A meso-scale constitutive model for heart valve soft tissue incorporating fibril kinetics

Abstracts: Fiber-rich natural heart valve (HV) soft tissues have a multiscale structure as well as superior deformability. Accurately capturing the deformation of HV is essential for predicting response. However, previous models have fitted poorly to planar stress states and lacked a comprehensive understanding of fibril kinematics. We describe tissue mechanics based on the waviness and orientation distribution of the fibrils by considering collagen, elastin, and matrix components, and introduce all currently known fibril kinematics (straightening, rotation, and slip). The model is validated by fibril orientation distribution, and its extensibility is demonstrated on aortic, mitral, and tricuspid valves. The proposed meso-scale constitutive model fully captures the J-type stress curve of HV at the tissue level, and can quantitatively respond to the mechanical contributions of each tissue component, which has promising application potential for the mechanical study of soft tissues and may provide new insights into the superior mechanical properties of HV.