Miniature Real-Time Volumetric Ultrasound Imaging System

描述（由申请人提供）： 我们建议开发一种采用二维（2D）电容微机械超声换能器（CMUT）阵列的微型实时体积超声成像系统。我们将设计并实现一个安装在内窥镜尖端的微型探头，该探头将使用少量电缆连接到外部波束形成单元。该探头将包含一个 2D CMUT 阵列和集成电路，用于处理数据采集和前端预处理。小型有源相控子阵列将在连续发射步骤中复用在大型换能器阵列上，以实现实时数据采集。获取的数据将传输到外部单元并进行处理以形成实时金字塔体积图像。 CMUT 技术提供出色的元件灵敏度、大的时间带宽以及将传感器与前端电子电路集成的潜力。图像重建算法基于相控子阵列处理，可实现低成本的前端架构，同时提供高质量的实时图像。 CMUT 技术和相控子阵列 (PSA) 成像的结合将使我们能够实现小型超声波扫描仪，其中前端电路的尺寸和成本至关重要。 我们取得了以下初步成果：(1) 确定了几种用于癌症治疗的图像引导手术应用，(2) 根据医生输入指定探头参数，(3) 制造了 128 元件 1D CMUT 阵列，(4) 用它形成高质量的 2D 图像，(4) 制造了原型 16x16 元件 2D CMUT 阵列，(5) 开发了用于 2D 和 3D 成像的 PSA 理论，(6) 测试了 2D PSA 理论与模拟和实验数据，以及 (7) 表明系统规格允许实时 3D 超声成像。 我们建议采取下一个主要开发步骤，通过实现以下具体目标来演示微型探头的实时 3D 成像：(1) 使用原型阵列和现有采集系统形成初步 3D 图像，(2) 设计和制造新的 16x16 2D CMUT 阵列，(3) 实现实时波束形成和可视化，(4) 设计和构建前端探头电子器件的集成电路，(5) 最终集成到功能齐全的实时 3D 中超声系统，(6)进行初步临床评估。

DESCRIPTION (provided by applicant): We propose to develop a miniature real-time volumetric ultrasound imaging system employing two-dimensional (2D) capacitive micromachined ultrasonic transducer (CMUT) arrays. We will design and implement a miniature probe fitting into the tip of an endoscope that will be connected to an external beamforming unit using a small number of cables. The probe will contain a 2D CMUT array and integrated circuits to handle the data acquisition and front-end pre-processing. A small-sized active phased subarray will be multiplexed over a large transducer array in consecutive firing steps to allow for real-time data acquisition. The acquired data will be transferred to the external unit and processed to form real-time pyramidal volumetric images. CMUT technology provides excellent element sensitivity, large temporal bandwidth, and potential for integrating the transducer with front-end electronic circuitry. The image reconstruction algorithm is based on phased subarray processing which allows for a low-cost front-end architecture while providing high-quality real-time images. The combination of CMUT technology and phased subarray (PSA) imaging will enable us to realize a small ultrasound scanner where the size and cost of the front-end circuitry is critical. We have achieved the following preliminary results: (1) Identified several image-guided surgical applications for cancer treatment, (2) specified the probe parameters based on physician input, (3) fabricated 128-element 1D CMUT array and (4) used it to form a high-quality 2D image, (4) fabricated a prototype 16x16-element 2D CMUT array, (5) developed PSA theory for 2D and 3D imaging, (6) tested 2D PSA theory with simulations and experimental data, and (7) shown that the system specs allow for real-time 3D ultrasound imaging. We propose to take the next major developmental step and demonstrate real-time 3D imaging from a miniature probe by accomplishing the following specific aims: (1) form preliminary 3D images using the prototype array and existing acquisition system, (2) design and fabricate new 16x16 2D CMUT arrays, (3) implement real-time beamforming and visualization, (4) design and build integrated circuits for the front-end probe electronics, (5) perform final integration into a fully function real-time 3D ultrasound system, and (6) perform preliminary clinical evaluation.