Patent ID: 8855384

Claim:
A method for continuous cardiac pulse rate estimation from video images captured of a subject of interest being monitored for cardiac function, the method comprising: receiving a time-series signal of a subject of interest being monitored for cardiac function; overlaying said received time-series signal with a sliding window, said sliding window defining segments of said received time-series signal for processing, each successive position of said sliding window defining a next segment of said time-series signal for processing; defining a seed reference signal with a frequency range that approximates a frequency range of said subject's cardiac pulse; and processing segments of said received time-series signal by repeatedly: performing constrained source separation (cICA) on said signal segment using said seed reference signal to obtain an estimated source signal, said cICA converging on an occurrence of one of: an error between said estimated source signal and said seed reference signal being less than a threshold, and a pre-defined number of iterations having occurred; A) in response to said error being less than said threshold: determining a frequency of said estimated source signal as said subject's estimated cardiac pulse rate for this time-series signal segment; using said estimated source signal as said seed reference signal for processing a next time-series signal segment on a next iteration; and shifting said sliding window to define a next segment of said time-series signal, said next segment at least partially overlapping a previous time-series signal segment defined by said window on a last iteration; and B) in response to said pre-defined number of iterations having occurred, performing one of: updating said seed reference signal by changing any of: a frequency, an amplitude, a phase, and a waveform of said seed reference signal, and using said updated reference signal as said seed reference signal to re-process said time-series signal segment; and selecting an estimated source signal obtained from having processed a previous time-series signal segment and using said selected estimated source signal as said seed reference signal to re-process said time-series signal segment.