Patent ID: 8747320

Claim:
An ultrasonic diagnostic apparatus including an ultrasonic probe configured to transmit and receive ultrasonic waves while in contact with an object, a transmitting unit configured to drive the ultrasonic probe, a receiving unit configured to receive and process an RF signal which is a reflected echo signal received by the ultrasonic probe, and an image creating unit configured to create an ultrasonic image based on the RF signal output from the receiving unit, comprising: an elastic coupler attached to an ultrasonic wave transmitter/receiver surface of the ultrasonic probe and including at least two plate-shaped layers disposed on each other, each of the at least two plate-shaped layers having a different ultrasonic wave reflectance property from each other; and a pressure calculating unit configured to obtain the pressure applied to the object based on the reflected echo signal and the deformation of the elastic coupler, wherein the pressure calculating unit is configured to: perform a detect operation to detect, via the reflected echo signal, a detected position of a boundary surface between the at least two plate-shaped layers of the elastic coupler, with the pressure applied to the object, determine a positional change of the boundary surface caused by the pressure applied to the object, using both the detected position of the boundary surface from the detect operation and an initial position of the boundary surface which has been obtained in advance, where the initial position concerns a position of the boundary surface with the pressure not applied to the object, and calculate an absolute pressure applied to the object, based on the positional change from the determine operation and based on an elasticity property of the elastic coupler.