Transcranial Ultrasound Algorithms and Device for Rapid Stroke Determination by Paramedics

项目概要/摘要 及时诊断卒中（缺血性与出血性）对于简化适当的治疗至关重要， 达到最佳的临床结果-最小化对脑组织和功能的损伤。大约87%的中风是 缺血性，大血管闭塞（LVO）占该亚组中死亡的>90%。患者 LVO最好在经认证的综合性卒中中心（CSC）医院接受机械血栓切除术治疗 但最近的非CSC卒中护理机构可能缺乏这种介入性导管插入术 能力。经颅多普勒（TCD）超声可以测量血管流量并检测LVO，但目前TCD 设备具有高度的操作员依赖性：为了获取TCD信号，用户必须同时找到最佳的 在患者颅骨的“声学窗口”中精确地对准超声束， 脑动脉 我们建议设计一种经颅超声设备，使医护人员能够快速识别LVO 并且很容易作为中风分类的一部分，以减少tPA和血栓切除术治疗递送的时间（数十年）。 分钟至>1小时），并改善缺血性中风的结果。这种新的TCD设备将包括定制的2D 换能器阵列，其可以（1）对颅骨区域上的声学特性的趋势进行采样和绘图，以及（2）检测 来自光束内移动的血液散射体的成角度的波前。为了实现这一设计，我们的团队 主要是本科生-将采取彻底的实验声学测量离体头骨，获得 使用商业阵列探头对定制体模进行经颅多普勒测量，并进行经颅多普勒测量。 独特的换能器阵列几何形状的模拟。这些努力将精确定位理想的声学窗口， 颞骨高分辨率数字声学模型，提供信号，从中改进算法以引导 TCD传感器的放置和角度，并最终优化定制2D 阵列简化，用于未经培训的用户进行TCD采集（和LVO检测）。 该项目将导致进一步的研究（原型制造和体内测试）和应用在检测 并监测各种神经和心血管状况。从长远来看，我们设想成本效益高，用户- 在全国各地的门诊护理单位中使用友好的TCD，并改善经颅成像和治疗 能力也。该项目将提供一个密切指导的生物医学研究经验，以多样化的 一组本科生，他们作为研究人员和榜样的成功将显着影响和提高 研究环境在孟菲斯大学和整个中南合作机构。

Project Summary/Abstract Timely diagnosis of stroke (ischemic vs. hemorrhagic) is critical to streamlining appropriate treatment and achieving optimal clinical outcomes–minimizing damage to brain tissue and function. About 87% of strokes are ischemic, with large vessel occlusions (LVOs) accounting for >90% of deaths among this subset. Patients with LVOs are best treated with mechanical thrombectomy at a certified comprehensive stroke center (CSC) hospital as soon as possible, but the nearest non-CSC stroke-care facility may lack this interventional catheterization capability. Transcranial Doppler (TCD) ultrasound can measure vascular flow and detect LVOs, but current TCD equipment has high operator dependence: to acquire a TCD signal, the user must simultaneously find the optimal “acoustic window” of a patient’s skull and precisely align the ultrasound beam with the middle, anterior, or posterior cerebral arteries. We propose to design a transcranial ultrasound device that enables paramedics to identify LVOs quickly and easily as part of stroke triage, to reduce the time to tPA and thrombectomy treatment delivery (by tens of minutes to >1 hour) and improve ischemic stroke outcomes. This new TCD device will include a customized 2D transducer array that can (1) sample and map trends in acoustic properties over an area of the skull and (2) detect angled wavefronts from moving blood scatterers within the beam. To achieve this design, our team–consisting primarily of undergraduates–will take thorough experimental acoustic measurements of ex vivo skull, acquire transskull Doppler measurements on a custom phantom using a commercial array probe, and perform transskull simulations of unique transducer array geometries. These efforts will pinpoint ideal acoustic windows and yield a high-resolution, digital acoustic model of temporal skull, provide signals from which to refine an algorithm to guide the placement and angle of a TCD transducer, and ultimately optimize the layout and operation of a custom 2D array streamlined for TCD acquisition (and LVO detection) by untrained users. This project will lead to further research (prototype fabrication and in vivo testing) and applications in detecting and monitoring various neurological and cardiovascular conditions. Long-term, we envision cost-effective, user- friendly TCD used in ambulatory care units across the country, and improved transcranial imaging and therapy capabilities as well. The project will provide a closely mentored biomedical research experience to a diverse set of undergraduates, whose success as researchers and role models will significantly impact and enhance the research environment at the University of Memphis and collaborating institutions across the Mid-South.