Patent ID: 9655589
Date: 2017-05-23
CPC Classifications: A61B,G01S,G16H

Claim:
1. A subject information acquisition apparatus for transmitting an elastic wave to a subject, receiving the elastic wave reflected from inside the subject, and acquiring information inside the subject, the subject information acquisition apparatus comprising: a conversion device configured to receive the elastic wave and convert the elastic wave into an electrical signal; a reference layer which is provided between the conversion device and the subject and whose viscosity coefficient and elastic modulus are known; a measuring unit configured to measure strain of the subject and strain of the reference layer which are generated when a pressure is applied to the subject and the reference layer by using the electrical signal; and a calculation unit configured to calculate a viscosity coefficient (η) of the subject by using a viscosity coefficient and an elastic modulus of the reference layer, the strain of the subject, and the strain of the reference layer, wherein a pressure applied to the subject and the reference layer is periodic pressure application including releasing the pressure, and the calculation unit calculates the viscosity coefficient (η) of the subject by using an area of a hysteresis loop drawn with strain values of the subject and strain values of the reference layer which are generated by the periodic pressure.