PROBLEM TO BE SOLVED: To provide an automatic blood pressure measuring apparatus obtaining a highly-accurate minimal blood pressure value.SOLUTION: In a process of reducing a compression pressure value PC2, pulse wave velocity PWV in an artery under pressure is successively computed, and the compression pressure value PC2 when the change rate of the pulse wave velocity PWV to the compression pressure value PC2 passes a preset change rate determination value Rc, that is, becomes larger than the change rate determination value Rc in a region where the change rate continuously increases with the increase of the compression pressure value PC2 from a lower limit value, e.g., zero, is determined as the minimal blood pressure value DBP of a living body. Consequently, since the minimal blood pressure value DBP is determined utilizing the fact that the change rate continuously changes in a region across the minimal blood pressure value DBP and that the change rate when the compression pressure value PC2 coincides with the minimal blood pressure value DBP is the same value regardless of a measured person, the minimal blood pressure value DBP of high accuracy can be obtained.COPYRIGHT: (C)2012,JPO&INPIT【課題】精度の高い最低血圧値が得られる自動血圧測定装置を提供する。【解決手段】圧迫圧力値PC2を降圧させる過程において、圧迫下の動脈における脈波伝播速度PWVを逐次算出し、圧迫圧力値PC2に対する脈波伝播速度PWVの変化率が、圧迫圧力値PC2が下限値たとえば零から増加するに伴って変化率が連続的に増加する領域において、予め設定された変化率判定値Rcを通過する即ち変化率判定値Rcよりも大きくなるときの圧迫圧力値PC2を、生体の最低血圧値DBPとして決定する。よって、変化率は最低血圧値DBPの前後領域において連続的に変化し、圧迫圧力値PC2が最低血圧値DBPに一致するときの変化率は被測定者に拘わらず同様な値となることを利用して最低血圧値DBPが決定されるので、精度の高い最低血圧値DBPが得られる。【選択図】図15
