PROBLEM TO BE SOLVED: To provide a blood pressure measurement instrument capable of accurately measuring a blood pressure value independent of the size or degree of winding of a cuff.SOLUTION: From a pressure of a cuff 30, attached to a part to be measured of a living body, detected during decreasing of a pressing pressure applied by the cuff to the part to be measured, a CPU 18 detects pulse waves, namely a pressure component superposed on the pressing pressure, finds out the cuff 30s pressing pressure which occurred at the time point of occurrence of a wave pulse whose amplitude value showed a predetermined ratio to the maximum amplitude value among the detected pulse waves, and determines the cuff 30s pressing pressure to be the measured blood pressure value. The CPU 18 detects the amplitude of a K sound which occurs during the decreasing period of the pressing pressure and sets the predetermined ratio according to the amplitude of a pulse wave detected at the time point at which the amplitude of the K sound exceeds a threshold value.COPYRIGHT: (C)2014,JPO&INPIT【課題】カフのサイズやカフの巻き付け度合いに依らずに、正確な血圧値を測定できるようにする血圧測定装置を提供する。【解決手段】CPU18は、生体の測定部位に装着されるカフ30による測定部位への圧迫圧力の減少期間中に検出されるカフ30の圧力から、圧迫圧力に重畳される圧力成分である脈波を検出し、検出した脈波のうち振幅値が最大値に対して所定割合となる脈波の発生時点に対応するカフ30の圧迫圧力を測定血圧値とする。CPU18は、圧迫圧力の減少期間中に発生するK音の振幅を検出し、この振幅が閾値を超えた時点に対応する脈波の振幅に応じて、上記所定割合を設定する。【選択図】図2
