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）： 该提案旨在开发一种功率 M 模式多普勒超声设备，用于监测大脑基底动脉的血流是否发生栓塞事件，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塞进入大脑的多个场所具有重要价值。在利用体外循环的手术中发现了栓子特征的重大临床意义，大量的结果研究已经记录了短期和长期的认知能力下降。大约三分之一与 CPB 相关的中风发生在术中[1]，其中大多数是栓塞。目前，直到患者从麻醉中苏醒并在重症监护病房表现出神经功能缺损时，人们才认识到栓塞的效果，此时为时已晚，无法采取预防或治疗措施。因此，手术期间超声区分栓子成分对于通过治疗或手术方法或技术的修改来适当响应栓塞类型具有重要价值。该提案基于成功的体外（流动体模）和体内（人体人工心脏瓣膜栓塞的表征）多普勒超声辨别气泡和颗粒的可行性实验。该技术的关键要素是：(1) 高动态范围多普勒超声平台，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，以及 (2) 在基波和二次谐波频率上具有相似灵敏度模式的换能器。拟议的工作是通过改进探头设计、增强来自栓子的基波和二次谐波回波的信号处理以及以易于理解的图像格式向操作员呈现表征结果来进一步开发这些关键要素。本提案中开发的系统将在流动回路、人类大脑中动脉动物模型以及接受经颅多普勒评估卵圆孔未闭的存在和严重程度的人类受试者上进行一系列实验测试。这些测试将包括观察单个栓子和栓子簇，具有不同的栓子大小和成分。这项工作预计将改善目标心脏手术应用中的神经系统结果，并且 III 期合作伙伴已准备好并等待将该技术推向市场。