| 摘要 |
PURPOSE:To obtain an accurate STC curve even when the state of an ultrasonic probe, a diagnostic region or an examinee are changed by controlling depth or the gain of the echo signal in the vicinity thereof on the basis of the value defined using a specific function with respect to the ultrasonic echo signal from an examinee. CONSTITUTION:In an ultrasonic diagnostic apparatus, a gain control circuit is formed in order to correct attenuation accompanied by the propagation of ultrasonic waves to more increase the gain of the echo signal of a deep part. When the intensity of the echo signal in the vicinity of depth (x) obtained by applying logarithmic conversion processing and detection processing to the echo signal is set to f (x) and the differential value in the depth direction thereof is set to f' (x), the gain control circuit uses a function a (f' (x)) (wherein, 0 <=a (f'(x))<=1) reduced or becomes 0 accompanied by an increase in the absolute value of the input value of f' (x) with respect to the input of f' (x) and controls depth or the gain of the echo signal in the vicinity thereof on the basis of the value of g (d) defined by the formula. |
