Determination of the zero-pressure configuration of cardiovascular structures from in-vivo configuration

In the biomechanical analyses of human cardiovascular structures, it is often necessary to start with a zero-pressure configuration and apply the relevant boundary conditions. However, imaging modalities can only provide the in-vivo configuration of a cardiovascular structure for a patient, where it is really under non-zero pressure. Presently, the in-vivo configuration is just assumed to be the zero-pressure configuration for biomechanical analyses. In all likelihood, the zero-pressure geometry is smaller than the in-vivo geometry. In this work, we have developed a methodology by which a patient-specific in-vivo configuration of a blood vessel or ventricle may be shrunk to determine its zero-pressure configuration. We demonstrate this by applying the methodology to the case of a patient-specific 3D model of an abdominal aortic aneurysm and compare the results to that obtained by the conventional approach.