Patent ID: 9307908
Filing Date: 2016-04-12
CPC Classification: A61B

Claim Text:
1. A system for measuring psychological stress, the system comprising: a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device includes a processor; and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the processor to: determine R-R intervals from an electrocardiogram (ECG) to calculate a standard deviation of the R-R intervals (SDNN); determine a stress feature (SF) using the SDNN by calculating a mean heart rate (HR) from the ECG within a predetermined time period and by utilizing an algorithm SF =HR+α*SDNN, wherein α is a predetermined negative variable that allows for combining HR and SDNN; in response to reaching a threshold, perform adaptation to update a probability mass function (PMF); and determine a stress level (SL) using the SF and the updated PMF to measure the psychological stress.