running uphill or "high-torque" situations like being mugged, etc. Just a thought.
Planaria have a unique system for excreting nitrogenous wastes. They have a secondary circulation system called a protonephridium, which consists of a connected system of "flame-bulbs." They essentially look like bulbs, with slits on the sides. At the top is a cap cell, which has cilia that descend into the hollow bulb. The cilia constantly spin, drawing water continuously, like a turbine, from the interstitial fluid through the slits. The reason they're called flame-bulbs is that the constant spinning of the cilia resembles a flame.
why not! it's a muscle that needs to push blood all arounnd you body.What if you dont need it,, the only downside i see....is if you cut yourself..well your going to bleed much faster.No more blood squirts in the movies,,only steady gush of blood!
I'd be interestecd in hearing how well it performs overall in testing.
Assuming it performs well, it will also be interesting to see if future athletes will have a built-in artificial heart-beat to pass performance enhancing tests.
If all you have is a hammer, everything looks like a nail.
What good would it be? it may very well become impossible to get an errection without a pulse...
If the pressure rises behind the impeller it will increase the pressure on the back side. This will cause the impeller to accelerate in the direction of travel (since presumably it will be connected in the proper direction) as the resistance drops. This will cause a reduction of load on the motor during the period of increased pressure.
Of course, not too many terminal heart patients can be found out jogging on Sunday morning... Or on any other day, or at any other time of day.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Until we see the first /. article on overclocking (underclocking?) your turbine heart?
I interviewed for a job in Ann Arbor, MI to work on the electrical design of just such a device. (They didn't offer enough.)
The one in question has issues because using blood to support the turbines causes too much sheer stress on the blood. The newest designs are bigger, but come use magnetically levitated turbine impellers that are specially designed for low sheer stress on the fluid.
Let evolution figure out that one, eh?
I wonder what impact this would have on child development, if the mother had such a pump.
A good portion of what a fetus hears is the blood pumping. I wonder if they would have hearing or sleeping problems growing up?
Turbo-prop engines run at a constant speed, whether the plane is slowing down for a landing or gaining altitude.
It's a fairly simple solution - the angle (of attack) of the props is changed. So it can be running full speed, but with the props not moving air in either direction (just spinning flat) or dug into the airflow to get some more kinetic energy the flow is still controlled.
My knowledge/training is limited to propellors, rather than impellors, but I imagine there's an analogous solution. If the unit tested for saturated oxygen, and sped up when that dropped, problem solved (at least for exercising). That's probably over-simplified, as AFAIK saturated oxygen is lower/higher for other reasons, some of which raising/lowering blood flow may actually work against them.
The medical details are unknown to me, if anyone wants to fill in the gaps here I'm curious as to how over-simplified simply monitoring saturated oxygen in the blood to regulate the pump speed solution is.
The only thing more dangerous than a file named -rf is renaming it -rf\ /
My pulse is my biggest hurdle when taking high-power rifle shots at long rages (>600 meters). Without a pulse I could hold steady on a much smaller target. If you've never shot a scoped rifle, your pulse makes the crosshairs bounce with each heartbeat. You can slow your heart-rate down and time the beats, but it would still be nice to be able to hold steady on a 1,000 meter target and not have any movement. If you get excited it all goes out the window - if your pulse quickens you might as well be riding on the back of a horse.
I imagine there are other tasks besides shooting that are impacted by pulse. I'm sure there are types of micro-surgery for example that could be negatively impacted by the surgeon's pulse.
-=-=-=-=- osjedi uses Debian GNU/Linux. -=-=-=-=-
I'll bite: I'm not golfing because I don't have the patience. IAAS (I am a Surgeon) and it would not be that difficult to measure a continuous flow generated pressure instead of a pulsed pressure. Plus you wouldn't have to teach us about turbines and such. For example, currently a patient in the ICU may have their blood pressure measured with an indwelling arterial line rather than a transduced cuff. We follow Mean Arterial Pressure (MAP) in this setting. Here's a quick definition: http://www.globalrph.com/map.htm (It was easier to google than find a textbook but this is short and sweet)- "Equation: MAP = [(2 x diastolic)+systolic] / 3 Diastole counts twice as much as systole because 2/3 of the cardiac cycle is spent in diastole. An MAP of about 60 is necessary to perfuse coronary arteries, brain, kidneys. Usual range: 70-110." We could still measure the equivalent of a MAP with a continuous pump. Some of the bioengineers who commented above probably know better, but whatever the range of pressure in the system from continuous pumping (whether it's always the same or if there's a smaller variation than the normal systolic/diastolic) it could still be accounted for and easily monitored and used to guide therapy. Probably the bigger problems are those already mentioned: baroreceptors that will now be in a new range, changes in coagulation, and destruction of blood borne cellular elements.
Sure, I could still measure the time I cover a distance.
But I would have no clue when my heart rate has come back down for me to do another repeat.
Say I am doing a VO2max workout and I get up to 195HR, I would currently jog until I get down to around 129 or so and then go again.
Were I to lack the pulse, I would need some other output from the device, such as Lpm (Liters per minute), or maybe an RPM readout from the turbine etc.
All I'm saying is that my workouts would suffer.
(no I did not RTFA, this is Slashdot, and also I suspect that people with such devices probably don't do a lot of competetive running)
There are some odd things afoot now, in the Villa Straylight.
I'm narcoleptic, you insensitive clod!
The only thing more dangerous than a file named -rf is renaming it -rf\ /
One of the factors that limits performance in athletic contests such as the recently completed Tour de France is cardiac output -- how much blood the rider's heart can pump. Fifty years from now will we have to have rules against riders with artificial hearts because they have an unfair advantage in cardiac capacity? Or will we borrow the kinds of regulations that the various auto racing organizations impose on engines? You can have an articial heart, but volume pumped must be constrained to be below X liters per minute, or the outlet into the aorta must be less than some number of square millimeters?
Go to new doctor for checkup . . .
The Kruger Dunning explains most post on
"Do they have an LCD control panel mounted on their chest so I can check and adjust their BP with a little screwdriver?"
Well if it's standard procedure in Star Trek, it must have been invented at some point in the future...
This replacement heart would really screw with the timing of that hacker dude who became the flat-line in Neuromancer. I'm guessing he would rather die than get one of these lol
My only regret... is that I have... bonitis..
If I ever am unfortunate enough to have one of these babies implanted I'm also gonna get a big tattoo on my chest that says something to the effect of "Hey you, paramedic, (misc. clinical information and info about where the on/off switch is), and I'll buy you a beer if I live.
Why do I have this? I don't smoke.
if you get knocked out, and they check your pulse thinking you're dead, how can they be sure?
unless they check for a breath.
Parallels to SCO fairly leap to mind....
in some countries... I believe China still harvests organs from prisoners.
In the US there's so much oversight that I can't see it even being possible. Many transplants aren't even done in-house... the organ gets flown to where it needs to go (I've flown on a couple of those... you get to jump to the front of the line on the taxiway, even if there are 30 planes waiting to take off).
Seriously, there are so many ethical questions, paperwork to be filled out, different physicians involved... declaring someone brain-dead and pulling the plug is a big deal, even more so if it's an equivocal case; it requires multiple physicians to sign off, consultation with the family (and their physician), appropriate consultations and diagnostic testing, and often a review from the hospital ethics committee. Hell, half of the doctors that sit on those committees don't even like one another... they just tolerate each other. There's NO WAY they'd all agree, in some nepotistic star-chamber fashion, to something as evil as wrongfully terminating someone's life and harvesting their organs. No way.
I can't see that caper ever being pulled off and not coming to light.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
The first thing I'd do is invest in one of those emergency medical bracelets: In big letters it would say "I'M NOT DEAD DAMMIT!"
Apparantly, the heart surgeon heard the comment and/or it was eventually directly pointed out to him. His response was simple:
"Have you ever tried to fix an engine while it's running?"
The only thing more dangerous than a file named -rf is renaming it -rf\ /
Don't sperma propel themselves with turbines of sorts?
At least now when I say I had sex with someone who didn't have a pulse, they won't look at me funny.
If only they knew....
That why if you run then stop abruptly you feel faint, because suddenly the load on your heart has suddenly increased and it needs to ramp up to pump blood all the way up to your head at a usable pressure (which is one reason you should warm down properly after exercising).
No, that's not why at all.
Your arteries are lined with involuntary muscles which constrict in order to maintain blood pressure. When your heart rate drops, so does your blood pressure, and there is a slight lag between that and the response from the muscles of the arterial wall to stabilize blood pressure.
Muscle activity has little effect on venous blood flow. You getting confused with the lymphatic network, which depends entirely on muscle contractions to maintain flow.
Given that the people who are getting these implants are on their deathbeds and are not expected to live out the year, I think the matter of their being unable to run is not so important at the moment.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
Perhaps you're right regarding contraceptives and tinkering with human systems, but the reproductive system is one system that can be tinkered with or even removed without too much harm to the rest of the body (re: castrations and all). Especially after puberty. I'm not sure if this is the best proof if you want to make a general argument.
___
It's the end of my comment as I know it and I feel fine.
I guess it has to happen at least once a week.
/.
A TRULY "insightful" post on
Congrats!
I'm not an expert, but would the shearing forces this introduces have any kind of impact on blood cells?
I imagine this could be helpful as well as harmful. Helpful: considering some of the problems associated with high blood pressure some people suffer. This would effectivly reduce the maximum pressure a body would have to tolerate.
___
It's the end of my comment as I know it and I feel fine.
You find the possibility of quintillions of bacteria living for billions of years happening onto something that is improbable to be less plausible than the existence all-knowing all-seeing imaginary friend who has never revealed his presence in any way?
Maybe you have a different mechanism for "created in place", but I haven't heard of one.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
I was tempted to say, "Decidedly short"...
--<Mike>--
So what if you die by other means, but your heart keeps pumping your blood around.
What about an archimedies screw, or an insideout one?
It wouldn't have any sharp edges to chop the cells up
thank God the internet isn't a human right.
Thanks for the subtitles, much appreciated :)
Visit http://ringbreak.dnd.utwente.nl/~mrjb/growingbettersoftware to download your free copy of the book
Actually, for most of evolutionary history, women had many fewer menstrual cycles than a "normal" woman these days. They were underfed, so had a later onset of menarche, and spent a much larger portion of their lives either knocked up or breast feeding, all of which means time not spent menstruating.
Bottom line is that the idea of "regular" menstrual cycles going on forever and ever from 13 to 50 is basically a modern made-up invention.
And it'd kill the white blood cells, also, which might be worse than just folding the red blood cells.
If corporations are people, aren't stockholders guilty of slavery?
But if you use continuous flow, then the arteries gain one more similarity to veins, and so arteries may start suffering from the problems you mention, which normally only occur in veins.
Mathematics is not a crime.
Another problem that could occur... imagine if said transplantee were involved in an accident, and he got hurt, was unconscious. The first thing the rescuers would do would be to look for a pulse. On not finding one, would probably pronounce the victim dead at the scene and make no attempt to rescue him and get proper medical attention.
-- Soruk
Of course, not too many terminal heart patients can be found out jogging on Sunday morning...
:-)
I'm thinking more about the Bionic Man
Can I have leds mounted in my wrist to show that my blood is still flowing? Or maybe a cool flow meter impanted in my chest - look, I am pumping at 5l/minute!
But if you use continuous flow, then the arteries gain one more similarity to veins, and so arteries may start suffering from the problems you mention, which normally only occur in veins.
I would think this to be unlikely, given that arteries are considerably more robust than veins. Arteries are reinforced as they have to carry a pressure load whereas veins, carrying relatively little pressure load, generally are not.
Especially when the patient is unconscious and the medics have no idea that the person has such a heart
I would assume that these people would be wearing Medic-Alert bracelets.
As someone who was born with a congenital heart defect, has had three surgeries, and has been ticking with an artificial valve for the last 22 year, I'd be worried about not having a pulse.
One of the things doctors/surgeons have noticed with heart patients that have their hearts stopped is that they lose all sense of time. I noticed it after my surgeries. I don't know if anyone has done research into the beating of the heart and the mechanisms in the brain that allow us to perceive the passage of time. Does the beat of the heart interact with the area(s) of the brain that perceive the passge of time? Do other bodily processes require a heartbeat for a "timeing signal"? I'm sure there are other questions to ask about this subject.
Show me a man with a song in his heart and I'll show you a man with an AM/FM pacemaker!
If "disco" means "I learn" in Latin, does "discothèque" mean "I learn technology"?
in the fine print or the fast talking of the ads recently pushing the idea of skipping periods, there are negative side effects.
the removal of parts of a womans repoductive system often results in the woman appearing more manish, requiring more tinkering from drs to conteract the lack of hormones.
I'm onsite at a federal agency. So I guess I'd be like everyone else is here.
For your security, this post has been encrypted with ROT-13, twice.
How do the paramedics know you're alive?
You find the possibility of quintillions of bacteria living for billions of years happening onto something that is improbable to be less plausible than the existence all-knowing all-seeing imaginary friend who has never revealed his presence in any way?
Yes, exactly. Some evolution is easily and logically understood as natural adaptation to changes in environment, or taking advantage of an ecological niche. I find the development of the flagellum - a freakish modification which led to greater survivability several million generations later - too outlandish to fit into either of those categories. To believe in such "natural" development requires a "faith" in the improbable that elevates science to a religion. A creator is much simpler, and much easier to believe.
The two more commonly accepted "creators" are:
1) The Creator (God, or, in your language, the all-knowing all-seeing imaginary friend)
2) An extra-terrestrial intelligent being (hacker?) who "seeded" life on this planet billions of years ago.
In theory, the two are very different. In practice, the two may be indistinguishable by us in our lifetimes, if either in fact exists.
I'd hazard a guess that those who don't believe in a Creator God are the most likely candidates to believe that there exist ET intelligence somewhere in the universe. Isn't the eye or the flagellum strong evidence that such intelligence exists, and has shown its hand here on Earth?
Don't let your reluctance to believe in "God" get in the way of scientific evidence.
The cure for cancer is coming: Reovirus
What is one of these turbine pacemakers gets on the fritz and the person essentially gets a heart attack? Because it no longer has the chamber structure, one really couldn't do pumping. And similarly, if someone passes out, the conciestious civilan will check for a pulse, find nothing, and start pumping, which could end up breaking the turbine and putting the person in even more danger.
Live life to the fullest. It's not that life is short, but that you are dead for so long.
I think they'd probably wear one of those medical bracelets to alert the rescuers that they don't have a pulse. At least I would!
If the new hearts use magnetic fields to move blood around, wouldn't this make it toooooo easy to kill someone with such a heart by disrupting the magnetic field for an extended period of time (say, 5 minutes)? You could be killed by some dude standing five feet away with his hands in his pockets.
Forgetting intentional death by magnet, what happens if a person with one of these hearts just happens to walk too close to a strong magnetic force?
These aren't the sigs you're looking for.
As cool as it sounds to not have a pulse, I have to wonder... what side effects could this cause. Looking at nature overall, it seems that everything is rhythmic. What if the pulse is used to keep the various parts of the body in sync. Yes, nerves probably do this, however, think about it. Every cell has respritory functions, and they are timed to coincide with a pulse. As a software engineer, a signal such as that would be hard to not take for granted. With no pulse, would your internal clock skew, so you start sleeping less or more? Any MD's or biologists have any data on this? Anyway, fun food for thought.
I paid the going retail price for a Windows screen reader and got a free Unix computer!
Hrrrmmm I think it's likely that every single person who has any sort of heart transplant has a medicalert bracelet with very specific instructions and contact information for their doctor...
-*The above statement is printed entirely on recycled electrons*-
Yes the need for flowback prevention is removed. But those mechanisms are still there. So what happens when pieces of the valve are kept open continuously? You are going to be putting a lot more stress on certain parts of the valve then they are used to. So could the valve rip? Or could a flap of the valve break off and cause a stroke?
No more of that pounding thunder in my head!
"The bigger the lie, the more they believe." - Det. Bunk
Well I'm not an internist, or a researcher, and my dad was definitely not a heart surgeon.... ... but I did stay at a Holiday Inn Express last night.
So I think I'm qualified to say this is bad, and that you should initialize the hydrogen recombiners before even attempting this procedure.
not sure about the pulse (or lack thereof) but i am certainly sure that human body needs to have a clot free blood stream.
regrettably the insertion of most foreign (non biological) materials into the blood causes clots. this is going to be true of the Lvad described here as well. true stagnation elimination helps but that is not the real problem. it is simply a materials issue. These materials readily recognized as not proper tissue and they are not soft and do damage blood cells. the result is they stimulate coagulation. in the case of this occurring in a region of fast blood flow you get the potential for clots flowing in the blood stream. this cans lead to stroke and other serious conditions.
Such risks underscore the need for even a artificial valve patent to need to be on life long anti-coagulation treatment. the down of this is that this had a cumulative risk of about 1% per year for a bleed in the brain as a direct result. may be this is ok if you are already 80 but for a younger heart paten these risks are huge.
sure hope they can figure a way to cover up the artificial materials of these appliances with flesh (possibly lab grown from the patents own cells) or build better surfaces into the devices than metals to reduce this insidious risk. i figure that this will be the fist big step to a truly decent heart transplant / appliance.
"have a heart you say, why my dear boy, i have two"
I've had all kinds of injured patients come directly from the bar, many with pretty severe preexisting medical problems.
Had a guy come in from a barfight, with his cervical-spine external fixation frame still on (titanium ring around the head, screws that go into the skull, and carbon fiber rods down to padded shoulder harnesses). Yep... one of these. Placed, I might add, from his previous DUI accident.
Patients with end-stage emphysema (still smoking) who carry around oxygen tanks everywhere they go... picked up by the paramedics from the smoky bar (smoky bingo halls are another favorite).
Liver-failure cirrhosis patients who are picked up from the bar after they start vomiting blood...
You'd be amazed where you can find sick people making themselves sicker (you current and Ex-EMS guys know what I'm talking about).
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Funny - in The Netherlands, we also use ABC to help remember what to check for, but over here it means "Ademhaling, Bewustzijn, Circulatie", or respiration, consciousness, and circulation.
Don't you people learn to check whether he patient is conscious (i.e., responds to questions, or reacts to pain)? It seems to me that "airway" is kind of superfluous, since you need it for breathing?
No one has linked to this yet? Are you kidding me?
_ cont.ht ml
Just in case you missed it, fascinating stuff. (Possible complications aside)
http://www.ventrassist.com/news/VentrAssist.pdf
from
http://www.ventrassist.com/product/descrip
Think about the billions of other interesting constructs that *didn't* happen - yes, we see lots of improbable results of evolution. These are the things that *did* happen. Statistically they were unlikely - but so were lots of things that didn't occur - these just happened to. We aren't 100% sure on the order that they happened in but I'm sure we'll figure it out in time.
Then again, we could just place everything we don't know in this big easy bucket called 'god' - who cares, that bucket gets emptied out a bit further each year as science advances and provides answers for the things mythology tried to explain when science couldn't.
- A creationist claimed that flagella are an example of Intelligent Design, as Darwinian evolution theory couldn't offer a possible explanation.
- Matzke was cited, and his is a reasonable possible explaination
- Dembski's reasonable complaints about Matzke's explanation is cited.
- Now we are debating if Dembski debunking of Matzke was complete!
However, the fact that reasonable people can argue about this demonstrates that the original assertion (flagella are an example of ID) is wrong!I paid the going retail price for a Windows screen reader and got a free Unix computer!
well, for one thing, every time you got drunk and passed out, someone would end up giving you CPR and busting your ribs.
I hope you realize that the statistical odds of an omnipotent creator (choice of the word not by accident) spontaneously appearing and than creating life are, by a long shot, worse than those of all life just appearing spontaneously by itself. The odds of 'Miracles by Evolution' are indefinatly better than both alternatives since the framework they imply at least submit to the thermodynamic laws and its implications. In other words: creationists have no place arguing about odds.
___
No power in the 'verse can stop me
1. Run Linux
2. Talk to my phone via Bluetooth
conventional wisdom looks at the heart, and sees a pump.
yet, realising it is contrary to everything has ever told me,
i can think of another possibility: like the build-up of sand
by the action of waves, we could explain the heart such as --
THE MOVEMENT EXISTS, AND THE ORGAN FORMS AROUND IT.
best regards,
j
it's not terribly different in the US, particularly in a large, urban ER.
If you come to the ER for a minor complaint, you can end up waiting 7 or 8 hours before you see a doctor (you'll be triaged long before that). It's not a first-come-first-served deal... anyone who's sicker than you gets seen before you, even if they come in after... it's just the way it is.
And that's just the beginning... lots of ERs end up holding sick and critical patients for days while waiting for an ICU or Telemetry bed to open up. JCAHO is trying to address the ER-holding issue, but hospitals are not responding quickly, for a couple of reasons.
Money. It costs money to keep and open additional units. Money for nurses, techs, beds, equipment, etc. In cash-strapped urban medical centers, that money's just not there, particularly with medicare and 3rd party payers ratcheting down reimbursements. As reimbursements get tighter and tighter, it gets harder and harder to cost-shift for all the non-paying trauma, etc. That's going to get worse, BTW, as our population ages and gets sicker. Buckle your seatbelt, Dorothy.
Staff. There's a nursing shortage, in case nobody was aware. I can see patients pretty quickly, but there's often no nursing staff to take care of them upstairs (nurses can only take care of so many patients per nurse... once they top out, they can't safely take more, regardless of how many empty beds are on the unit). Ergo, the patients get held in the ER. Then, when I run out of ER beds, I end up putting people in the hallway. Once I run out of hallway space, the whole process grinds to a halt. All the while, the patients in the waiting room are rioting because they're been waiting for so many hours... I've actually lined up and seen patients in the waiting room once I ran out of space in the department proper... it's certainly not by-the-book medicine, but we do what we can.
Facilities. Lots of ERs are just not big enough. I've worked in ERs with volumes from 15,000 patients per year to over 90,000, level-1 urban trauma centers to small community hospitals, and I've yet to work in one that had enough space. ER volumes are going up every year, all over the country... hospitals can't build fast enough to keep up with demand.
It's amazing to me that some ERs do as well as they do... longer wait times are just a symptom of several larger problems.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Of course their life expectancy was about 30, so we can't be sure what happens when women do not ovulate/menstruate. The current thinking is that it will increase a risk of uterine cancer (since you don't "recycle" your uterine lining every month), however the shorter term studies seem to be
Wouldn't a Doppler steth still be able to hear flowing vs non-flowing? That would at least give you one number to work with.
I don't know if you could make IR oximetry work without the convenience of a built-in chopped signal.
Nope. From the article:
GreyPoopon
--
Why is it I can write insightful comments but can't come up with a clever signature?
Being a biomedical engineer at a top twenty US medical center, trained as a LVAD engineer for the Worldheart Novacor LVAS, I always wondered why we went to so much trouble to have pulsatile flow. We have to worry about bearings wearing out, and the internal sac sealing shut and not reopening if we squeeze too much blood out, an air vent to open the pump to atmospheric pressure, and also watch for tears in the inlet/outlet valves to the pump. A single moving part, impeller pump seems so much better in comparision. We are supposed to be moving towards the Jarvis 2000 here. Of course, the main problem with these LVAS pumps is the percutaneous line exiting from the patient's abdomen which leads to frequent pocket infections. I believe a totally implantable, continuous flow pump will be the future.
It's not a *pro*peller, but an *im*peller... which, as far as I am aware, it just a spinning disc. I've seen household humidifiers that use these, they're just a spinning cone submersed in the water and it gets the whole mess moving pretty well with no blades.
Found at sceane, no pulse, pronounced dead. Makes it harder to measure BP, though the turbine could have smart sensors to do that, then use any number of power sources to transmit it out of body. I'd be interested in how they resolve cavitation, since the micro heating and local pressure waves could cause some issues as well. Maybe if there is appropriate cavitation you'd get sonoluminecience (horrid spelling most likely) and people with turbine "upgrades" wouyld have glowing hearts just like 'toons say they should. :-)
- Tjp
I am in wallow with my inner money grubbing capitalistic pig. ... Oink!
Hrmmm. Ment "I'm" but then missed it on the spelling it out (IAAD looks silly).
Thankfully I am a pathologist and don't have patients..
DJMD - The fourth man - Planetary
. . .but they'll never take my . . .
FARTS! (*)~~~~~~~~~
I feel so much better now.
Used to say I'd do any chick with a pulse... now I'll have to think up a new line...
---- It puts the lotion on its skin or else it gets the hose again. It does this whenever it's told.
It's been over 20 years since I read it, but I think the story is called "Amazons." Space ship pilots have to have their hearts replaced with mechanical pumps, and they lose their pulse.
In some case, it messes up their normal rythems - like when are ready to fall asleep or wake up.
Since it's essentially a DC motor (as near as I can tell from the article), doesn't that mean it will start pumping backwards if you get your battery wires crossed? I can imagine even a short time pumping backwards would do significant damage. The one-way valves in the vessels would teary, the vessels would rupture, or both would be weakened.
I realize you'll probably only be able to connect the battery the right way, but what if...
I have a friend with an insulin pump. He has to change the small tube inserted just below the skin of his abdomen every couple of days. I watched him get the part connecting to the insulin pump caught on a doorknob once. Not only did it hurt (a lot), but it pulled the tube out.
If this happened to the cord leading to the rechargable battery pack and the wires broke it would cost the person their life if they twisted them back together wrong.
I guess I'm just a worrier. Does anyone know if the circuitry they built into these protects against this?
On the other hand, there are certain groups of people for whom the lack of a pulse would hold a distinct advantage, such as biathalon competitors and snipers. :-)
Interestingly, this is exactly the sort of thing that I wonder about when I'm driving or in the shower. I've thought about this, and the only potential problems I could come up with were in relation to the lymphatic and renal systems.
-Cybrex
Boundless Expansion, Self-Transformation, Dynamic Optimism, Intelligent Technology, Spontaneous Order- BEST DO IT SO!
Yeah, but it could detect the loss of blood pressure and re-route around the damage.... c'mon it's Friday afternoon!
reproductive system is one system that can be tinkered with or even removed without too much harm to the rest of the body (re: castrations and all).
Er, no. Without testosterone, the male body is prone to osteoporosis, low muscle tone, low strength, as well as a lot of other nasty side effects. The quality of life will plummet, and the length of life is probably affected.
With castration, the testosterone levels in the male body will plummet.
Why would there be a non-flowing? Turbines don't usually have an off cycle.
I think we've pushed this "anyone can grow up to be president" thing too far.
Your doctor has a valid point; there's little case data to back it up. It's a recommendation, nothing more.
The incidence of Endocarditis is fortunately very low in the normal population... there may not even be enough non-IV-drug-user-cases per year such that you could really design a study of sufficient statistical power to prove/disprove the benefit of antibiotics. The benefit of antibiotics must be weighed the risks (ie. you might have an allergic reaction). A patient fully appraised of the risks is a wonderful thing... I absolutely support such a person deciding for themselves what to do.
Consider this, however. Endocarditis is bad news... it's not a minor illness, and may be preventable by a couple of doses of antibiotics. Minimal risk... but potentially great benefit... or not.
It all depends on how you like your odds. You've clearly thought about it, and made an educated decision; may the odds be with you.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
That may very well be the reason why pulsing circulation evolved, but that doesn't mean that we can simply drop in a pulseless replacement system and expect everything to be hunky dory.
For instance: At the pulse there is a peak in blood pressure, which causes the water and small molecules in your blood to osmose across the walls of small blood vessels into the surrounding tissue; between two pulses the pressure drops, causing the surrounding tissue's water and small molecules to osmose back into the blood vessels. This back and forth cycle helps to circulate the cellular environments fluids. Presumably, a pulseless circulatory system would keep a constant pressure, eliminating this flow; who knows what that will do to the cellular environments which are used to that. So while nature might have evolved pulsing circulation due to architectural limitations, it may have made good use of the pulsing once it was in place.
Or, how about IAAMD, or probably in your case IAAMD/PHD.
Or you could try YYTIIAAMDBFLRYSNCMSAMAAMOOAROACOT(Yes, you twittering idiot, I am a medical doctor, but for liability reasons you should not construe my statement as medical advice, a medical opinion, or a recommendation of a course of treatment)
using non-pulsatile blood distribution is to accept several risks. Vascular hemodynamics is a very complicated matter, indeed! In some organs, eg, certain regions obtain their oxygenation during 'dyastole' where the blood pressure is lower than the average B.P.. An example is the heart muscle itself! Oxygenating blood cant flow thru heart muscle itself: its during dyastole that the heart is oxygenated. Even on more basic cellular levels the movement of oxygen molecules thru cell membranes would certainly be affected: remember, other moities must also leave the cell. That could depend on a minimal time of lower than average BP. The partial-pressures of oxygen, inside the cell, at the mitochondrial membranes, is very low: on the order of only 5 mm. Hg !!... theres not much room to play around! I'm not saying it'd be impossible to survive long-term with such a system but that there are many possible risks. tkjtkj, m.d.
"There are 11 kinds of people: those who know binary, those who don't, and those who could not care less!"
No, the "problem" that "normally only occurs in veins" is the loss of pressure downstream from the heart. When blood reaches the venous system, it's like that last sprinkler on a badly setup lawn irrigation system.... not much power; the pressure is gone. The longer any pipe is, the greater the pressure loss by the time you reach the end (yay, engineering fluids taught me something!) The system of valves in the veins is in place to move blood back to the heart without the heart's assistance. Because the artificial heart supplies pressure to the blood in the arteries, they don't have need for this elaborate valve system.
Repetition does not transform a lie into the truth. - FDR
"but it's now considered medically safe for women to take continuous contraceptives and go without menstrual cycles for all or most of the year."
Interestingly, I've heard it's actually considered more healthful, since the female body was actually made to be pregnant/giving birth/breastfeeding, which leaves long periods without a menstrual cycle.
If you're not going to have kids, it may actually be damaging to have a menstrual cycle.
That said, I'm against the use of most of today's contraceptives because, although the medical establishment doesn't want people to know it, most contraceptives today include abortive properties (they don't just keep the egg from coming out, if one does come out and gets fertilized, they prevent implantation as well). Since I believe life begins at conception, using such things is against my beliefs.
Engineering and the Ultimate
Pulse ox will work fine. You get sats even if you don't get a rate - try it sometime, if you jiggle it enough you'll find the machine locks on to the sat before it locks onto a rate.
for over a decade. As I remember, they had a problem with the circulatory system; it is designed to work with the small pulses of pressure that a natural heart produces, not the constant pressure from these artificial hearts.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
Oh, I see you tried it on a nearby co-worker too.
On a less pedantic note, do you remember roughly how long she was using the pump? Years? Weeks? It's not hard to imagine that the sort of problems that might surface in a patient using the device for 20 years would not come up in a patient on it for only a month or a year.
Not get all ad hominem here, but my impression is that Reader's Digest favors feel-good stories over realism. That also makes me wary of using this one data point in claiming there are no long-term effects.
Steven N. Severinghaus
you're dead!!
no I'm not....
yes you are...
no I'm not...
etc
"goodbye and hello, as always" ~Prince Corwin, from Zelazny's Amber series
Length of life is affected. Castration increases lifespan by an average of 14 years.
/ 30 /immortal/print.html
http://archive.salon.com/health/feature/2000/03
Castration reduces testostrone by about 90% but it doesn't eliminate it and some castrati were still capable of romantic encounters. In fact, they were prized as lovers, in part because they were said to last longer in bed.
The effects seem similar to caloric restriction, and I sometimes wonder if the the lifespan gains from the two are related. Would a castrated animal on CR get two lifespan boosts or just one?
___
It's the end of my comment as I know it and I feel fine.
I feel like I've been duped - my professors told me otherwise. Just goes to show, you can't believe everything you hear. Thanks for setting me straight.
it's called organ "donation" for a reason... it's also called an anatomical "gift." You're giving somebody else life, with something you no longer need; it's strictly voluntary...nobody's going to force you.
So You're going to die and bury that organ... yet you're going to try to scratch and scrabble for that last thin dime, even as you die? You refuse to take part in a process that benefits others, simply because you cannot benefit yourself? No streak of altruism? Not one iota of selflessness in you? You were given life... yet you insist on being paid for giving others life, via something you were just going to throw away to rot?
Hmmmm... I'm guessing I won't be seeing you volunteering down at the homeless shelter much... suit yourself.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
Tattoo on chest: Do not use defib, subject has no pulse, subject may not be dead, please call 1-888-heartless for more information.
Or call On-Star!
I killed da wabbit -Elmer Fudd
Strongly agree. The pulse is a function of the arteries, not the heart, and has a lot to do with neuro-electric fluctuations. (Not a Doctor, but hung around a drug store when I was a kid.)
I can see this type of thing really compilcating/confusing emergency medicine.
No problem, just a quick call to their tollfree technical support line, and some knowledge worker from India will be happy to walk you through an emergency BP adjustment.
most contraceptives today include abortive properties
I have two kids that would disagree with that statement.
RTFA, RTFA...
This pump is a "left ventricular assist" device; it doesn't replace the heart, just adds to the left ventricle's pumping effectiveness.
Which, incidentally, may mean the problem my post's grandparent was discussing may not be an issue. Depending on where/how they connect it, perhaps part of the aorta is still intact, allowing the coronaries to do their job.
I stole this sig from someone cleverer than me.
Women started menses later due to malnutrition? Yes, in some very small subsets of the general population. However, the great mass of humanity got enough to eat to start bleeding at the right age. If you want to discuss evolutionary history, let me ask you this. Why, if this was evolutionary, are women having periods earlier now? Wouldn't evolution have determined that a later period is beneficial, and those genes would have carried over into modern women? A contradiction indeed.
Women were underfed? That's doubtful, and again, malnutrition has little bearing on menses overall. Remember the save the africans commercials on television? People there are starving as hell and have plenty of kids. Look to any Third World or developing country for examples.
The only modern made-up invention is the concept of rampant teenage sex. Guess what, teenagers were having sex all along. Changing your viewpoint from a prudent one to a realistic one can open your eyes.
Of course, this is just one study, and most of the subjects had other pathologies besides just heart failure. It would be interesting to see what happens in trauma patients who are otherwise healthy. But I think these particular findings would be relevant even if you were replacing the heart rather than just assisting it.
I thought there was still a lot of disagreement about the long term hormonal effects of contraceptives.
----- Question authority, but not ours. Hate the man, but we're not him.
"The VentrAssist, which is made by Australian company Ventracor, is of a type known as left ventricular assist devices. LVADs are not designed to replace the heart but are implanted alongside it under the rib cage."
Emphasis mine.
You're getting the full thrust of my frustration with the two sibling posts before you that also made this error... sorry.
It is a permanent device, but the heart must survive for this device to work. Grandparent brings up a valuable point about whether the heart will be weakened by non-pulsatile flow.
The other problem is that for either technique, you need anti-coagulation, which leads to a need for replacing red blood cells, platelets, and various coagulation cascade regulation factors. This study suggests that the replacement requirements for ECMO are much greater than that of ventricular assist, and, let me tell you, platelets aren't cheap, not to mention anti-thrombin III.
I've had dead/near dead people do some pretty freaky things, including one guy who flipped me off moments before he finished bleeding to death.
I'm pretty sure that carries quite a bit of cosmic weight... a "F*** you" from a dying man...
Yep... If reincarnation's real, on the basis of that episode alone I'm probably coming back in my next life as a dung beetle.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
While you have it anatomically correct with regards to the cardiovascular system, you have it physiologically wrong. Varicose veins and portal hypertension are affected by cardiac function and pulsatility. While varicose veins are typically caused by gravity and portal hypertension is often caused by alcoholic cirrhosis independent of heart function, back pressures generated by a failing heart that does not generate effective contractility (systolic dysfunction) or fails to accomodate inflowing blood (diastolic dysfunction) makes these problems worse. In fact, you can get portal hypertension just because of right heart failure.
Boy, you must live for stories like this
Actually I do... but not for the reason you might be thinking. (I hit the karma cap years ago, and get mod points all the time that I don't use).
I can't tell you how much I've learned from reading this forum... I love it. I've picked up some excellent info, websites, references, and technical pearls that it would have taken me years to discover on my own. The least I can do is contribute to the discussion, especially when it addresses something in which I am sufficiently expert to (hopefully) offer some useful comment.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
"I am an internist..."
To henryhbk:
Nothing much here, except to say that it is very obvious the difference in expertise between a real medical doctor and every other wannabe out there so willing to speak and sound intelligent.
Your comment was very insightful, and very well appreciated in bringing some sense to the discussion.
[And to everyone else out there, you would do very well for yourself to listen to any internist around you. Speaking from experience.]
no more heart-pounding orgasms :(
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
You volunteering? Don't eat and don't have sex? What would be left in life?
Just a Tuna in the Sea of Life
Maybe the pounding inside my head would stop... ;-)
Oh, wait... he's dead. But they interviewed the crap out of him while he was alive. I'm sure you can find something.
- The omnipotent creator individually designs each and every creature and individually, and makes it look like they were evolved, or
- The ominipotent creator creates one process - evolution - and lets it run it's course.
Occam's Razor says the simplest solution is the right one, so therefore the design theories are bunk.The first thing that comes to mind when I think of "what good is a pulse?" is: blood pressure.
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
Heart Pump , 30 October 2003
old news. patients are already benefiting from LVADS in melbourne. There was a story on ABC Catylst (Australian Broadcasting Corporation), Heart Pump , 30 October 2003 (full transcript) where one of the recipients received a pump. The news presenter tried to find a pulse, but none could be found due to the continuous pump. Interestingly the body seems to adapt to it.
The company who is commercialising this technology, Ventracor lists more faqs here.
peterrenshaw ~ Another Scrappy Startup
This is rather off-topic, but from what I understand the average age of menarche has always been roughly between 12 and 14 years of age, including in places like ancient Rome.
The reason people thought that it has been dropping is that the doctors who were compiling information on in the 19th century were studying undernourished women who were in poor health.
However, there has been a slight (6 months or so) drop in the average age of menarche in recent years which has been attributed to artificial estrogen-like chemicals in the environment. Also, it has been shown that on average, girls who live in families afflicted by domestic violence reach menarche earlier.
On the other hand, low body fat and vigorous excercise will delay menarche: for gymnasts the average age is 14 to 15.
As for your comment about rampant teenage sex: people forget that they had an easy way to deal with teenage sex in the middle ages: they married the girls off extremly young. Even quite recently women would marry at 18 or even younger. I imagine "waiting until you are married" is a bit easier under those circumstances.
"If you want to discuss evolutionary history, let me ask you this. Why, if this was evolutionary, are women having periods earlier now? Wouldn't evolution have determined that a later period is beneficial, and those genes would have carried over into modern women? A contradiction indeed."
Not necesarrily there are other factors now IANA evoltion expert, but the factors contributing to early puberty in modern women would be due to contraception if you ask me.
This is just a minor pet hypothysis with little data. But it seems to me that there would be a normal variation in age of puberty, now the older it hits the shorter a time frame till contraception is likely to be used (how many 12-13 year olds are likely to go looking for it, especially early on when it was 'for married couples') this means that those with younger entry into peuberty are more like to start child bearing earlier, witch has economic effects, which decreases fiscal ability to afford contraception, which increases the number of children born during her lifetime thus propagating the gene for early start more. Also the main evolutionary drawback to early pregnancy, higher maternal fatality, is greatly reduced by modern medicine.
My main point with this is that the number of factors involved are enough to make the obvious answer not so obvious, whether or not my pet hypothesis has any merit.
Gak that first paragraph is horrible, hope it dosen't ruin the message. I'd re-write it but I'm short time and sleep.
Mycroft
https://signup.leagueoflegends.com/?ref=4c3ed6600b6ea
what would happen when you bleed then instead of spurting wounds we would spray and bleed to death faster :(
Good post from an AC. I agree with your assessment of the onset of menarche; thousands of years and nothing has changed and the data recording a perceived change was flawed.
Higher levels of artificial hormones in the environment (read: growth hormones in beef and other meats) do indeed contribute to puberty in teenagers as well.
Evolution has nothing to do with this, period (no pun intended). Evolution's role in this is to get humans to puberty as early as possible, so that women can reproduce at a very healthy age when they are likely to produce good offspring. Keep in mind that in times past the median old age was around 35, with death following shortly thereafter. I'm talking Cro-magnon man and his ilk. For early humans, breeding young was very beneficial. However, there are a few genetic changes that have stuck with us with little benefit despite environmental and health changes. The age of menstruation can be considered one.
And I have one that I had before I knew about the pill's bad effects. But it is still the case. Without the abortive agents, the success rate of "the pill" is 95%. With the abortive agents, they were able to bump it up to 99%.
Engineering and the Ultimate
Nope. Just like a scientist who performs experiments on mice isn't interested in injecting himself with the same stuff.
My poit was
#1 My point was in response to the original and the reply to my original post. The reproductive system is mostly redundant. It affects life, but isn't required to maintain it, and thus successful alterations of the reproductive system are not good models for the saftey of altering other systems. Not that we can't alter other systems, but alterations to the reproductive system are not good models.
#2 Anything that affects lifespan in animals or humans is interesting because it helps us to understand the process of aging, scientifically. I'm not volunteering for CR any more than a scientist who does tests on rats wants to inject the same garbage into himself. I didn't advocate it anywhere. Understanding things like the role of oxidative damage, the role of telomeres, etc. in the process of senescence may eventually be helpful in extending lifespan without the negative effects associated with things like CR, castration, etc.
If the life extensions caused by CR and castration were linked, this would help to explain the underlying mechanism for CR.
___
It's the end of my comment as I know it and I feel fine.
I would think that one would die faster from blood that can't carry oxygen at all well due to decreased cell surface area and capacity than from a damaged immune system.
# cat
Damn, my RAM is full of llamas.
he had tried to kill himself by getting drunk and laying in front of a train (and he succeeded... not too many people survive having an enormous chunk of their torso literally torn off).
I suppose he was angry because he thought I was going to save him... Well, he needn't have worried; his suicidal efforts/injuries absolutely crushed any skills I might have had to save him... it's a miracle he even survived the 1/4-mile ambulance ride.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
If you had an artificial heart, you would have a medic alert bracelet. I can't imagine what it would say though.
"Patient has an artificial heart. Should not have a pulse. No we're not shitting you!"
Your initial post sounded like naked greed, rather than a reasoned position... I wish you'd expounded a bit more initially; you'd have saved me having to apologize for my scourging.
Let me throw out a few thoughts... consider them, even if you do not agree.
Payments would drive up the cost of organ donation. What's to prevent it from becoming a bidding game, where the poor and underinsured can no longer compete? Medical necessity should rule all, yet injecting profit may turn it into a financial decision. Putting a value on life is a slippery business in the best of circumstances... I frankly don't feel sufficiently wise to make that kind of decision.
I'm very leery of injecting financial incentives into the organ donation process. My fear is that offering such incentives will lead to gaming the system for profit, to the detriment and death of patients. Almost no physician who's been in practice very long will argue this point: unscrupulous people will do unspeakable things for a pittance, even to their own kin.
So far in my career, I more than once have witnessed family members stall/delay ending a relative's suffering, just so they could make it to the first of the month and collect that next check. I've seen people stab/shoot siblings for a pair of tennis shoes. Injecting payments to the families may tempt many families to not seek aggressive treatment, at precisely the time they should be their critically-ill relative's greatest advocate. When you're waving thousands of dollars under a family's nose, it's not difficult to imagine someone forging an amendment to the ill relative's living will. Those critically-ill and brain-injured patients are absolutely helpless; I'm terrified of the prospect of offering their families a cash payment to part them out.
What dollar amounts are we talking here? 10k for a kidney? 25k for a liver? I've seen people tortured and killed for far, far less.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
You did your job and you did it well. The way I figure it, at least he was practice for the next trauma patient you had that needed your skills. He also died with someone giving their best to try to save him. He couldn't say that no one cared.
Ya done good, kid. Be proud.
This sig seemed like a good idea at the time....
You have it exactly backwards. The theory of evolution is just that, a theory. This is how science works. One postulates a hypothesis. Only if it is useful, that is, it furthers our understanding, and allows testing against, is it kept. Theories that are not testable, like intelligent design, are not scientific, they are matters of faith. Theories can easily be proved false, all one needs is a single concrete counter example, but being mere theories, they are never quite proved true. If after years and years of being tested (and not once being false), and continuously demonstrated as being useful, theories are accepted as fact. The creationists like to put this backwards: concluding that since scientist cannot prove evolution, the competing model (ID) is on equal footing. ID is faith, it is by definition not testable, and it is not useful in science. You can feel free to believe it you wish, but your conclusion is not based on logic. Scientific models, laws even, do not have to be fully understood to be useful. The effects of gravity, for example, are well understood -- and we have plenty of equations for it -- even though science hasn't quite explained where gravity comes from (except that it is an intrinsic feature of mass). Gravity isn't mentioned in the Bible, so the religious nuts don't feel compelled to manufacture un-testable competing theories.
I paid the going retail price for a Windows screen reader and got a free Unix computer!
I am glad to see that a day latter, your post has gone from a 5 to a 2, much more reasonable. I actually appreciate you bringing up the flagella on a bacterium as an interesting example, I just cannot abide your conclusion that this provides evidence of ID. I have been interested in animals with wheels since I saw a picture of some monster proposed for Empire of the Petal Throne in Dragon magazine some twenty five years ago.
I paid the going retail price for a Windows screen reader and got a free Unix computer!
Ya done good, kid. Be proud.
Oh, I'm not ashamed of my efforts at all... it was just one of those surreal moments; reminded me of Roddy Piper's final scene in "They Live" (Old B-movie reference, I know).
Never a dull moment.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
The article doesn't go into depth about why the castrated live longer. Google seems to bring up reports that the lifespan of castrati singers vs non-castrati singers wasn't apperciably longer.
There are several real-life conditions that will cause effective castration, such as Kallman's Syndrome. The jazz singer Jimmy Scott is afflicted with Kallman's, and has a voice similar to a castrato. (Nowadays, Kallman's Syndrome is easily treated with either testosterone injections or other drugs, so Jimmy Scott is probably going to be the last singer with his unique voice).
It's not long ago that some crazy Australian
doctor proved, against all the experts, that
bacteria do indeed survive in the stomach and
cause ulcers.
There wouldn't have to be just one cause for
heart disease of course.
Duh, this should be obvious.
I'd sign up if my wife and kids would get paid.
Who wouldn't? You can't have my parts except
by auction.
As it is, the parts very nearly go to the highest
bidder. It's just that all the middle-men accept
their "handling fees". I want my family to have a
part of that. Those organs can go for millions!
Why can't my children even get a tiny share of that?
I agree that just saying add millions (or billions) is no answer, but that's not an argument a good Darwinists would make. It is usually the creationists who are accused of begging the question! This is something I have noticed in recent years, the creationists trying to turn arguments around. It seems to me the Republicans have gotten good at this too! Science has no use for faith. If it can't be used for prediction, it isn't science.
I couldn't find the name of the logic fallacy you are trying to use. I did want to share this quote:
But I am not a very good athesist, so here's my gift to you... The Heisenberg uncertainty principle puts a little black box around each sub atomic particle. Is this not enough room for God to work miracles?
I paid the going retail price for a Windows screen reader and got a free Unix computer!
Why would there be a non-flowing? Turbines don't usually have an off cycle.
No..he's right. When you take a BP, the systolic is when the blood flow stops (you know how they pump that cuff up when you're at the doctor's office?). But that might be a moot point, as your BP would be a function of the turbine (see me earlier post....LCD screen?) than anythign else....why get an indirect reading when you can get it from the source. And the "systolic" on a continuous flow pump might not be accurate....something seems wrong about it. Maybe not.
I'm done rambling now. Sorry. Havnen't finished my coffee yet.
Do not fold, spindle or mutilate.
Read the article. The point is not to replace the hearth, it's to assist the heart. It was designed that way. Thus, the comment you replied to was entirely relevant.
You obviously missed my reference to the scientific method so I will quote one succinct definition here.
The piece goes on to discuss 1.3: Can science ever really prove anything? Most hard science doesn't work out as simple math. There is huge amounts of evidence for evolution but I guess if that doesn't sway your opinion, then nothing will. (By the way, do you hold that the religion of your absolute reality should reduce to a mathematical proof as well?)This is why the theory of evolution with mutation and natural selection is science. It is useful. It can be (and has been) used to make predictions. It can be (and has been) tested.
Creationism is faith. One could reasonably argue that as an explaination it is just as good as evolution. The problem is that it is not scientific theory (no matter how much the ID folks dress it up) because it cannot be used to make predictions and it is impossible to devise tests for it.
The best creationist can do is "to trying to make itself real by trying to make" evolution false by focusing on the very marginal areas where the current evidence is weak or incomplete.
I paid the going retail price for a Windows screen reader and got a free Unix computer!
One reason girls (not women) have periods earlier now is because of an increase level of hormones externally introduced to the body at earlier ages.
Many parents don't realize that adult shampoos (and other products) have a lot of adult hormones that affect their children... sometimes "kickstarting" puberty. I know of several families who stay away from hormonal products specifically for this reason and their daughters didn't start having periods until 2-3 years after all of their peers.
There is a Universal Life Value Check it
Would there still be enough pressure to force blood to flow to all extremities including the brain? or would the blood flow just take the easiest path?
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
1) Mu. (I don't accept the premises.)
2) I'm very disheartened that someone could make this kind of trip, especially a Jew, and still not believe that God has revealed His presence in any way. Mind-boggling. Were you paying attention when they talked about the Six Day War? That alone ought to convert any skeptic.
1) Mu. (I don't accept the premises.)
The part you don't accept is the "never revealed his presence", right? That's perfectly acceptable. If you legitimately believe that God has revealed His presence to you, then you can believe in Him all you like. However, He has not revealed Himself to me in any way, and I will not believe in Him until that changes in an obvious way.
Don't get me wrong; I'm not a militant athiest. I don't care if you believe in God or whatever. However, I do think that trying to show any phenomenon X as evidence of the existence of God is going about the entire business completely wrong. I've been exposed to a lot of religion. The common thread between all believers that I've known has been faith. Evidence is the exact opposite of faith. Trying to "prove" the existence of God is going about things backwards, as far as I can tell. As you can tell, I am not a man of faith. Somebody who tries to "prove" that God exists in order to make me believe in him is attempting something that does not make sense.
2) I'm very disheartened that someone could make this kind of trip,
An amazing trip, to be sure. A lot of evidence of people who believe in God. No evidence of God Himself.
especially a Jew,
This makes no sense. Just because some members of my family go to Shul every week and some relatives were killed by Hitler means I should be more susceptible to finding evidence of God? Why not say, "especially a white guy", or "especially a tall guy", or "especially somebody who wears glasses"?
and still not believe that God has revealed His presence in any way. Mind-boggling.
I find it equally mind-boggling that somebody can see evidence of God when His presence is not needed. The difference is that I know that I don't understand faith, and I'm willing to let people of faith believe whatever they want, as long as they don't try to convert me. You don't see me starting arguments about how God doesn't exist just because somebody brings up something vaguely linked to the subject.
Were you paying attention when they talked about the Six Day War? That alone ought to convert any skeptic.
I think you're confusing the Six Day War with the Yom Kippur War. The Six Day War was a preemptive attack by Israel which was a resounding success all around. The Yom Kippur War is where the Arab states attacked by surprise, and things were very touch-and-go for a while. But even so, God is not necessary to explain, only a belief in the resiliency of people, and an understanding of the greater situation at the time. It was amazing, but not supernatural, at least in my eyes.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!