PROBLEM TO BE SOLVED: To easily find a scanning line without refraction from among a group of scanning lines of ultrasonic waves transmitted/received from an ultrasonic probe.SOLUTION: Ultrasonic waves are transmitted to a subject from the ultrasonic probe including a plurality of elements the ultrasonic waves reflected by the subject are received received signals from a plurality of reflection points with different depths are obtained, and local sonic speeds in respective regions where the plurality of reflection points are present are calculated. The changes (inclinations) of the calculated local sonic speeds with respect to the depth direction are calculated, and a scanning line within a prescribed threshold value in the neighborhood of zero is determined as the scanning line without refraction from the calculated inclinations.COPYRIGHT: (C)2013,JPO&INPIT【課題】超音波探触子から送受信される超音波の走査線群のうちの屈折のない走査線を簡単に求める。【解決手段】複数の素子を含む超音波探触子から超音波を被検体に送信するとともに、該被検体によって反射される超音波を受信し、深さの異なる複数の反射点からの受信信号を取得し、前記複数の反射点が存在する各領域における局所音速を算出する。これらの算出した局所音速の深さ方向に対する変化(傾き)を算出し、前記算出した傾きによりゼロ近傍の所定の閾値以内となる走査線を、屈折のない走査線として判定する。【選択図】 図8
