measure heart pulse with microphone

Hello all,


My final project to complete c++ in university is to write application which will measure heart pulse via standard microphone.Because i am not so familiar with stl and c++ as with c# and .net i would like ask you to help me choose library for capture audio from mic and then filter out background noise signals and detect only the sound of the pulse. As far as i know there are available following libraries:

DirectSound
OpenAL
DirectShow
Windows Core Audio
XAudio2
SFML

What library will be most suitable for this task and will have some nice tutorials ?
OS MS Windows, IDE VS2010.

I would be grateful for any tips.


Thanks,
Patryk

Choose the dedicated cross platfom, independant ones over any microsoft job. The library should feature access to good quality noise filter algorithms as I see that as the most challenging part of the task. You might also consider SDL though am not sure on the capture aspects, it certainly allows media device control. There may well be an extension library written for it specifically audio capture.

I have never done anything like this myself but I would imagine a GUI will be required so you can indicate by selecting a portion of your sample that this is noise, this is heartbeat etc. Unless you recorded five seconds say noise, five seconds noise with heartbeat input also. and had those first five seconds coded to represent the noise sample

thre is an open Source project called audacity you may wish to investigate the code access / dev options there

Thanks Rogster for tip :)

there's also openAL.

i would forego building a complicated gui editor.

i would detect the heartbeats algorithmically. the heartbeats should be significantly louder than the background noise, so you can infer when a heartbeat occurs when the RMS average of the signal exceeds some threshold.

Heartbeats can be detected with cepstral analysis

that's awesome.

does this mean recursive FT is a possible way to get the eigenfrequencies of a periodic function? o_O

Quote:

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Originally Posted by m37h0d

that's awesome.

does this mean recursive FT is a possible way to get the eigenfrequencies of a periodic function? o_O

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Maybe. Some adaptation of PCA might be more suitable to that, though.

Just go to your microphone settings and turn the sensitivity up to... at least 9001%. And there you go.