Micromachined Single Crystal HF Arrays for Interventional Cardiology Ultrasound

描述（由申请人提供）：动脉粥样硬化和冠状动脉疾病影响了美国的大量人群，并且是死亡的主要原因。血管内超声（IVUS）已经开始在这些疾病的诊断和治疗中产生重大影响。它已被用于病变可视化、支架置入和支架监测，并且与其他模式相比具有优势，因为它能够区分各种组织类型。许多可视化方法，如弹性成像和RF分析，都有先进的IVUS，尽管这些方法需要大带宽的换能器。许多现有的换能器不具有足够的性能，并且需要声镜或不以提供最大临床意义的方式定向。在第一阶段，TRS技术公司和宾夕法尼亚州立大学开发了一种微加工方法，使用单晶来制造复合压电体。这种PMN-PT材料具有非常高的机电耦合系数（k33 > 90%），这为超声换能器提供了固有的宽带宽。在第一阶段计划中，构建了一个单元件换能器，其具有80%的带宽，具有一个声学匹配层，这显著高于当前商业IVUS换能器。对于II期计划，TRS建议通过构建用于介入心脏病学的宽带宽IVUS分段环形阵列来建立这些结果。该装置将提供动脉的三维表示和前瞻性架构。在该计划中，将使用体内动物研究对阵列换能器进行建模、制造和评估。

DESCRIPTION (provided by applicant): Atherosclerosis and coronary artery disease affect a large number of people in the United States, and is a leading cause of death. Intravascular ultrasound (IVUS) has begun to make a significant impact in diagnosis and treatment of these conditions. It has been used in lesion visualization, stent placement and stent monitoring, and has advantages over other modalities in that it is capable of distinguishing various tissue types. A number of visualization methods such as elastography and RF analysis have advanced IVUS, though these require a large bandwidth transducer. Many existing transducers do not have adequate performance, and require acoustic mirrors or are not directed in a way that provides the most clinical significance. In Phase I, TRS Technologies and Penn State University developed a micromachining method to create composite piezoelectrics using single crystals. This PMN-PT material has a very high electromechanical coupling coefficient (k33 > 90%) which provides ultrasound transducers with an inherently wide bandwidth. In the Phase I program, a single element transducer was constructed that exhibited 80% bandwidth with one acoustic matching layer, which is significantly higher than current commercial IVUS transducers. For the Phase II program, TRS proposes to build on these results by constructing an IVUS segmented annular array with broad bandwidth for use in interventional cardiology. This device would provide a three dimensional representation of the arteries, and a forward looking architecture. In the program, the array transducer will be modeled, fabricated and evaluated using in vivo animal studies.