Affiliation

The Cardiovascular Mechanics Laboratory (CML) is a research laboratory set up in 2005 by Dr. Michel Labrosse in the Department of Mechanical Engineering at the University of Ottawa. Over the years, various collaborations have developed, and the CML has been actively supported by the Division of Cardiac Surgery at the University of Ottawa Heart Institute.

Mission Statement

The objectives of the CML are to improve basic science in cardiovascular mechanics (e.g. description and understanding of soft tissue mechanics, cardiac valve geometry, cell mechanobiology), and combine this knowledge with the development, testing and validation of new computational tools to ultimately benefit patients. For instance, we are currently developing systems to help cardiac surgeons with the planning of repair procedures on the aortic and mitral valves. Another important goal of the laboratory is to provide undergraduate and graduate students with a stimulating environment where they can learn about the experimental, theoretical and computational tools necessary to progress towards the objectives above, and possibly develop their own research projects.


How can geometry and mechanics be related to pathology?

When faced with changes in their mechanical stimuli due to dilatation, hypertension or abnormal blood flow dynamics, the living cells in veins, arteries, heart valves and heart muscle adjust using different chemical and physical responses. They may for instance become larger, replicate (possibly changing their genetic information in the process) or die. This response may be enough to stop the progression of the underlying problem. If not, the problem will get more severe and, depending on the affected area, may result in different pathologies such as stenotic (stiffened and partially blocked) arteries or valves, valve regurgitation (leak), or aortic aneurysms that will eventually need medical or surgical treatment. 

 

Scientific approach

Investigation of such complex issues requires interaction between engineers, physicians, surgeons and biologists, and usually calls for the combined study of patient and in-vivo data, in-vitro experimentation, analytical modeling, 3-D reconstruction from medical imaging, and computational studies. Finite element analysis (FEA) is a computational tool of choice for the determination of mechanical stress and strain present in organs. Given that cardiovascular soft tissues are anisotropic (showing different mechanical properties in different orientations), hyperelastic and contain residual stress (stress that is present in the absence of loading), their study and modeling present interesting challenges.