US 12,268,485 B2
Photoplethysmogram circuit, biological characteristics detection device and biological characteristics detection method
Si Herng Ng, Guangdong (CN); and Wen-Chi Wang, Guangdong (CN)
Assigned to SHENZHEN GOODIX TECHNOLOGY CO., LTD., Guangdong (CN)
Filed by SHENZHEN GOODIX TECHNOLOGY CO., LTD., Guangdong (CN)
Filed on Dec. 15, 2020, as Appl. No. 17/122,983.
Application 17/122,983 is a continuation of application No. PCT/CN2019/121910, filed on Nov. 29, 2019.
Prior Publication US 2021/0161413 A1, Jun. 3, 2021
Int. Cl. A61B 5/024 (2006.01); A61B 5/00 (2006.01); A61B 5/307 (2021.01)
CPC A61B 5/02416 (2013.01) [A61B 5/307 (2021.01); A61B 5/6802 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A photoplethysmogram (PPG) circuit, configured to control a light source and N photoelectric converters to sense biological characteristics of an object under test, wherein N is an integer greater than 1, and the PPG circuit comprises:
a transmitting channel, configured to control the light source to perform light emitting operations during pulse repetition cycles;
K receiving channels, wherein K is an integer greater than 1, and the N photoelectric converters are divided into K sets of photoelectric converter sets, the K receiving channels respectively correspond to the K sets of photoelectric converter sets; and
a controller, configured to control the PPG circuit to operate in a partial sampling phase or a full sampling phase, when the controller controls the PPG circuit to operate in the partial sampling phase, the controller activates J receiving channels of the K receiving channels as current receiving channels and activates J sets of photoelectric converter sets of the K sets of photoelectric converter sets corresponding to the J receiving channels to sense received light for performing the sampling operation, so as to generate J biological characteristics sampling results during each of the pulse repetition cycles, wherein J is smaller than K; and when the controller controls the PPG circuit to operate in the full sampling phase, the controller activates all receiving channels of the K receiving channels and activates all of the K sets of photoelectric converter sets to sense the received light for performing the sampling operation, so as to generate K biological characteristics sampling results during each of the pulse repetition cycles, and from the K receiving channels, re-select J receiving channels as the current receiving channels to be activated during the next partial sampling phase according to the K biological characteristics sampling results generated during each of the pulse repetition cycles of the full sampling phases,
wherein the controller is configured to control the PPG circuit to enter the full sampling phase from the partial sampling phase every preset update interval, so as to periodically generate the J biological characteristics sampling results and the K biological characteristics sampling results,
wherein J is 1, and a duration of the full sampling phase comprises M pulse repetition cycles, wherein M is an integer greater than 1,
wherein the controller determines the current receiving channels according to M*K biological characteristics sampling results,
wherein the controller generates K quality factors corresponding to the K receiving channels according to the M*K biological characteristics sampling results and determines the current receiving channels according to the K quality factors,
wherein the controller generates the K quality factors according to a signal intensity of the M*K biological characteristics sampling results at a specific frequency band.