Development of an Artificial Myocardium using a Covalent Shape-memory Alloy Fiber and its Cardiovascular Diagnostic Response

The authors have been developing a newly-designed totally-implantable artificial myocardium using a covalent shape-memory alloy fibre (Biometalreg, Toki Corporation), which is attached onto the ventricular wall and is also capable of supporting the natural ventricular contraction. This mechanical system consists of a contraction assistive device, which is made of Ti-Ni alloy. And the phenomenon of the martensitic transformation of the alloy was employed to achieve the physiologic motion of the device. The diameter of the alloy wire could be selected from 45 to 250 mum. In this study, the basic characteristics of the fiber of 150 mum was examined to design the sophisticated mechano-electric myocardium. The stress generated by the fiber was 400 gf under the pulsatile driving condition (0.4W, 1 Hz). Therefore it was indicated that the effective assistance might be achieved by using the Biometal shape-memory alloy fiber