US 12,064,270 B2
Apparatus for blood pressure estimation using photoplethysmography and contact pressure
Jae Min Kang, Seoul (KR); Yong Joo Kwon, Yongin-si (KR); Seung Woo Noh, Seongnam-si (KR); and Sang Yun Park, Hwaseong-si (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Dec. 22, 2021, as Appl. No. 17/559,721.
Application 17/559,721 is a division of application No. 16/164,076, filed on Oct. 18, 2018, granted, now 11,241,197.
Claims priority of application No. 10-2017-0135384 (KR), filed on Oct. 18, 2017; and application No. 10-2018-0111192 (KR), filed on Sep. 18, 2018.
Prior Publication US 2022/0110535 A1, Apr. 14, 2022
Int. Cl. A61B 5/00 (2006.01); A61B 5/02 (2006.01); A61B 5/021 (2006.01); A61B 5/022 (2006.01); A61B 5/024 (2006.01); A61B 5/026 (2006.01); A61B 5/029 (2006.01); A61B 5/145 (2006.01); G16H 10/00 (2018.01); G16H 40/63 (2018.01); G16H 50/20 (2018.01); G16H 50/50 (2018.01)
CPC A61B 5/7278 (2013.01) [A61B 5/02007 (2013.01); A61B 5/02108 (2013.01); A61B 5/02116 (2013.01); A61B 5/02125 (2013.01); A61B 5/022 (2013.01); A61B 5/0261 (2013.01); A61B 5/029 (2013.01); A61B 5/14532 (2013.01); A61B 5/681 (2013.01); A61B 5/6831 (2013.01); A61B 5/6843 (2013.01); G16H 10/00 (2018.01); G16H 40/63 (2018.01); G16H 50/20 (2018.01); G16H 50/50 (2018.01); A61B 5/02416 (2013.01); A61B 2562/0219 (2013.01); A61B 2562/0247 (2013.01); A61B 2562/0252 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A wearable device, comprising:
a main body; and
a strap connected to the main body and formed to be flexible and to be wrapped around an object,
wherein the main body comprises:
a photoplethysmography (PPG) sensor configured to measure, from the object, a first pulse wave signal by using a first light of a first wavelength, and a second pulse wave signal by using a second light of a second wavelength, the first wavelength being different from the second wavelength;
a force sensor configured to measure a contact pressure between the object and the PPG sensor; and
a processor configured to:
obtain a cardiovascular characteristic value by calculating a change rate of the contact pressure with respect to time between a first point in time corresponding to a valley point of a direct current (DC) component signal of the first pulse wave signal and a second point in time corresponding to a valley point of a DC component signal of the second wave signal, during a contact pressure transition period in which the contact pressure continuously increases or continuously decreases; and
estimate blood pressure based on the cardiovascular characteristic value.