PROBLEM TO BE SOLVED: To enable blood pressure measurement even when measurement accuracy of a blood vessel diameter is reduced in the blood pressure measurement using an ultrasonic wave.SOLUTION: An ultrasonic blood pressure measuring instrument 10 performs transmission of an ultrasonic wave toward a blood vessel and reception of a reflection wave and measures a blood pressure. In the ultrasonic blood pressure measuring instrument 10, a storage section 300 stores a β blood pressure calculation expression being a first relation between a blood vessel diameter D of the blood vessel and a blood pressure P, a pulse wave velocity calculation section 208 measures a pulse wave velocity PWV of the blood vessel, a β blood pressure calculation expression change section 214 calculates a β blood pressure calculation changing expression being a third change relation obtained by changing the β blood pressure calculation expression using the pulse wave velocity PWV, a blood vessel diameter measurement section 206 measures the blood vessel diameter D of the blood vessel by the ultrasonic wave, and a temporary blood pressure calculation section 220 determines the blood pressure P from the β blood pressure calculation changing expression.SELECTED DRAWING: Figure 7COPYRIGHT: (C)2016,JPO&INPIT【課題】超音波を用いた血圧計測において、血管径の測定精度が低下した場合にも、血圧計測を可能にすること。【解決手段】血管に向けた超音波の送信および反射波の受信を行って血圧を計測する超音波血圧計測装置10は、記憶部300が、血管の血管径Dと血圧Pとの第1関係であるβ血圧算出式を記憶し、脈波伝搬速度算出部208が、血管の脈波伝搬速度PWVを計測し、β血圧算出式変更部214が、脈波伝搬速度PWVを用いてβ血圧算出式を変更した第3関係であるβ血圧算出変更式を算出し、血管径測定部206が、超音波により前記血管の血管径Dを計測し、臨時血圧算出部220が、β血圧算出変更式から血圧Pを決定する。【選択図】図7
