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Build Your Own ECG
Jason writes "I finally finished documenting my $4 home made electrocardiograph (heart monitor). If anyone is interested or wants to build one for themselves, please come by and take a look. Makes me wonder why medical care costs so much. :)"
...please come by and take a look.
Translation:
Please slashdot me and don't even peek... :-)
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Error 500: Internal sig error
This could make a great gnome toolbar applet. Then I could enjoy watching my heart race when I accidently type 'rm -rf *' in the wrong directory!
when you can tell me how to build one of 'dem four dollar defibrillators. With my steady diet of coffee, butter and bacon, heck, that thing would pay for itself.
And to think that today I used $4 to buy two Nacho Cheese Steak Chalupas at Taco Bell. While you were out trying to save your heart, I was slowly beating it into submission with slightly substandard but confusingly delicious Fast Food(TM).
Small potatoes make the steak look bigger.
I finally finished documenting my $4 home made electrocardiograph (heart monitor).
From the website:
Here you will find information how how to build one with less than $10 in parts.
Lies damned lies!
Bored with karma, be a fan/freak
His vital are dropping, maybe he should have looked into monitoring his school's server.
- clear -
Beep beep...beep beep...beep beep
-Mr. Fusion
Beep, Beep, Beep, Beep... Beeeeeeeeeeeeeeeeeeeeeee.......
0110100100100000011000010110110100100000011000100
Yea, but does it interpret the data. That's one of the big expenses according to her: have the cardiologist examine the data and give his opinion. Since it's all waveform stuff, I wonder how much of that could be automated in the future?
This space for rent.
PLEASE be careful with ECG or EEG circuits, especially if you're planning to use an oscilliscope to see the wave or a data acquisition board to log the data. The pads and the gel used to adhere them to the skin and lower the resistance to get a good signal can sometimes cause current to flow into the body, especially if the circuit is not optoisolated.
Normally, the skin resistance is high enough to make the current flow negligible; however, when the pads are on, the resistance in the path is very low, and you could seriously injure or kill yourself if even a small amount of circuit flows 'back' through the electrodes.
Professional ECG machines usually have a lot of protection circuitry on their front ends (the instrumentation amplifiers) as well as between the amplifier and the ADC/output circuits to prevent this from happening. This is obviously even more critical in line- (i.e. 110V or 220V-) operated devices.
Karma: Excellent Birds (mostly as a result of listening to Laurie Anderson)
Oh don't get me started on medical equipment, [read: I'm going to get started on medical equipment]
Being disabled (SMA type 2, A type of MD, Donate to MDA!) I deal with medical equipment a lot, less then some in more critical situations, but more then your average user.
It's outrageous the markup medical tag gives to an item, one of the most outlandish of them that I saw was a flag, a metal mounting bracket, fyberglass rod, and cheap neon flag. You know the kind, sold in the walmart bike department for a measly 3$
Do you know how much they wanted at a medical store? No you dont.... 18$
So the price of "medical" is 15$ on top of 3$ It's insane.
You can buy an Ok car for the price of an electric wheelchair. And that's just for what's on the low end.
How exactly are people who can't walk suppossed to affoard this shit? Sure it's possible, and often times picked up by the government (thank god)
And if you're not covered, forget footing this bill your self, unless you've got cash to burn. And it's not like the freedom of mobility is important or any thing. Just one of life's liberties some people take for granted.
"I wish I could sit all day"
Fuck you buddy
Grrr, can you tell I'm bitter?
And then theres red tape. I've been using this same wheelchair for several years now, it needs replaced. But fighting for them is a nightmare. So much paper work.
Computational Madness in a round package.
Makes me wonder why medical care costs so much.
Damn near everything used in a hospital has to be certified to be used for medical purposes. People's lives are at stake, and you have to be sure that your device operates within tolerances, doesn't crash, doesn't electrocute people, etc. It costs money to think of every possible problem and design a device around that. Also, as other people have said, the people that run these things are some of the most educated people in the world. Try to start a hospital with your $4 device and let me know how it goes.
It's not impossible to kill yourself with a badly-designed ECG device.
Places like UL/CSA say that voltages under 40V or so are safe. But if you apply it to electrodes pasted to your chest, the unsafe voltage is WAY lower than 40V.
If you build a simple ECG and connect it to a computer, that computer had better be battery-powered. If not, then you might get a nasty surprise (waking up in the afterlife of your choice.)
((((((((((((( ( ( ( (o) ) ) ) )))))))))))))
SCIENCE HOBBYIST amasci.com
Congrats on what you've done so far...if you want to take the next step:
Higher-quality ECGs systems don't use generic op-amps, they use special devices called instrumentation amplifiers that are able to reject common-mode signals at the inputs really well. Turns out then when you place electrodes on the skin, the skin between the electrodes acts like a crude battery (we're full of electrolyte after all!) and you get a large, shifting potential difference between the two electrodes that can drown out the millivolt-range ECG signal.
Oh and by the way, the electrodes and wires will make great radio antennas (esp for 60 hz noise)! Check out the AD624AD instrumentation amp from Analog Devices.
The ECG measurement is a key piece of the standard polygraph. One of these can be combined with a galvanometer (easy), a skin thermometer (easy), and possibly a respiratory rate measurement (harder: standard technique is to wrap the chest with a stress-sensitive band and build a circuit similar to the ECG one) for a lie detector that should be great fun at parties.
A disgustingly large amount of our medical expenses goes to malpractice insurance, and mostly to protect from one of the millions of malpractice cases that never should have been that occur each year. Granted, the ability to sue for malpratice *is* a good thing. However, it is grossly misused, and results in higher medical bills for all.
Not to say that's the only factor... but that's one of them.
---^v---^v---^v-------
Eeep...eep...eep..eeeeeeeeeeee
time of death 927PM CST.
Damnit jim I'm a doctor not a webserver admin..
Partnership for an idiot free America!
EXACTLY! Just what I was thinking when I saw this.
.1 amp to kill you dead, and about .01 amp can interfere with normal heart operation. Normally, skin runs about 10 to 100 kohms resistance - to get 10 milliamps you would need about 100 to 1000 volts delivered across the chest.
Kids, DO NOT TRY THIS AT HOME.
Real medical gear has full galvanic isolation - that means there is NO current path that goes from the patient's body to the equipment - the signals pass through either an isolation transformer, an optocoupler, or a capacitive coupling. That way, any ground leakage in the equipment won't fry the user.
It takes about
When you put the gel on, you reduce the resistance to a few hundred ohms. Now you need only a volt.
Normal consumer equipment can have "leakage currents" - places current shouldn't be flowing but is. You hook your home-brew circuit up to the printer port on your PC, and maybe you are OK. Then one day, while screwing around with it, a cap starts to fizzle in your power supply, or maybe you reach up to adjust your monitor, or maybe you put your foot on the ventilation register. Then you get to start (posthumously) on the 6 o'clock news.
At a MINIMUM, you should power the circuit with a nine volt battery, and communicate with the PC via an opto-isolated RS-232 link.
Even better, splurge and get the real medical isolation amplifier modules. Yes, they will cost a bit more than US$4, but then, if that is all the value you place on your life....
On second thought - go for it! And make sure you clip the ground lead off your computer's power cord while you are at it. And do it in the bathtub - that will help shield the fnord rays out.
www.eFax.com are spammers
Umm, people pay for VB?
What are you going to tell me next, people buy Windows? ahahaha
There are several reasons healthcare is so expensive.
1. Litigation. Does the phrase "malpractice insurance crisis" ring a bell?
2. A side effect of (1.) is something called "CYA medicine". Ever receive a chest CT because your heartburn just might be a pulmonary embolism? It happened to me just recently.
3. Failed accountability. This one takes a bit more explaining. Ever bother to look at your bill? Of course not. Why? Because chances are, the insurance company pays it. Aha! You say. What if I'm not insured? Well then, many people who aren't insured "spend down" and go on Medicaid. Once more, nobody looks at what Medicaid is being billed, except for the hardworking beurocrats (cough)bull***(cough). Only the very narrow slice of the population that is "self paying" actually looks at a bill (more on thatlater) You would think that insurance companies would be on guard for their bottom line, but corporate inefficiency is often no better than government inefficiency.
4. Complex and inefficient billing. Health care is one of the few businesses where you receive service at a single location, yet billing goes from subconractors directly to insurance companies or patients. Worse yet, billing from some contractors takes weeks, or even months. Yuck! Imagine if every business worked like this. Imagine getting your car fixed, and you get bills from the mechanic, the parts department, and the oil supplier spread out over 2 months. It's not just inconvenient. It actually hinders your ability to make financial plans because you don't know what's coming. And why don't you know what's coming? That leads us to...
5. ...Secrecy. That's right. Secrecy. Try to call up a hospital and ask them for their price list. Chances are, you'll get the same answer I got: "That's on a computer and it's confidential". I was transferred to a manager who had her phone on voicemail. In retrospect, I should have known I was in trouble when the phone tree had "press 2 if you're an attorney". This is probably one of the biggest reasons healthcare costs too much. Sure, there are several hospitals within driving distance, but if I think I am going to need an exam that is likely to involve half an hour with a doctor, some medication, and an x-ray... I have no idea who charges the least for an x-ray, or what the hourly billing rate is for a doctor, or what the average examining time is for diagnosing a condtion. We have more accountability at the garage than we do at the hospital (Chilton's guides, posted labor rates, etc).This alone is probably the single biggest factor driving up healthcare costs. Lack of pricing information makes comparison impossible, resulting in a virtual monopoly even though there are multiple companies. So, what did I do? I gave up and paid a price that I could not verify as accurate because I knew that the only way to get the price list was to make a federal case out of it, and spend 100 times more in legal fees than my bill was.
6. Vested interests. You can call me a conspiracy theorist if you like, but I think various interests want the price of healthcare to skyrocket so that they can use that as an excuse to socialize it. The corporations actually secretly like the idea of socialized medecine, because then they get to become government agencies. If you are a corporate sleazeball, the next step up is to become a government sleazeball; the perks are just that much better. You can just hear them salivating.
Want to fix healthcare? Fine. Require providers to give one bill in a timely manner--no pass-throughs to subcontractors. Require providers to post price-lists online if they have a website, or to make price-lists available to the local libraries. Require employers who insure their employees to provider high deductable insurance. There should be no claims or forms until annual out-of-pocket costs exceed 10% of your annual pay. Place a cap punitive damages, as many have suggested.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Well, issues of "medical care" and "medical equipment" costs being two rather separate things(one of the biggest costs in medical care is liability insurance, probably followed by administrative overhead)...
...it might be because the expensive REAL version won't kill you when there's a lightning strike nearby, or when someone touches the case after building up a static charge, or something shorts out in the computer half...the list goes on. It only takes a few microamps to stop your heart- it's all in the path the current takes. Having those nice electrodes in the right places, making great electrical conduct with your skin...well, umm...you should get the picture.
Medical equipment is designed to be 'bulletproof' in almost every way- there's a standard, for example, for medical-rated Edison plugs and sockets.(Edison plug = US electrical plug). It's VERY heavy duty, makes really good contact, has excellent stress relief on the cord, etc...because something VERY important might be using it, like an artificial heart pump in an operating room, or a dosage machine for an IV, or a ventilator. The REAL version also can't crash or stop working- so, for example, if it has a computer, the instruction code, the chips...everything is heavily tested. Jokes aside, the Pentium math dividing bug is a perfect example of why you can't just use "anything" for medical equipment. What if that bug caused the heart monitor to display the wrong heart beat rate? Electronics used for medical equipment get a LOT more testing- lives are at stake. Same idea behind the MIL specs, although with MILSPEC stuff, the idea is more that the military really abuses the crap out of stuff ON TOP of similar concerns as medical stuff.
All of the above are why you often see these days disclaimers from chip makers that say "this device is not certified for use in life support equipment" and such. The statement often extends to industrial automation- "situations where malfunction may result in injury or death", stuff like that. Ie, "don't use this where if it screws up, it dumps 10 tons of molten steel on a bunch of steel workers' heads."
Please help metamoderate.
That's the sound of yet another web server flatlining.
BTW the only lame thing around here is your bloody "lameness" filters! How in hell else can I simulate a flatline in text without using repetition?
You're using her as bait, Master!
I can tell you that many of us clinicians laugh out loud at some of the machine "interpretations" that ECG machines generate.
NEVER trust a physician who allows his ECG machine to interpret your tracing... run for the door... I'm quite serious about that. If the guy doesn't have the expertise to read your tracing himself, don't trust your cardiovascular health to him.
I've sent people home with ECGs that read ****ACUTE MI***** in large, upper-case font on the top, because the machine was totally, completely wrong. The only thing it's sometimes useful for is in reading QT intervals, and occasionally rate (though the machine can be easily fooled on this one as well).
Have a doc read it, preferably a cardiologist. Of course, if you don't want to pay a guy like that for his expertise you don't have to... but you get what you pay for.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
How to build an ECG for $4:
parts list:
* one surplus patient cable with sensor and plug ($4 on ebay)
instructions:
* Plug the sensor into a strip chart recordor or heart monitor you might have lying around the house. For instance I found and old Hewlett-Packard model 78534C EKG and dual-channel pressure monitor.
You're done! It's THAT EASY! And just FOUR BUCKS!
Tune in next week when I tell you how to build your own x-ray machine for the cost of some X-ray film (you might need to find some medical equipment you might have laying around the house to complete the project).
If you can, please mirror my mirror. I'm sure a large number of slashdot readers have servers available they can put to good use.
I am a third year medical student at a state medical school in the United States
This is a multifactoral problem. The average medical student graduates with about $180,000 debt (closer to $220,000 by the time it's paid off). Monthly payments can be about $1,000 per month.
Secondly, technology has largely supplanted physical diagnosis. Doctors have gotten sloppy in the past due to reliance on expensive diagnostic tests rather than relying on patient's history and their 5 senses (Greeks used to taste urine to diagnose diabetes). This problem is being addressed. Medical students are trained more like engineers in that cost to the patient (and by extension the system as a whole) is an important consideration in ordering tests. Of course, the health of the patient is paramount. For example, a good abdominal exam can obviate the need for an expensive CT scan.
The legal system in the US contributes in no small way to the cost of health care. Professional liabilty insurance ("malpractice insurance" to the laypublic) premiums can range upwards of $100,000 per year for high-risk specialty. An OB/GYN I know in Florida was recently offered $250,000 of coverage at a $216,000 premium. He is now practicing without coverage. Doctors pass these increased costs onto patients.
Lastly, medical equipment is held to tremendously high quality control standards. From my software engineering classes, I seem to recall that the importance of reliability testing was consistently invoked by mentioning areospace and healthcare equipment. If your $4 EKG misses one MI, you've got a big assed lawsuit on your hands (which we all pay for through increased costs).
My $0.02
--b
I don't know what everyone's one about. I just built one of these. I'm monitoring my heart rate in a window right now and it works gr9'0wrtup
CEE5210S The signal SIGHUP was received.
From the article:
"but don't come crying to me if you find yourself dead."
You also see dead people?
There was something like this in Scientific American a while ago, only it used an instrumentation amplifier instead of an op-amp, which would reduce common mode interference and give you a cleaner signal. Analog Devices makes a cheap one, AD620 which sells for around $5 and wouldn't raise the cost of the project too much. They also make an expensive one, AD624AD, around $20 with better gain and better common mode rejection, still not outrageously expensive. some diodes to give some protection against getting electrocuted by a power surge might be a good idea too, for those girly men who can't handle their electricity. you can buy real ekg electrodes cheap too. Of course, you'll blow your entire budget hiring a cardiologist to interpret the results.
I have always said that if engineering were practiced like medicine is practiced by doctors, people would be dead. Gone due to a bridge or building falling down, or electrocution, or a chemical plant exploding because they rely on what they've seen before rather than what the problem might really be.
Real engineers are thorough thinkers. That is the most fundamental skill one is supposed to learn in engineering. Engineers should think about what the real root cause of the problem is and every possible answer to the problem. While cost is a consideration, an engineer will tell it like it is and tell you that you have to choose between something that works and something that costs what you want it to cost.
Doctors, on the other hand...well, I've gone to doctors telling them that I can't sleep and the first thing they do is want to pump me full of Xanax. They never asked me if there was something wrong going on personally in my life, or if I'm consuming too much caffeine or MSG, or anything. Just wanted to prescribe crap and get me out of their office. Fortunately, I told the doctor I wasn't taking Xanax and promptly found another doctor who sorted it out (too much caffeine). These are the same idiots who prescribe Ritalin to kids who won't behave in class because their parents are too busy stuffing them full of sodas.
But that's my point. As an engineer, it's my job both to identify the root cause of the problem and investigate the most feasible solution. I will never sign off on an engineering document if I feel someone will be in danger, including my reputation. Piss-poor engineers (and, unfortunately, your average doctor) will let it go through. So please, don't make that comparison, because it's patently ridiculous.
then for capital punishment why bother with an electric chair with hundreds of volts and significant amerage? Why not just use a 12-volt car battery and a little gel? A Die-Hard perhaps?
Scientific American published such a circuit in their Amateur scientist area a few years ago... link to article .
It is a commonly referenced site.
I'm going to spring for the $30 ECG.
I learned my lesson with the $4 dentistry set, and even worse, the $4 electroshock therapy machine.
I STILL can't quite get my hair to stop standing on end. I can't even wear hats - hair pokes through like skewers through butter (which, incidentally, is one of the only things I can eat now thanks to the dentistry set).
I thank the lord I didn't invest in the $4 eye-surgery kit.
Mod me down and I will become more powerful than you can possibly imagine!
Speaking of medical safety...did anyone notice that this device is running under Windows? I don't know about you, but I'd never hook anything running Windows up to my body.
IAAL
He gives you the compiled software, as well as the source, so you don't need VB to make your own. Guess you could still complain that he didn't give you a computer though, if you just want to cry about something.
I'm an American. I love this country and the freedoms that we used to have.
Well, chances are if you can visit the site, you already have a computer. It's not like he used it up in order to display the results.
But I understand your point. A hospital wouldn't be able to dedicate the price of a $400 computer and monitor or a $200 pda just for displaying the ecg results.
Oh wait. I guess they wouldn't have to dedicate it if the computer is can handle any of the computing requirements. And they already spend much more than that on the medical industry made ecg machines.
How much is a dedicated ecg machine? I saw on http://www.numed.co.uk/prices.html that pda's with the attachment and the software cost upwards of $1350.
Still, I'd rather have a tricorder.
Makes me wonder why medical care costs so much.
Although I will agree that medical costs are high, it's not due to the costs of the parts used to build ECG machines. Geez!
You would trust your diagnosis to a $4 machine built by some hobbyist on the weekend? I sure as well wouldn't. But even if the parts for a real ECG cost $400, it still doesn't demonstrate why you can't buy one for $400. So let me explain why it costs so much more: the price of ECGs has nothing to do with the price of its parts. Price is subject to the buyer's and seller's wants. If the price is too low the seller won't sell. If it's too high the buyer won't buy. If you've just spent two years developing a new ECG machine involving the work of a couple dozen engineers, testers, clinicians and marketroids, and hammered it out in clinical trials, fenced with the FDA, and met all the spurious checkboxes of the bureaucracies, you want some return on your investement. If you manage to sell only 50,000 then $400 a pop isn't going to cut it! (do the math) On the other hand, if you're a hospital with an increasingly shrinking budget and overseen by a hospital board composed of well-meaning but ignorant politicians, then $40,000 isn't going to cut it either. So a price is eventually reached that is mutually acceptable. It's going to be a lot higher than the price *you* would have paid, but you're not a hospital.
Why don't you get any input into the price? After all, you're the patient, and thus indirectly the buyer. The reason is that you have absolved yourself of any buyer responsibilities by foisting them off on an insurance company. If everyone who had an ECG reading had to pay for them out of their own pockets, you damn well better believe the price will come down! One reason medical prices are high because people (you, your employer, etc) don't shop for medical prices, they shop for monthly payments to an insurance company instead.
But ignore what I just said. I'll tell you what the real price of ECGs is. Free. Zero dollars and zero cents. You see, when a company like Siemens, Philips or GE makes a sale to a hospital, they throw in the ECG (and lightbulbs) for free. I may still cost those companies $500 in parts and $5,000,000 in R&D, but they'll make it up on the MRI, CAT, and US. And of course, on the service plans.
A Government Is a Body of People, Usually Notably Ungoverned
Econ 101.
Inelastic pricing.
You pay whatever we ask, or you die, or lie there in pain and fear.
Oh, and we'll pretend we have these standards for quality of drugs and equipment and caregivers, but that's just to forestall liability. This stuff is just as crappy as the stuff you buy at Walgreens, and these people are just as incompetent as the people who work at Walgreens.
And half of it is padding and sandbagging because you're too ignorant to know that you don't use a rheostat in a colonoscopy.
And we have all the money now, so we own the votes we need to stop you whenever you try to change the system by changing the law.
Now. Back to the price.
Yes, it's true, and if you do enough searching from that link (you gotta go all the way down for your link) you'll find what happens if you're affected badly by colloidal silver: silver colored skin
I don't see where your post addresses the inefficiency issue. You spoke more about accuracy and procedure than efficiency.
Most people in this thread are bitching about how expensive medical care is, and we're not blaming you doctors. We're blaming the people who have your hands tied: the lawyers and insurance companies. As an ER doctor, you probably aren't subject to a lot of the abuse that family practice doctors are. You aren't forced to promote the latest fad drug just so you can stay in business. You aren't told by some bureaucrat how much you can charge for your services (or are you?). You probably aren't a puppet to big-pharma, big-insurance, and big-litigation, but maybe you are, we don't know.
You have a great opportunity in this public forum to expose a lot of the crap that we lay-people speculate about. We know lots of things go on behind closed doors that seriously inflate the cost of medical care - like price-fixing among big-pharma, secretive pricing structures, and flat out "pay us $100,000 or you die" extortion of seriously ill people.
In Pennsylvania, even expensive doctors can't afford to say in business because of high malpractice insurance premiums and the fear of being sued. Also, CYA-medicine is rampant (patient: *cough* I think I'm sick, doctor: here, I want you to go in for a full-body MRI, an echocardiogram, a colonoscopy, and a full-body diagnostic) because if a doctor overlooks something or makes even the slightest error, he/she can be sued out of business regardless of whether there were even any negative consequences for the patient.
You'd be doing a much better public service by confirming or denying some of these allegations or at least shedding some light on why medical care has become such a fat bloated pig.
I refuse to go to doctors anymore. I don't care how sick I feel or how high my fever is. The last time I went to the doctor with some persistent heartburn (from binge eating) I ended up going to the hospital for $4k worth of unneccesary tests when a little bit of therapy for my eating disorder was all I needed. The physician didn't even ask about any medical history, my eating habits, or ANYTHING. He asked what the problem was. I said I had had heartburn consistently for 3 or 4 days, and he wrote up the Rx and shoved me out of his office. That was the end of medical care for me - about 2 years ago.
There's no reason for any of this crap to be going on. If there were no insurance companies or lawyers, human medicine would cost about the same as veterinary medicine, which is much more reasonable.
If you try this at home, please document your efforts at this site.