Patent ID: 8382670

Claim:
An ultrasonic diagnosis system comprising: an ultrasonic probe for performing transmission/reception of ultrasonic signals to/from a subject; correlation computing means for sequentially moving, at set intervals relatively in an axial direction of an ultrasonic beam, a pair of envelopes of ultrasound echo signals from the subject with and without pressure applied to the subject by the ultrasonic probe, and obtaining a maximum coefficient position where a correlation coefficient of the envelopes with and without the pressure application is greatest and a phase difference at the maximum coefficient position; and strain computation means for obtaining displacement of tissue of the subject due to the pressure application and strain distribution of tissue of the subject, based on the maximum coefficient position and the phase difference obtained by the correlation computing means; the correlation computing means including, a first unpressed quadrature detection circuit for performing quadrature detection of reflection echo signals without pressure application, a second pressed quadrature detection circuit for performing quadrature detection of reflection echo signals with the pressure application, and a plurality of delay circuits for sequentially delaying an output of the second pressed quadrature detection circuit each by a set amount of time, wherein the correlation coefficient and the phase difference are obtained based on an output of the first unpressed quadrature detection circuit and the plurality of delay circuits.