Contraction support for the right ventricle by a shape memory alloy fibered artificial myocardium

Mechanical cardiac support by using artificial organs improves the circulatory condition in the patients with heart failure. However, the thrombotic and bleeding complications might be caused by the use of these artificial prosthetic internal organs because of their direct attachment with blood. We have been developing an implantable artificial myocardial assist device that can support the natural ventricular contraction from outside of the heart. A shape memory alloy fiber was employed for the implantable design of the myocardial assistance. In this study, we focused on the right ventricular assist by the artificial myocardium using shape memory alloy fibers. We fabricated a prototype of the right ventricular contraction support based on the hinge mechanism design with shape memory fibered actuators. Fundamental characteristics of the contractile effects of the design, as well as its deformation, were examined, and the hemodynamic changes were investigated in the acute animal experiments. As a result, the supporting depth from the ventricular wall increased to be 35 mm, and the volumetric assistance showed around 50 mL incremental assist by the changes in the displacement of the actuator.