Getting pulse oximeter values and logging with arduino

[Marc MERLIN]

I'm interested in logging my heartrate, and SpO2 while I sleep. There
are commercial devices that do that and they are stupidly expensive.

I do have a $50 clamp on oximeter I could use, but I'm not much of an EE
guy and wouldn't really know how to tap its signals before they get
converted and displayed as decimal on the LCD display.

As for using an LED or two and photo diode and doing it myself, from
what I read it's not that trivial do it right myself.

I found this
http://tinkerish.com/blog/?p=181
It does explain the concept fairly well, but it doesn't have SpO2 (O2
saturation in the blood, from 100% down).
Ideally I'd also re-use an already made medical sensor that tapes over
your finger since it already has the right LEDs and light sensor in a
convenient package (I'm sure they really only cost $20).

Then, there is
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238175638
but it doesn't have much successful info either.

Does anyone have any more ideas on where I could get a pre-made sensor
and control it from an arduino?

Thanks,
Marc

PS: I suppose I would consider a pre-made device but most are medical
and in the thousand dollar range. I was also looking at doing it myself so that I
could use the modsendat board's accelerometer and measure my blood saturation versus
which side of my body I'm currently sleeping on.
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems & security ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/

[Paul Szymkowiak]

Hi Marc,

As it happens, I've been researching this on and off for a little while now. I'm not at a stage where I'm actively prototyping due to (too many) other projects, but here's what I've found.

I got interested in this first when my son was in hospital with double pneumonia, and he was hooked up to one of the disposable pulse oximeter sensors. It struck me at the time that this was probably hackable, so I kept it to have a hack at some point: if you'd like to have a look at it, I can bring it along to the hackerspace. It appears these can be purchased over the net in bulk or apparently as single items: 

    Disposable Pulse Oximeters

    http://www2.mooremedical.com/index.cfm?PG=CTL&FN=ProductDetail&PID=14088

    http://www.buyemp.com/product/11230130.html

    Bulk disposable Pulse Oximeter sensors (24 to a case):

    http://diagnostic-supplies.medical-supplies-equipment-company.com/product/ppf/id/16278/new_prod_full.asp

    http://diagnostic-supplies.medical-supplies-equipment-company.com/product/ppf/id/22506/new_prod_full.asp

My thought had been to figure some kind of glove or sheath that would protect the sensor and enable it to be used multiple times, possibly with something like this:

  http://www.musicmart.com/The-UltimaGlove-2-Black-Glove-No-Dots-P270550.aspx

I also bought a Pulse Oximiter units from EBay, similar to this one:

  http://cgi.ebay.com.au/FDA-CE-Proved-Fingertip-Pulse-Oximeter-SPO2-w-Free-Case-/220685807717?pt=AU_Business_Industrial_Medical_Scientific_Equipment2&hash=item3361e63065#ht_3735wt_902

I thought it might be worth seeing if this could be usefully hacked, but haven't investigate that yet (I took the case off a while ago, but didn't look too far).

From there I looked into various chest band heart rate monitors, and there is a reasonable amount hacker info available on the Polar bands already, including the a module & breakout board from Sparkfun:

  Polar

  http://www.sparkfun.com/products/8660

  http://www.sparkfun.com/products/8661

and there are a few cheaper alternative brand names, including a watch and band set that JayCar were selling at the time for about $15, a bit like this:

http://cgi.ebay.com.au/Pulse-Heart-Rate-Monitor-Watch-Transmitter-Chest-Belt-/390291826471?pt=AU_Exercise_Accessories&hash=item5adf34a727#ht_2614wt_978

The TI Chronos watch developers kit and associated band is also worth considering:

  Chronos  

  http://au.mouser.com/tiez430chronos/

  http://wn.com/eZ430-Chronos_Wireless_Watch_Development_Tool_Preview

  

  Chronos Chest Band

  http://www.bm-innovations.com/index.php/chest_straps.html

  A GitHub Chronos code repo

  https://github.com/poelzi/OpenChronos/

Later, I discovered an even cheaper heart rate sensor through dealextreme: essentially an earlobe clip, with various circuit designs, discussions, etc.

   Heart Rate Monitor/ Pulse Oximeter:

    http://www.dealextreme.com/details.dx/sku.16009

    http://electronicdesign.com/images/Schematic.pdf

    http://www.dealextreme.com/forums/Default.dx/sku.16009~threadid.434077

    http://zedomax.com/blog/2006/10/22/diy-circuit-heart-rate-monitor/    

    http://www.embedds.com/heart-rate-indicator/

Hope that helps.

Paul
 

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[Marc MERLIN]

On Sat, Mar 05, 2011 at 01:20:37PM +1100, Paul Szymkowiak wrote:
> Hi Marc,
>
> As it happens, I've been researching this on and off for a little while now.
> I'm not at a stage where I'm actively prototyping due to (too many) other
> projects, but here's what I've found.

Cool, thanks for sharing :)

> I got interested in this first when my son was in hospital with double
> pneumonia, and he was hooked up to one of the disposable pulse oximeter
> sensors. It struck me at the time that this was probably hackable, so I kept
> it to have a hack at some point: if you'd like to have a look at it, I can
> bring it along to the hackerspace. It appears these can be purchased over
> the net in bulk or apparently as single items:
>
> Disposable Pulse Oximeters
> http://www2.mooremedical.com/index.cfm?PG=CTL&FN=ProductDetail&PID=14088
> http://www.buyemp.com/product/11230130.html

Perfect. That's exactly what I was hoping to use as a base.

> My thought had been to figure some kind of glove or sheath that would
> protect the sensor and enable it to be used multiple times, possibly with
> something like this:
> http://www.musicmart.com/The-UltimaGlove-2-Black-Glove-No-Dots-P270550.aspx

So I wouldn't worry that too much. I've used those before for at home sleep
studies (seeing how much my SPO2 would drop at night due to sleep apnea),
and simple medical tape around your finger is all you need for those.
They are of course very reusable, but the medical field likes to make
everything single use so that they can sell more and avoid contamination
(even if here it's really not an issue).

> I also bought a Pulse Oximiter units from EBay, similar to this one:
>
> http://cgi.ebay.com.au/FDA-CE-Proved-Fingertip-Pulse-Oximeter-SPO2-w-Free-Case-/220685807717?pt=AU_Business_Industrial_Medical_Scientific_Equipment2&hash=item3361e63065#ht_3735wt_902

I have a slightly different one, but effectively have the same than you.
While it wouldn't be ideal to sleep with this on my finger and while they
are not designed for continuous use, for the EE type it would be nice to
take apart and steal the already processed signal from.

> From there I looked into various chest band heart rate monitors, and there
> is a reasonable amount hacker info available on the Polar bands already,
> including the a module & breakout board from Sparkfun:
>
> Polar
> http://www.sparkfun.com/products/8660
> http://www.sparkfun.com/products/8661

I'm not really interested in heart rate by itself since I need/want SPO2 and
heart rate comes for free with it :)

> Later, I discovered an even cheaper heart rate sensor through dealextreme:
> essentially an earlobe clip, with various circuit designs, discussions, etc.
>
> Heart Rate Monitor/ Pulse Oximeter:
> http://www.dealextreme.com/details.dx/sku.16009
> http://electronicdesign.com/images/Schematic.pdf
> http://www.dealextreme.com/forums/Default.dx/sku.16009~threadid.434077
> http://zedomax.com/blog/2006/10/22/diy-circuit-heart-rate-monitor/
> http://www.embedds.com/heart-rate-indicator/

Those are interesting, but no SPO2.

To get those, I think it would be a matter of getting one or all 3 sensor
kinds from http://www.buyemp.com/product/11230130.html and figure out the
pinout from at least one of them.
After that, I'm guessing it shouldn't be too hard to drive and read from an
arduino.

I don't have a lot of time to investigate this right now, but I may later
when I'm on some extended vacation :)
If you make progress with this, let me know too (note that I'm not in
Melbourne, not even in Australia for that matter, I got this list through
the arduino miniconf at the last LCA :)

> Hope that helps.

It sure does. Thanks much for all the links.

Marc

[Monica Austin]

Did any of this ever result in a project? I'm about to embark on this kind of project since my dad has been in the hospital and I need to prove to him that his apnea is affecting his O2 at night. . .avid arduino programmer.  Did you find any other helpful solutions/links you could share?

[Darren Freeman]

Monica, Paul, Marc, and others,

On Sat, 2013-10-12 at 10:19 -0700, Monica Austin wrote:
> Did any of this ever result in a project? I'm about to embark on this
> kind of project since my dad has been in the hospital and I need to
> prove to him that his apnea is affecting his O2 at night. . .avid
> arduino programmer. Did you find any other helpful solutions/links
> you could share?

I don't want to be a wet blanket, but I've had some horrible experiences
that I won't be too specific about right now. I wish I didn't have to
know all this, as I'm not a lawyer and it hurts my brain. But in the
interests of keeping my fellow hackers informed and out of trouble with
the law, I'll share the following.

This is my layperson's understanding of the subject. I take no
responsibility for the accuracy or completeness of this information. If
you wish to proceed, you should seek expert legal advice and you must
not rely on any of what I've written. Ignorance of the law is not a
defence.

What you propose to create may be considered a "medical device"
according to the Therapeutic Goods Act 1989 (Commonwealth). Here is some
text that may be relevant:

"41BD What is a medical device
(1) A medical device is
(a) any instrument ... including the software necessary for its proper
application) intended ... to be used for human beings for the purpose of
one or more of the following:
(i) diagnosis, prevention, monitoring, treatment or alleviation of
disease; or
(b) an accessory to an instrument ... covered by paragraph (a) ..."

Making your own medical devices is, except under special circumstances,
against the law. When hospitals and companies do this for development
purposes, they have to follow many rules, and there are administrative
processes that must be in place. Then in order to test medical devices
on human beings, there usually has to be an official clinical trial in
place, approved by a human research ethics committee.

I know that you all mean well, and the possibility may seem remote, but
it's conceivable that an incorrect diagnosis could be made because of a
bug in your software, or for any other reason. You could also cause
problems for a doctor who unwittingly makes an assessment based on the
results you have collected. If there is any way that you can just buy a
suitable product that is included in the Australian Register of
Therapeutic Goods, this might be preferable to going down the path of
developing a new medical device in a manner that complies with the law.

I know that medical devices are expensive, but a lot of testing goes
into them. This is what you pay for. They also bear all sorts of legal
liabilities in case something goes wrong, for which they are probably
insured.

If no suitable device is available in Australia, you may have the option
to import a device on a one-off basis, but beware that this is also
covered by the Act. If the device doesn't carry a CE mark, preferably
with some numbers alongside the letters CE, then view it with suspicion.
(Our system is mostly harmonised with the European system.)

If you continue with this project without obtaining legal advice, then
you risk being in breach of these sections of the Act (and possibly
others):

41MA(8), 41ME(4), 41MI(4) - these are criminal offences that carry a
maximum penalty of 12 months imprisonment and/or 1,000 penalty units.

41MAA(2), 41MEA(1), 41MIB(1) - these are civil offences that carry a
maximum penalty of 5,000 penalty units.

A "penalty unit" is defined in the Crimes Act 1914 (Commonwealth),
section 4AA, to be $170. So the maximum penalties above are $170,000 and
$850,000.

Again, I could be wrong about all of this. I'm not a lawyer, I'm just
reading from the Act, and it may happen that the Act means the opposite
of what I think it means. I just want you to be aware that the Act
exists and that it could carry certain penalties. What you do with this
information is entirely at your discretion.

Have fun,
Darren

[Marc MERLIN]

On Sat, Oct 12, 2013 at 10:19:59AM -0700, Monica Austin wrote:
> Did any of this ever result in a project? I'm about to embark on this kind
> of project since my dad has been in the hospital and I need to prove to him
> that his apnea is affecting his O2 at night. . .avid arduino programmer.
> Did you find any other helpful solutions/links you could share?

The SPO2 part was tricky and looked like too much work for me to do
myself, so I used another pre-made device.
That said, you want to get your dad a real sleep study, or at the very
least get him an SP02 sensor that does logging.

On Mon, Oct 14, 2013 at 07:49:47PM +1100, Darren Freeman wrote:
> Making your own medical devices is, except under special circumstances,
> against the law. When hospitals and companies do this for development
> purposes, they have to follow many rules, and there are administrative
> processes that must be in place. Then in order to test medical devices
> on human beings, there usually has to be an official clinical trial in
> place, approved by a human research ethics committee.

That is indeed why you should not do anything like this to be used as a
medical device, you shouldn't sell it and if you give it, it should very
carefully be labelled as "not to be used as a medical device".

My wife works in the medical device industry and ensures that they can
pass FDA testing (in the US), so I know enough about this that I don't
want to get anywhere close to that.
Back to Monica, do not build anything yourself for an actual medical
need. I built mine for fun and curiosity while getting real medical help
and tests when needed.

Marc
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.

Microsoft is to operating systems ....

.... what McDonalds is to gourmet cooking

Home page: http://marc.merlins.org/ | PGP 1024R/763BE901

[Darren Freeman]

On Mon, 2013-10-14 at 07:33 -0700, Marc MERLIN wrote:
> On Sat, Oct 12, 2013 at 10:19:59AM -0700, Monica Austin wrote:
> > Did any of this ever result in a project? I'm about to embark on this kind
> > of project since my dad has been in the hospital and I need to prove to him
> > that his apnea is affecting his O2 at night. . .avid arduino programmer.
> > Did you find any other helpful solutions/links you could share?
>
> The SPO2 part was tricky and looked like too much work for me to do
> myself, so I used another pre-made device.
> That said, you want to get your dad a real sleep study, or at the very
> least get him an SP02 sensor that does logging.

That reminds me, yes, for this application you can get a home sleep
study.

AND it's Medicare rebateable. Item number 12250.

http://www.mbsonline.gov.au/internet/mbsonline/publishing.nsf/Content/News-20081001-Home_Base_Sleep_Studies

Your father's doctor refers him to a sleep study provider, who performs
an initial consultation and then lends him a data logger. Then it is
reviewed by somebody qualified, and you have solid evidence that might
lead to further treatments, which may include a subsidised CPAP machine.

If you do it yourself, you risk not getting a formal diagnosis, so then
you're forever having to explain to people that you know what it is but
you have no formal diagnosis. And that leads to paying full price on the
CPAP machine, not getting help from Medicare and health funds, etc.

Have fun,
Darren

[Lauren Shearer]

Or, to misquote,

The patient who diagnoses themselves has a fool for a doctor.

On the other hand;

The disposable sensors (the $20 bit) are cheap (not) because they're simply 1 to 4 leds and 1 to 4 photoresistors.

The expensive bit (the box) does a fair amount of signal processing, compatison against multi-dimensional lookup matricies, and varies in the algorhythms from manufacturer to manufacturer.

For tinkering purposes only (Not for clinical use), you might be able to get an OEM sensor unit such as the Masimo (No affiliation, my facility recently purchased some) and then take communiations out via the Samtec SFM-105-02-S-D-A connector. You might find it difficult getting an evaluation board though.

Lastly, you could always just poll the LCD screen and interpret it's digits, logging them on an arduino or connected host computer.

 

And ultimately, your favourite wholesale portal to the east has a number of CE mark and FDA approved pulse oximeters, some of which come with computer logging software for under $200. They would be unlikely to give you high quality results but if you were going to (for instance) monitor your non-human pat they might work.

Or, overnight sleep study in any australian public hospital is free for medicare card holders. Comes with years of medical expertise and training, as well as throrough communication with appropriate surgeons and physicians without additional monetary expense. The wait time at my service is about 6 weeks; 2 weeks with private insurance (The government does not pay you more just because you do more tests; therefore you are only funded to do so many at once / staff so many at once)

I am not aware of public hospitals doing the at-home studies, but if there is private insurance about, one of the private providers would do. There is a quality trade-off, though.

[David Lyon]

Hi Darren,

It's actually more cut-and-dry than that. Let me clarify.

I have worked professionally developing medical devices. You are actually allowed to make up any device you like and install it on yourself. You are allowed by law, to measure your own temperature and check your own pulse. You can make up whatever fancy devices to improve the process and test that on your own person.

Where the legislation comes in is making a device and selling it to others to install it on themselves. That's very tightly regulated and rightly so.

It's not an easy field to come up with a saleable product so you'd be looking at a decade of work before you would reach that point.

I'm just trying to put 'diy-hackery' into perspective. It's interesting but I doubt it will be so useful that you can easily break the existing laws. All legislation in this area is pretty well thought through, and in my opinion reasonable.

:-)

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[Roboticist Mark]

Just to throw in my 2c

I have also worked professionally developing medical devices,

I can confirm what David and Marc said, you can use a measurement device on yourself, and if you go around exhibiting it to others then it needs to carry the disclaimer "not to be used as a medical device" or "not for human use"

if you use it on anyone else then you may need any or all of, EMI testing / safety testing / toxicity analysis / verification of software or ethics approval 

In the end anything you hack together is a risk, just don't diagnose anyone with it or sell it to anyone and you'll be fine.

Mark

[Darren Freeman]

On Mon, 2013-10-14 at 20:15 +1100, David Lyon wrote:
> Where the legislation comes in is making a device and selling it to
> others to install it on themselves. That's very tightly regulated and
> rightly so.

Not just selling it to others, but "supplying" it to others.

My understanding is that if you offer your home-made data-logger for
your father to use, you're supplying it.

> It's not an easy field to come up with a saleable product so you'd be
> looking at a decade of work before you would reach that point.

Well, it's an easy field to come up with a rapid prototype that somebody
would want to pay money for. The Arduino data logger could be thrown
together in an afternoon, and somebody would eventually suggest that
they want one and don't have the time to built it for themselves.

But you couldn't supply it, or even tell someone where to get one from a
third party.

Have fun,
Darren

[Scott Penrose]

Howdy

DISCLAIMER: No legal advice to follow !

I just want to put my few cents worth in on a few items here:

* I have also been hacking/building one - firstly using an amplifier and reusable device, then looking at the cheap entries.

* Legal issues listed here are todo with intent, not device.

The last one is very important for understanding the legal ramifications of selling devices. You will see this one used(abused?) a lot - e.g. you can buy an item for decoration and not use (drug related items appear in this category). 

With medical it is all in the words originally quoted, which is to use for medical diagnosis.

What I know - not what is right:

* Pulse oximeters you purchase online are in the vast majority not considered medical devices - cheap chinese things off eBay. They still work, just wouldn't rely on them in a hospital.

* Vast majority of oximeters I see (me, not vast majority over all) are used in gliding to check your oxygen level during flying. They are not required instruments, just another one of many tools we use. Not designed to plug into an ambulance.

* Heart rate monitors attached to watches easily fall in the same category as pulse oximeters, and are not medical devices. Try and use one of those in a hospital though and you will be told to get medical equipment.

Now all that said... there is two types of law - legal and civil. The thing about civil - is there is no rules. My old boss said "sue where the money is". You build a device, and you sell it, and you put on 100 warnings about using this thing only as a toy. Does this help? No not really, you could still end up in court - but by adding warnings and limitations you might save yourself some money, but not your lawyer fees.

There is lots of references for heart rate monitors

http://www.mioglobal.com/docs/mio_alpha_userguide_eng.pdf - not a medical device

http://www.timex.com/sites/default/files/product_manual/W201_M593_NA_EN.pdf - not a medical device

http://www.timex.ca/library/misc/52063178-334e-494b-8bac-345d53c38c23.pdf - not a medical device

In the United States "Pulse oximeters that are not approved as medical grade for the Food and Drug Administration for over-the-counter sale".

ie. When you buy a pulse oximeter over the counter, it is automatically considered not a medical grade !

This is from eBay policy, which state that they will only sell non medical pulse oximeters.

Lots of eBay entries have "measuring oxygen saturation and pulse rate and is not for medical use".

If it were true that anything that could measure anything on a person was a medical device, then new iPhone would have to be a medical device :-) It is not true that because it can, it is (although even that case there are exceptions, like guns). All those IR temperature probes we have, they can measure people temperature - and other peoples too :-) Not medical devices.

* This means, from a legal side - you are not producing medical equipment - all safe.

* From a civil side - always protect yourself, family, house etc :-)

BTW. My reasons for building/hacking one (and I am moving towards hacking next, since they are now about $20 and even the reusable components are more) is to add levels of alarm. So when I am using it to monitor, I get an extra input to alert me if my oxygen is dropping - which is usually because I am concentrating and have not taken enough deep breaths, or I am using my mouth instead of nose.

Scott

[Darren Freeman]

On Fri, 2013-10-18 at 15:51 +1100, Scott Penrose wrote:
> DISCLAIMER: No legal advice to follow !

> * Legal issues listed here are todo with intent, not device.

Under Australian Commonwealth law, it is possible for someone to be
convicted and sent to prison with no intent to break the law.

You might want to become a qualified lawyer before you start giving
legal advice. Even if you say that it isn't legal advice, clearly it is.

> There is lots of references for heart rate monitors
> http://www.mioglobal.com/docs/mio_alpha_userguide_eng.pdf - not a
> medical device
> http://www.timex.com/sites/default/files/product_manual/W201_M593_NA_EN.pdf - not a medical device
> http://www.timex.ca/library/misc/52063178-334e-494b-8bac-345d53c38c23.pdf - not a medical device

I shouldn't have to say this, but the law differs from country to
country.

Ignorance of the law is not a defence.

Saying that somebody on a mailing list told you it was perfectly legal
is not a defence.

> In the United States "Pulse oximeters that are not approved as medical
> grade for the Food and Drug Administration for over-the-counter sale".
> ie. When you buy a pulse oximeter over the counter, it is
> automatically considered not a medical grade !
> This is from eBay policy, which state that they will only sell non
> medical pulse oximeters.

eBay policy is not a defence.

> * This means, from a legal side - you are not producing medical
> equipment - all safe.

As I said above, you are clearly giving out legal advice. Please stop
it. It is reckless and irresponsible.

Have fun,
Darren

[Zac Watts]

Can we stop with the penis measuring contest? Penis measuring may be against the law.

No one is getting prosecuted for making a home made finger IR transmittance measurer.

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[Zac Watts]

FYI relevent legisislation is http://www.comlaw.gov.au/Details/F2010L01889

Schedule 4—Exempt devices

  Part 1—Exempt devices—general

1.5

Custom‑made medical device

    

[Marco Bresciani]

Thanks for the info Zac, I was beginning to get worried.

It would have been madness if there was a situation where you couldn't easily build a harmless bio-measuring device, yet it is OK for companies to sell water for medicine (homeopathy), or for practitioners to perform procedures that have scientifically been proven time and again to be no more effective than a placebo (acupuncture), or to pay for 'treatment' that manipulates your spine in such a way that you won't get cancer (which is what orthodox chiropractors still believe).

Marco

[Darren Freeman]

On Fri, 2013-10-18 at 19:36 +1100, Zac Watts wrote:
> FYI relevent legisislation
> is http://www.comlaw.gov.au/Details/F2010L01889

That link is not relevant, as it relates to in vitro diagnostics.

I expect that you intended to refer to the Therapeutic Goods Act 1989.

> Schedule 4—Exempt devices
>
> Part 1—Exempt devices—general
> 1.5
> Custom‑made medical device

This is taken from the Therapeutic Goods (Medical Devices) Regulations
2002.

So now we need to know the definition of a custom-made medical device.
Is it made by a hospital or by a company that has a license to
manufacture? Is it in full compliance with the Essential Principles?
(I.e. all the standards.)

I recently came across a regular switch-mode plug-pack that produced a
leakage current from mains input to the DC output that was >0.5 mA. I
discovered this when it electrified a metal plate to about 100 V AC, and
I could feel a tingle when I touched it. (It turns out the device it was
powering was not isolated from the plate it was sitting on.) A poorly
made medical device could cause an electrocution even though the
hobbyist thought it was isolated by a non-medical plug pack. There is
quite a lot to know in order to do this properly.

It seems to me that this exemption doesn't cover the Essential
Principles or conformity assessment procedures. It only covers having to
get the custom device onto the register. But I'm not legally qualified
and I don't know whether it's safe to make your own medical devices at
home. All I'm saying is that people should seek legal advice rather than
get into trouble.

Lots of people break the law in a way that doesn't lead to prosecution.
For example, sometimes people drive over the speed limit and don't get
caught. That doesn't mean we should be dismissive of the law, or
encourage people to assume that it doesn't apply to them.

Have fun,
Darren

[Darren Freeman]

On Fri, 2013-10-18 at 18:59 -0700, Marco Bresciani wrote:
> It would have been madness if there was a situation where you couldn't
> easily build a harmless bio-measuring device, yet it is OK for
> companies to sell water for medicine (homeopathy), or for
> practitioners to perform procedures that have scientifically been
> proven time and again to be no more effective than a placebo
> (acupuncture), or to pay for 'treatment' that manipulates your spine
> in such a way that you won't get cancer (which is what orthodox
> chiropractors still believe).

Actually, apart from the "easily build a harmless bio-measuring device",
I believe all those other things are legal. (But!! I'm not a lawyer!!)

Yes, the situation with complementary and alternative medicine is
appalling. There appears to be either no regulation or no enforcement.

I know a guy who took his cue from them, and he started manufacturing
custom pharmaceuticals and medical devices at home. He said that the TGA
would never do more than write an angry letter. One day they showed up
at his house with a warrant and some police officers, and they took all
his stuff. He only escaped criminal charges by getting himself deported.

Don't look at the alt. med. community and think that you're invulnerable
to prosecution. Let's set a higher standard and refer our friends to
reputable suppliers of medical devices instead of hacking things
together. There are times when you really need your equipment to work
reliably, and diagnosing an illness is one of them.

Have fun,
Darren

[Luke Weston]

When it comes to basic DIY experiments with pulse oximetry (or single-wavelength pulse measurement with no oximetry, which is easy and common in DIY experiments) or basic EKG then in practice, if people want to experiment on themselves in practice nothing is enforceable, even if possibly illegal, and people are going to do it themselves if they want to.

So what I would go for, personally, is an educational harm minimisation approach if people are determined to experiment with such technology.

Don't use mains switched-mode plugpacks which can be dodgy. Use very-low-voltage battery power only to be extra safe. If you're interfacing to a PC, say with logic-level serial, then optically isolate it to be extra safe. This is particularly a good idea with do-it-yourself EKG hardware, which is intrinsically higher in risk (although still small) compared to an optical oximetry clip, which has essentially zero risk unless you decide to do something bizarre like build an oximetry clip with 1W laser diodes or something.

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[Luke Weston]

Presented without further comment:

http://america.aljazeera.com/articles/2013/10/18/the-brave-new-worldofbiohacking.html?utm_content=bufferf63f8&utm_source=buffer&utm_medium=facebook&utm_campaign=Buffer

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[David Lyon]

On Fri, Oct 18, 2013 at 3:23 PM, Darren Freeman <dar...@freemaninstruments.com> wrote:

On Mon, 2013-10-14 at 20:15 +1100, David Lyon wrote:
> Where the legislation comes in is making a device and selling it to
> others to install it on themselves. That's very tightly regulated and
> rightly so.

Not just selling it to others, but "supplying" it to others.

My understanding is that if you offer your home-made data-logger for
your father to use, you're supplying it.

As far as I know, Pulse Oximeters aren't in the controlled device category.

They can even be bought as junk on dx.com eg http://dx.com/s/pulse+oximeter

 

Well, it's an easy field to come up with a rapid prototype that somebody
would want to pay money for. The Arduino data logger could be thrown
together in an afternoon, and somebody would eventually suggest that
they want one and don't have the time to built it for themselves.

I'm not so sure.

One major problem also is that I'm not sure if AVR and the Arduino toolchain have any history of certification in the medical world. I could be wrong, but most of the medical devices electronics that I've seen are based around Texas Instruments processors.

 

But you couldn't supply it, or even tell someone where to get one from a
third party.

 

oops - did I say dx.com sell pulse oximeters ? http://dx.com/s/pulse+oximeter and ebay as well ?

[David Lyon]

On Sat, Oct 19, 2013 at 12:59 PM, Marco Bresciani <hypnor...@gmail.com> wrote:

It would have been madness if there was a situation where you couldn't easily build a harmless bio-measuring device, yet it is OK for companies to sell water for medicine (homeopathy), or for practitioners to perform procedures that have scientifically been proven time and again to be no more effective than a placebo (acupuncture), or to pay for 'treatment' that manipulates your spine in such a way that you won't get cancer (which is what orthodox chiropractors still believe).

To be fair though, the history of modern medicine is quite fascinating.

It's been a rapidly evolving field for just over a few hundred years.

The feeling that you get from people actively developing the technology is immensely positive. And if any solution is found to any problem, then the benefits to all concerned are great also.

Making products that work in all circumstances is not cut and dry. Because of many factors. And simply because some particular product or service doesn't work in all cases, doesn't automatically get it banned by the Authorities. Far from it usually, they like things to work because it helps their own core businesses such as Hospitals and the Healthcare system in General.

It's easy to think that everything-should-work, but in fact with modern medicine it's come from a background where the cure was once worse than the disease. :-) Do some reading up and you will know what I mean. :-)

[Darren Freeman]

On Fri, 2013-10-18 at 15:53 +1100, David Lyon wrote:
> As far as I know, Pulse Oximeters aren't in the controlled device
> category.

I disagree, but I might be wrong.

>
> They can even be bought as junk on dx.com eg http://dx.com/s/pulse
> +oximeter

That's not really the point. You can buy bongs from cigarette shops, and
yet it's illegal to use them for the widely understood intended purpose.

I suppose if you slap a "not for clinical use" sticker on them and you
intend to use them for parts, it's not an issue. But we're talking about
building a device for diagnostic purposes in a human, which is clearly
different.

> Well, it's an easy field to come up with a rapid prototype
> that somebody
> would want to pay money for. The Arduino data logger could be
> thrown
> together in an afternoon, and somebody would eventually
> suggest that
> they want one and don't have the time to built it for
> themselves.

> One major problem also is that I'm not sure if AVR and the Arduino
> toolchain have any history of certification in the medical world. I
> could be wrong, but most of the medical devices electronics that I've
> seen are based around Texas Instruments processors.

I didn't mean that you could do it legally, just that you could do it
easily.

Hence the need to point out that it might not be legal, since it is in
fact dead easy and anyone might decide to do it.

As for medical certification of software, take a look at the number of
medical devices that incorporate a PC running some version of Windows.
And pray that you never, never get sick.

People have been killed by software bugs, e.g. on radiotherapy
equipment.

> But you couldn't supply it, or even tell someone where to get
> one from a
> third party.
>
> oops - did I say dx.com sell pulse oximeters ? http://dx.com/s/pulse
> +oximeter and ebay as well ?

Therapeutic Goods Act 1989, 41MM, maximum penalty $10,200. (But I'm not
a lawyer and it's possible that the death penalty applies. Seek
qualified legal advice.)

Yes, we have a wonderful system. Free speech and all that.

If you tell people where to get unapproved medical devices, the
terrorists win.

Have fun,
Darren

[David Lyon]

Hi Darren,

I'm out of comments to follow up with. :-)

David

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[Mike Gray]

Here is a pulse oximeter that records oxygen saturation and pulse rate for less than $100.00: http://www.ebay.com/sch/Healthcare-Lab-Life-Science-/11815/i.html?_from=R40&_nkw=cms50e&_sop=15 .  This oximeter comes with software that analyzes obstructive sleep apnea.  I would like to hook it up to arduino so that I can change the rate of oxygen going into my bipap line while I am sleeping as needed per data coming off the oximeter.  Anyone have any ideas?

[Marc MERLIN]

On Mon, Sep 22, 2014 at 03:12:33PM -0700, Mike Gray wrote:
> Here is a pulse oximeter that records oxygen saturation and pulse rate for
> less than $100.00:
> http://www.ebay.com/sch/Healthcare-Lab-Life-Science-/11815/i.html?_from=R40&_nkw=cms50e&_sop=15 .
> This oximeter comes with software that analyzes obstructive sleep apnea.
> I would like to hook it up to arduino so that I can change the rate of
> oxygen going into my bipap line while I am sleeping as needed per data
> coming off the oximeter. Anyone have any ideas?

First note that even with tape, those things didn't say on my finger that
well.
As for your question, you'd have to contact the distributor to see if they
can give you programming information for it.

Marc

Microsoft is to operating systems ....

[Darren Freeman]

On Mon, 2014-09-22 at 15:12 -0700, Mike Gray wrote:
> Here is a pulse oximeter that records oxygen saturation and pulse rate
> for less than
> $100.00: http://www.ebay.com/sch/Healthcare-Lab-Life-Science-/11815/i.html?_from=R40&_nkw=cms50e&_sop=15 . This oximeter comes with software that analyzes obstructive sleep apnea. I would like to hook it up to arduino so that I can change the rate of oxygen going into my bipap line while I am sleeping as needed per data coming off the oximeter. Anyone have any ideas?

What is the input that you'd be controlling? Do you already have a mass
flow controller on the O2 line? Or is this to be controlled through some
input on the BiPAP?

What would be the worst-case consequences of a failure in your home-made
medical device? (And.. are you SURE?)

Have fun,
Darren

[Mike Gray]

Fellows, I just want to acknowledge your email.  My first objective was to let you all know that an oximeter already exists for your purposes.  You can go here to see the outputs from the oximeter by scrolling down to the "reports" on the page:  http://www.clinicalguard.com/product_info.php?products_id=465{11}38{10}50{7}41  I am totally arduino illiterate as well as illiterate with microprocessor controlling.  But, I can learn. 

The thing now is that after over 3,000 of my own sleep studies using this little oximeter ,just recently, I may have found a "cure" in that I can use cannula oxygen instead of infusing 02 into my bipap line which apparently I no longer need, at least for the time being.  So... my interest in doing ardurino control may be falling by the wayside.  

Still, since I started this conversation which may catch the attention of "apneacs" I feel I should mention that a possible cure for apnea worth investigating is to be found here: https://www.youtube.com/watch?v=h7cbBB1c0IM  

If anyone has questions about my experience in using my oximeter and apnea I will try to answer them.

Best wishes, and thanks for your responses.

Mike Gray

I love what I have learned of arduino, and hope to someday tackle it.

 

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