IEEE Trans Biomed Circuits Syst. 2018 Dec;12(6):1246-1255. doi: 10.1109/TBCAS.2018.2881909. Epub 2018 Nov 16.
This paper presents a single chip reduced-wire active catheter application-specific integrated circuit (ASIC), equipped with programmable transmit (Tx) beamforming and receive (Rx) time-division multiplexing (TDM). The proposed front-end ASIC is designed for driving a 64-channel one-dimensional transducer array in intracardiac echocardiography (ICE) ultrasound catheters. The ASIC is implemented in 60 V 0.18-μm HV-BCD technology, integrating Tx beamformers with high voltage pulsers and Rx front end in the same chip, which occupies 2.6 × 11 mm that can fit in the catheter size of 9 F (<3 mm). The proposed system reduces the number of wires from >64 to only 22 by integrating Tx beamformer that is programmable using a single low-voltage differential signaling data line. In Rx mode, the system uses 8:1 TDM with direct digital demultiplexing providing raw channel data that enables dynamic Rx beamforming using individual array elements. This system has been successfully used for B-mode imaging on standard ultrasound phantom with 401 mW of average power consumption. The ASIC has a compact element pitch-matched layout, which is also compatible with capacitive micromachined ultrasound transducer on CMOS application. This system addresses cable number and dimensional restrictions in catheters to enable ICE imaging under magnetic resonance imaging by reducing radio frequency induced heating.
本文提出了一种单芯片简化线主动导管专用集成电路 (ASIC)，配备可编程发射 (Tx) 波束成形和接收 (Rx) 时分复用 (TDM)。所提出的前端 ASIC 专为驱动心内超声心动图 (ICE) 超声导管中的 64 通道一维换能器阵列而设计。该 ASIC 采用 60 V 0.18-μm HV-BCD 技术实现，在同一芯片中集成 Tx 波束形成器和高压脉冲器以及 Rx 前端，占用 2.6×11mm 的空间，可适应 9 F(<3mm) 的导管尺寸。该系统通过集成可编程 Tx 波束形成器，将电线数量从>64 根减少到仅 22 根，该 Tx 波束形成器使用单根低压差分信号数据线进行编程。在 Rx 模式下，该系统使用 8:1 TDM 与直接数字解复用相结合，提供原始通道数据，可使用单个阵列元件进行动态 Rx 波束形成。该系统已成功用于标准超声体模的 B 模式成像，平均功耗为 401mW。该 ASIC 具有紧凑的元件间距匹配布局，也与 CMOS 应用中的电容式微机械超声换能器兼容。该系统解决了导管中电缆数量和尺寸的限制问题，通过减少射频感应加热，实现了磁共振成像下的 ICE 成像。
