Harmonic Doppler Ultrasound Embolus Characterization

谐波多普勒超声栓塞表征

• 批准号: 7027750
• 负责人: Mark A Moehring
• 金额: $ 26.12万
• 依托单位: SPENCER TECHNOLOGIES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-07 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7027750
• 关键词: adult human (21+); bioimaging /biomedical imaging; biomedical equipment development; cerebral artery; cerebrovascular imaging /visualization; clinical research; computer program /software; diagnosis design /evaluation; embolism; female; human subject; laboratory rabbit; phantom model; physical process; ultrasound blood flow measurement

DESCRIPTION (provided by applicant): This proposal is to develop a power M-mode Doppler ultrasound device for monitoring blood flow in the basal arteries of the brain for embolic events, and characterizing these emboli as gas bubbles or particulates. This device is of significant value in several venues where medical procedures result in emboli going to the brain. Substantial clinical significance of embolus characterization is found in surgeries utilizing cardiopulmonary bypass, for which numerous outcomes studies have documented short and long term cognitive decline. Approximately one third of strokes associated with CPB are intra operative[l], a majority of which are embolic. The effects of embolization are currently not appreciated until the patient comes out of anesthesia and manifests neurologic deficits in the intensive care unit, which is too late to take preventive or therapeutic action. Ultrasound differentiation of embolus composition during surgery is therefore of great value for appropriately responding to the type of emboliziation with therapy or modification in surgical approach or technique. This proposal is based on successful in vitro (flow phantom) and in vivo (characterization of emboli from prosthetic heart valves in a human subject) feasibility experiments for Doppler ultrasound discrimination of gas bubbles and particulates. The critical elements for this technology are: (1) a high dynamic range Doppler ultrasound platform capable of processing Doppler shifts from fundamental and second harmonic reflections from moving scatterers and (2) a transducer with similar sensitivity patterns at both fundamental and second harmonic frequencies. The proposed work is to further develop these critical elements by refinement of probe design, enhancement of signal processing of the fundamental and second harmonic echoes from emboli, and presentation of the characterization results to the operator in an easily appreciated image format. The system developed in this proposal will be tested in a series of experiments on a flow loop, an animal model of the human middle cerebral artery, and on human subjects undergoing Tran cranial Doppler evaluation for presence and severity of patent foramen ovale. These tests will include observation of single emboli and embolus showers, with variable embolus size and composition. This work is anticipated to result in improved neurological outcomes in the targeted heart surgery application, and a Phase III partner is ready and waiting to take the technology to market.

描述（由申请人提供）： 本提案旨在开发一种功率M型多普勒超声设备，用于监测脑基底动脉中的血流以发现栓塞事件，并将这些栓塞表征为气泡或颗粒。该设备在医疗程序导致栓子进入大脑的几个场所具有重要价值。在使用心肺转流术的手术中发现了栓子表征的实质性临床意义，许多结局研究已经记录了短期和长期认知能力下降。大约三分之一的CPB相关卒中发生在术中[1]，其中大部分为栓塞性卒中。栓塞的效果目前尚不清楚，直到患者从麻醉中苏醒并在重症监护室表现出神经功能缺损，此时采取预防或治疗措施为时已晚。因此，在手术过程中超声区分栓子成分对于通过治疗或手术方法或技术的改进适当地应对栓塞类型具有重要价值。该提议基于成功的体外（流动体模）和体内（人体人工心脏瓣膜栓子的表征）可行性实验，用于多普勒超声区分气泡和颗粒。该技术的关键要素是：（1）能够处理来自移动散射体的基波和二次谐波反射的多普勒频移的高动态范围多普勒超声平台，以及（2）在基波和二次谐波频率下具有相似灵敏度模式的换能器。拟议的工作是进一步开发这些关键要素的探头设计的细化，从栓子的基波和二次谐波回波的信号处理的增强，并呈现的表征结果，以一个容易理解的图像格式的操作员。在本提案中开发的系统将在一系列实验中进行测试，这些实验是在流动回路、人类大脑中动脉的动物模型和接受经颅多普勒评价的人类受试者上进行的，以确定卵圆孔未闭的存在和严重程度。这些测试将包括观察单个栓子和栓子簇射，以及不同的栓子尺寸和成分。这项工作预计将在有针对性的心脏手术应用中改善神经系统的结果，第三阶段的合作伙伴已经准备好并等待将该技术推向市场。