GOALI: The Assessment of Stent Effectiveness using a Wearable MEMS Microphone Array System

冠状动脉疾病(CAD)是世界上主要的死亡原因之一，三分之一的死亡归因于这种疾病。据估计，全世界有600万患者接受了药物洗脱支架，这可能构成亚急性血栓形成的潜在风险。支架植入后一年或更长时间内可能会发生再狭窄。在45%的病例中，支架植入后这么远发生的血栓形成是致命的。由于晚期支架血栓形成是血管成形术后的严重并发症，因此能够在随访中量化再狭窄的进展是很重要的。如果闭塞可以通过放置在患者胸部外部的简单听诊仪器来量化，那么就可以监测再狭窄，并在发生致命血栓之前安排介入。这种用于支架患者监测的替代仪器还显著降低了成本，因为它取代了进行血管造影术或超声波来确定动脉是否有闭塞。在这个GALI项目中，研究小组将开发一种可穿戴的听诊系统，以改进冠状动脉闭塞的检测和定位，该系统基于对与闭塞冠状动脉中的湍流相关的孤立舒张期心音的记录和分析。可穿戴系统包括用于记录的智能、小尺寸、低噪音和高动态范围的MEMS麦克风阵列，以及用于预处理和无线传输与冠状动脉闭塞相关的湍流心音的手持系统。由于它们的精确匹配响应，所提出的麦克风阵列系统将能够实现高精度的声源定位和方向性。该系统还结合了使用个人数字助理(PDA)系统进行声音分析的先进处理和可视化技术。考虑到冠状动脉内支架置入的风险，本研究的目的是调查高度专业化的听诊系统在支架置入前后检测冠状动脉狭窄的严重程度和位置的能力。另一个长期临床目标是通过收集参与研究两年多的患者的随访数据，调查该系统的诊断能力，以评估裸金属支架或药物洗脱支架是否与较高的再狭窄发生率有关。将与产业伙伴Renegesis，Biomedical INC合作，对MEMS麦克风阵列、微电子学和无线系统的开发进行基础研究。该系统还可用于研究包括肾动脉和颈动脉闭塞在内的周围血管疾病以及下肢闭塞。它还可用于检测心脏瓣膜病。此外，该项目还为工程师、医生、医学物理学家和产业界之间的互动提供了一个跨学科的环境，并将进一步加强学术界、产业界和诊所之间的学术和研究互动。

CBET-0828912AkayCoronary artery disease (CAD) is one of the leading causes of death in the world with one third of all deaths attributed to this disease. It was estimated that 6 million patients have received drug eluting stents world wide which may pose the potential risk of sub acute thrombosis. Restenosis can occur up to one year or more after implantation of the stent device. A thrombosis that occurs this far after the stent has been inserted is fatal in 45% of cases. Because late stent thrombosis is such a serious complication after angioplasty it is important to be able to quantify the progression of restenosis in follow-up visits. If occlusion can be quantified by a simple auscultation instrument placed externally on the chest of the patient then restenosis can be monitored and an intervention can be scheduled before a fatal thrombosis occurs. This alternate instrumentation for stent patient monitoring also offers a significant cost reduction as it takes the place of performing an angiography or ultrasound to determine if there is an occlusion in the artery. In this GOALI Project, the research team will develop a wearable auscultation system to improve the detection and localization of coronary occlusions using an approach based on the recording and analysis of isolated diastolic heart sounds associated with turbulent blood flow in occluded coronary arteries. The wearable system consists of an intelligent, small-size, low noise and high dynamic range MEMS microphone array for the recording, and a handheld system for preprocessing and wireless transmission of turbulent heart sounds associated with coronary occlusions. Due to their precisely matched response, the proposed microphone-array system will enable high accuracy localization, and directionality of the acoustic source. The system also incorporates advanced processing and visualization techniques using a personal digital assistant (PDA) system for the analysis of sounds. Given the risks associated with the stent placement within the coronary arteries, the aim of this study is to investigate the ability of a highly specialized auscultation system to detect the severity and location of coronary artery stenoses before and after the stent placement. An additional long-term clinical goal is to investigate the diagnostic ability of the system to assess whether bare metal or drug eluting stents are related to higher incidence of restenosis by collecting follow up data from patients enrolled in the study for more than two years. Fundamental research on the development of MEMS microphone array, micro electronics and wireless system will be performed in collaboration with the industrial partner, Renegesis, Biomedical Inc.The proposed system can also be used for the investigation of peripheral vascular diseases including renal artery and carotid occlusions as well as lower extremity occlusions. It can also be used in detection of valvular heart disease. In addition, the project provides an interdisciplinary environment for interactions between engineers, physicians, medical physicists and industry and will further enhance the academic and research interactions between academic, industry and clinics.