piezo electric sensors

I am in need of a piezo electric sensor.. my aim is to measure heart beat using it.. I tried of obtaining heart beat using the sensor obtained from buzzer, butit does'nt worked satisfactorily......so can anyone please tell me the electronic components or equipments from which I can get piezo electric sensor with medium sensitivity...

Thanks in advance.....

Why dont you use Infrared LED for measuring heart beat?

Sorry I dont know how to use IR leds to measure heart beat.. Can you please explain in detail...

Counting heart beat with the help of infrared transmitter and receiver is not proper way. but it works fine if you are working on a student project. there is lot of information available on google regarding heart beat sensing through infrared sensors. You may surf internet. then if you dont find any good info you may contact me. i will help you. i have done such a project.

Hi
you can use a capacitance microphone and a battery and simple earphone and simple amplifier and a small pipe!
for simple amplifier you can use lm386 ...

best wishes
Green tree

Hi Jis,

This may helps you..

https://www.edaboard.com/threads/238531/

A piezo transducer (not a beeper or buzzer that has a built-in oscillator) can pickup vibration and high frequency sounds. But a heartbeat produces no vibration and produces a very low frequency sound.
An electret microphone (not a capacitance mic that is similar) mounted on a large jar lid picks up heartbeats very well. The lid keeps the mic from being smothered by skin and blocks some background sounds.

hi
I tried a ckt using high intensity led and ldr... Iam able to see the pulses via a led..But when i gave it as clk to pic its not detecting the clk.. its below threshold level and i tried of amplifying but it does'nt worked... So can you pls give me the ckt which you have used..

Regards,
Jis

---------- Post added at 23:24 ---------- Previous post was at 23:19 ----------

I already tried to get pulse rate by using electret microphone and an amplifier...and i havent got good result.. Can you pls explain why you used ear phone and pipe...It would really helpful if you post the ckt

Regards,
Jis

---------- Post added at 23:33 ---------- Previous post was at 23:24 ----------

I tried using electret mic but have'nt got good variations.....
the ckt which i used is as follows :-
* A 4.7k resistor was put between Vcc and mic , & between mic ang gnd
* a coupling capacitor of 0.1uf was used to connect the mic's o/p to amp (ic lm358).

should i do anything else?waiting for your reply

Regards,
jis

You did not show a complete schematic so I don't know what you did wrong.
Here is an electronic stethoscope that plays a heartbeat into over-the-ears headphones and blinks an LED:

Thanks a lot

hi, can you please show me the circuit for heartbeat sensor?
thank you..

greentree said:

Hi
you can use a capacitance microphone and a battery and simple earphone and simple amplifier and a small pipe!
for simple amplifier you can use lm386 ...

best wishes
Green tree

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