US 12,446,806 B2
Medical photometer and medical photometry system
Yoshinori Ueda, Tokorozawa (JP); Naoki Kobayashi, Tokorozawa (JP); Kazumasa Ito, Tokorozawa (JP); Hideki Fujisaki, Tokorozawa (JP); and Teiji Ukawa, Tokorozawa (JP)
Assigned to NIHON KOHDEN CORPORATION, Tokyo (JP)
Filed by NIHON KOHDEN CORPORATION, Tokyo (JP)
Filed on Mar. 8, 2023, as Appl. No. 18/180,217.
Application 18/180,217 is a division of application No. 16/134,539, filed on Sep. 18, 2018, granted, now 11,642,053.
Claims priority of application No. 2017-180016 (JP), filed on Sep. 20, 2017.
Prior Publication US 2023/0218208 A1, Jul. 13, 2023
Int. Cl. A61B 5/1455 (2006.01); A61B 5/00 (2006.01); A61M 16/00 (2006.01)
CPC A61B 5/14552 (2013.01) [A61B 5/0053 (2013.01); A61M 16/024 (2017.08); A61B 2562/0238 (2013.01); A61B 2562/04 (2013.01); A61M 2202/0208 (2013.01); A61M 2205/3313 (2013.01); A61M 2230/205 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A medical photometer comprising:
a processor; and
a memory that stores instructions executable by the processor,
wherein the medical photometer is configured to acquire:
a first intensity signal corresponding to an intensity of a first light beam which is transmitted through or reflected from tissue of a subject, and which has a first wavelength;
a second intensity signal corresponding to an intensity of a second light beam which is transmitted through or reflected from the tissue, and which has a second wavelength different from the first wavelength;
a third intensity signal corresponding to an intensity of a third light beam which is transmitted through or reflected from the tissue, and which has a third wavelength; and
a fourth intensity signal corresponding to an intensity of a fourth light beam which is transmitted through or reflected from the tissue, and which has a fourth wavelength different from the third wavelength;
wherein the first wavelength and the second wavelength are selected as two wavelengths at each of which an extinction coefficient of blood in a state where an oxygen saturation is 100% has a first value,
the third wavelength and the fourth wavelength are selected as two wavelengths at each of which the extinction coefficient of the blood in a state where the oxygen saturation is 100% has a second value that is different from the first value, and
when the instructions are executed by the processor, the medical photometer
acquires a first signal set including the first intensity signal, second intensity signal, third intensity signal, and fourth intensity signal in a state where the tissue is not pressurized,
acquires a second signal set including the first intensity signal, second intensity signal, third intensity signal, and fourth intensity signal in a state where the tissue is pressurized, and
calculates a venous oxygen saturation in a state where an arterial oxygen saturation of the subject is 100%, based on the first signal set and the second signal set.