info on a heartbeat sensor

[cyberpunk]

hi there!!!!

i would like to ask for the frequency of the human heart beat. i am planning to make a heartbeat sensor for my project on electronics. i would appreciate all the information you can share. thanks!!!

p.s. is it possible to interfaced it to the computer??

hhmm....


thnks!!!
cyberpunk

 

[Klaus]

Well, if you feel your pulse and count it over 10 seconds, divide this by 10, you have your heart frequency in Hz for the precise present time. It changes, of course, depending how much exercise you are doing, how fit you are or how pretty the girl just walking by is :wink:

For a very fit person one could expect around 50 beats per minute to 180 per minute for someone very unfit having just run up a flight of 100 steps ( 0.8 - 3 Hz in this case)

The easiest way to record heartbeat frequency is via electrodes and a sensitive amplifier, just like an ECG machine.
However, sticking electrodes on someones chest is NOT something I recommend unless that person knows exactly what he/she is doing.

There are circuits for that, some times found in electronic magazines. If you think you have the knowledge to build one, make sure it is powered ONLY by BATTERIES, less than 10 V preferably and you use proper medical electrodes ( these are stick on with a connector 'button' on the outside).
You are measuring a few Millivolts at quite low frequencies and the signal is easily swamped by external electrical noises - it is NOT a simple project for school electronics.

The other methods of recording are acoustical and via finger or ear lobe probes that measure light reflected by the pulsing blood under the skin.
Both are way out of home experimenters reach.

Yes, those methods are often interfaced with a computer to record the heart beat frequency changes over time.

So, I suggest you stick to the old and tried method of a finger on the pulse and a stop watch until you have enough electronic experience for safely measuring things on the human body by electronic means - sorry.

Klaus

 

[Klabbis]

Hi!

Maybe you could try this one...

**broken link removed**

 

[kinjalgp]

Normal heart rate above the age of 12 is 72 beats per minute.
For child younger than 12 years it is 120-160 bpm.

Heart rate eventually goes on decreasing with age and finally......it stops.