Medical photometer and medical photometry system

Patent metadata

Field	Value
Publication number	US-12446806-B2
Application number	US-202318180217-A
Country	US
Kind code	B2
Filing date	Mar 8, 2023
Priority date	Sep 20, 2017
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A medical photometer includes a signal producing section that produces a first control signal to emit a first light having a first wavelength, a second control signal to emit a second light having a second wavelength, a third control signal to emit a third light having a third wavelength, and a fourth control signal to emit a fourth light having a fourth wavelength, a signal acquiring section that acquires a first to fourth intensity signals, a processor, and a memory that stores instructions. In the medical photometer, the first wavelength and the second wavelength are selected as two wavelengths at each of which an extinction coefficient of blood is 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 is a second value which is different from the first value.

First claim

What is claimed is:

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.

2. The medical photometer according to claim 1 , wherein
the first wavelength is 660 nm,
the second wavelength is 700 nm,
the third wavelength is 645 nm, and
the fourth wavelength is 730 nm.

3. The medical photometer according to claim 1 , wherein the medical photometer is configured to produce a control signal which controls an operation of an oxygen administration apparatus for administrating oxygen to the subject, and,
when the instructions are executed by the processor, the control signal is produced, based on the calculated venous oxygen saturation.

4. A medical photometry system comprising:
a first light emitter that emits a first light beam having a first wavelength;
a second light emitter that emits a second light beam having a second wavelength different from the first wavelength;
a third light emitter that emits a third light beam having a third wavelength;
a fourth light emitter that emits a fourth light beam having a fourth wavelength different from the third wavelength;
a light detector that outputs a first intensity signal corresponding to an intensity of the first light beam that is transmitted through or reflected from tissue of a subject, a second intensity signal corresponding to an intensity of the second light beam that is transmitted through or reflected from the tissue, a third intensity signal corresponding to an intensity of the third light beam that is transmitted through or reflected from the tissue, and a fourth intensity signal corresponding to an intensity of the fourth light beam that is transmitted through or reflected from the tissue; and
a medical photometer to which the first light emitter, the second light emitter, the third light emitter, the fourth light emitter, and the light detector are connected with wire or wireless connection,
wherein the medical photometer includes:
a processor; and
a memory that stores instructions executable by the processor,

wherein the medical photometer is configured to acquire the first intensity signal, the second intensity signal, the third intensity signal, and the fourth intensity signal;
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.

5. The medical photometry system according to claim 4 , wherein
the first wavelength is 660 nm,
the second wavelength is 700 nm,
the third wavelength is 645 nm, and
the fourth wavelength is 730 nm.

6. The medical photometry system according to claim 4 , wherein the medical photometer is configured to produce a control signal which controls an operation of an oxygen administration apparatus for administrating oxygen to the subject, and,
when the instructions are executed by the processor, the control signal is produced, based on the calculated venous oxygen saturation.

Assignees

• Nihon Kohden Corp

Inventors

• Ueda Yoshinori
• Kobayashi Naoki
• Ito Kazumasa
• Fujisaki Hideki
• Ukawa Teiji

Classifications

• A61B2562/04

  Arrangements of multiple sensors of the same type · CPC title

• A61B2562/0238

  Optical sensor arrangements for performing transmission measurements on body tissue · CPC title

• A61M2205/3313

  used specific wavelengths · CPC title

• A61M2202/0208

  Oxygen · CPC title

• A61M2230/205

  partial oxygen pressure (P-O2) · CPC title