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View Full Version : Medical sensors: parts and sources needed please



Ken Gracey
01-30-2012, 01:16 AM
Hello,

Several of our forum members have experience in medical sensing applications. I'm working on a project where we need to identify and eventually procure about a dozen different types of medical sensors in 100+ unit quantity. I'm not familiar with the technical terms to describe the class of these sensors, but I'm looking for non-intrusive (external to the body) which could be used to measure the following kinds of parameters:

- heart rate
- temperature
- simple chemical sensors
- light
- oxygenation
- tilt, incline, movement
- etc (parameters I have not thought of already - I'm sure there are many)

These sensors could be in a final packaged form as used in a hospital or as an individual integrated circuit, sensor, or similar device. We prefer the latter if there's any easy way of prototyping with the component. The ideal cost for such sensors are less than five or ten dollars.

These sensors would be Propeller-compatible, directly or through necessary conditioning circuitry.

Could you please post suggestions here, along with sourcing information and anything you know about the cost of such devices? We're looking for parts that are actually available.

Thanks,

Ken Gracey

EDIT: The following projects seem to fit the requirements.

TSL235R and Pulse Oximetry (Post #9)
Polar Heart Rate Monitor and Wireless Receiver
pH Sensor Strip with ColorPal Feedback

erco
01-30-2012, 01:52 AM
Building your Tricorder on the weekend, Ken? :)

As a proud papa of twin toddlers, please consider a remote PP sensor!

Ken Gracey
01-30-2012, 02:00 AM
Personal shopper erco, when are you taking me up on the invitation to Parallax?

Can you identify a source for such a "PP" sensor?

erco
01-30-2012, 02:08 AM
Working on it now! Might work better if I drive up. Will advise.

I can identify the smell of PP from 50 yards. Trying to calibrate & standardize sensor data. Will advise!

bill190
01-30-2012, 03:11 AM
Here is a start...

Blood pressure - sphygmometer
Blood Gas Analyzer

Contec Cms50dl Finger Pulse Oximeter Blood Oxygen Spo2 Monitor...
http://www.clinicalguard.com/contec-cms50dl-finger-pulse-oximeter-blood-oxygen-spo2-monitor-p-292.html

Pulse Oximeters
Peak Flow Meters
Doppler Fetal Heartbeat Monitors
ECG/EKG & Patient Monitors
Infant Cuff for CMS-08A Blood Pressure Monitor

What is CMS-08A ?

Pulse oximetry...
http://en.wikipedia.org/wiki/Pulse_oximetry

Fluke Biomedical - See Products...
http://www.flukebiomedical.com

Digital Medical Themometers
http://www.digitalthermometers.net

bill190
01-30-2012, 03:28 AM
Then many moons ago I used to be an electronic technician for a company which manufactured an electronic medical testing machine.

We were tightly regulated by the FDA as I recall? And had to document EVERYTHING done to any circuit board or whatever. It was quite ridiculous.

Anyway electronics in the medical field are "different"! For one notice that the plugs on 120 volt medical machines have "Hospital Grade" plugs...
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=110-403

And these are plugged into "Hospital Grade" outlets...
http://www.mockett.com/furniture-hardware/hospital-grade

And there is a BIG concern around medical facilities that connectors on electrical and electronic gizmos be UNIQUE! That is because a nurse somewhere was able to plug a patient's heart monitor wiring into a 120 volt electrical source by mistake!

Anyway here is a bit on the special regulatory iissues for medical devices. And scroll up that page and it discusses the field of Biomedical Engineering...
http://en.wikipedia.org/wiki/Biomedical_engineering#Regulatory_issues

MacTuxLin
01-30-2012, 03:31 AM
I tend to get good support from TI's distributor here but I'm not sure in the States. You can take a look at some of the solutions for medical:

http://www.ti.com/apps/docs/appcategory.tsp?appId=270&DCMP=TIHeaderTracking&HQS=Other+OT+hdr_a_medical

Phil Pilgrim (PhiPi)
01-30-2012, 03:43 AM
This article by Ray King of TAOS, may prove useful, especially since Parallax already carries the TSL235R mentioned there for pulse oximetry:


http://www.sensorsmag.com/specialty-markets/medical-devices/optoelectronic-sensors-medical-applications-1078

-Phil

rod1963
01-30-2012, 04:02 AM
Like Bill I worked for a medical equipment manufacturer years ago and I am pretty much in sync with him in regards to the issues surrounding the field.

That said check out the following IC houses, they like TI have sections regarding medical equipment.

http://www.freescale.com/webapp/sps/site/overview.jsp?nodeId=02Qt1s5B89
http://healthcare.analog.com/en/consumer-healthcare/segment/health.html

Ken Gracey
01-30-2012, 04:29 AM
This article by Ray King of TAOS, may prove useful, especially since Parallax already carries the TSL235R mentioned there for pulse oximetry:

http://www.sensorsmag.com/specialty-markets/medical-devices/optoelectronic-sensors-medical-applications-1078

-Phil

Perfect. This sounds entirely feasible even though we might have trouble turning the results into some values with known units (calibration?). The Sensors article says "In pulse oximetry, a clip containing 2 LEDs and the light sensor is placed on the patient's finger or earlobe. One LED emits red light (600700 nm) and the other emits light in the near IR (800940 nm) region. The clip is connected by a cable to a microprocessor unit. The LEDs are rapidly and sequentially pulsed, and the detector is synchronized to capture the light from each LED as it is transmitted through the tissue. Backgrounds such as fluid, tissue, and bone are factored out of the measurement by monitoring the steady-state absorption from bone, tissue, venous blood, and arterial blood. During an arterial pulse there is an increase in blood volume, and this time-varying component is used to calculate the absorption of oxy- and deoxy-hemoglobin."

Now, being a business guy like I am, I'm going to need some help to get this accomplished. I need a simple example of how this could work with a Propeller. I'd like to find somebody who can identify the LEDs from Digi-Key, build a simple electronic prototype and develop code example. We don't want to design a piece of medical equipment; we need to provide a simple example of how it could be achieved, but leave the rest of the development effort out of this project.

Note: I'll edit the first post I made to keep track of the specific projects that seem to be what we're looking for.

Ken Gracey
01-30-2012, 04:41 AM
@rod1963, Bill190, MaxTuxLin:

OK, I'll take a look. If you have a specific sensor in mind that could achieve one of the goals I mentioned above (or other general purpose medical use) please let me know. I'm dribbling out bits of information here, but basically these examples will be for demonstration purposes. Raw sensor data output, non-packaged (almost DIY, unless we need to make a simple mechanical solution or PCB) for demonstration is what we're after - not the finished product.

Thank you very much for the background. I'll read the links now.

Phil Pilgrim (PhiPi)
01-30-2012, 04:54 AM
Here's a link to an article that provides more detail about pulse oximetry, along with some formulae:


www.ph.surrey.ac.uk/~phs3ps/surj/v2/li.pdf

-Phil

Peter KG6LSE
01-30-2012, 05:38 AM
http://search.yahoo.com/r/_ylt=A0oGkkLuLSZPgAIAsClXNyoA;_ylu=X3oDMTEyOWhrdXN nBHNlYwNzcgRwb3MDMQRjb2xvA3NrMQR2dGlkA0RGUjVfNzU-/SIG=12irtgmn3/EXP=1327930990/**http%3a//www.sparkfun.com/datasheets/Wireless/General/RMCM01.pdf




You can read a POLAR brand heart rate strap ( like they use on bikers Ect )
Its wireless so there is not a chance that some buggy Rx Chip could back feed Voltage in to some one .
Also as from what I have read , they are the most popular ones out there.



And BTW I own a Lifepak 10 Defib/ECG ( with the nasty cap removed ) so if you need a Real instrument to CAL with I would love to send it to you ..


One of the LONG term projects I want to base on a Prop is a hand held cheap ECG .
the O-scope code that beau made is ideal .. some day Ill get to it.





Peter

OppaErich
01-30-2012, 06:32 AM
Now, being a business guy like I am, I'm going to need some help to get this accomplished. I need a simple example of how this could work with a Propeller. I'd like to find somebody who can identify the LEDs from Digi-Key, build a simple electronic prototype and develop code example. We don't want to design a piece of medical equipment; we need to provide a simple example of how it could be achieved, but leave the rest of the development effort out of this project.
.
http://www.ti.com/lit/an/slaa274a/slaa274a.pdf

ElectricAye
01-31-2012, 05:29 AM
GSR (Galvanic skin response)? Biofeedback devices? Can you give us some idea of what the ultimate goal might be?

John A. Zoidberg
02-01-2012, 11:57 AM
And don't forget - every ECG/EKG electrodes must be also bought and used together with the conductive gel.

Dmashek
02-02-2012, 07:44 AM
As a proud papa of twin toddlers, please consider a remote PP sensor!

Not so sure about the PP sensor, but I think I might have a #2 sensor...

http://www.parallax.com/Store/Sensors/GasSensors/tabid/843/CategoryID/91/List/0/SortField/0/Level/a/ProductID/557/Default.aspx

:tongue:

bill190
02-02-2012, 04:38 PM
From my poking around looking for medical stuff the other day, medical ads are now poping up on websites I visit with "smart advertising". Anyway the following popped up today. Looks interesting...

ProSim Vital Signs Simulators...
http://www.flukebiomedical.com/Biomedical/usen/Events/Promos/ProSim-Landing-Page-PPC.htm

Phil Pilgrim (PhiPi)
02-02-2012, 05:11 PM
A ColorPAL could be used to read test strips, such as pH paper.

-Phil

Invent-O-Doc
02-02-2012, 09:23 PM
@Ken - the frequencies on the LED are very important for pulse oximeters because there are different absorption spectra for oxygenated and deoxygenated hemoglobin.

@Phil - awesome idea on the ColorPAL - now I have use for the one I got as a freebie at UPENE! I can use it to make an automatic urinalysis test strip reader!

Ken Gracey
02-02-2012, 11:21 PM
I'd like to provide a little more information about why we've made this post.

Parallax is in the early stages of planning a medical applications contest for the Defense Department. No promises on it being approved, however. One of our forum members (Invent-O-Doc) might be able to say more about it in a couple months. Until then, I'm collecting up an assortment of medical applications around microcontrollers that meet the requirements I identified above.

We can add ColorPal to this for automated test-strip results.

Sincerely,

Ken Gracey

Beau Schwabe
02-02-2012, 11:24 PM
Ken,

Can employees enter? ....remember? I used to play with that stuff way back when. :-)

Ken Gracey
02-02-2012, 11:27 PM
Ken,

Can employees enter? ....remember? I used to play with that stuff way back when. :-)

Of course I remember your prior work with electronics in prosthetic devices. Nope, you can't play in this one but we'll tap your expertise!

ElectricAye
02-03-2012, 12:54 AM
@Ken - the frequencies on the LED are very important...

By "frequency" I presume you mean that the wavelength (color) of the light is important, not the repetition rate of blinking?

bill190
02-03-2012, 06:16 AM
Parallax is in the early stages of planning a medical applications contest for the Defense Department...

Let's see, thinking out loud...

If that is a DARPA thing, I know they want research to target the future 20 years from now.

And what might be on their mind?

Perhaps mass casualties and "triage"?
http://en.wikipedia.org/wiki/Triage

Maybe the rapid ability to sort patients/casualties with electronic gizmos?

And where might these mass casualties be? War outside of U.S., attack on U.S. which might include a terrorist attack. Biological, chemical, radiation, nuclear.

And what might these terrorists do? And how could electronic gizmos quickly determine if a person was "zapped" by a terrorist weapon?

I should think the more like one of those "no touch" Star Trek medical scanners, the better for the contest?

For that there is a "no touch" thermometer...
http://www.tecnimed.it/thermofocus-forehead-thermometer-H1N1-swine-flu.html

Or an infrared thermometer
http://en.wikipedia.org/wiki/Infrared_thermometer

http://www.amazon.com/Fluke-62-Mini-Infrared-Thermometer/dp/B000MX5Y9C

What all would be clues to a person's medical condition?
Temperature
Look at eye pupils?
Redness in eyes.
Color of lips/skin. (If purple, patient is in trouble.)
Blood pressure.
Pulse.
Blood Oxygen.
Listen to heart.

What would be the symptoms of a chemical attack?
Biological attack?
Radiation attack? (Geiger counter)

What gizmos could measure those things?

Chemical Detection
From the following site...
["Chemical detection equipment (CDE) is an essential component of hazardous material (HAZMAT) emergency response. This equipment should detect the harmful agent, correctly identify the agent, and define the area of exposure. Rapid detection is essential so that responders and military targets can recognize a threat and don protective gear (ideally in < 9 s). It is also important to know the extent of contamination. During several documented chemical attacks, first responder casualties have been vast enough to delay the rescue. During the Tokyo subway sarin attack in 1995, 9% of emergency medical services (EMS) providers suffered the affects of acute exposure. Effective CDE may help prevent these occurrences."]
http://emedicine.medscape.com/article/833933-overview

frank freedman
02-03-2012, 07:31 AM
I'd like to provide a little more information about why we've made this post.

Parallax is in the early stages of planning a medical applications contest for the Defense Department. No promises on it being approved, however. One of our forum members (Invent-O-Doc) might be able to say more about it in a couple months. Until then, I'm collecting up an assortment of medical applications around microcontrollers that meet the requirements I identified above.

We can add ColorPal to this for automated test-strip results.

Sincerely,

Ken Gracey

Ken,

Suggest you drop a note to the tymkrs. One half makes her living using this stuff and can probably give you a fair overview of what is out there, realistic, as well as application specific (contra)indications for potential devices. She can probably provide some insights on risk concerns.

Frank Freedman, CRES