Preliminary tests of new composite material based on shape memory alloys for artificial aortic valve leaflets

摘要

Nowadays bioengineers actively search for new materials for different kind of implants. The natural tissues used for these purposes have many defects, of which the most important is the possibility of transplant rejection. However, properties of artificial biomaterials have also many deficiencies among which there are insufficient mechanical and fatigue properties. The example of this can be the aortic valve leaflets, which anatomy is complicated both in terms of geometrical shape and internal structure. This causes significant difficulties with finding suitable material for this type of implants. The most frequently used methods of obtaining material for that purpose are based on the processing of biopolymers (e.g. electrospinning) and also on extraction of porcine pericardial tissue. This paper presents a new concept of composite biomaterial based on shape memory alloys (SMA) with biopolymer matrix. The SMA thin fibers imitate collagen fibers in aortic valve leaflets which stabilize the aortic valve motion and reduce stresses. The numerical simulation of blood flow was done to verify assumptions and investigate the extent of deformation of the new composite structure.