Biomedical Engineering Program, University of Connecticut, Storrs, CT, USA.
IEEE Trans Ultrason Ferroelectr Freq Control. 2012 Jul;59(7):1344-53. doi: 10.1109/TUFFC.2012.2335.
In this paper, we report, to the best of our knowledge, a unique field-programmable gate array (FPGA)-based reconfigurable processor for real-time interlaced co-registered ultrasound and photoacoustic imaging and its application in imaging tumor dynamic response. The FPGA is used to control, acquire, store, delay-and-sum, and transfer the data for real-time co-registered imaging. The FPGA controls the ultrasound transmission and ultrasound and photoacoustic data acquisition process of a customized 16-channel module that contains all of the necessary analog and digital circuits. The 16-channel module is one of multiple modules plugged into a motherboard; their beamformed outputs are made available for a digital signal processor (DSP) to access using an external memory interface (EMIF). The FPGA performs a key role through ultrafast reconfiguration and adaptation of its structure to allow real-time switching between the two imaging modes, including transmission control, laser synchronization, internal memory structure, beamforming, and EMIF structure and memory size. It performs another role by parallel accessing of internal memories and multi-thread processing to reduce the transfer of data and the processing load on the DSP. Furthermore, because the laser will be pulsing even during ultrasound pulse-echo acquisition, the FPGA ensures that the laser pulses are far enough from the pulse-echo acquisitions by appropriate time-division multiplexing (TDM). A co-registered ultrasound and photoacoustic imaging system consisting of four FPGA modules (64-channels) is constructed, and its performance is demonstrated using phantom targets and in vivo mouse tumor models.
在本文中，我们据我们所知报告了一种独特的基于现场可编程门阵列 (FPGA) 的可重构处理器，用于实时交错配准超声和光声成像及其在肿瘤动态响应成像中的应用。FPGA 用于控制、采集、存储、延迟求和以及传输实时配准成像的数据。FPGA 控制包含所有必要的模拟和数字电路的定制 16 通道模块的超声发射和超声和光声数据采集过程。16 通道模块是插入主板的多个模块之一；它们的波束形成输出可通过外部存储接口 (EMIF) 供数字信号处理器 (DSP) 访问。FPGA 通过超快重新配置及其结构的自适应来发挥关键作用，以允许在两种成像模式之间实时切换，包括传输控制、激光同步、内部存储结构、波束形成以及 EMIF 结构和存储大小。它还通过内部存储器的并行访问和多线程处理来减少数据传输和 DSP 的处理负载。此外，由于激光在超声脉冲回波采集期间将是脉冲式的，因此 FPGA 通过适当的时分复用 (TDM) 确保激光脉冲与脉冲回波采集之间有足够的距离。构建了一个由四个 FPGA 模块（64 通道）组成的配准超声和光声成像系统，并使用 phantom 目标和体内小鼠肿瘤模型对其性能进行了演示。
