An improved heart rate monitor is provided that can detect and distinguish a heartbeat from an otherwise contaminated system with noise components potentially larger than the signal of interest. Embodiments of the inventive monitor have an amplification system that eliminates large noise components so as not to saturate the system during detection of a desired low amplitude signal. In embodiments the elimination of noise components is accomplished through wavelet decomposition, and the removal of undesired components including interference components during adaptive gain control (AGC), in addition to hunting algorithms which minimize the error with techniques such as neural network least mean squares type back propagation algorithms.
