US Patent 10390762 Physiological metric estimation rise and fall limiting

Methods and apparatus disclosed herein use a filtering technique to improve the accuracy of the results achieved when processing data provided by a physiological sensor. The disclosed filtering technique corrects many of the accuracy problems associated with physiological sensors, particularly PPG sensors. Broadly, the filtering technique adjusts a current filtered estimate of a physiological metric as a function of a rate limit based on a comparison between an instantaneous estimate of the physiological metric and the current filtered estimate.