Development of SMP's for Cardiovascular Use

用于心血管用途的 SMP 的开发

• 批准号: 6967027
• 负责人: ROBIN SHANDAS
• 金额: $ 20.91万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6967027
• 关键词: bioengineering /biomedical engineering; biomaterial compatibility; biomaterial development /preparation; biomaterial evaluation; biomaterial interface interaction; biomechanics; biotechnology; blood vessel prosthesis; cardiovascular prosthesis; medical implant science; molecular shape; physical property; polymers; prosthetic heart valve; surgery material /equipment

DESCRIPTION (provided by applicant): Minimally invasive surgical techniques to implant cardiovascular devices for treatment of a variety of valvular, vascular and extra-vascular complications are increasingly exploited to improve patient outcomes, and reduce morbidity and cost. Originally based on simple metals, these devices are now becoming more sophisticated through the use of precisely engineered materials such as metal bimorphs (shape memory alloys) and new polymer structures. Polymers, in particular, exhibit significant advantages in these applications over metals and metal alloys, including ease of surface modification that enhances biocompatibility, greater mechanical flexibility to more accurately simulate native mechanical behavior, and availability of a wide variety of base structural configurations. Manipulation of polymers to produce shape memory characteristics is the most recent evolution, which due to their high degree of shape recoverability (order of magnitude greater than metal alloys) promises significantly greater freedom in designing minimally invasive cardiovascular devices. However, several substantial challenges preclude reliable and direct applications of shape memory polymers (SMPs) as innovative biomaterials for surgical implants. The goal of this project is to remove this limitation in the SMP design process by explicitly quantifying the thermomechanical properties of one promising type of SMP, and infusing this information into a commercially available finite element model (ABAQUS). This will provide designers of cardiovascular devices who wish to use SMPs with two enhancements required to enable exploitation of SMP biomaterials in future surgical devices: (1) new SMP engineering benchmarking characteristics required for rational design and proof-of-concept for SMP-based devices, and (2) a powerful a priori evaluation tool to refine and test device designs prior to fabrication. The model will then be exercised to produce two increasingly complex prototype devices: a vascular stent with significantly greater shape recoverability than currently available using metal shape memory alloys, and a prosthetic heart valve.

描述（由申请人提供）： 人们越来越多地利用微创手术技术植入心血管装置来治疗各种瓣膜、血管和血管外并发症，以改善患者的治疗效果，并降低发病率和成本。这些设备最初基于简单的金属，现在通过使用金属双压电晶片（形状记忆合金）和新的聚合物结构等精确设计的材料而变得更加复杂。特别是，与金属和金属合金相比，聚合物在这些应用中表现出显着的优势，包括易于进行表面改性以增强生物相容性、更大的机械灵活性以更准确地模拟天然机械行为以及多种基础结构配置的可用性。操纵聚合物产生形状记忆特性是最新的发展，由于其高度的形状可恢复性（比金属合金大一个数量级），为设计微创心血管设备提供了显着更大的自由度。然而，一些重大挑战阻碍了形状记忆聚合物（SMP）作为外科植入物的创新生物材料的可靠和直接应用。该项目的目标是通过明确量化一种有前途的 SMP 类型的热机械特性，并将这些信息注入商用有限元模型 (ABAQUS)，消除 SMP 设计过程中的这一限制。这将为希望使用 SMP 的心血管设备设计者提供两项增强功能，以便在未来的手术设备中利用 SMP 生物材料：(1) 基于 SMP 的设备的合理设计和概念验证所需的新 SMP 工程基准特性，(2) 强大的先验评估工具，用于在制造之前完善和测试器件设计。然后，该模型将被用来生产两种日益复杂的原型装置：一种血管支架，其形状可恢复性比目前使用的金属形状记忆合金的支架要大得多，以及一个人工心脏瓣膜。