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

描述（由申请人提供）：一种高度灵活的导管，其尖端具有前瞻性，体积超声成像阵列，对于完全闭塞的动脉和心脏的指导干预是无价的。虽然新的导管设计已经开发出来，但目前的血管内超声（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产生真实的体积图像。环形盘状超声成像阵列中心为空心，可容纳导丝和其他介入工具，利用合成孔径波束形成方法，在导管前方提供体积成像能力，并使用少量电连接。我们以一种创新的方式使用电容式微机械超声换能器（CMUT）技术来形成具有独立发射和接收元件的二维阵列。这种方法不仅简化了电子器件，而且允许人们在可用的硅区域上塑造和定位阵列元件，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，可以将所有所需的发射和接收电子设备集成在与CMUT阵列相同的硅芯片上。这种方法消除了大量的芯片到芯片的电气连接，并且可以通过简单的柔性胶带互连直接连接导管中减少的电缆数量（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1mm厚的磁盘）的极低轮廓将导致灵活的结构，可以通过弯曲的动脉导航，并且应该更容易集成到各种现有的可偏转导尿管中。在这个项目中，我们将在直径1.5mm和2.5mm的空心硅片上开发完全集成电子器件的单芯片CMUT阵列，工作频率为10-20MHz，用于前瞻性IVUS和ICE应用。集成的CMOS电子器件将是低功耗（<150mW），并将具有集成的温度传感，以确保安全运行。我们将探索这种方法的潜力，以提高图像质量，通过新颖的阵列设计。我们将用CMUT阵列形成导管尖端，并通过与现有侧视IVUS导管的直接比较来表征其在定制成像目标上的性能。我们希望这项研究是将CMUT技术转化为心脏病学临床应用的重要一步。

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.