Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!elroy!cit-vax!wetter
From: wetter@cit-vax.Caltech.Edu (Pierce T. Wetter)
Newsgroups: sci.electronics
Subject: Re: Wanted: Heart Rate Sensor
Message-ID: <8411@cit-vax.Caltech.Edu>
Date: 25 Oct 88 23:20:49 GMT
References: <57916DMC109@PSUVM>
Organization: California Institute of Technology
Lines: 26

in article <57916DMC109@PSUVM>, DMC109@PSUVM.BITNET says:
> 
> I remember seeing plans for a pulse monitor a while back in some magazine
> (Popular Electronics, Radio Electronics, etc.  I can't remember.)
> What I remember is a sensor that clipped on your finger.  Does anyone
> have plans for anything along these lines?
> Many thanks in advance.
> 
> Frank
  
  Your skin is invisible in the IR range. Your blood is opaque in that
range. All you need for a sensor is a IR led on one side and a IR 
photo transistor on the other side.

  Now, I've never actually built one of these, but I'm going to. Someone
is paying me to build a lie detector.

 The correct range is approx. 4000 to 7000 A I think.

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