System development improvements using stackable high-channel-count ultrasound hardware

This paper describes several of the design issues associated with building a modular, stackable system that can provide the desired level of channel count expansion. A specific development example will be used to highlight the issues involved in going from prototype to superior clinical performance. The most critical aspect is the accuracy of the timing and clocking system. We have developed a clock system approach that keeps the jitter performance throughout the entire system to less than 2.5 ps. To beamform across all the channels, a method has been developed to daisy-chain the beamformer across modules. The system is also designed for RF capture with or without decimation. In this configuration, every 64 channels has a 4× PCie 1.1 link with the host computer. The device can sustain 450 Mbytes/sec of bandwidth with peak bandwidth over 500 Mbytes/sec for each 64-channels in a system.