Concentration measurement device and concentration measurement method

• US 10,405,783 B2
• Filed: 06/01/2017
• Issued: 09/10/2019
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Ozaki, Takeo, Suzuki, Susumu
• Primary Examiner(s): Winakur, Eric F
• Assistant Examiner(s): Liu, Chu Chuan
• Application Number:
  US15/611,142
• Publication Number:
  US 20170258381A1
• Time in Patent Office: 831 Days
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: G01N 2021/3144 for oxymetry
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G06F 17/17 Function evaluation by approximation methods, e.g. inter- or extrapolation, smoothing, least mean square method G06F17/18 takes precedence ; interpolation for numerical control G05B19/18

Abstract

A concentration measurement apparatus includes a probe, having a light incidence section making measurement light incident on the head and a light detection section detecting the measurement light that has propagated through the interior of the head, and a CPU determining temporal relative change amounts of oxygenated hemoglobin concentration and deoxygenated hemoglobin concentration and determining a correlation coefficient of the relative change amounts and a polarity of a slope of a regression line.

Claims

1. An apparatus for measuring temporal relative change amounts of oxygenated hemoglobin concentration and deoxygenated hemoglobin concentration, that vary due to repetition of chest compression, in a head, comprising:

a light source configured to output measurement light;

a light detector configured to detect the measurement light that has propagated through the interior of the head and generate a detection signal in accordance with the intensity of the detected measurement light; and

a processor that is electrically coupled to the light detector and programmed to;

determine, based on the detection signal, a temporal relative change amount of the oxygenated hemoglobin concentration and a temporal relative change amount of the deoxygenated hemoglobin concentration that vary due to repetition of chest compression,

determine a phase shift between the temporal relative change amount of the oxygenated hemoglobin concentration and the temporal relative change amount of the deoxygenated hemoglobin concentration, and

evaluate the chest compression based on the phase shift.

2. The apparatus according to claim 1, wherein the processor is programmed to evaluate occurrence of reverse direction blood transmission from the vena cava to the head in the chest compression based on the phase shift.

3. The apparatus according to claim 1, wherein the processor is programmed to apply a filtering process to the temporal relative change amounts of the oxygenated hemoglobin concentration and the deoxygenated hemoglobin concentration to remove frequency components less than a predetermined frequency for extracting temporal variation components of the oxygenated hemoglobin concentration and the deoxygenated hemoglobin concentration due to the repetition of the chest compression.

4. The apparatus according to claim 1, wherein the measurement light is near-infrared light.

5. The apparatus according to claim 1, further comprising a display configured to display a measurement result.

6. A method for measuring temporal relative change amounts of oxygenated hemoglobin concentration and deoxygenated hemoglobin concentration, that vary due to repetition of chest compression, in a head, comprising:

irradiating the head with measurement light;

detecting the measurement light that has propagated through the interior of the head and generating a detection signal in accordance with the intensity of the detected measurement light;

determining, based on the detection signal, a temporal relative change amount of the oxygenated hemoglobin concentration and a temporal relative change amount of the deoxygenated hemoglobin concentration that vary due to repetition of chest compression;

determining a phase shift between the temporal relative change amount of the oxygenated hemoglobin concentration and the temporal relative change amount of the deoxygenated hemoglobin concentration; and

evaluating the chest compression based on the phase shift.

7. The method according to claim 6, wherein the evaluating evaluates occurrence of reverse direction blood transmission from the vena cava to the head in the chest compression based on the phase shift.

8. The method according to claim 6, further comprising applying a filtering process to the temporal relative change amounts of the oxygenated hemoglobin concentration and the deoxygenated hemoglobin concentration to remove frequency components less than a predetermined frequency for extracting temporal variation components of the oxygenated hemoglobin concentration and the deoxygenated hemoglobin concentration due to the repetition of the chest compression.

9. The method according to claim 6, wherein the measurement light is near-infrared light.

10. The method according to claim 6, further comprising displaying a measurement result.