Signal processing for a non-invasive microwave heart rate estimator

A number of processing methods for estimating heart rate from low-level, remote microwave signals have been developed. From the return of a microwave signal reflected off the chest, a decision is made whether a heart beat signal is present, and if it is, an estimation of the heart rate is made. To achieve this, the return analog signal is amplified, filtered, sampled, and quantized. The resultant digital signal is passed through a nonlinear filter used to emphasize the impulsive character of the heart. Detection is done at this point using partial correlation and pattern recognition.<>