Research / Valve Biomechanics

Heart valve tissue mechanics and function

Our research spans the mechanical properties of heart valve tissue, constitutive modeling, leaflet deformation, and the interaction between valve motion and cardiovascular flow.

01 / Experimental leaflet strain

Aortic valve opening and leaflet strain

Experimental study of the aortic valve in a mock circulatory loop, combining valve-opening visualization with quantitative measurements of leaflet deformation and strain.

Valve opening and area. Bioprosthetic aortic heart valve with markers on the aortic surface.

Aortic valve leaflet strain. Time-dependent circumferential and radial strain under normal, parallel, and series flow configurations. May-Newman et al. (2010).

Related publication: May-Newman, K., L. Enriquez-Almaguer, P. Posuwattanakul, and W. Dembitsky. “Biomechanics of the aortic valve in the continuous flow VAD-assisted heart.” ASAIO Journal 56(4):301–308, 2010.

02 / Foundational research

Heart valve tissue mechanics & constitutive modeling

Biaxial mechanical testing of mitral and aortic valve leaflets reveals nonlinear, direction-dependent tissue behavior. We developed fiber-oriented hyperelastic constitutive laws that reproduce measured responses and predict behavior under additional loading protocols, providing material descriptions for computational valve models.

Biaxial testing. Original published schematic, enhanced for legibility; specimen mounting and marker-based strain measurement.

Mitral leaflet response. Anterior and posterior leaflet stress–stretch behavior, May-Newman & Yin (1998).

Foundational publications: May-Newman & Yin, A Constitutive Law for Mitral Valve Tissue (1998); May-Newman, Lam & Yin, A Hyperelastic Constitutive Law for Aortic Valve Tissue (2009). Aortic valve paper ↗

03 / Published research

Aortic root flow and sinus vortex formation

The aortic sinuses develop vortices as blood flows through the valve. In our experimental study, these vortices persisted as LVAD support reduced native aortic valve flow, disappearing when the valve remained closed. The recordings show the valve motion and corresponding PIV flow visualization.

Aortic sinus flow. Experimental PIV sequence during HeartMate II support.

Valve motion. Conventional recording of opening and closing during the PIV study.

Pangelina, Vu & May-Newman, Aortic Root Vortex Formation During Left Ventricular Assist Device Support, ASAIO Journal 71:149–156 (2025). View publication ↗