PROBLEM TO BE SOLVED: To enhance accuracy of an index value for a fat amount acquired by using an ultrasonic wave.SOLUTION: An ultrasonic wave is transmitted/received for each search route of a plurality of search routes in an area including an object region. A route designation unit 40 designates a reference route that serves as a reference for measurement in the object region based on a reception signal of an ultrasonic wave that has propagated in each search route of the plurality of search routes. A sound speed measuring unit 50 acquires measurement data on a sound speed in the object region based on a reception signal of an ultrasonic wave that has propagated in the reference route. A fat amount calculation unit 60 derives an index value for a fat amount in the object region based on the measurement data on the sound speed.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】超音波を利用して得られる脂肪量の指標値の精度を高める。【解決手段】対象部位を含む領域内において複数の探索経路の各探索経路ごとに超音波が送受される。経路指定部40は、複数の探索経路の各探索経路を伝播した超音波の受信信号に基づいて、対象部位内における測定の基準となる基準経路を指定する。音速測定部50は、基準経路を伝播した超音波の受信信号に基づいて対象部位内の音速の測定データを得る。そして、脂肪量演算部60は、音速の測定データに基づいて対象部位内の脂肪量の指標値を導出する。【選択図】図1
