US 12,465,223 B2
Dual-altitude-based non-invasive blood pressure monitoring
Yi He, San Diego, CA (US); and Bo Pi, San Diego, CA (US)
Assigned to SHENZHEN GOODIX TECHNOLOGY CO., LTD., Shenzhen (CN)
Filed by Shenzhen Goodix Technology Co., Ltd., Shenzhen (CN)
Filed on Jun. 28, 2022, as Appl. No. 17/851,051.
Prior Publication US 2023/0414115 A1, Dec. 28, 2023
Int. Cl. A61B 5/021 (2006.01); A61B 5/024 (2006.01)
CPC A61B 5/02108 (2013.01) [A61B 5/02416 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A system for non-invasive measurement of blood pressure of a user, the system comprising:
a sensor head comprising:
an illumination subsystem to project illumination through a body part that includes at least one elastic blood circulatory pathway through which flows a continuously changing volume of blood; and
an optical detection subsystem to generate a detection output signal based on detecting changing amounts of received portions of the illumination passing through the body part corresponding to the continuously changing volume of blood; and
a control processor to generate a blood pressure measurement (BPM) output by:
in a first measurement time window with the body part held positioned at a first altitude relative to the user's heart, directing the illumination subsystem to project the illumination through the body part, directing the optical detection subsystem to generate the detection output signal, and computing a first mean intensity of the detection output signal over the first measurement time window;
in a second measurement time window with the body part held positioned at a second altitude relative to the user's heart, directing the illumination subsystem to project the illumination through the body part, directing the optical detection subsystem to generate the detection output signal, and computing a second mean intensity of the detection output signal over the second measurement time window; and
computing the BPM output to indicate a slope-calibrated mean BPM as a function of the first mean intensity, the second mean intensity, and a slope-calibration factor,
wherein the optical detection subsystem comprises a plurality of photodetectors to detect the received portions of the illumination passing through the body part, at least a first photodetector of the plurality of photodetectors configured to output an illumination stability signal indicating a quality of the received portions of the illumination, and at least a second photodetector of the plurality of photodetectors configured to output an illumination gradient signal indicating an intensity of the received portions of the illumination; and
the optical detection subsystem is to generate the detection output signal based on illumination gradient signal as normalized by the illumination stability signal.