论文标题
分阶段的阵列束成式方法，用于为生物医学超声植入物供电
Phased array beamforming methods for powering biomedical ultrasonic implants
论文作者
论文摘要
已经提出了使用超声进行功率和通信的毫米级植入物，用于一系列深层组织应用，包括神经记录和刺激。但是，已发表的实现对与外部超声传感器的未对准有很高的敏感性。使用阶梯阵列到这些植入物进行超声波束形成可以提高对未对准的容忍度，减少植入物的体积，并允许在不同位置同时操作多个植入物。本文详细介绍了定制平面段阵列超声系统的设计，该系统能够在3D体积内转向和聚焦超声电源。进行分析和仿真以确定阵列元素音高的选择，并特别注意最大化植入物的功率，同时满足诊断超声的FDA限制。时间逆转被提出是一种计算上简单的光束形成方法，尽管声学介质的散射和不均匀性，该方法是可靠的。在活动驱动和脉搏回波模式下既证明了这一技术，又可以通过测量能量传递效率与其他波束成型技术进行实验。还展示了同时向多个植入物传递的电力。
Millimeter-scale implants using ultrasound for power and communication have been proposed for a range of deep-tissue applications, including neural recording and stimulation. However, published implementations have shown high sensitivity to misalignment with the external ultrasound transducer. Ultrasonic beamforming using a phased array to these implants can improve tolerance to misalignment, reduce implant volume, and allow multiple implants to be operated simultaneously in different locations. This paper details the design of a custom planar phased array ultrasound system, which is capable of steering and focusing ultrasound power within a 3D volume. Analysis and simulation is performed to determine the choice of array element pitch, with special attention given to maximizing the power available at the implant while meeting FDA limits for diagnostic ultrasound. Time reversal is proposed as a computationally simple approach to beamforming that is robust despite scattering and inhomogeneity of the acoustic medium. This technique is demonstrated both in active drive and pulse-echo modes, and it is experimentally compared with other beamforming techniques by measuring energy transfer efficiency. Simultaneous power delivery to multiple implants is also demonstrated.
