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

描述（由申请人提供）：尖端带有前瞻性容积超声成像阵列的高度柔性导管对于引导完全闭塞动脉和心脏中的介入治疗非常重要。虽然已经开发了新的导管设计，但当前的血管内超声（IVUS）和心内超声心动图（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。具有中空中心的甜甜圈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成形方法在导管前面提供体积成像能力，只需少量电连接。我们使用电容式微机械超声换能器（CMUT）技术，以创新的方式形成这些2-D阵列与单独的发射和接收元件。这种方法不仅导致更简单的电子器件，而且允许人们在可用的硅区域上成形和定位阵列元件，以增加发射功率、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器件集成在同一个硅芯片上作为CMUT阵列。这种方法消除了大量的芯片到芯片的电连接，并且使得能够利用简单的柔性带互连直接接口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阵列的极低轮廓-基本上是1 mm厚的圆盘-将导致柔性结构通过迂曲的动脉导航，并且应该更容易集成到各种现有的可偏转导引导管。在这个项目中，我们将开发单芯片CMUT阵列，在1.5mm和2.5mm直径的中空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电子器件将是低功耗的（<150 mW），并将具有集成的温度传感功能，以确保安全运行。我们将探索这种方法的潜力，通过新颖的阵列设计，提高图像质量。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应用的临床设置的重要一步。 公共卫生相关性：这项研究将开发最终微型化的超声成像设备，可以连接在导管的尖端，通过直接在导管前面提供体积图像来引导冠状动脉和心脏中的干预。这将有助于提高介入治疗的成功率，特别是在完全阻塞的动脉和经导管心脏手术中。

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.