Real-time Power Doppler on an Ultrafast High-Frequency Hardware Beamformer

This work presents a custom-developed high-frequency ultrafast power Doppler imaging system with real-time hardware-based processing and display. Previous work was presented on the development of an ultra-fast high-frequency hardware-based beamformer capable of performing diverging wave imaging with up to 0.72 kHz frame rates. In this study, modifications to the ultra-fast beamformer enabled power Doppler imaging at a real-time display frame rate of 20 Hz. Using a 40 MHz 64 element phased array endoscope, the system transmitted 16 diverging waves/frame for at a frame rate of 0.72kHz. The high acquisition rate enables the capture of 38 B-Mode frames at a 20 Hz display rate. A 6-tap elliptic infinite impulse response (IIR) filter with a cut-off at 75 Hz was implemented on a field-programmable gate array (FPGA) to suppress tissue motion. The IIR filter required 20 frames to initialize the filter and used the remaining 16 frames to generate a power Doppler image.