US Patent 7797038 Heart rate monitor with cross talk reduction

A heart rate monitor determines a heart rate for a primary subject by reducing noise and cross-talk from unwanted signal transmission sources. A set of pulse peaks having about the same amplitude and an amplitude greater than any other set of peaks are processed to determine a subject's heart rate, while data having an amplitude below that of the set of peaks is ignored. To retrieve enough data to determine a peak amplitude, the signal having heart rate information is sampled at a frequency higher than a normal sampling frequency. In some embodiments, if no data is received for a set time period which is in or above the range, the threshold resets to zero under an assumption that the primary subject is no longer within transmitting range.