Project on Analog Heart Rate Monitor(Cardiotach):

The CaRdiatach is an advanced solid state design useful for experimental or clinical monitoring of the Human heart rate. Experimentalist and clinical Technician can use it as response indicator of anxiety states or relaxation responses to such external stimuli as words, music, odors, visual displays etc. The pulse rate increase is usually quite rapid in response to anxiety-producing stimuli and can be a more accurate indicator of the body's state than verbal responses.

Download Link:
Analog heart reate monitor.Pdf