Miniature Real-Time Volumetric Ultrasound Imaging System

描述(由申请人提供)： 我们提出了一种采用二维电容式微机械超声换能器(CMUT)阵列的小型实时体积超声成像系统。我们将设计和实现一个安装在内窥镜尖端的微型探头，它将使用少量电缆连接到外部波束形成单元。该探头将包含一个二维CMUT阵列和集成电路来处理数据采集和前端预处理。小型有源相控子阵将在连续发射步骤中在大型换能器阵列上进行多路复用，以实现实时数据采集。采集的数据将被传输到外部单元并进行处理，以形成实时的金字塔形体图像。CMUT技术提供了出色的元件灵敏度、大的时间带宽以及将换能器与前端电子电路集成的潜力。该图像重建算法基于相控子阵列处理，允许低成本的前端架构，同时提供高质量的实时图像。CMUT技术和相控子阵(PSA)成像的结合将使我们能够实现小型超声扫描仪，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)确定了几种图像引导手术在癌症治疗中的应用；(2)根据医生的输入指定了探头参数；(3)制作了128元的一维CMUT阵列并将其用于形成高质量的2D图像；(4)制作了16x16元的2D CMUT阵列的原型；(5)发展了用于2D和3D成像的PSA理论；(6)用模拟和实验数据测试了2D PSA理论；以及(7)表明该系统的规格可以实现实时的3D超声成像。 我们建议采取下一步的重大开发步骤，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的采集系统形成初步的3D图像；(2)设计和制造新的16×16 2D CMUT阵列；(3)实现实时波束形成和可视化；(4)设计和制造前端探头电子电路；(5)最终集成到全功能实时3D超声系统中；(6)进行初步的临床评估。

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.