Hi The first layer to the onion is that the ECG signal is a bit complex. There's also likely to be a bit of this and that on it.
How about taking the output of the instrument amp into the A/D port on a cheap PIC? That would let you do some AGC and dynamic filtering. At even a modest sample rate (say 10 KHz) the heart rate could be worked out in software. I think I'd run a PWM out and drive an analog meter with it. The nice thing about keeping it simple is being able to run it off a 9 volt battery. That takes care of a *lot* of issues. Bob On Feb 19, 2013, at 7:58 PM, Paul Cianciolo <[email protected]> wrote: > Hello Folks, > > I am working on a project intended to convert an analog ECG signal to a > voltage proportional the heart rate, > The actual electrodes instrumentation amp is pretty much working fine so no > worries there. > > The problem is, and here is where the relationship to time nut comes in. > The signal output from the instrumentation amplifiers will be at a rate of > approx 60 BPM or pulses, up to perhaps 90 BPM. > > The purpose of this apparatus is to print a rolling chart on the screen of a > computer of heart BPM and then try different technicues of meditaion and > calming technicues to lower my heart rate for short periods of time. > > My first tthought was a frequency to voltage IC like the LM2907 or the 2917 > but I get the impresiion from the data sheets that these chips will not work > at these very low 1 Hz applications, > > Then I thought maybe one of the frequecy counters could be configured as a > rate meter and output a proportional voltage I need. > No luck here either. > Te latter components seem tobe somewhat time relatedand that is why I posted > here.\\ > > Thank you for reading this and for any suggestions you folks might offer. > > PaulC > W1VLF > > > > > > > > > > 1Hxz > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
