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Heartbeat Monitor -Help reqd!

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UroBoros

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piezo heartbeat

Hello
My next project happens to be a Heartbeat monitor.I am looking for the sensors.What I have in mind is something like a piezo electric transducer normally used in such medical equipments.I have seen it but not able to locate that piece.Can anybody suggest a possible sourse,if possible in India?
That transducer picks up heartbeating sound when placed close to chest and then that audio peaks are converted into pulsus and counted.So what are the suggessions for a possible front end amplifier for that piezo sensor? The audio has to be amplified filtered and should be audible throutgh a speaker. or can you suggest the best possible sensor for this purpose? the stage have to be very sensitive because such commercial products are and should be able to detect the heart beat of foetus inside the utreus.

Picstudent
 

Mr_Programmer

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My first approch would be something like this:
A membrane like a stetoskope and a pressure transducer (Analog Devices).
My suggestion only...


:)
 

Ricardo

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I don't know if you are allowed to, but I think the heart beat corresponds directly with the pulse you detect in the wrist or finger. There may be a slight delay, but at least for a normal person with no arrythmias, I would think this would be the case. If you are struggling to find components, perhaps you could try shining an LED in at the top of the finger and picking up a signal with a photodiode at the bottom. The light should shine on the photodiode until blood passes through in which case the light should be reflected, and the hence the intensity of light reaching the photodiode should be less.

I don't know if you may do this though, because I don't know exactly what you want to build. However, modern heartbeat or pulse monitors work of this principle I think... :)
 

Cluricaun

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Hi

Here is link with hopefully some usefull information.



Cl
 

mami_hacky

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I have an abnormal idea, I thinked about it, it is possible. :D using a good camera, you can detect the changes in the wrist. then you can obtain the number of heart bits. :D
 

traxonja

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Ricardo said:
I don't know if you are allowed to, but I think the heart beat corresponds directly with the pulse you detect in the wrist or finger. There may be a slight delay, but at least for a normal person with no arrythmias, I would think this would be the case. If you are struggling to find components, perhaps you could try shining an LED in at the top of the finger and picking up a signal with a photodiode at the bottom. The light should shine on the photodiode until blood passes through in which case the light should be reflected, and the hence the intensity of light reaching the photodiode should be less.

I don't know if you may do this though, because I don't know exactly what you want to build. However, modern heartbeat or pulse monitors work of this principle I think... :)

Yes they work on this principle. They use infrared transmitter and receiver. I have one of these monitors myself.
 

UroBoros

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Ricardo said:
I don't know if you are allowed to, but I think the heart beat corresponds directly with the pulse you detect in the wrist or finger. There may be a slight delay, but at least for a normal person with no arrythmias, I would think this would be the case. If you are struggling to find components, perhaps you could try shining an LED in at the top of the finger and picking up a signal with a photodiode at the bottom. The light should shine on the photodiode until blood passes through in which case the light should be reflected, and the hence the intensity of light reaching the photodiode should be less.

I don't know if you may do this though, because I don't know exactly what you want to build. However, modern heartbeat or pulse monitors work of this principle I think... :)

Hai
Thanks everybody.I have recently tried that LED method.It is working .Not satisfactory to my expectations.the problem was the amplifier I used to amplify that light variation was not of good performence.The pulse output was not steady for all fingers and as a result the count seems to be erratic.
But this time I want to make that hertbeat audible through an audio amplifier also.That is why I am looking for a audio piezo sensor to generate that pulse.
ultrasound Dopler heartbeat monitors usually uses a dual sensor assembly.One piezo transmits an ultrasound signal ,the other piezo picks up the reflections and from that signal the audio is derived as well as pulseus.Any suggessions for implimenting this?
 

traxonja

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Try putting the sensor on your ear, on the place where earings usually go, it should work great there.
 

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