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Tiny Pacemaker Can Be Installed Via Catheter
the_newsbeagle writes "About four million people around the world have pacemakers implanted in their bodies, and those devices all got there the same way: surgeons sliced open their patients' shoulders and inserted the pulse-generating devices in the flesh near the heart, then attached tiny wires to the heart muscle. ... A device that just received approval in the EU seems to solve those problems. This tiny pacemaker is the first that doesn't require wires to bring the electrical signal to the heart muscle, because it's implanted inside the heart itself, and is hooked onto the inner wall of one of the heart's chambers. This is possible because the cylindrical device can be inserted and attached using a steerable catheter that's snaked up through the femoral artery."
The things we can do now adays in medicine are shocking...
Ah, through the femoral artery. My imagination went to a much more horrifying place when I read "catheter."
The quickest way to a man's heart is through his catheter.
And, yet, it is our capitalist society which has managed to produce these amazing advances in such a short period of time. 60 years ago a pacemaker weighed 100 pounds and was worn externally. 10 years before that it didn't even exist except in theory. So, hate on capitalism if you want but I like it and wish we'd worry more about getting rid of some of the abuses than scrapping the whole system.
"Well, there's a delicate corneal inversion procedure... a multi-opti-pupil-optomy. But, in order to keep from damaging the eye sockets, they've got to go in through the rectum. Ain't no man going to take that route with me! "
"I opened my eyes, and everything went dark again"
Around Christmastime 2011, I developed paroxysmal non-nodal reentrant supraventricular tachycardia, likely stemming from my maternal grandmother's history of similar cardiac problems, and underwent radiofrequency catheter ablation of the bad conducting circuit in my atrial tissue. I'm left with no fast pacing circuit to increase my heart rate on demand when I'm exercising. I know people with implanted pacer/defibrillators, and I work as medical transcriptionist and have typed a zillion of those procedures, and the things they despise about it is the problems with tissue pocket infections and interval battery replacements, requiring the site to be reopened, the equipment removed and replaced, antibiotic washout, reclosure, etc. I'll be bugging my doc at next visit to research it and determine if I can get one of these.
Yes, it's a urinary catheter. To get to the heart. The two are directly connected, similar to your case where the brain is directly connected to the asshole.
If the pacemaker is in the heart, and it somehow got loose (maybe because of an imperfect installation), that could lead very quickly to a dead patient. Maybe they've tested for this, but the article doesn't say.
"surgeons sliced open their patients' shoulders and inserted the pulse-generating devices in the flesh near the heart, then attached tiny wires to the heart muscle
I'm more comfortable thinking about surgery where my shoulders are opened than thinking about something snaking up through my blood vessels from my leg. Though if I was to choose, the benefits would probably overcome my reservations.
They knock you out -- they have to test the automstic defibrillator part and you don't want to be conscious.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Probably a lot less susceptible.
The main concern with MRI and pacemakers is not so much the magnetic field but the RF field. The magnetic field is not without problems as most pacemakers contain a reed switch which is used to activate "safe mode", where the pacemaker enters a special diagnostic mode. This is largely for historical purposes, as early pacemakers used this for battery level testing. The doctor would hold a magnet to the patient's chest. The pacemaker would enter diagnostic mode and would stimulate the heart to beat a rate dependent on battery voltage. The doc would feel the patient's pulse and could look up the estimated battery level in a table.
Modern pacemakers contain rather more sophisticated NFC capability, so much more useful readouts are available with a proper scan tool (battery voltage, stimulation mode, inputs from various sensors, lead impedances, stimulation voltages and currents, etc.) as well the ability to reconfigure various modes (e.g. vibration response - where the pacemaker increases rate in response to exercise induced vibration), whether the pacemaker can sense other heart parameters (so that different chambers of the heart contract synchronously), etc. In general, however, a magnet will switch the pacemaker into a basic mode of operation. (Defibrillators are different, as basic stimulation can be very dangerous in people with severe heart disease, as it can trigger ventricular fibrillation; therefore magnet mode in implantable defibrillators usually only just tweaks some parameters, rather than anything more dramatic).
The major issue with MRI is the RF field. MRI requires a very powerful RF pulse. A typical MRI power amplifier will take up 6U of rack space, and about 5 gallons per minute of cooling water and need a 3phase 480V power supply, while providing a peak RF power output of 35-70 kW.
A modern pacemaker will typically sense the ECG as well as stimulating. It will include a watchdog timer, and if a beat is not detected before the timer expires, it will trigger a stimulation pulse. One risk with the MRI environment is that the capability of the pacemaker to sense the 1 mV ECG signal may be degraded by the pulsed transmission from the 70 kW RF transmitter 6 inches away.
There are other issues with conventional pacemakers. Being implanted near the shoulder, the pacemaker connects to the heart muscle via leads approx 8-12 inches long. These typically form an arc in shape due to the anatomy. It just so happens that this wire loop forms quite a nice 1/4 wave loop antenna tuned to the scanner's RF frequency; it can absorb the RF energy and channel RF into the tissues around the pacemaker "box" and at the electrode tips. In minor cases, the RF pulses can act as pacemaker pulses on the cardiac muscle. Fine at 1 Hz scan rate. Not so good at 5 Hz scan rate. In extreme cases, the voltage build up across the pacemaker leads can cause RF burns to the cardiac muscle or damage the pacemaker circuitry. (There are MRI compatible pacemakers around which use various tricks - upgrading from normal coax cables to coax with heavy copper screens so rigid that they actually have to be articulated in order to bend + a liberal helping of ferrite beads; or dividing the leads up into 1" segments interconnected by small ferrite transformers)
The nanostim device doesn't have any exposed leads, so it is likely to be much less susceptible to RF problems. Due to size and location, it's also likely that it doesn't feature a conventional magnet mode, relying instead completely on NFC for control and communication. It also has the option of being completely removable. Conventional pacemakers often aren't, as the leads are generally not retrievable from where they screw into the heart muscle. Because it is RF pick-up in the leads that is the No 1 hazard with MRI, simply removing the pacemaker device, but leaving the leads isn't a safe option (it may actually make it worse, as the pacemaker itself often contains clamping and termination circuits to protect itself from EMI, and
The things we can do now adays in medicine are shocking...
The article claims the thing can last "up to 13 years" before having to be replaced.
In the past, we used Pu-238 RTGs called "Plutonium cells", and the pacemakers never had to be replaced.
I guess this step backwards, towards treating pacemakers as a treatment, rather than a cure, guarantees a recurring revenue stream. One wonders, given the industry that surrounds it, whether we will ever get a cure for anything that started out with just a treatment, such as diabetes, when there's so much money tied up in "recurring revenue streams" and so little in "pay for it once". The whole SAS field itself is based on it.
Shit. Under a local anesthetic?
Yup. If you ask they will give you a valium (or equivalent). It does not really hurt.
I wouldn't want something implanted in my arterial system ready to shower clots in me. We don't put pacemaker leads in the arterial system, we put the leads through the venous system. Even a BiV pacer stunning the left ventricle does so through the venous coronary sinus.
Chewbacon
The Bible is like Wikipedia: written by a bunch of people and verifiable by questionable sources.
Usually not, although the description is not entirely accurate - the shoulder joint isn't touched. The device is put just under the skin next to the collar bone.
The video clearly shows it's venous access. I don't imagine you're want to be screwing a metal object into an active LV.
Best posting on the thread. Tx
Faster! Faster! Faster would be better!
Should they call it a "pissmaker"?
They're probably saving that for the artificial kidney.
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
PissTake(tm) The artificial kidney and bladder system, that gives as good as it takes!
Believe me, urine for a treat!
"Flyin' in just a sweet place,
Never been known to fail..."
Wow - thanks for the detail. I spent two years working on a Defib tester with an option on a Pacer tester and for an EE the details can take some learning, especially when your client is in marketing. Most of the two years was spent grappling with immature technology and on UI, though I did have a bit of fun with pulsed biphasic capture in the early days.
Have you ever considered contributing to Wikipedia?
That's what patents are supposed to be. That's also what they usually aren't. I don't believe in patents not only because they are generally something obvious, but because they generally do *not* "make patent" the devices that they are claiming a patent on. This may be an exception (though I haven't read the patent, and don't intend to). It is clearly the kind of thing that patents are intended to cover. So if the description does "make patent" the device, i.e. reveal it in sufficient detail that those skilled in the art can reproduce it, then I would consider this a valid instance of a patent. I estimate that this is true of perhaps 1 out of 1,000 patents, to be optimistic. Usually they are written in patent lawyer bafflegab and are of no use whatsoever to those skilled in the art that is not being described. I do not believe that those should be considered valid patents (and I do not so consider them). OTOH, I'm not a judge in a patent court. They seem happy to swallow any garbage and pronounce it valid.
I think we've pushed this "anyone can grow up to be president" thing too far.
Can't wait to start working on this.