An Ultrafast High-Frequency Hardware Beamformer for a Phased Array Endoscope

A ultra-fast high frequency ultrasound hardware based beamformer is described. The system was tested using a miniature 40 MHz 64 element phased array endoscope. The system used diverging wave beamforming with a total of 16 diverging waves in order to obtain a good beam profile at a 700+ Hz frame rate. Experimentally, the system was able to operate at a frame rate of 500 Hz, close to the implementations theoretical limit of 760 Hz. A novel technique was used to store 8.3 Million beamforming delays for 8 channels on a field programmable gate array (FPGA). The measured secondary lobe levels for the radiation pattern measurements were less than -35 dB and the main lobe had a beam width of 0.7 mm. Using field II, the simulated radiation pattern had secondary lobes suppressed to -50 dB and a beam width of 0.15 mm. Real-time images of wire phantoms were generated and displayed with custom developed imaging software.