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Build Your Own ECG

Posted by michael on from the home-health-care-made-easy dept.

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. :)"

4 of 357 comments (clear)

  1. My wife the nurse said ... by TheGrayArea · · Score: 5, Interesting

    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.
    1. Re:My wife the nurse said ... by mgv · · Score: 5, Interesting

      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?

      Its possible to automate alot of this stuff. However, its not as simple as it first sounds. I have used alot of ECG's with automatic interpretation, and they mostly get it right nowadays. About 95% of the time. Which isn't really good enough yet to risk your life on.

      I think that you will find that eradicating the last few percent of errors will get harder and harder, and who is going to back (and assume liability for) any errors if not trained people - be they medical staff or highly skilled nurses?

      I think that by the time that we can have automated diagnosticians, there will be alot of other things in our lives that are far less comples going automatic. Like cars that drive themselves and software computer programmers. But wait, I hear you say, nobody is anywhere near replacing programmers with software - but you think you are going to replace cardiologists?)

      Just my 2c worth.

      Michael

      --
      There is no cryptographic solution to the problem where the intended receiver and the attacker are the same entity.
  2. ...you get what you pay for by rfischer · · Score: 5, Interesting

    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.

  3. Re:A warning to experimenters by mgh02114 · · Score: 4, Interesting

    We cannot emphasize this enough. By applying electrodes or gel to yourself, you are opening yourself up to "microshock" Current at the correct frequency can STOP YOUR HEART (technical term = ventricular fibrillation) This can happen at shocks as low as 300 mA if applied at exactly the wrong time and place. The risk depends on the frequency of the AC current. And guess what the worst frequency is? 60 Hz ... exactly what is coursing through your household current and appliances ... including the computer that you're looking at right now. Building an EKG was a simple homework problem in my Biomed Engineering course. My final exam was an EEG (brain electrical activity, not heart electrical activity). We paid a lot of attention to ground isolation and electrical safety. The key was to use a battery and not be hooked up to AC wall current at all. Unfortunately, the strength of an EEG signal is much less than EKG, and my final exam instrument wasn't working well enough to pick the signal out of the background noise. I got it to work by rubbing the skin off my temples so that the gell pads were on raw flesh (cutting down the resistance). Now that is what I call a "bloody hard" final exam.