PROBLEM TO BE SOLVED: To provide a concentration measurement device and method for objectively determining whether or not chest compression is appropriately executed.SOLUTION: The concentration measurement device 1 determines the amount of temporal and relative changes (ΔcHb, ΔOHb) in total hemoglobin concentration and/or oxygenated hemoglobin concentration in the head, due to repeated chest compressions. The concentration measurement device 1 includes: a light-input unit 21 that inputs measurement light to the head； a light-detection unit 22 that detects the measurement light propagated through the head, and generates a detection signal corresponding to the intensity of the measurement light； and a CPU 14 that determines the amount of relative changes (ΔcHb, ΔOHb) on the basis of the detection signal, and removes frequency components having frequencies lower than a predetermined frequency out of frequency components included in the amount of relative changes (ΔcHb, ΔOHb) through a filtering process.【課題】胸骨圧迫が適切に行われているか否かを客観的に判断することが可能な濃度測定装置及び濃度測定方法を提供する。【解決手段】濃度測定装置１は、胸骨圧迫の繰り返しに起因して変動する、頭部の総ヘモグロビン濃度及び／又は酸素化ヘモグロビン濃度の時間的な相対変化量（ΔｃＨｂ、ΔＯ２Ｈｂ）を測定する装置であって、頭部に測定光を入射する光入射部２１と、頭部の内部を伝搬した測定光を検出し、該測定光の強度に応じた検出信号を生成する光検出部２２と、この検出信号に基づいて、相対変化量（ΔｃＨｂ、ΔＯ２Ｈｂ）を求め、相対変化量（ΔｃＨｂ、ΔＯ２Ｈｂ）に含まれる周波数成分のうち所定周波数より小さい周波数成分をフィルタ処理によって除去するＣＰＵ１４とを備える。【選択図】図３
