A Digital Signal Processor for Doppler Radar Sensing of Vital Signs
01 September 2002
A digital signal processor for Doppler radar sensing of vital signs is described. A voltage waveform signal containing respiration and heartbeat signatures is low-pass filtered (0.7 Hz)for the respiration rate and band-pass filtered (1.0-3.0 Hz) for the heart rate.
Using the auto-correlation function, the rate per minute for each of these signals is calculated. To make the processor more robust, several additional signal processing techniques are applied. One of these techniques is a method of pitch extraction called center clipping, commonly used for audio signals. The processor is programmed in LabVIEW.