Buliding a fingertip pulse device

See "Earpulse.pdf" on the S.E.D/Schematics page of my website. This uses light, but works on fingers just as well as it does on ear lobes.

...Jim Thompson

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You've got it right, Jim. I recently had a work up (I have both AF and COPD). The tech had me walk briskly up and down the hall for a total of a few hundred meters while keeping an eye on a hand held pulse meter. The pickup was an IR (or red?) LED and photo pickup. I can't see a pressure transducer working reliably in that application.

Ted

I read in sci.electronics.design that Pauly_G2002 wrote (in ) about 'Buliding a fingertip pulse device', on Fri, 11 Nov 2005:

Use a ceramic sounder disc. They make excellent low-frequency pressure transducers and are very low-cost.

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Hey, John -

What is a sounder disc?

Thanks, John

Thanks for all the help guy, massive help

Thank you all

Paul

This has been done using a laser that can also read out blood pressure...

Pressure sensing is going to be VERY sensitive to mechanical influences. Don't the commercial ones use optical techniques? mike

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Hi Robert,

Cool, do you have any sources?

Marte

You mean like this one?

You could also try

Good Luck! RIch

Something else of interest: you can measure the oxygen level in the blood by using 2 leds instead of one: 1 red, one IR. The difference between the two (once calibrated) is related to how many red blood cells are carrying oxygen. The hospital ones do this.

-Daniel

anyone have a basic shematic for this to use with an i/o device? im buying an ethernet 24port i/o device soon, and monitoring my pulse and blood oxygen levels would be very nice, also as i suffer sleep apnea i could see how often my oxygen levels drop

ive come across this

looks like it's what i need, now i just need to know more on this oxygen sensor?

On Wed, 16 Nov 2005 13:55:50 +0100, Marte Schwarz wrote: [someone wrote]

This one?

Did that guy get paid by the word? ;-)

Thanks! Rich

Hi,

real things are more difficult than principle schemas looks like ;-) But it is true you need only one Photodiode. But for layman it would be easier to built the device from Circuit Cellular Dec 2004 Issue 173 Page 26 "TSL230R-Based Pulse Oximeter"

Marte

ahh yeah, thanks, i foudn on wiki the wavelengths needed,

should be interesting to build.. how would one calculate it though? it asks for 2 leds, and a photodiode, i thought it would need 2 photodiodes...