US 9,808,163 B2
Method and apparatus for heart rate monitoring
Steven T. Dunbar, Lafayette, CO (US); and Sourabh Ravindran, Dallas, TX (US)
Filed by Steven T. Dunbar, Lafayette, CO (US); and Sourabh Ravindran, Dallas, TX (US)
Filed on Apr. 27, 2010, as Appl. No. 12/768,488.
Claims priority of provisional application 61/174,291, filed on Apr. 30, 2009.
Prior Publication US 2010/0280402 A1, Nov. 4, 2010
Int. Cl. A61B 5/04 (2006.01); A61B 5/0245 (2006.01); A61B 5/00 (2006.01)
CPC A61B 5/0245 (2013.01) [A61B 5/7203 (2013.01); A61B 5/7221 (2013.01); A61B 5/7246 (2013.01)] 8 Claims
OG exemplary drawing
1. A method for monitoring a heart rate, comprising:
receiving ECG (electrocardiogram) signals;
converting the ECG signals to a digital heart monitoring signal as a sequence of heart monitoring samples;
receiving at a processor the digital heart monitoring signal;
dividing the digital heart monitoring signal into successive overlapping frames, each with an odd number N of samples, and each frame encompassing multiple heart beats;
setting amplitude and distance parameters, the distance parameter corresponding to a minimum distance between valid heart beat peaks based on a current estimate of heart rate;
processing a current frame to determine a current heart rate using the amplitude and distance parameters by:
generating folded correlation values based on a folded correlation of (N−1)/2 samples preceding a center sample, and time-reversed (N−1)/2 samples following the center sample;
identifying a number of peaks using the folded correlation values, including
removing false peaks using the amplitude parameter, and
removing false peaks using the distance parameter corresponding to a length of time between valid heart beat peaks;
determining the current heart rate based on the identified peaks using at least the distance parameter;
selectively updating at least the distance parameter in preparation for processing a next frame; and
generating heart rate signals corresponding to the determined current heart rate.