A Computer-Controlled FPGA-Based Pulser/Receiver System for Ultrasound Instrumentation

Developing novel ultrasound methods for biomedical investigations typically requires costly instruments, which are not always available in research laboratories. This paper describes the implementation of a flexible computer-controlled FPGA-based pulser/receiver (P/R) system for ultrasound research. The system's main features are limited dimensions, the capability to generate complex waveforms using the Pulse Width Modulation (PWM) technique, and direct access to raw data. The proposed system was characterized in the first evaluation by measuring the central frequency and bandwidth of the output waveforms generated using a 5 MHz transducer. A 3-cycle 5 MHz sinusoidal excitation pulse with the Hanning window and a 5 mu s chirp pulse from 3 to 7 MHz with the Tukey window were applied. Next, phantom experiments were performed using a 1.6 MHz transducer to measure the resolution of 15 targets with 1 mm diameter and 10 mm apart in the axial direction using the FWHM method. The results demonstrate that the P/R system can be used for medical ultrasound research and instrumentation, including piezoelectric transducer driver, high-intensity focused ultrasound (HIFU), non-destructive testing (NDT), and pulse waveform generator.