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Do-it-yourself EEG, EKG, and EMG

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21–30 of 44 posts

Re: Do-it-yourself EEG, EKG, and EMG

#21

Projects like this suggest to me there is a combination of collusion and bs from the FDA driving up the cost of medical equipment in this country, as well as blocking innovation.

Having worked in the pharma industry, I can attest that there is no shortage of extreme risk aversion at the FDA. That being said, we just had an article here where someone claimed to have created a spreadsheet in pure javascript for some absurdly low number of lines of code. When you read through that thread there are all sorts of people pointing out that this isn't a real spreadsheet by any stretch. It merely looks like one, but is missing some pretty complex and necessary stuff. I would submit that what you see here is the medical device equivalent. There are no safety mechanisms, the system doesn't monitor itself for failure, there's no characterization of the limits of the system in various conditions, etc... That's fine because it's a hobbyist setup. But let's not kid ourselves about what it takes to have a reliable device that works in a hospital setting under a multitude of environmental conditions.

Things didn't end up the way they are by accident. The current situation is the result of decades of medical devices and interventions killing people because of faulty design. It's not unlike the situation with the FAA and airlines.

Re: Do-it-yourself EEG, EKG, and EMG

#22
There are some really good cheap prosumer level EEG devices on the market now, for example the Avatar EEG (http://avatareeg.com/) and a few of the Emotiv devices.

I've been working on a side project (https://octopusmetrics.com) that allows you to connect these devices to your computer to record, visualize and analyze your EEG data in the browser. I think it's great that there are people out there thinking about how to do this more cheaply as it'll bring _real_ EEG devices into the price range where it'll be more available to hobbyists.

Re: Do-it-yourself EEG, EKG, and EMG

#23
post #11

I have been under the impression that doing this kind of thing is not that difficult (as explained here) but somewhat "dangerous" in that if you get the wiring at all wrong and accidentally apply even a small amount of current you can confuse the heart and get it to damage itself. I do not see any paragraphs here of "dire warning" or even any specific mentions of parts of this process being dangerous, just a comment…

No real danger for EEG if powered from an isolated laptop. ECG can cause safety issues if there is a significant current across the sensor leads, but even that is unlikely unless the completely wrong resister values used and the person hypothetically has a heart condition. Disclaimer: I'm not a physician, neurosurgeon or lawyer. I did however design and repair EEG systems.

There is quite a bit of current in a laptop battery, enough to stop a heart.

Re: Do-it-yourself EEG, EKG, and EMG

#24
Last time I had an EMG involved 45 minutes of a doctor poking needles into me to measure current. Moderately uncomfortable, and does not seem feasible to do on oneself. I assume this one just involves an electrode on the skin? Is that even going to do anything?

Re: Do-it-yourself EEG, EKG, and EMG

#26
post #19

Earlier quoted context omitted.

No real danger for EEG if powered from an isolated laptop. ECG can cause safety issues if there is a significant current across the sensor leads, but even that is unlikely unless the completely wrong resister values used and the person hypothetically has a heart condition. Disclaimer: I'm not a physician, neurosurgeon or lawyer. I did however design and repair EEG systems.

You are incorrect. This circuit can potentially apply unsafe currents across the patient. A standard medical biopotential measurement circuit will have single-point failure protection to prevent conditions like this. This is required by standards like EC11, EC13, and 60601. Those systems are extremely safe. Most hobbyist designs, like the one in this article, do not have such protection. Indeed, for this particular c…

[deleted]

Re: Do-it-yourself EEG, EKG, and EMG

#27
post #19

Earlier quoted context omitted.

No real danger for EEG if powered from an isolated laptop. ECG can cause safety issues if there is a significant current across the sensor leads, but even that is unlikely unless the completely wrong resister values used and the person hypothetically has a heart condition. Disclaimer: I'm not a physician, neurosurgeon or lawyer. I did however design and repair EEG systems.

You are incorrect. This circuit can potentially apply unsafe currents across the patient. A standard medical biopotential measurement circuit will have single-point failure protection to prevent conditions like this. This is required by standards like EC11, EC13, and 60601. Those systems are extremely safe. Most hobbyist designs, like the one in this article, do not have such protection. Indeed, for this particular c…

Do you know any hobbyist design that can be built safely?

Re: Do-it-yourself EEG, EKG, and EMG

#28
post #23

Earlier quoted context omitted.

No real danger for EEG if powered from an isolated laptop. ECG can cause safety issues if there is a significant current across the sensor leads, but even that is unlikely unless the completely wrong resister values used and the person hypothetically has a heart condition. Disclaimer: I'm not a physician, neurosurgeon or lawyer. I did however design and repair EEG systems.

There is quite a bit of current in a laptop battery, enough to stop a heart.

But I believe that what kills you is the voltage and not the current.
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