US 9,808,162 B2
Pulse wave sensor and semiconductor module
Yoshitsugu Uedaira, Kyoto (JP); and Koji Saito, Kyoto (JP)
Assigned to Rohm Co., Ltd., Kyoto (JP)
Filed by Rohm Co., Ltd., Kyoto (JP)
Filed on Oct. 22, 2015, as Appl. No. 14/919,861.
Claims priority of application No. 2014-216334 (JP), filed on Oct. 23, 2014.
Prior Publication US 2016/0113585 A1, Apr. 28, 2016
Int. Cl. A61B 5/02 (2006.01); A61B 5/024 (2006.01); G01J 1/44 (2006.01); G01J 1/42 (2006.01); A61B 5/00 (2006.01)
CPC A61B 5/02427 (2013.01) [A61B 5/7214 (2013.01); G01J 1/4228 (2013.01); G01J 1/44 (2013.01); A61B 5/7257 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A pulse wave sensor comprising:
a light emitting unit configured to emit light including green light and red light to a living body;
a first light receiving unit configured to convert, into a first electrical signal, the green light included in light emitted from said light emitting unit and reflected within said living body;
a second light receiving unit configured to convert, into a second electrical signal, the red light included in the light emitted from said light emitting unit and reflected within said living body; and
an arithmetic control unit configured to detect information related to a pulse wave in said living body based on a level difference between said first electrical signal and said second electrical signal,
said arithmetic control unit including:
a subtracter configured to generate a third electrical signal showing the level difference between said first electrical signal and said second electrical signal,
a first frequency component analysis unit configured to obtain a frequency spectrum of said first electrical signal, and
a second frequency component analysis unit configured to obtain a frequency spectrum of said third electrical signal, and
wherein the arithmetic control unit is configured to compare the frequency spectrum of said first electrical signal and the frequency spectrum of said third electrical signal to obtain the information related to the pulse wave in said living body based on a comparison result.