PROBLEM TO BE SOLVED: To detect central sleep apnea while sleeping which is difficult to detect only by blood oxygen saturation calculated by using pulse wave components of the artery.SOLUTION: A blood oxygen saturation measuring apparatus 100 includes: a light emitter 10 which emits, to a living tissue 500 of a subject, at least two light beams having different wavelengths a light receiving section 20 which receives the light beams, emitted from the light emitter 10 and transmitted through or reflected from the living tissue 500, and converts the received light beams to electric signals corresponding to receiving intensities of the light beams, respectively an extracting section 30 which extracts, from the respective electric signals, components corresponding to changes of the receiving intensities in response to fluctuations of the blood volume of a vein in the living tissue 500 due to respiration an attenuation ratio calculating section 40 which calculates an attenuation ratio on the basis of amplitudes of frequency components extracted from the respective electric signals and an oxygen saturation calculating section which calculates a blood oxygen saturation in the vein on the basis of the attenuation ratio.COPYRIGHT: (C)2010,JPO&INPIT【課題】動脈の脈波成分を用いて算出される血中酸素飽和度だけでは判別が難しい睡眠時の中枢性無呼吸状態を検知することができる。【解決手段】少なくとも2つの異なる波長の光を被測定者の生体組織500に照射する発光部10と、前記発光部10から照射されて前記生体組織500を透過又は反射したそれぞれの波長の光を受光し、それぞれの光の受光強度に応じた電気信号に変換する受光部20と、呼吸に基づく前記生体組織500における静脈の血液容積の変動に応じた前記受光強度の変化に対応する成分をそれぞれの前記電気信号から抽出する抽出部30と、それぞれの前記電気信号から抽出される前記周波数成分の振幅に基づいて減光度比を算出する減光度比算出部40と、前記減光度比に基づいて前記静脈における血中酸素飽和度を算出する酸素飽和度算出部とを備えることを特徴とする血中酸素飽和度測定装置100を提供する。【選択図】図1
