| 摘要 |
PURPOSE:To measure a propagation time and sonic velocity over the whole of the interior of a living body, by independently correcting and setting a gain so as to accurately perform the processing of the receiving signals of regions different in the reflection intensity from the interior of the living body. CONSTITUTION:The transmitting array group of the array type ultrasonic transducer 1 arranged to the surface of a living body 2 is driven by the pulse from a transmission circuit 3 to transmit ultrasonic beam to the living body 2. The transmitted ultrasonic beam is reflected from the point P of the living body 2 and subsequently received by the receiving array group of the transducer 1 to be converted to an electric signal while the receiving signal is sent to a gain controllable amplifier 5 through a receiving circuit 4. After corrected gain data is accumulated in a gain memory 11, said data is converted to an analogue signal by a D/A converter to become the AGC (automatic gain control) input signal of the amplifier 5 and the gain of the amplifier 5 is corrected and set on the basis of the AGC input signal. The correction of the gain of the amplifier 5 is repeatedly performed until the receiving signal obtained from the point P of the same region in the living body reaches the optimum level from an aspect of data processing by a control circuit 13. |
