Ultrasound-guided, Robotically Steerable Guidewire for Endovascular Interventions

动脉粥样硬化性血管疾病的负担在美国成年人中是巨大的，导致大约 每年有80万人死亡。慢性完全性闭塞(CTO)是风险最高、挑战最大、成功率最低的 使用传统的支架或血管内装置治疗这些血管病变。程序复杂性和 CTO的失败归因于病变结构，其近端包括纤维钙化斑块。 病变的入口侧，以及横跨其长度的不规则微腔。穿过这个损伤处的导丝 是具有挑战性的，因为2D透视成像提供的侧视图不能直接识别 “口”/进入管腔。导丝的柔性尖端由于多次撞击而弯曲，损伤坚硬， 每增加一次尝试，就会增加技术挑战。即使是成功的手术也很耗时， 涉及偶然性，需要患者和医生长期暴露在辐射中，并使用过量的 对比度。这一临床挑战在社区中得到了很好的认可。机械化破钙法 振动或钻探被几个人采用，但需要一个大的孔尖来容纳这种机械 组件使其仅适用于较大的容器。此外，这种方法产生的碎片 存在远端器官缺血或中风的风险。由于血管内途径越来越多地被使用 对于CTO的外科搭桥术，迫切需要开发新的技术来满足这一关键需求！ 因此，该项目的总体目标是开发一种新型的带有微型前进器的可导向导丝-- 查看超声(US)换能器以实现实时图像引导的CTO遍历。我们将解决三个问题 特定目标-Sp.目标1：设计和开发一种可机器人操控、直径0.014英寸(0.355毫米)的导丝 该系统的尖端可容纳.350 mm x.350 mm US换能器，并可通过图像进行操纵 来自传感器的反馈。SP.目标2：为机器人设计和制造前视换能器 可转向导丝和重建遇到的遮挡的图像的算法。SP.目标3：实现 使用3D打印的CTO患者特定模型反复优化美国导向导丝设计， 带有CTO的逼真人类身体肢体，以及CTO的活体动物模型。该项目在几个方面具有创新性 前排。它代表着首次使用血管内可操纵的机器人导丝，能够向前看美国 通过血管系统和闭塞血管的成像和图像引导导航。驾驶能力，视觉化能力 和导航导丝是非常新颖的，最终将导致临床工作流程的改进和 患者的治疗结果。这个高度跨学科的项目结合了美国医疗机器人领域的专业知识 动物模型中的成像、脉动流模型和图像引导干预、介入心脏病学和 介入放射学。美国引导的血管内可操纵机器人系统将具有重大的社会意义 通过改善患者结局、减少医生和患者的辐射暴露来产生影响， 降低了程序失败率，降低了医疗成本。

The burden of atherosclerotic vascular disease is immense among adult Americans, contributing to about 800,000 deaths per year. Chronic total occlusions (CTO) are the riskiest, most challenging, and least successful of these vascular lesions to treat with traditional stenting or endovascular devices. Procedural complexity and failure with CTO's are attributed to the lesion structure, which includes a fibrous calcific plaque on the proximal entry side of the lesion, and an irregular micro-lumen spanning its length. Passing a guidewire across this lesion is challenging, as the lateral view provided by 2D fluoroscopic imaging does not directly identify the “mouth”/entry to the lumen. The flexible tips of the guidewires bend due to multiple-impacts with stiff lesions, increasing the technical challenge with each additional attempt. Even successful procedures are time-consuming, involve chance, require prolonged patient and physician exposure to radiation and use excessive amounts of contrast. This clinical challenge is well recognized in the community. Breaking the calcium with mechanical vibrations or drilling was adopted by several, but the need for a large bore tip to house such mechanical components makes it applicable only in larger vessels. In addition, the debris resulting from such an approach carries the risk of ischemia or stroke in the distal organs. Since endovascular approaches are increasingly utilized over surgical bypass of CTO's, there is an urgent need to develop new technologies to meet this critical need! Thus, the overall goal of this project is to develop a novel steerable guidewire with a miniature forward- viewing ultrasound (US) transducer to enable real-time image-guided CTO traversal. We will address three specific aims – Sp. Aim 1: Design and develop a robotically steerable, 0.014” diameter guidewire (0.355 mm) system that can accommodate a .350 mm x .350 mm US transducer at its tip and can be steered with image feedback from the transducer. Sp. Aim 2: Design and build a forward-looking transducer for the robotically steerable guidewire and an algorithm to reconstruct an image of the encountered occlusion. Sp. Aim 3: To iteratively optimize the US-steerable guidewire design using 3D printed patient-specific models of CTO's, realistic human cadaver limbs with CTO, and a live animal model of CTO's. This project is innovative on several fronts. It represents the first use of intravascular steerable robotic guidewire capable of forward looking US imaging and image-guided navigation through vasculature and occluded vessels. The ability to steer, visualize and navigate the guidewire is highly novel and will eventually result in improvement of clinical workflow and patient treatment outcomes. This highly interdisciplinary project combines expertise in medical robotics, US imaging, pulsatile flow models and image-guided interventions in animal models, interventional cardiology, and interventional radiology. The US-guided, intravascular steerable robotic system will have significant societal impact through improved patient outcomes, reduced radiation exposure for the physician and the patient, reduced rate of procedural failures, and lower healthcare costs.