US 12,268,486 B2
Reflective photoplethysmogram sensor and biological information measurement apparatus
Shusaku Kon, Hino (JP); Ryo Nakabayashi, Hachioji (JP); and Kosuke Ando, Akishima (JP)
Assigned to KONICA MINOLTA, INC., Tokyo (JP)
Filed by Konica Minolta, Inc., Tokyo (JP)
Filed on Sep. 30, 2021, as Appl. No. 17/490,699.
Claims priority of application No. 2020-167377 (JP), filed on Oct. 2, 2020.
Prior Publication US 2022/0104718 A1, Apr. 7, 2022
Int. Cl. A61B 5/024 (2006.01)
CPC A61B 5/02416 (2013.01) 9 Claims
OG exemplary drawing
 
1. A biological information measurement apparatus comprising a controller and a reflective photoplethysmogram sensor, the reflective photoplethysmogram sensor comprising: a planar first light emitting element and a planar first light receiving element, wherein
the first light emitting element and the first light receiving element do not face each other in an up/down direction, and
a minimum distance h (mm) between at least a pair of the first light emitting element and the first light receiving element satisfies the following expression (1)
(t×0.7)2≤h≤(t×1.3)2  Expression (1):
where the minimum distance between the first light emitting element and the first light receiving element is h (mm), and a thickness of skin (epidermis+dermis) of a human body is t (mm), and the thickness is within the range 0.1 to 4 mm,
the first light emitting element or the first light receiving element comprises an arc shape,
the reflective photoplethysmogram sensor further comprises a second light emitting element or a second light receiving element so,
when the second light emitting element is provided, each of the first and second light emitting elements is arranged in the arc shape with a center point of the first light receiving element as a center, the controller is configured to subtract data obtained based on light emitted from the second light emitting element that does not satisfy the Expression (1) with the first light receiving element from data obtained based on light emitted from the first light emitting element that sataisfies the Expression (1) to remove a noise, and
when the second light receiving elements are provided, each of the first and second light receiving elements is arranged in the arc shape with a center point of the first light emitting element as a center, and the controller is configured to subtract data obtained based on light received from the second light receiving element that does not satisfy the Expression (1) with the first light emitting element from data obtained based on light received from the first light receiving element that satisfies the Expression (1) to remove the noise.