Apparatus for measuring concentration 1 measures instantaneous opposite variation (Δ cHb amounts, Δ O2Hb) total hemoglobin concentration in the two and oxyhemoglobin concentration variation in the head those due to repeating chest compression, and keep measurement incident to the end including a light incidence section 21, the inside for propagating across head for the measurement light that test section 22 detects, and according to the measurement light of the detection signal strength, it is determined with CPU 14, based on detection signal, relative variation (Δ cHb, Δ O2Hb) it is filtered removal frequency content and is less than opposite variation (Δ cHb of the scheduled frequency from the content of frequency content, Δ O2Hb). The equipment of concentration mensuration method for measurement of concentration and it is a kind of can it is objective judge whether be appropriately performed chest compression, to realize.
