Method and system for contactless vital sign monitoring via calculating displacement signal by applying adaptive nonlinear least squares method

Abstract

A method for vital sign monitoring using a radar sensor system that includes a transmitter, a receiver, and processing device. The transmitter irradiates a body region of a person with radar radiation, the receiver generates a receiver signal from reflected radiation from the body region, and the processing device generates, for each of a plurality of processing windows, a displacement signal based on the receiver signal. The displacement signal characterizes a body motion having, as oscillating motions, a breathing motion and a heartbeat motion, and calculates an estimated fundamental frequency for at least one oscillating motion. The processing device applies an adaptive Nonlinear Least Squares method to calculate a plurality of frequency estimates, each of which corresponds to one of a plurality of harmonics of a first oscillating motion, wherein the processing device calculates a first estimated fundamental frequency for the first oscillating motion based on the frequency estimates.