Concentration-measurement device and concentration-measurement method

A concentration measurement apparatus measuring a temporal relative change amount of at least one of total hemoglobin concentration, oxygenated hemoglobin concentration, and deoxygenated hemoglobin concentration in the head that vary due to repetition of chest compression, comprising:

• a light source that makes measurement light having at least a first wavelength λ1 and a second wavelength λ2 incident on the head;
• a light detector that detects the measurement light that has propagated through the interior of the head and generating a first detection signal corresponding to the first wavelength λ1 and a second detection signal corresponding to the second wavelength λ2 in accordance with an intensity of the measurement light;
• and
• a processor electrically connected to the light detector and programmed to determine, based on the first detection signal and the second detection signal, the temporal relative change amount of at least one of the total hethoglobin concentration (ΔcHb), the oxygenated hemoglobin concentration (ΔO2Hb), and the deoxygenated hemoglobin concentration (ΔHHb),
• wherein the processor is programmed to perform a filtering process that removes frequency components less than a predetermined frequency of not more than 1.66 Hz to extract information on the concentration change due to chest compression, and calculate information related to a variation frequency of the relative change amount corresponding to a current frequency of chest compression, and
• wherein a calculation cycle of the relative change amount is not more than 0.2 seconds.