Author Topic: How to solve the “TI ADS1299 EEG demo kit is not save for humans” problem?  (Read 3264 times)

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Offline Peter Gamma

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The TI ADS1299 EEG demo kit is an affordable board for EEG data acquisition. I found two papers of Indonesian scientists who tested the accuracy of the TI ADS1299 EEG demo kit and compared it to a medical garde EEG device:
 
For a 8 channels EEG Data Aquisition System:

https://www.researchgate.net/publication/325635924_Design_of_EEG_Data_Acquisition_System_based_on_Raspberry_Pi_3_for_Acute_Ischemic_Stroke_Identification

For 32 channels EEG Data Aquisition System :

https://www.researchgate.net/publication/332321992_Development_of_Electroencephalography_EEG_Data_Acquisition_System_based_on_FPGA_PYNQ

EEG data acquisition system 32 channels based on Raspberry Pi with relative power ratio and brain symmetry index features:

https://www.researchgate.net/publication/337896178_EEG_data_acquisition_system_32_channels_based_on_Raspberry_Pi_with_relative_power_ratio_and_brain_symmetry_index_features


TI ADS1299 EEG demo kit is not a medical device and not approved for medical use. But still the accuracy data of the Indonesian scientists are very helpful.

I asked in the OpenBCI forum about OpenBCI software support for the TI ADS1299 EEG demo kit. OpenBCI supporter William Croft, said the TI EEG board is not safe for humans:

 https://openbci.com/forum/index.php?p=/discussion/2686/could-openbci-support-texas-instruments-ads1299eegfe-pdk#latest

Why is the TI ADS1299 EEG demo kit not save for humans. Here the answer from the Texas Instruments support:

https://e2e.ti.com/support/data-converters/f/73/p/940917/3476990#3476990

Is the answer of the Texas Instruments support helpful? The  TI ADS1299 EEG demo kit can be completely battery powered, and is not safe for humans? The OpenBCI EEG board is a comparable board and also completely battery powered. Why is the OpenBCI EEG board safe for humans, while the  TI ADS1299 EEG demo kit should not be save for humans?
« Last Edit: September 19, 2020, 11:58:14 pm by Peter Gamma »
 

Online razvan784

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I personally think the reply from TI is very clear. It's a demo kit, an advertising tool for their integrated circuit. It's not a medical decive. It's not designed as such. It's not designed according to safety standards or principles. It's to be used with a simulator. They don't want to be legally responsible if something goes wrong. There's nothing to solve, you can't use the kit on humans and guarantee their safety under all conditions, especially component failure. It that's what other researchers did, it's their problem.
Think what happens if for example, instead of batteries, someone were to supply the board from a cheap charger that has less than 1 mm of isolation gap between the mains and the output. bigclivedotcom on youtube reviews those from time to time, it's fun watching but the idea is they're dangerous. What would happen if the power supply inside the PC connected to this board were to fail and connect 230V to the USB port? This may be a very unlikely event, but it's not impossible and the kit is not designed to be safe under such an event -- therefore is not to be used on humans and it would create a liability if it were - that's also what TI is saying.
 
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Offline perieanuo

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hi,
medical electronics is a complicated subject when it come to voltage/current protections, insolation, emi.
you can't even touch the subject if you don't act in this area for 3-5 years.
I worked in radiotherapy and medical security equipment r&d, it's not as simple as it appears, you can't just take some dev board and put electrodes on a human or inject some laser or emi in a medical treatment room with arduino-competence level
the paperwork only in developed countries is a nightmare for proving that your board is ok for this matter.that's why is not so simple to draw this line, even TI avoid to decide it's safe, and they're right
so, 'safe for human' is only for those inside this r&d environment.I prefer to hear guys that worked in the real life developing this type of equipment or at least someone who has some years repairing it
regards,pierre
 

Offline Peter Gamma

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These arguments cannot convince me either, why I should buy a OpenBCI board instead of a TI EEG board, which costs half the price of the OpenBCI board.

Are the Texas Instruments board and the OpenBCI board not very similar? The Texas Instruments board is very basic, the OpenBCI board has more features, which I don t use.

Both boards are based on the TI ADS1299 chip. Therefore, data of the paper "comparison of Cyton with medical grade g.tec devices" should apply for both boards, as the paper says:


https://arxiv.org/pdf/1606.02438.pdf

William Croft argues:

"Do you understand that open-source hardware projects, are only supported by the revenues from hardware products sold? There are no other income sources. Open source hardware is very different than open source software. As there are large and significant overhead costs for hardware projects."

But what can I do, when there are on other income sources for OpenBCI, than revenues for hardware products?

The community of EEG device users is small, the biggest part of it is probably OpenBCI. OpenBCI has a support forum for EEG devices which is bigger than that of Texas Instruments for EEG.

What about this solution: Those who need support in every single step, choose OpenBCI, those who need only support for the basics, choose Texas Instruments EEG.OpenBCI users have to pay for this extended support twice the price.   
« Last Edit: September 19, 2020, 04:31:03 pm by Peter Gamma »
 

Offline Peter Gamma

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I don t wan t to make a medical approved device out of the TI EEG board. I need the EEG equipement for a research project.
 

Online ralphrmartin

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Assuming your research involves human (or even animal) subjects, you will almost certainly need to get approval from an ethics committee before your research can go ahead. It seems very unlikely that a responsible ethics committee would approve an experiment using equipment which states that it is not intended for direct interface with a patient, and is only for evaluation with a simulator.

The point is that the device has not been designed with safety in mind. It has been designed for component evaluation. It may ostensibly be safe, but the designers may have overlooked something. This is one of the reasons real medical equipment is costly. Designs must be validated, and approved by safety panels, and so on.
 
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Offline janoc

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I don t wan t to make a medical approved device out of the TI EEG board. I need the EEG equipement for a research project.

Feel free to buy the TI board. Just don't use it on humans.

You didn't say what you want to measure, perhaps for capturing EEG of a cow or a dog this would be fine.

OTOH, for human research you are putting your job on the line if you decide to "save" money in this way. And if anything goes wrong, it will be prison time for you. But hey, you are an adult, you are supposed to be able to make your own decisions.
 

Online razvan784

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These arguments cannot convince me either, why I should buy a OpenBCI board instead of a TI EEG board, which costs half the price of the OpenBCI board.
You shouldn't buy either one!
Quote from the OpenBCI website https://shop.openbci.com/collections/frontpage/products/cyton-biosensing-board-8-channel?variant=38958638542, emphasis mine:
Quote
Important Notice: OpenBCI, Inc. provides the enclosed product(s) under the following conditions: This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY and is not considered by OpenBCI, Inc. to be a finished end-product fit for general consumer use. Persons handling the product(s) must have electronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety
It's basically the exact thing the Texas Instruments representative told you - there's nothing physically stopping you from using the product as you describe, but you shouldn't. If you do howerver, you do so at your own risk.
 

Offline SilverSolder

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Isn't it hard to imagine anything going wrong if the device is battery powered, and not connected to anything else?  (assuming 9V battery or less)

 

Offline aristarchus

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These arguments cannot convince me either, why I should buy a OpenBCI board instead of a TI EEG board, which costs half the price of the OpenBCI board.
..

Dont know why you keep refering to OpenBCI, but from what I understand even theirs is not medical approved according to their own 'Liability' clause.

"OpenBCI products are not medical, clinical, or diagnostic devices nor are they intended for medical diagnosis and are provided to you "as is," and we make no express or implied warranties whatsoever with respect to its functionality, operability, or use, including, without limitation, any implied warranties, fitness for a particular purpose, or infringement."

https://docs.openbci.com/docs/08FAQ/Liability
 

Offline Peter Gamma

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Nobody could convince me that these battery powered devices are risky to use. If there is a risk, it is one which I can take.

 Also with Scott Hardens sound card ecg there was a discussion:



“Hi Scott , just a little word of caution. The ground pin of the sound card is probably connected to the mains earth. This could be a source of danger in case of some devices which have a ground fault. Hence it is probably much more safer to use a battery powered laptop. Of course the best would be to use a wireless Bluetooth device, i guess.
Cheers and hope you are in the best of health !

Hi @mumbai, I hear this comment frequently. The input impedance between the AD8232 and the pads is extremely high. Even if the AD8232 were grounded (e.g., through the sound card), risk is eliminated because the person is not connected to the AD8232 through a low impedance path, so a ground fault is not a concern.

Interestingly, grounding yourself to your computer is common. Many people physically ground themselves to their computer with a wrist strap connected to their computer chassis when they work inside their computer. Since that is a low impedance path to ground, a wrist ground strap strikes me as much more of a concern for ground faults than a setup like this. It's an interesting topic to ponder!

@Scott Harden  Thanks for the reply. A ground strap has a 1Meg resistance to ground, hence it is not a " low impedance path to ground", quite the opposite actually. Also when working on mains equipment always unplug the device , else/and use suitably rated probes and test equipment. The last thing you want in such circumstances is a  "low impedance path to ground"
"risk is eliminated because the person is not connected to the AD8232 through a low impedance path"
Actually isn't the conductive gel drastically reducing this impedance ? I could not get the circuit diagram of your module, so am not too sure about this.
Indeed it is an interesting topic to ponder.
 

Offline Bassman59

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Nobody could convince me that these battery powered devices are risky to use. If there is a risk, it is one which I can take.

If you are hooking yourself up to this thing, then sure, you can take the risk. Don't expect to be able to sue for damages if there is a harmful failure.

As for using it on other people? What the others have said about that, especially in the areas of human-subject testing, is spot on, and you open yourself up to all sorts of bad consequences should something, ANYTHING, go wrong. Because if that happens, even though this device isn't the cause, that doesn't matter -- you were using something not approved for medical use/human subject use and the lawyers will staple your balls to the floor, and then they'll REALLY get to work.

Don't say you weren't warned, and oh, by the way, this thread is proof of the fact that you were warned but chose to ignore the warnings.
 
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Offline SilverSolder

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
 
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Offline TurboTom

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It's not only the safety to use the instrument but also the "suitability for the job". If a physician bases a treatment on an ECG, he's got to be sure that the figures the ECG displays are correct.

Moreover, also low DC voltages applied to electrodes attached to the skin, can, if present over long time, cause serious harm, including death, to the patient.

I've once been involved in designing a medical diagnostics device prototype and I had to go through a lot of paperwork and do a lot of documentation...
 
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Offline Someone

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
Hello Dunning-Kruger?

This has come up before
https://www.eevblog.com/forum/projects/leakage-current-problem-in-emg-circuit/
Explain how hypothetical device under single fault condition remains safe.
 
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Offline Peter Gamma

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@ ralphrmartin

Thank you for your answers, this is a good point. Since there is a high agreement that the risk with completely battery powered EEG or ECG devices connected to a battery powered PC is low to damage humans or animals, how has someone to proceed to get a device which is validated for research on humans and animals?
 

Offline janoc

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@ ralphrmartin

Thank you for your answers, this is a good point. Since there is a high agreement that the risk with completely battery powered EEG or ECG devices connected to a battery powered PC is low to damage humans or animals, how has someone to proceed to get a device which is validated for research on humans and animals?

So you are not really looking for advice from people who actually know something about the subject, only for confirmation of your (incorrect) preconceived idea. And then are selectively picking evidence that suits you and disregarding the rest.

Dude, I really really wouldn't want to be your research subject if this is the way you are conducting your experiments!

 
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Offline Peter Gamma

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Everybody is free to give advice or not to give advice in the EEVblog, following the slogan "no script, no fear, all opinion". If someone can convince me, I change my mind.
 

Online Zorc

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@ ralphrmartin

How has someone to proceed to get a device which is validated for research on humans and animals?

Just buy the real deal  8)
There are plenty of options & companies to buy fully medical certified ECG/EEG solutions. You don't want to write any medical research paper about picking some electronic parts and soldering it together, hook up some wires and clamps on someone and presenting the results anyway....
Sure if you want to do some hobby (research) experiments on yourself, you can do whatever you like so it won't be of any real scientific value.
 

Offline Peter Gamma

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I make the real deal here in the EEVblog, and publish my knowledge about these devices here for free. Maybe someone else gives here something for free, too.

Do i need security tests at all for battery powered devices to use them for research? Is it possible to negotiate a special disclaimer for this purpose to decline liability, for instance when someone uses for instance a TI EEG board and connects it to AC during research experiments?
 

Offline 2N3055

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Everybody is free to give advice or not to give advice in the EEVblog, following the slogan "no script, no fear, all opinion". If someone can convince me, I change my mind.

Do you consider 9V battery a high or low voltage?

Now go, get one and stick it to your tongue. And hold....
And then get back to me and tell me if that is OK to apply to someone or not.

Attaching electrodes with electrolyte gel to body produces similar impedances....

That is why medical devices have to have specific failure modes, that  in event of every possible failure, you can DEMONSTRATE and PROVE it cannot produce dangerous currents to the body.
Together with proving it cannot cause any malfunctions to other medical and medical assistance devices (like pacemakers, neural stimulators and such) that patients might have.

Also you misunderstood: what people is telling you is a FACT.  It is a fruit, a body of knowledge, of 50+ years of medical electronics industry. Nobody have to prove anything to you. It is already proven fact within the industry.

It is you who need to learn many things before you can even understand why is medical electronics in a current state of the art. And once you become expert in the field, you can develop new technologies that will push boundaries of performance, price etc...

It's not a conspiracy theory. Like it or not, by reading your answers, it simply seems that it is simply too complicated for you to understand, at your current level of knowledge.
Which is OK, nobody was born with PhD. You simply should start reading and learning about it.
 
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Offline SilverSolder

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
Hello Dunning-Kruger?

This has come up before
https://www.eevblog.com/forum/projects/leakage-current-problem-in-emg-circuit/
Explain how hypothetical device under single fault condition remains safe.

It is the opposite of Dunning-Kruger to ask questions!  :D

The lethal current limit appears to be quite a bit higher than the 0.5mA quoted as safe for skin contact, when we are talking electrical safety in general.  Wonder why that is?

In principle, that very low limit means that even the output of a AAA battery is not considered safe to apply to skin.  That sounds very conservative - are there really examples of people who have been seriously injured by current from a 1.5V battery?


« Last Edit: September 20, 2020, 02:30:05 pm by SilverSolder »
 

Offline Peter Gamma

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Not to my knowledge. But my knowledge in this field is limited, I admit. Maybe one could start a research project to find out about this?

What I found out that Chinese sellers for EEG brainwave modules are quiet responsive to discussions in the OpenBCI forum and the EEVblog. Since I started questions regarding this topic, a new product appeared on Aliexpress with an instruction not to use an AC powered laptop in combination with EEG sensors, but only a battery powered. Before I started asking question, there was no such product with this instruction there. The Chinese seem to follow the safety discussion with interest, and immediately adapt their products to new customer needs:

https://www.aliexpress.com/item/32969264474.html?spm=a2g0o.productlist.0.0.2d4e77f5NMc1lj&algo_pvid=84102863-692f-4544-bb07-6fb5da865f91&algo_expid=84102863-692f-4544-bb07-6fb5da865f91-0&btsid=0bb0624516006139479535232edbf6&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
 

Offline DrG

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@Peter Gamma

Many of the responses, in my view, make good points.

The manufacturer of the board(s) that you mentioned at first has (have) outright said that is not for human use. They are not obligated to tell you why it is not approved for human use and they are certainly not obligated to explain to you what you have to do to make it approved, or safe, for human use.

You have said that you are not trying to market a medical device, but instead, want to use the device in research. You do not want to state exactly what you want to do and with what subjects. You have not even said outright that you want to use the device with humans. You are not being forthright.

Written in one of your references is:
Even though medical grade equipment possesses certification and still outperforms the OpenBCI board in terms of classification, the latter gives very close EEG readings

Spend some time and effort to understand what goes into human-use approval for an EEG device for research or for marketing as a medical device. Learn what certification means in this context.

Go to the regulators in your country or in any other country that you want to conduct research with humans with your device and see what is required. EEG devices for use in humans get FDA (US) approval all the time. You can see the approval letters online and sometimes devices are approved based, in large part, because they duplicate designs in existing and approved devices. More importantly, you can see the regulations online (although you may have to look hard and long) and you can bring your design and purpose to the attention of the regulating agency and ask for an opinion / approval – why not?

Learn the details of medical grade, consumer grade and research grade (even if those terms have little legal meanings). Again, have you tried asking regulators in your country – or even published electrophysiologists in Universities in your country?

Think about it – who wants to tell you that it is safe for use with humans after the manufacturer(s) has (have) already stated that it is not intended for use in humans?

Who here wants to be that irresponsible and if they were, why would you accept that?
- Invest in science - it pays big dividends. -
 

Offline SilverSolder

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I found this chart that looks kind of interesting in this context:




Source: https://www.asc.ohio-state.edu/physics/p616/safety/fatal_current.html
 

Online ralphrmartin

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@ ralphrmartin

Thank you for your answers, this is a good point. Since there is a high agreement that the risk with completely battery powered EEG or ECG devices connected to a battery powered PC is low to damage humans or animals, how has someone to proceed to get a device which is validated for research on humans and animals?

Assuming you are based in Switzerland, this would seem to offer advice on the subject:

https://www.swissmedic.ch/swissmedic/en/home/medical-devices/regulation-of-medical-devices/medical-device-regulation_online-guide.html

You really need to study this carefully, but I note this guidance includes:
----------
"Research with medical devices carried out prospectively on humans is regarded in Switzerland as a clinical trial with medical devices. ... The recruitment of trial participants may commence only when the following conditions are met:

The investigational device must have reached a stage of development that allows it to be used in humans...
All organisational measures must have been taken....
The approval of the cantonal Ethics Committee must have been obtained. This approval is required for all clinical trials without exception. Decisions of other ethics committees (e.g. own committees of hospitals, foreign or private ethics committees) are not sufficient...
The approval of Swissmedic must have been obtained...
----------

Basically, there is a standardised set of rules and procedure you must go through.
« Last Edit: September 20, 2020, 06:07:45 pm by ralphrmartin »
 
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Offline 2N3055

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I found this chart that looks kind of interesting in this context:




Source: https://www.asc.ohio-state.edu/physics/p616/safety/fatal_current.html

That is across body volume. If you attach electrodes directly to your chest, together with electrolyte gel, impedances get really low and current flows directly over danger zone...
Not to mention some people have medical implants...
If you don't know exactly what you're doing it's playing with fire..
 
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Offline Someone

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
Hello Dunning-Kruger?

This has come up before
https://www.eevblog.com/forum/projects/leakage-current-problem-in-emg-circuit/
Explain how hypothetical device under single fault condition remains safe.

It is the opposite of Dunning-Kruger to ask questions!  :D
Because you so confidently state as "fact" all the nonsense in your posts, which people who work in this field immediately see as misleading and untrue. Pretending like you are asking a question amongst all that, when its a leading question, is not helping. This is not an area for guessing or relying on uniformed estimates/interpretations.

The standards encompass decades of accumulated knowledge on the subject, they are the quickest/cheapest way to achieve safety and some level of defensible position if something goes wrong. Trying to work it out from first principles or published data, you are almost certain to miss some of the important details or critical pieces of evidence that underlies the safety standards.

You can start pulling up research and trying to piece together a full explanation, but thats usually reserved for when its a new area that isn't fully covered by the standards. At that point its still unproven and needs to head down the pathways that the medical field require, trials and statistically valid proof. Not just picking some unrelated figures you think might be applicable.
 
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Offline electrolust

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I make the real deal here in the EEVblog, and publish my knowledge about these devices here for free. Maybe someone else gives here something for free, too.

Do i need security tests at all for battery powered devices to use them for research? Is it possible to negotiate a special disclaimer for this purpose to decline liability, for instance when someone uses for instance a TI EEG board and connects it to AC during research experiments?

wow! your judgement is progressively worse! now you just want your subject to accept the risk?

in the US, one cannot waive gross negligence via contract or waiver. if asked, it's ok to sign because the waiver itself is void. (so-called ordinary negligence can be waived away, just not gross negligence)

you can get liability insurance to cover gross negligence in some US states. it's gonna be expensive.

i've no idea about any other country.

the fact that you would use a non-certified device, to me, is gross negligence.

further poor judgement is demonstrated by your request for legal advice from an anonymous internet forum! never take legal advice from non-lawyers! above advice included.
 

Online KaneTW

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How to solve the "not safe for humans" problem? Don't use it on humans. Medical equipment needs to be certified to very strict standards because the allowable probability for failure is extremely small, and for good reason. Money is cheap, human lives aren't.

If you don't have the monetary capabilities to buy a proper certified EEG, don't do research using it.
 
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Offline Tarloth

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Two years ago an acquaintance, who was a medical student at a university in the interior of my country, contacted me to help him on exactly this matter. He wanted to use the exact same or a similar module sold by adafruit.

His knowledge of electronics was so, so low that he did not even understand why he could not use it in research with living beings. His stubborn mind already imagined conspiracy reasons protecting "the big pharmaceuticals". He never assumed that he was simply not qualified to do what he was doing. He even sent me pictures with the module connected to a patient and powered by a cell phone source of dubious (poor) quality. He told me he was doing it to "save" batteries. What risk could there be if when connecting the phone it did not burned? He possessed a whole series of absolutely wrong thoughts, fallacies in every sense that he nevertheless considered correct, so correct that he perceived himself as ahead of his time.

The reasoning was exactly your reasoning, he had no idea what he had to do, not even what he needed to learn, but nevertheless he supposed to know a lot about the subject and did gave his opinion on everything and believed blindly in his genius, despite being absolutely lacking in knowledge of physics, electronics, biology or sensors. Actually one of those people who have no idea, but by reading something on a blog, they believe they are capable of doing anything and anyone who contradicts it is part of a conspiracy that tries to stop him.

Luckily, and to my peace of mind, he no longer experimented with those modules and changed his career. Hopefully over time he learns that he did not know what he was doing, and if he is really lucky, one day he will learn what he should have done.

Sorry Peter if this is too hard or offensive for you, but it is fantastic and desirable that you play with your inventions, until the moment comes when your ignorance threatening others life. In that case it is the obligation of the rest to tell you that if you have to ask "why is it dangerous" it indicates that you do not have the knowledge to realize it on your own and therefore it is a danger for others that you continues to experience.

I really wish that no one ever gets hurt by your stubbornness.
 

Offline george.b

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TI's statement that it's not safe for use on humans has one very simple reason: they did not get the relevant certification for that piece of equipment to be used on humans. Nor should they, since it's intended for evaluating the performance of their ADS1298, not for medical usage. By disallowing its usage on humans, they're waiving liability for any problems that might occur therefrom, and others have already pointed out things that could go wrong. Guess with whom does this liability sit if you decide to go ahead and use it on humans anyway?
 

Offline Ice-Tea

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in the US, one cannot waive gross negligence via contract or waiver. if asked, it's ok to sign because the waiver itself is void. (so-called ordinary negligence can be waived away, just not gross negligence)

Probably true anywhere. Have you seen those signs at playgrounds stating "managment can not be held accountable for accidents"?

This is bollocks. If it turns out the playground devices were in ill repair or did not comply to regulations, they are still liable. Even if you manage to find a moron that signs a waiver for your tests, if something happens and they figure out you've been using a device that *explicitly* states it should not be used on humans the burden of proof will be squarely placed on your shoulders.

Offline SilverSolder

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
Hello Dunning-Kruger?

This has come up before
https://www.eevblog.com/forum/projects/leakage-current-problem-in-emg-circuit/
Explain how hypothetical device under single fault condition remains safe.

It is the opposite of Dunning-Kruger to ask questions!  :D
Because you so confidently state as "fact" all the nonsense in your posts, which people who work in this field immediately see as misleading and untrue. Pretending like you are asking a question amongst all that, when its a leading question, is not helping. This is not an area for guessing or relying on uniformed estimates/interpretations.

The standards encompass decades of accumulated knowledge on the subject, they are the quickest/cheapest way to achieve safety and some level of defensible position if something goes wrong. Trying to work it out from first principles or published data, you are almost certain to miss some of the important details or critical pieces of evidence that underlies the safety standards.

You can start pulling up research and trying to piece together a full explanation, but thats usually reserved for when its a new area that isn't fully covered by the standards. At that point its still unproven and needs to head down the pathways that the medical field require, trials and statistically valid proof. Not just picking some unrelated figures you think might be applicable.

I do see where you are coming from,  but it is still a little harsh.  After all, we are still dealing with science / technology, and not religion.   So if an unintuitively low voltage is not safe, it seems reasonable enough, and in the eevblog spirit, to approach the answer in a scientific / technological way instead of "strike down the heathen, that hath entered the holy inner sanctum!" :D
 

Offline 2N3055

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
Hello Dunning-Kruger?

This has come up before
https://www.eevblog.com/forum/projects/leakage-current-problem-in-emg-circuit/
Explain how hypothetical device under single fault condition remains safe.

It is the opposite of Dunning-Kruger to ask questions!  :D
Because you so confidently state as "fact" all the nonsense in your posts, which people who work in this field immediately see as misleading and untrue. Pretending like you are asking a question amongst all that, when its a leading question, is not helping. This is not an area for guessing or relying on uniformed estimates/interpretations.

The standards encompass decades of accumulated knowledge on the subject, they are the quickest/cheapest way to achieve safety and some level of defensible position if something goes wrong. Trying to work it out from first principles or published data, you are almost certain to miss some of the important details or critical pieces of evidence that underlies the safety standards.

You can start pulling up research and trying to piece together a full explanation, but thats usually reserved for when its a new area that isn't fully covered by the standards. At that point its still unproven and needs to head down the pathways that the medical field require, trials and statistically valid proof. Not just picking some unrelated figures you think might be applicable.

I do see where you are coming from,  but it is still a little harsh.  After all, we are still dealing with science / technology, and not religion.   So if an unintuitively low voltage is not safe, it seems reasonable enough, and in the eevblog spirit, to approach the answer in a scientific / technological way instead of "strike down the heathen, that hath entered the holy inner sanctum!" :D

You are 100%  correct. It is science and technology. And precisely because of that, what is proven is already proven and documented.
It is not open to opinions, and beliefs. We KNOW some things. And even IF something is wrong, you have to enter the field and first get to know the knowledge and how it came to be, before you decide you can do better.

You cannot just ignore 40 years of research and say, "I don't have a clue about this, but this, here, is inconvenient so I will just ignore it, and will try to find and idiot who will sign it is safe so I can do what I need, and if something goes wrong, it's not my fault"

That is wrong on so many levels..
 

Offline SilverSolder

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If you keep everything battery powered, including the laptop that is processing the data,  I would like to hear anyone explain how that could possibly pose a risk from a technical / engineering perspective.
Hello Dunning-Kruger?

This has come up before
https://www.eevblog.com/forum/projects/leakage-current-problem-in-emg-circuit/
Explain how hypothetical device under single fault condition remains safe.

It is the opposite of Dunning-Kruger to ask questions!  :D
Because you so confidently state as "fact" all the nonsense in your posts, which people who work in this field immediately see as misleading and untrue. Pretending like you are asking a question amongst all that, when its a leading question, is not helping. This is not an area for guessing or relying on uniformed estimates/interpretations.

The standards encompass decades of accumulated knowledge on the subject, they are the quickest/cheapest way to achieve safety and some level of defensible position if something goes wrong. Trying to work it out from first principles or published data, you are almost certain to miss some of the important details or critical pieces of evidence that underlies the safety standards.

You can start pulling up research and trying to piece together a full explanation, but thats usually reserved for when its a new area that isn't fully covered by the standards. At that point its still unproven and needs to head down the pathways that the medical field require, trials and statistically valid proof. Not just picking some unrelated figures you think might be applicable.

I do see where you are coming from,  but it is still a little harsh.  After all, we are still dealing with science / technology, and not religion.   So if an unintuitively low voltage is not safe, it seems reasonable enough, and in the eevblog spirit, to approach the answer in a scientific / technological way instead of "strike down the heathen, that hath entered the holy inner sanctum!" :D

You are 100%  correct. It is science and technology. And precisely because of that, what is proven is already proven and documented.
It is not open to opinions, and beliefs. We KNOW some things. And even IF something is wrong, you have to enter the field and first get to know the knowledge and how it came to be, before you decide you can do better.

You cannot just ignore 40 years of research and say, "I don't have a clue about this, but this, here, is inconvenient so I will just ignore it, and will try to find and idiot who will sign it is safe so I can do what I need, and if something goes wrong, it's not my fault"

That is wrong on so many levels..

Another observation is that when beginning with basic electronics, the human body may not be the first "breadboard" that you should be playing with!  :D

Better to begin by blowing up some less valuable things first.

 
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Offline Peter Gamma

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Several researchers have done research with the TI ADS1299 EEG board. I found one work where it was used to measure EEG currents on a treadmill. Indonesian scientists evaluate the EEG board since several years:

https://www.researchgate.net/publication/337896178_EEG_data_acquisition_system_32_channels_based_on_Raspberry_Pi_with_relative_power_ratio_and_brain_symmetry_index_features

Their works does not make any sense when it cannot be used with humans. How will the Indonesian scientists solve this problem? It does not makes sense to do research on a board which cannot be used with humans. Why does Texas Instruments not make an update so that it can be used with humans? If Texas Instruments does not do it, the Chinese will to the job.
 

Online KaneTW

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If you actually read the paper, they did NOT use it on humans. Only on simulators. Their research showed that the design is potentially valid so that a company can potentially turn it into a product.

In any case, here's how it is: Texas Instruments provides evaluation kits. Medical equipment manufacturers turn it into a safe and certified device. An eval kit is not an actual product.
 

Offline Peter Gamma

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The Indonesian scientist used a simulator. But the evaluation was for Acute Ischemic Stroke Identification, Electroencephalography and relative power ratio and brain symmetry index features. As long as there is no device available which is safe for humans, the research results of the Indonesian research scientists cannot be applied, not even when it is not for a medical purpose, but only to use the TI board as a reference device for accuracy tests.

I was successful with another Aliexpress seller. He agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops.

https://www.aliexpress.com/item/4000244594585.html?spm=5261.ProductManageOnline.0.0.1f1a4edfSeZqwP
 

Offline TheUnnamedNewbie

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Several researchers have done research with the TI ADS1299 EEG board. I found one work where it was used to measure EEG currents on a treadmill. Indonesian scientists evaluate the EEG board since several years:  [link omitted in quote]
Their works does not make any sense when it cannot be used with humans. How will the Indonesian scientists solve this problem?

Maybe they did not solve the problem, used it anyways. The product works, it just shouldn't be used that way. Just because others did something wrong and unethical, and used it for tests anyways (which I'm not sure they did - I did not read the paper and am not familiar with the field), does not make it right to do so. There are also people who use lead in their paint, or who don't wear seat belts, or do any number of other stupid and dangerous things. That does not make it okay for you to do the same.

Even by powering it with batteries, you could through a fault endanger a person. Next to the more obvious 'shock leading to death' (which is really not even negated by using batteries, as you really don't need a whole load of voltage to pose a risk when attaching stuff with conductive gells to the body!), things like leaking charge into the body (through DC offset) can have dangerous results.

Why does Texas Instruments not make an update so that it can be used with humans? If Texas Instruments does not do it, the Chinese will to the job.

Because of very obvious reasons:
1) They don't want to. They are not a medical devices company, but a chipvendor trying to sell their devices. Investing the research and effort into making this a medically qualified product is just not what they are interested in.
2) They don't want to deal with the legal headaches that come from having something qualified
3) Their goal with this board is to prove that their chip can do cool stuff so they can sell it. That is what evaluation boards are for. Making it safe for humans does not help them in any way - it makes the board more expensive, makes it more complicated obscuring their device performance, etc...

The best part about magic is when it stops being magic and becomes science instead

"There was no road, but the people walked on it, and the road came to be, and the people followed it, for the road took the path of least resistance"
 

Online Fungus

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Why does Texas Instruments not make an update so that it can be used with humans? If Texas Instruments does not do it, the Chinese will to the job.

4) Because Texas Instruments doesn't know exactly how people will use it, how they'll power it, or any modifications or "repairs" somebody might make before attaching it to other people.

If you use this on humans, you're entirely on your own. You can't go online and get other people to approve or support your decision.

(and if you do go online and ask, you should expect a thread exactly like this one...)

 

Offline SilverSolder

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[...]  another Aliexpress seller [...]  agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops. [...]


Removing mains power from the equation is a good first step, but it appears you could still get in trouble from the 19V battery in a typical laptop.  There should probably be resistors in the leads going to the pads, to limit the current to something safe in case of the full battery voltage occurring on it while skin resistance is low. 

Disclaimer:  I'm not condoning unsafe practices, but if someone is reading this and absolutely insists on doing crazy stuff, these are among the kinds of things you should be thinking about!
 
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Offline electrolust

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I was successful with another Aliexpress seller. He agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops.

that won't protect you [from liability] in the slightest
 
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Offline Someone

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[...]  another Aliexpress seller [...]  agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops. [...]


Removing mains power from the equation is a good first step, but it appears you could still get in trouble from the 19V battery in a typical laptop.  There should probably be resistors in the leads going to the pads, to limit the current to something safe in case of the full battery voltage occurring on it while skin resistance is low. 

Disclaimer:  I'm not condoning unsafe practices, but if someone is reading this and absolutely insists on doing crazy stuff, these are among the kinds of things you should be thinking about!
This is NOTHING to do with 19V (or some other voltage) in a laptop power supply or battery. You really need to stop posting on this topic encouraging the half-arsed dodging of real knowledge.

This cannot be distilled down to a couple of simple dot points to follow, many of the requirements are interdependent, there is no simple answer as to how to make a safe electromedical device.
 

Offline SilverSolder

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[...]  another Aliexpress seller [...]  agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops. [...]


Removing mains power from the equation is a good first step, but it appears you could still get in trouble from the 19V battery in a typical laptop.  There should probably be resistors in the leads going to the pads, to limit the current to something safe in case of the full battery voltage occurring on it while skin resistance is low. 

Disclaimer:  I'm not condoning unsafe practices, but if someone is reading this and absolutely insists on doing crazy stuff, these are among the kinds of things you should be thinking about!
This is NOTHING to do with 19V (or some other voltage) in a laptop power supply or battery. You really need to stop posting on this topic encouraging the half-arsed dodging of real knowledge.

This cannot be distilled down to a couple of simple dot points to follow, many of the requirements are interdependent, there is no simple answer as to how to make a safe electromedical device.

It seems to me that even without being an expert on the subject, a moderately bright high school science student should be able to tell you that 19V on the pads of a medical device is a bad idea, given the body resistances quoted in this thread (down to a couple of hundred Ohm) and the max limit of 500uA through the body.

Unless that conclusion is directly wrong...   what's your point?












 

Offline Tarloth

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Indonesian Scientists that publish in Researchgate? Researchgate it is not a publication with reference or controls, it is a good place to get something a little better than the average internet garbage, but it does not guarantee any seriousness or certainly. At least use responsible and traditional sources if you're going to make any kind of claim about "scientist" work.

What are you actually expecting from this thread? Someone doing your job because you have no idea what to do?
 

Offline Someone

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[...]  another Aliexpress seller [...]  agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops. [...]


Removing mains power from the equation is a good first step, but it appears you could still get in trouble from the 19V battery in a typical laptop.  There should probably be resistors in the leads going to the pads, to limit the current to something safe in case of the full battery voltage occurring on it while skin resistance is low. 

Disclaimer:  I'm not condoning unsafe practices, but if someone is reading this and absolutely insists on doing crazy stuff, these are among the kinds of things you should be thinking about!
This is NOTHING to do with 19V (or some other voltage) in a laptop power supply or battery. You really need to stop posting on this topic encouraging the half-arsed dodging of real knowledge.

This cannot be distilled down to a couple of simple dot points to follow, many of the requirements are interdependent, there is no simple answer as to how to make a safe electromedical device.

It seems to me that even without being an expert on the subject, a moderately bright high school science student should be able to tell you that 19V on the pads of a medical device is a bad idea, given the body resistances quoted in this thread (down to a couple of hundred Ohm) and the max limit of 500uA through the body.

Unless that conclusion is directly wrong...   what's your point?
Because you dumb it down to these simple points. What does the laptop battery have to do with the (hypothetical) electrodes? How many parts/steps/components/interactions are there between those points?

Its distraction, and not relevant to the larger issue. You can keep pushing "clever" points and we'll keep shouting you down for being an idiot.
 

Offline SilverSolder

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[...]  another Aliexpress seller [...]  agreed to update the website on Aliexpress with his offer, to write in the documentation to use the EEG board only with battery powered laptops. [...]


Removing mains power from the equation is a good first step, but it appears you could still get in trouble from the 19V battery in a typical laptop.  There should probably be resistors in the leads going to the pads, to limit the current to something safe in case of the full battery voltage occurring on it while skin resistance is low. 

Disclaimer:  I'm not condoning unsafe practices, but if someone is reading this and absolutely insists on doing crazy stuff, these are among the kinds of things you should be thinking about!
This is NOTHING to do with 19V (or some other voltage) in a laptop power supply or battery. You really need to stop posting on this topic encouraging the half-arsed dodging of real knowledge.

This cannot be distilled down to a couple of simple dot points to follow, many of the requirements are interdependent, there is no simple answer as to how to make a safe electromedical device.

It seems to me that even without being an expert on the subject, a moderately bright high school science student should be able to tell you that 19V on the pads of a medical device is a bad idea, given the body resistances quoted in this thread (down to a couple of hundred Ohm) and the max limit of 500uA through the body.

Unless that conclusion is directly wrong...   what's your point?
Because you dumb it down to these simple points. What does the laptop battery have to do with the (hypothetical) electrodes? How many parts/steps/components/interactions are there between those points?

Its distraction, and not relevant to the larger issue. You can keep pushing "clever" points and we'll keep shouting you down for being an idiot.

The power supply voltage (in this case, the laptop battery at 19V) seems a reasonable worst case voltage that is likely to appear on the pads in a worst case  fault condition, assuming you don't do anything crazy that can step that voltage up even higher.

Assuming you actually do have a technical/scientific foundation for your argument, you are failing miserably to present it in an understandable way.
 

Offline exmadscientist

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The power supply voltage (in this case, the laptop battery at 19V) seems a reasonable worst case voltage that is likely to appear on the pads in a worst case  fault condition, assuming you don't do anything crazy that can step that voltage up even higher.

Assuming you actually do have a technical/scientific foundation for your argument, you are failing miserably to present it in an understandable way.
And the problem is, 19V is lethal under certain fault conditions for a Type CF Applied Part (IEC 60601), which is what you have.

Let me repeat that in more blunt terms, with emphasis: YOU CAN STILL KILL SOMEONE IF YOU SCREW THIS UP BADLY ENOUGH.

Look. I do this for a living. You can not and should not under any circumstances put that eval kit on a patient. You might put it on yourself -- we have done that before. And in that case, we were literally in the same building as the nearest hospital, knew where the two nearest defibrillators were, had skilled staff monitoring the whole time (both engineers and first responders), nothing was anywhere near the heart, proper isolation was observed at all times, the person with the electrodes on volunteered themself, and we still thought it was crazy dangerous and there was no way we would ever, ever, ever ask one of our research patients to do it.

Face it. Eval kits don't go on patients. Period. End of bloody discussion.

Best to stop this nonsense now before your IRB sees any of it.
 
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Online Fungus

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The power supply voltage (in this case, the laptop battery at 19V) seems a reasonable worst case voltage that is likely to appear on the pads in a worst case  fault condition, assuming you don't do anything crazy that can step that voltage up even higher.

Assuming you actually do have a technical/scientific foundation for your argument, you are failing miserably to present it in an understandable way.
And the problem is, 19V is lethal under certain fault conditions for a Type CF Applied Part (IEC 60601), which is what you have.

Let me repeat that in more blunt terms, with emphasis: YOU CAN STILL KILL SOMEONE IF YOU SCREW THIS UP BADLY ENOUGH.

Look. I do this for a living. You can not and should not under any circumstances put that eval kit on a patient. You might put it on yourself -- we have done that before. And in that case, we were literally in the same building as the nearest hospital, knew where the two nearest defibrillators were, had skilled staff monitoring the whole time (both engineers and first responders), nothing was anywhere near the heart, proper isolation was observed at all times, the person with the electrodes on volunteered themself, and we still thought it was crazy dangerous and there was no way we would ever, ever, ever ask one of our research patients to do it.

Face it. Eval kits don't go on patients. Period. End of bloody discussion.

Best to stop this nonsense now before your IRB sees any of it.

I wonder how anybody survives a single session with one of these attached to them:

https://en.wikipedia.org/wiki/Electrical_muscle_stimulation
 

Offline george.b

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Wait, you guys have 19V laptop batteries? ;D
 

Online KaneTW

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Indonesian Scientists that publish in Researchgate? Researchgate it is not a publication with reference or controls, it is a good place to get something a little better than the average internet garbage, but it does not guarantee any seriousness or certainly. At least use responsible and traditional sources if you're going to make any kind of claim about "scientist" work.

What are you actually expecting from this thread? Someone doing your job because you have no idea what to do?

Researchgate is an aggregator. The paper is published in the AIP conference proceedings. https://aip.scitation.org/doi/abs/10.1063/1.5139376
The relevant conference is the International Symposium of Biomedical Engineering.
« Last Edit: September 23, 2020, 01:23:25 pm by KaneTW »
 
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Offline electrolust

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I wonder how anybody survives a single session with one of these attached to them:

https://en.wikipedia.org/wiki/Electrical_muscle_stimulation

you mean with regulated, certified, fault consideration/designed devices?

i think you've missed the point of the argument.
 

Offline SilverSolder

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The power supply voltage (in this case, the laptop battery at 19V) seems a reasonable worst case voltage that is likely to appear on the pads in a worst case  fault condition, assuming you don't do anything crazy that can step that voltage up even higher.

Assuming you actually do have a technical/scientific foundation for your argument, you are failing miserably to present it in an understandable way.
And the problem is, 19V is lethal under certain fault conditions for a Type CF Applied Part (IEC 60601), which is what you have.

Let me repeat that in more blunt terms, with emphasis: YOU CAN STILL KILL SOMEONE IF YOU SCREW THIS UP BADLY ENOUGH.

Look. I do this for a living. You can not and should not under any circumstances put that eval kit on a patient. You might put it on yourself -- we have done that before. And in that case, we were literally in the same building as the nearest hospital, knew where the two nearest defibrillators were, had skilled staff monitoring the whole time (both engineers and first responders), nothing was anywhere near the heart, proper isolation was observed at all times, the person with the electrodes on volunteered themself, and we still thought it was crazy dangerous and there was no way we would ever, ever, ever ask one of our research patients to do it.

Face it. Eval kits don't go on patients. Period. End of bloody discussion.

Best to stop this nonsense now before your IRB sees any of it.

We are having a violent agreement...     19V is too much, so a battery powered laptop is not a guarantee of safety, which is the point I have been trying to make.

We are also violently agreeing that no patient / consumer should EVER be exposed to a medical electronic device that has not been designed, tested, and approved according to all relevant regulations and best practices.

With that out of the way, I don't see why the subject of medical electronics as a hobby should be banned completely from any discussion - why is it worse than making Tesla coils, huge capacitor banks, X-ray machines, microwave beams, laser cutters, or any other potentially dangerous project?  Why is it worse than driving a 700hp muscle car or riding a turbo motorcycle?  If Darwin has your number, you will have a bad day no matter what your hobby, pretty much.   

If you want to play, you have to understand the risks and know what you are doing. Personally, I did not know (until this thread) that the safe limit of current through the body can be as low as 50uA.  It has increased my respect for electricity vs biology, not decreased it...   anyone thinking of playing with this kind of stuff needs to know those limits.


« Last Edit: September 23, 2020, 02:18:25 pm by SilverSolder »
 

Online Fungus

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If Darwin has your number, you will have a bad day no matter what your hobby, pretty much.   

Stamp collecting?
 

Offline jogri

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With that out of the way, I don't see why the subject of medical electronics as a hobby should be banned completely from any discussion - why is it worse than making Tesla coils, huge capacitor banks, X-ray machines, microwave beams, laser cutters, or any other potentially dangerous project?  Why is it worse than driving a 700hp muscle car or riding a turbo motorcycle?  If Darwin has your number, you will have a bad day no matter what your hobby, pretty much.

Emphasis on the "you" part... You can stick whatever you want on your body or on your bench, but the issue here is not that the OP wants to stick it on his body, but onto unsuspecting patients that have no effing clue how dangerous it could be for them, with absolutely no regard for their safety (the title doesn't scream "I want to make this safer", it screams "I am too cheap to lend proper medical devices, how can i DIY something that was never intended to be used this way so that it might not kill some suckers")
 
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Offline SilverSolder

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If Darwin has your number, you will have a bad day no matter what your hobby, pretty much.   

Stamp collecting?

You could cut yourself with your tweezers, catch tetanus, and die!   Sitting still for hours causes a blood clot in your thigh, which dislodges an moves to your brain, causing you to die!  -  I would definitely avoid stamp collecting, it is just too dangerous!  :D
 
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Offline SilverSolder

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With that out of the way, I don't see why the subject of medical electronics as a hobby should be banned completely from any discussion - why is it worse than making Tesla coils, huge capacitor banks, X-ray machines, microwave beams, laser cutters, or any other potentially dangerous project?  Why is it worse than driving a 700hp muscle car or riding a turbo motorcycle?  If Darwin has your number, you will have a bad day no matter what your hobby, pretty much.

Emphasis on the "you" part... You can stick whatever you want on your body or on your bench, but the issue here is not that the OP wants to stick it on his body, but onto unsuspecting patients that have no effing clue how dangerous it could be for them, with absolutely no regard for their safety (the title doesn't scream "I want to make this safer", it screams "I am too cheap to lend proper medical devices, how can i DIY something that was never intended to be used this way so that it might not kill some suckers")

The original poster asked if there is a workaround to make the TI demo kit officially approved as safe for use on humans.   The short answer is NO, as has been repeated several times by most intelligent posters here -  QED!  :D

Obviously, this being the eevblog, people will want to know the details...
 

Offline joeqsmith

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With that out of the way, I don't see why the subject of medical electronics as a hobby should be banned completely from any discussion - why is it worse than making Tesla coils, huge capacitor banks, X-ray machines, microwave beams, laser cutters, or any other potentially dangerous project?  Why is it worse than driving a 700hp muscle car or riding a turbo motorcycle?  If Darwin has your number, you will have a bad day no matter what your hobby, pretty much.   
...
If you want to play, you have to understand the risks and know what you are doing.
...

I could care less if someone wants to experiment with what others may consider a high risk, as long as they are not placing anyone else at risk.   As many people have whined about me not providing details about the hand held meters I have modified, it's very rare that I would attempt to help someone in their high risk endeavors.    Maybe with the turbocharger.... 

With that, I used to get Byte magazine back in the 80s and remember an article on an EKG project.   I don't remember much about it other than I think this was my introduction to the TL084.   Someone had posted a link here for the old Byte magazines and I suspect with a little searching, someone could dig it up.   Maybe it would add something to the discussion.   
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline joeqsmith

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How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Online JackJones

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Quote
When the electrodes are attached, skin contact resistance is very low: only a few hundred ohms. A leakage current of just 100 pA can be fatal.

...

A cheap method of attaining minimal isolation is to use batteries to power an instrumentation amplifier. This sounds fine in theory, but it is very risky in practice.
 

The article pretty much agrees on everything that has been said so far. It's foolish to save money on medial devices like this, especially if they're used on others.

The 284J  isolation amplifier used in the article is still available, for only $300!

https://octopart.com/284j-intronics-998777?r=sp
 

Offline SilverSolder

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June of 1979, page 49.   

https://worldradiohistory.com/Archive-Byte/70s/Byte-1979-06.pdf

Awesome article, thanks for linking.  Reminds me of some of the amateur scientist articles back in the old days, from Scientific American...  some of those projects would probably not be approved today!
 

Offline electrolust

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With that out of the way, I don't see why the subject of medical electronics as a hobby should be banned completely from any discussion

I don't see that happening here. maybe i'm misreading it.
 

Offline Someone

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Assuming you actually do have a technical/scientific foundation for your argument, you are failing miserably to present it in an understandable way.
You keep trying to chip away with "solved it no problems now, prove me wrong" addressing single minuscule points at a time, and missing the problem that solving one tiny barely relevant issue does nothing towards showing systemic safety.

There is no way you can just fix a few points here and there and say its safe, the number of possible threat vectors is huge. And the reasoning, limits, and methods are way outside your experience/knowledge. So stop posting things you think prove safety, because they are only distracting and giving a false sense of security to others.

We are intentionally avoiding presenting the ways to make it safe, as they are likely to be misquoted/misinterpreted by people unable to comprehend the nuances. Like all the "battery powered, 100% safe" rubbish where this started. If you want to learn about this area, buy the standard, buy a book about it, there are resources out there and they are both extensive, and expensive.
 

Offline SilverSolder

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[...] We are intentionally avoiding presenting the ways to make it safe [...]

I think that is the wrong attitude...  far better to teach the kids about safe sex and let them get on with it, rather than try to prevent the inevitable course of human nature...

The Byte article referenced by @joeqsmith is 41 years old, so the principles talked about therein should be fair game to talk about without anyone risking divulging trade secrets or releasing information that is not already public.
 
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Offline CatalinaWOW

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From my point of view there is quite a bit of mis-information and mis-direction in this thread.  Let me summarize what I think truth is.

1.  TI has stated their eval kit is unsafe to use on humans.   I don't believe that this actually means that it is unsafe, only that TI has not proven that it is safe.  There is a big difference between safe and certified safe.  They are making it very clear that they don't want it used as a medical device as is, and they are doing so to avoid liability issues.  You will find a disclaimer on a great many ICs stating that they are not suitable for use in medical devices for the same reason.  I doubt that they intentionally or knowingly designed it in an unsafe manner, but it is entirely possible they have overlooked one or more things.

2.  The way to work around this disclaimer is to incorporate the TI device in a medical device and go through the certification process.  I don't know how much, if any, modification would be required on the TI Eval board and it is not clear to me that there would be any advantage to this.  By the time all of the work is done to make the overall device demonstrably safe and go through the certifications it is entirely possible that the unit cost would have to be higher than existing devices.

3.  All of this hinges on medical ethics, which has become a very strange field.  My standard question for illustrating this is:  I have a pill here.  If you take it there is one chance in twenty five that you will die miserably and instantly.  But if you don't die you will live a healthy life for the next fifty years or age 85, whichever comes first.  Such a pill would never pass ethics boards, it is clearly unsafe to take.  But it would lower the death rate of a population who took it.

4.  This is further complicated here in the US and possibly in much of the western world by the legions of lawyers looking for get rich class action suits.  This field is so lucrative that forty years after a liability suit against asbestos manufacturers shut down most of this industry worldwide law firms are still finding it profitable to buy many TV ads per day on cable television looking for new plaintiffs to represent (and collect fees from).
 
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Offline Someone

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[...] We are intentionally avoiding presenting the ways to make it safe [...]

I think that is the wrong attitude...  far better to teach the kids about safe sex and let them get on with it, rather than try to prevent the inevitable course of human nature...

The Byte article referenced by @joeqsmith is 41 years old, so the principles talked about therein should be fair game to talk about without anyone risking divulging trade secrets or releasing information that is not already public.
That has been clear from the outset, want safe? Buy the already certified product rather than trying to replicate their knowledge on the cheap. You don't make your own condom or suggest glad warp is "pretty much the same thing, so it must be good enough", you just pay up for the off-the-shelf product.
 
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Offline Peter Gamma

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Many thanks for this profound discussion of my problem with the TI EEG board. I know now much more than when I asked the question :).

What about attaching the TI EEG board to a mini PC with tiny batteries, or with no batteries at all, and only solar cells?
 

Offline DrG

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What about attaching the TI EEG board to a mini PC with tiny batteries, or with no batteries at all, and only solar cells?

What about it? Be specific please. You can fill in the blank here and not let it serve as some kind of projective test.

Sixty-eight posts later, are you understanding the complexity of the issue or are you [still] looking for a step-by-step guide for "forum safety certification", which is, by the way, NOT a thing.
- Invest in science - it pays big dividends. -
 

Offline SilverSolder

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[...] We are intentionally avoiding presenting the ways to make it safe [...]

I think that is the wrong attitude...  far better to teach the kids about safe sex and let them get on with it, rather than try to prevent the inevitable course of human nature...

The Byte article referenced by @joeqsmith is 41 years old, so the principles talked about therein should be fair game to talk about without anyone risking divulging trade secrets or releasing information that is not already public.
That has been clear from the outset, want safe? Buy the already certified product rather than trying to replicate their knowledge on the cheap. You don't make your own condom or suggest glad warp is "pretty much the same thing, so it must be good enough", you just pay up for the off-the-shelf product.

The R&D efforts for a DIY condom sounds like it could be entertaining, though!  :D
 

Offline Peter Gamma

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I agree. I found that there is also a security problem with Bitalino. Bitalino Biomedical low-cost Toolkit has no answer to the question whether their products are safe for humans or not. So the discussion could also be continued in the Bitalino forum:

https://forum.bitalino.com/viewtopic.php?f=1&p=2286#p2286
 

Offline Peter Gamma

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The Indonesian researchers used the TI EEG board paired to a Rasperri PI. I also informed the reseach group who wrote the papers about the TI EEG board about the discussion here in the EEVblog, but there was no response from the research team yet. I wonder whether they used to Rasperri PI for safety reasons?

https://www.researchgate.net/publication/325635924_Design_of_EEG_Data_Acquisition_System_based_on_Raspberry_Pi_3_for_Acute_Ischemic_Stroke_Identification
 

Online Fungus

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The Indonesian researchers used the TI EEG board paired to a Rasperri PI. I wonder whether they used to Rasperri PI for safety reasons?

The real problem here is that you don't know how to answer that for yourself.

You're proposing to build a "medical" device and attach it to people but you don't know the basics.
 

Offline Peter Gamma

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In the paper, a Rasperri PI is used to aquire data from the TI EEG board and then stored on a SD card on the Rasperri PI. and then further analyzed by a MATLAB based GUI. i did not find any hints in the paper that the Rasperri PI was used for safety reasons. But does the Rasperri PI not solve the problem to prevent current to run from a PC to the TI EEG board to the EEG headseat?
 

Offline aristarchus

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@Peter Gamma

I just wonder what is your age since you keep coming back to this without understanding the basic concepts.
(no need to say your age as I do not generaly believe what people in forum posts say..)

Instead of asking this type of questions here, you should go and read the relevant accreditation freamework in your country.

If for Swiss, then
https://www.swissmedic.ch/swissmedic/en/home/medical-devices/regulation-of-medical-devices/medical-device-regulation_online-guide.html
https://www.swissmedic.ch/swissmedic/en/home/medical-devices/neue-eu-verordnungen-mdr-ivdr.html

For US
https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/overview-device-regulation

EU
https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG%3A1993L0042%3A20071011%3Aen%3APDF
https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG%3A1998L0079%3A20090807%3AEN%3APDF


Then decide if you gonna mark your device as for use on humans or not.
As you see, others that created similar gizmos they decided that they should not put that label on their design and inform any potential buyer with legal liability warnings.
For me, I do not endorse even that practice with liability warning, I personaly think this is fraudulent as users do not generaly read the fine print, eg you say that you give an EEG but you do not certify that it can be attached to humans, written in some page somewhere in your site..... actually this is what others do.

I guess you now understand why real medical equipment cost is high.
 

Offline Saskia

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Working in pharma I can tell that we do spend at least a decade to develop a substance into a medication and do the proper non clinical and clinical safety tests before we get the approval to bring the medication to the market.

At our company there is an army of safety experts, pathologists, toxicologists, etc (far more than 1000 employees) involved just to get approval to prepare the submission for requesting approval to start a clinical study. We have our QA department and extremely regular audits by the EMA, FDA, etc. In these audits we have to explain all of those measures we take to ensure drug safety. Including our SOPs, processes to deal with adverse events, incident management, etc. up to sourcing of components and validation of test equipment. If e.g. a scale does not meet validation criteria, it will get thrown out.

Non-compliance with the rules would get us shut down. Obviously our management is liable for ensuring compliance with the rules, and non-compliance will get employees fired on the spot. No one here wants to catch the blame for any patient mishap.

Medical devices that pose a risk to the patient will undergo similarly rigorous inspections and regulatory approvals.

Can you prove, that

- you have the proper certification and training to be conducting this kind of experiments ?
- you have the proper guidelines to be able to do a validation of the device that you are trying to build ?
- that the manufacturer of your evaluation board certified it for use in this kind of experiments ?
- that you have a setup which does not negate the board manufacturer's certification and specifications for use in medical experiments ?
- did you validate your setup according to good laboratory practice and good clinical practice PRIOR to any experiment taking place ?
- is this validation documented according to good documentation practice ?
- that your lab is actually fit for this kind of experiments ? A validation for labs is also required, see above ....
- that your lab equipment is certified and validated ?
- did you validate the software you are using to take those measurements ? if not, study Computer System Validation & Compliance first.

These are just a few superficial remarks scratching on the surface of this topic.

If the manufacturer does explicitly exclude his evaluation board for use in medical experiments, you should not even think about using it in such manner.



 
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Offline Tarloth

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In the paper, a Rasperri PI is used to aquire data from the TI EEG board and then stored on a SD card on the Rasperri PI. and then further analyzed by a MATLAB based GUI. i did not find any hints in the paper that the Rasperri PI was used for safety reasons. But does the Rasperri PI not solve the problem to prevent current to run from a PC to the TI EEG board to the EEG headseat?

No, RPI not improve the device or turn it "safer", probably turn it more riskie. I did read superficially the paper and scientist didn't test in humans, only it's a proof of concept, they didn't affirm that this configuration it's SAFE, only affirm that it's possible to meassure the signals.

You need to learn basic concepts, first at all signal isolation.

I suppouse that you are not thinking to start a crowd founding campain with another dangerous product,  isn't it?
 

Offline Peter Gamma

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It seems like the authors of the papers did not adress the topic safety at all. I saw that safety recommendations for instance for OpenBCI EEG are to use a Wifi setup. The Rasperri PI has wifi transmission, therefore the risk of unwanted current from a PC to the EEG headset could be solved by a Wifi bridge from the PC to the Rasperri PI.
« Last Edit: September 25, 2020, 02:32:27 am by Peter Gamma »
 

Offline Peter Gamma

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In the paper, a Rasperri PI is used to aquire data from the TI EEG board and then stored on a SD card on the Rasperri PI. and then further analyzed by a MATLAB based GUI. i did not find any hints in the paper that the Rasperri PI was used for safety reasons. But does the Rasperri PI not solve the problem to prevent current to run from a PC to the TI EEG board to the EEG headseat?

I suppouse that you are not thinking to start a crowd founding campain with another dangerous product,  isn't it?

No, since finding a croud for a research project is hopeless.
 

Offline Peter Gamma

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I saw someone else is looking for a crowd for his HackEEG (by Starcat, LLC)

8-32 channel TI ADS1299 Arduino shield for EEG, EMG, and EKG bio-signals acquisition

https://www.crowdsupply.com/starcat/hackeeg

but is this device safe for humans?
 

Offline aristarchus

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I saw someone else is looking for a crowd for his HackEEG (by Starcat, LLC)

8-32 channel TI ADS1299 Arduino shield for EEG, EMG, and EKG bio-signals acquisition

https://www.crowdsupply.com/starcat/hackeeg

but is this device safe for humans?


Their disclaimer on the page you specify tell it all..

"Important Warning

Although HackEEG has some of the features of a medical device, it does NOT have any certifications (FDA, CE, IEC, etc.) and is NOT officially approved for medical or diagnostic use. It is your responsibility to ensure your safety when using the device. Furthermore, you should never power the device from a non-isolated power source."


Don't you read the page that you, yourself, show to us?

 

Offline DrG

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Don't you read the page that you, yourself, show to us?

It does not appear so to me. He also does not appear to answer questions. There is also very little evidence that any of the considerable advice that has been given has had any real effect. It is a *very* important topic and yet he seems to be stuck on "is it safe", unwilling to pursue any study of even the fundamentals - as has been noted.

It is possible that he was the dentist in Marathon man. Now, I don't know that for a fact, I am just saying it is possible :)


- Invest in science - it pays big dividends. -
 
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Offline Peter Gamma

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I've read the pages and saw that the HackEEG can be connected to a Raspberry Pi 4 sending Lab Streaming Layer data over WiFi, which is a similar setup as was used for the TI EEG board in the papers. There is nothing to answer or not to answer anymore.
 

Offline Saskia

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well, if he tries this on humans, report it to the authorities and watch in awe when they throw the book at him.

 

Offline aristarchus

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This guy is just a shill.
Never really discussed nor listened what others said and finally indirectly advertised a crowdfunding campaign trying to convince us that its just fine to use it.
Clever way indeed!

Suppose that some moderator if not ban him, then at least move this thread to Crowd Funded Projects......
 


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