Transcranial Ultrasound Algorithms and Device for Rapid Stroke Determination by Paramedics

项目摘要/摘要 及时诊断中风(缺血性与出血性)对于简化适当的治疗和 实现最佳临床结果-将对脑组织和功能的损害降至最低。大约87%的中风是 缺血性，大血管闭塞(LVO)占这一亚组死亡的90%。患有疾病的患者 LVO最好在经过认证的综合卒中中心(CSC)医院进行机械血栓摘除术。 尽快，但最近的非CSC卒中护理机构可能缺乏这种介入性导管术 能力。经颅多普勒(TCD)超声可以测量血管流量和检测LVO，但目前的TCD 设备对操作员有很高的依赖性：要获取TCD信号，用户必须同时找到最优的 并精确地将超声波束与颅骨的中部、前部或后部对齐 大脑动脉。 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左心室 作为中风分诊的一部分，可以轻松地减少tPA和血栓切除术治疗交付的时间(减少数十 几分钟到一小时)，并改善缺血性中风的预后。这款新的TCD设备将包括定制的2D 换能器阵列，可以(1)采样和绘制颅骨区域上的声学特性趋势图，以及(2)检测 光束内移动的血液散射体产生的成角度的波前。为了实现这一设计，我们的团队-由 主要是本科生-将对体外颅骨进行彻底的实验声学测量，获得 使用商用阵列探头在定制体模上进行经颅多普勒测量，并进行经颅多普勒测量 模拟独特的换能器阵列几何结构。这些努力将精确定位理想的声学窗口，并产生 高分辨率、数字的颞骨声学模型提供信号，从中改进算法以指导 TCD换能器的位置和角度，并最终优化定制2D的布局和操作 针对未经培训的用户的TCD采集(和LVO检测)简化了阵列。 该项目将导致进一步的研究(原型制造和体内测试)和在检测中的应用 并监测各种神经和心血管疾病。从长远来看，我们设想的是经济高效、用户- 友好的TCD用于全国各地的门诊护理单元，并改进了经颅成像和治疗 能力也是如此。该项目将为不同的生物医学研究提供密切指导的经验 一批本科生，他们作为研究人员和榜样的成功将显著影响和促进 孟菲斯大学和中南部合作机构的研究环境。

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.