Advanced IVUS Imaging with MUTs

描述(申请人提供)：由于压电换能器技术的创新应用，血管内超声(IVUS)成像在过去十年中已成为有效诊断和治疗心血管疾病的基本成像方式。相同的压电换能器的局限性阻碍了IVUS在新出现的重要临床应用方面的改进，例如用于引导介入的前视阵列，用于易损斑块、血管和纤维帽等动脉结构的高分辨率成像，以及用于实施诸如动脉组织和造影剂的谐波成像等技术。在这个项目中，我们计划在两条平行的道路上进行，并产生直接和长期的影响。在一条道路上，我们建议开发低成本、低轮廓、基于CMUT的宽带IVUS探头，带有2到4个单芯片环形阵列，以产生中心频率约为25 MHz、带宽为100%的M型冠状动脉切片。这些阵列将提高静脉内超声导管的交叉能力，并有可能在介入期间被扫描并拉回以生成图像。这些探头的实施和测试将增强我们对基于CMUT的IVUS阵列制造相关问题的理解，并可能导致设计改进。在这一努力的同时，第二条道路旨在探索CMUT设计的创新，以实现新的IVUS应用。具有双电极结构的CMUT不仅提高了高穿透深度和组织谐波产生的压力输出，而且这些换能器可以通过消除发射-接收开关的需要来简化探头电子设备。双电极CMUT结构与质量负载的CMUT膜相结合开辟了其他可能性。随着对基于这些新型CMUT的选定谐波的敏感性增强，拟议的研究可能会在总体上促进医学超声成像，产生比IVUS更广泛的影响。

DESCRIPTION (provided by applicant): Intravascular ultrasound (IVUS) imaging has become an essential imaging modality for the effective diagnosis and treatment of cardiovascular diseases during the past decade due to innovative applications of piezoelectric transducer technology. The limitations of the same piezoelectric transducers have impeded the improvement of IVUS for emerging clinically important applications such as forward viewing arrays for guiding interventions, high resolution imaging of arterial structure such as vulnerable plaque, vasa vasorum and fibrous cap, and for implementation of techniques such as harmonic imaging of the arterial tissue and of the contrast agents. In this project, we plan to proceed on two parallel paths with immediate and long term impact. On one path we propose to develop low cost, low profile, broadband CMUT-based IVUS probes with 2 to 4 single chip annular arrays to generate M-mode slices of coronary arteries around 25MHz center frequency and 100% fractional bandwidth. These arrays will improve the crossing capabilities of IVUS catheters and can be potentially scanned and pulled back manually to generate images during interventions. Implementation and testing of these probes will enhance our understanding of issues related to the manufacturing of CMUT-based IVUS arrays and result in possible design improvements. In parallel with this effort, the second path aims to explore innovations in CMUT design to enable novel IVUS applications. CMUTs with dual electrode structures not only improve the pressure output for high penetration depth and tissue harmonic generation, but these transducers may simplify the probe electronics by removing the need for transmit-receive switching. Dual electrode CMUT structure coupled with mass loaded CMUT membranes opens up other possibilities. With enhanced sensitivity to selected harmonics based on these novel CMUTs, the proposed research may advance medical ultrasound imaging in general generating an impact much broader than IVUS.