A Computer-Controlled Ultrasound Pulser-Receiver System for Transkull Fluid Detection using a Shear Wave Transmission Technique

摘要

The purpose of this study was to evaluate the performance of a computer-controlled ultrasound pulser-receiver system incorporating a shear mode technique for transkull fluid detection. The presence of fluid in the sinuses of an ex vivo human was examined using pulse-echo method by transmitting an ultrasound beam through the maxilla bone towards the back wall on the other side of the sinus cavity. The pulser was programmed to generate bipolar pulse trains with 5 cycles, at frequency of 1MHz, repetition frequency of about 20Hz, and amplitude of 100V to drive a 1MHz piezoelectric transducer. Shear and longitudinal waves in the maxilla bone were produced by adjusting the bone surface incident angle to 45° and 0°, respectively. CT scans of the skull were performed to verify the ultrasound experiment. Using the shear mode technique, the echo waveform clearly distinguishes the presence of fluid, and the estimated distance of the ultrasound traveled in the sinus is consistent with the measurement from the CT images. Contrarily, using the longitudinal mode, no detectable back wall echo was observed under the same condition. As a conclusion, this study demonstrated that the proposed pulser-receiver system with the shear mode technique is promising for transkull fluid detecting, such as mucous in sinus.