| 摘要 |
PROBLEM TO BE SOLVED: To discriminatively extract a higher harmonic component contained in a response signal of biological tissue and a higher harmonic component contained in a response signal of a contrast medium. SOLUTION: A transmission part 20 has a function for transmitting ultrasonic beams in a same direction at some time intervals a plurality of times M (however, M is a natural number of M≥2); wherein an ultrasonic signal of each time has a frequency formed by continuously forming N waveforms f1, f2-fn and fN (however, N is a natural number of N≥2), when an average frequency from f1 to fN is defined as f<SB>0</SB>, the frequency distribution widthΔf from f1 to fN is variably set within the range from 0.0f<SB>0</SB>to 0.4f<SB>0</SB>according to the depth of an ultrasonic irradiation focus, and the signals of the respective times are transmitted to become mutually asymmetric with respect to a polar inversion; and a receiving section 30 is configured to have a function of phasing the response signals of a plurality of times M of ultrasonic signals and a function of adding and subtracting the phased response signals and attenuating the response signal of the biotissue. COPYRIGHT: (C)2009,JPO&INPIT |
