Compensation of transducer element positions in a ring array ultrasonic computer tomography system

摘要

An ultrasonic ring array system was newly developed and ultrasonic computer tomography (USCT) image reconstruction was performed. The USCT transducer of 104mm diameter had a center frequency of 1.75MHz and a -6 dB transmit and receive two-way fractional bandwidth of 66%. It had a full 360 degrees circumference divided into four blocks, each of which had 256 elements. All 1024 elements were connected to a high-voltage multiplexer IC. The potential problem of image degradation, which might have been caused by insufficient alignment accuracy between the blocks, was solved by fitting and compensating the delay due to the misalignment. This resulted in a measured transmit and receive beam width of 0.20mm, which is close to the theoretical value. (C) 2015 The Japan Society of Applied Physics