Fully Integrated Single Chip CMUT Arrays for Forward Looking IVUS and ICE

描述（由申请人提供）：尖端具有前瞻性体积超声成像阵列的高度灵活的导管对于指导完全闭塞的动脉和心脏的干预具有无价的价值。虽然已经开发出新的导管设计，但当前的血管内超声 (IVUS) 和心脏内超声心动图 (ICE) 系统要么是侧视的，要么不能直接在导管前面生成真实的体积图像。具有中空中心的圆环盘形超声成像阵列允许导丝和其他介入工具，可以使用合成孔径波束形成方法在导管前面提供体积成像能力，并具有少量的电连接。我们以创新的方式使用电容式微机械超声换能器 (CMUT) 技术来形成这些具有独立发射和接收元件的二维阵列。这种方法不仅可以使电子设备更加简单，而且可以在可用的硅区域上对阵列元件进行整形和定位，以提高发射功率、成像速度并可能减少串扰。同样重要的是，我们的研究表明，可以将所有必需的发射和接收电子器件集成在与 CMUT 阵列相同的硅芯片上。这种方法消除了大量芯片到芯片的电气连接，并能够通过简单的柔性胶带互连直接连接到导管中减少数量的电缆（10-12）。除了这些制造优势之外，完全集成的 CMUT 阵列（本质上是一个 1 毫米厚的圆盘）的外形极薄，将形成灵活的结构，可以在曲折的动脉中导航，并且应该更容易集成到各种现有的可偏转导管中。在该项目中，我们将开发单芯片 CMUT 阵列，该阵列在 1.5 毫米和 2.5 毫米直径的空心硅芯片上完全集成电子器件，工作频率范围为 10-20 MHz，用于前瞻性 IVUS 和 ICE 应用。集成的 CMOS 电子器件功耗低（<150mW），并具有集成温度传感功能，可确保安全运行。我们将探索这种方法通过新颖的阵列设计来提高图像质量的潜力。我们将使用 CMUT 阵列形成导管尖端，并通过与现有侧视 IVUS 导管直接比较来表征其在定制成像目标上的性能。我们预计这项研究将成为将 CMUT 技术转化为心脏病学临床应用的重要一步。 公共健康相关性：这项研究将开发最终的小型化超声成像设备，该设备可以连接在导管尖端，通过直接在导管前面提供体积图像来指导冠状动脉和心脏的干预。这将有助于提高干预的成功率，特别是在动脉完全阻塞和心脏经导管手术中。

DESCRIPTION (provided by applicant): A highly flexible catheter with forward-looking, volumetric ultrasound imaging array at its tip would be invaluable for guiding interventions in totally occluded arteries and in the heart. While new catheter designs have been developed, current Intravascular ultrasound (IVUS) and intra cardiac echocardiography (ICE) systems are either side-looking or do not generate the true volumetric images directly in front of the catheter. A donut disk shaped ultrasound imaging array with a hollow center allowing for guidewire and other intervention tools can provide volumetric imaging capability in front of the catheter with small number of electrical connection using synthetic aperture beamforming methods. We use capacitive micromachined ultrasonic transducer (CMUT) technology in an innovative way to form these 2-D arrays with separate transmit and receive elements. This approach not only results in simpler electronics, but allows one to shape and locate the array elements on the available silicon area to increase transmit power, imaging speed and possibly reduce cross-talk. As important, our research shows that one can integrate all the required transmit and receive electronics on the same silicon chip as the CMUT array. This approach eliminates the large number of chip-to- chip electrical connections and enables direct interface to a reduced number of cables (10-12) in a catheter with a simple flex-tape interconnect. In addition to these manufacturing advantages, the extremely low profile of the fully integrated CMUT array - essentially a 1mm thick disk -- will result in flexible structures to navigate through tortuous arteries and should be easier to integrate to a variety of existing deflectable guide catheters. In this project, we will develop single chip CMUT arrays with fully integrated electronics on 1.5mm and 2.5mm diameter hollow silicon chips operating at 10-20MHz frequency range for forward-looking IVUS and ICE applications. The integrated CMOS electronics will be low-power (<150mW) and will feature integrated temperature sensing for safe operation. We will explore the potential of this approach for improved image quality through novel array designs. We will form catheter tips with CMUT arrays and characterize their performance on custom imaging targets with direct comparison to existing side-looking IVUS catheters. We expect this study to be an important step in translating CMUT technology to clinical settings for cardiology applications. PUBLIC HEALTH RELEVANCE: This study will develop ultimately miniaturized ultrasonic imaging devices that can be attached at the tip of a catheter to guide interventions in coronary arteries and in the heart by providing a volumetric image directly in front of the catheter. This will help increase the success rate of interventions especially in totally blocked arteries and trans- catheter operations in the heart.