detecting heartbeat peakpower using iphone sdk?

i want to detect heart rate using iphone sdk does someone knows any method for calculati开发者_StackOverflow中文版ng heartbeat rate?

Fast Fourier Transform is a class of algorithms that can quickly turn samples into an analysis that tells you how prominently ceratin frequencies occur in that sample. For more check out:

1. Wikipedia: FFT
2. Literate program example: Cooley-Tukey FFT

This is relevant to your problem because: (1) heart rate is itself a frequency, and (2) most of the sound that comes through the body that you can measure will be within a certain frequency range. Dropping frequencies outside this range means dropping all or mostly noise.

Good luck!

Well I've seen various implementations. Some of them use the accelerometer to detect minute movements in your arm/hand when you hold the phone, some of them can use the microphone, you could also do a manual 'tap' interface where you tap the screen while checking your own pulse.