Development of time dependent biomechanical models for vascular tissue and implant design optimization

动脉粥样硬化疾病是北美的主要死亡原因之一。血管组织破裂是与几种终末期心血管疾病相关的常见现象，包括可导致心肌梗死或心脏病发作的冠状动脉疾病、可能导致出血的主动脉破裂和主动脉夹层。目前，医生使用简单的直径测量来估计疾病的严重程度。这些措施被证明是不准确的。研究人员最近提出了基于工程原理的新标准，以更好地评估这些疾病。然而，即使这些新的指数也不能解释所有观察到的不良事件。例如，对于冠状动脉疾病，新标准不能解释约30%的不良事件。因此，需要更好的标准，适合于这些复杂的软组织，表现出大的变形，如橡胶。在过去的几年里，我研究了一种新的方法，该方法基于对裂缝如何在这种软组织中发生和发展的理解，以补充评估组织破裂的风险。该研究计划将允许更好地了解这些软组织如何，在什么条件下以及何时失败，这可能导致心脏病发作和出血等不良事件。获得的关于天然组织通常如何变形的新知识也将用于设计下一代植入物，这些植入物也可以以相同的方式变形，以便更好地与身体相互作用。同样，这些信息也将用于开发医学成像技术，以改进对组织状态的非侵入性评估。这些新的诊断和治疗策略应该有重要的影响，因为大量的人口受到这些医疗条件。

Atherosclerotic diseases are amongst the principal causes of death in North America. The rupture of vascular tissue is a common phenomenon associated with several end-stage cardiovascular diseases including coronary disease which can cause myocardial infarction or heart attacks, aorta rupture and aorta dissection possibly leading to hemorrhage. Currently physicians are using simple diameter measurements to estimate the severity of the disease. These measures were proven to be imprecise. Researchers have recently proposed new criteria based on engineering principles to better assess these diseases. However, even these new indices cannot account for all observed adverse events. For example, for coronary disease the new criteria cannot account for about 30 % of the adverse events. There is thus a need for better criteria suited for these complex soft tissues that exhibit large deformations like rubber. I investigated, in the last years, a new approach based on the understanding of how cracks can happen and progress in such soft tissue for a complementary assessment of the risk of tissue rupture.******The research program will allow to better understand how, under what conditions and when these soft tissues fail which can lead to adverse events like heart attacks and hemorrhage. The new knowledge acquired about how the native tissue normally deform will also be used to design the next generation of implants that can also deform in the same way in order to better interact with the body. Similarly, the information will also be used for developing medical imaging techniques for an improved non-invasive assessment of the state of the tissue. These new diagnostic and treatment strategies should have important impact as a large number of the population is affected by these medical conditions.