PROBLEM TO BE SOLVED: To provide a method of deriving a highly accurate blood pressure value adapted to the individual difference of a person to be measured.SOLUTION: The blood pressure measuring apparatus is provided with: a cuff part including an air bag for ischemia, a sub air bag and an air bag for pulse wave detection a pressure control means for pressurizing or depressurizing the respective air bags a pressure sensor for detecting the pressure inside the respective air bags a pulse wave signal extraction means for extracting the time sequential data of pulse wave signals superimposed on the pressure inside a cuff detected by the pressure sensor in the process of pressurizing or depressurizing the respective air bags and a blood pressure value deriving means for deriving a systolic blood pressure value and/or a diastolic blood pressure value on the basis of the change of the feature amount of the pulse wave signals and the pressure inside the cuff at the point of time of the change. The systolic blood pressure value and/or the diastolic blood pressure value is derived using a time difference between the maximum gradient point for each of 1-cycle pulse wave signals and a bottom point which appears preceding the maximum gradient point.COPYRIGHT: (C)2009,JPO&INPIT【課題】被測定者の個体差に適応したより精度の高い血圧値の導出手法を提供する。【解決手段】血圧測定装置において、阻血用空気袋とサブ空気袋と脈波検出用空気袋とを含むカフ部と、各空気袋を加圧または減圧する圧力制御手段と、各空気袋内の圧力を検出する圧力センサと、各空気袋を加圧または減圧する過程において、圧力センサにより検出されるカフ内の圧力に重畳した脈波信号の時系列データを抽出する脈波信号抽出手段と、脈波信号の特徴量の変化と当該変化時点でのカフ内の圧力とに基づき、収縮期血圧値及び/又は拡張期血圧値を導出する血圧値導出手段と、を備え、1周期脈波信号の各々に対する最大勾配点と該最大勾配点に先行して現れるボトム点との間の時間差を用い収縮期血圧値及び/又は拡張期血圧値を導出する。【選択図】図7
