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， 每年有80万人死亡。慢性完全闭塞（CTO）是风险最大、最具挑战性和最不成功的 这些血管病变的治疗与传统的支架或血管内装置。程序复杂性和 CTO的失败归因于病变结构，包括近端纤维钙化斑块 病变的入口侧，以及跨越其长度的不规则微腔。将导丝穿过该病变 具有挑战性，因为2D荧光透视成像提供的侧视图不能直接识别 “口”/进入内腔。导丝的柔性头端因多次撞击坚硬病变而弯曲， 每一次额外的尝试都增加了技术挑战。即使是成功的手术也是耗时的， 涉及偶然性，需要患者和医生长时间暴露于辐射，并使用过量的 对比度这一临床挑战在社区中得到了广泛认可。机械破钙 振动或钻孔被一些人采用，但需要大孔尖端来容纳这种机械 因此，它只适用于大型船舶。此外，这种方法产生的碎片 会有远端器官缺血或中风的风险。由于血管内方法的使用越来越多， 在CTO的外科旁路手术中，迫切需要开发新技术来满足这一关键需求！ 因此，本项目的总体目标是开发一种新型可操纵导丝，其具有微型前向导丝， 查看超声（US）换能器，以实现实时图像引导CTO遍历。我们将讨论三个 特定目标-特殊目标1：设计和开发机器人可操纵的0.014”直径导丝（0.355 mm） 系统可在其尖端容纳0.350 mm x 0.350 mm US换能器，并可通过成像进行操控 来自传感器的反馈。目标2：设计和制造一种用于机器人的前视传感器 可操纵导丝和重建所遇到的闭塞的图像的算法。特别目标3： 使用CTO的3D打印患者特定模型迭代优化US可操纵导丝设计， 具有CTO的真实人类尸体肢体和CTO的活体动物模型。该项目在多个方面具有创新性 战线它代表了能够前瞻性US的血管内可操纵机器人导丝的首次使用 通过脉管系统和闭塞血管的成像和图像引导导航。驾驶的能力，想象的能力 和导航导丝是非常新颖的，并将最终导致临床工作流程的改进， 患者治疗结果。这个高度跨学科的项目结合了医疗机器人技术的专业知识， 成像、脉动流模型和动物模型中的图像引导介入、介入心脏病学，以及 介入放射学US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， 降低手术失败率，降低医疗成本。

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.