First, you must make sure what your employer mean by a heart signal. Chances are, he means an electrocardiogram (ECG), which is a representation of the potential differences between various sites in the body that reflects the changes in magnitude and direction of the electric field produced as an excitation spread over the heart.
There are many web sites with information about ECG and other biomedical signals. For example, the following is a simple tutorial about ECG:
ECG Tutorial
http://cal.nbc.upenn.edu/lgcardiac/ecg_tutorial/introduction.htm
There are several parameters that define a ECG signal: the PQRTS deflections referred as "waves", the PR and QT intervals, the distance between two waves (segments), R-R interval (period of the beat cycle) and amplitudes (pot
ential usually are less than 1mV)
Because ECG are periodical signals, you can model it by using Fourier Series. The calculation of the necessary parameters to do this can be tedious, though.
Recently, I posted an answer that include a file which include a real ECG signal. You can found it at:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000A6260000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0
Best regards;
Enrique
www.vartortech.com
