SMA artificial anal sphincters with transcutaneous energy transmission systems for complete implantation

¹ Institute of Fluid Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
² Graduate School of Medicine, Tohoku University
³ Institute of Development, Aging and Cancer, Tohoku University
⁴ Graduate School of Mechanical and Electrical Engineering, Tohoku University
⁵ Tel/Fax : +81-22-217-5298, E-mail: luo@ifs.tohoku.ac.jp

Abstract

This paper describes an artificial anal sphincter with transcutaneous energy transmission system for complete implantation. The artificial anal sphincter consists of two shape memory alloy (SMA) plates as the main functional parts, and heaters attached on SMA plates for heating. Electrical heating and natural cooling induced temperature changes result in phase transformation, accompanied by shape changes of the plates. These shape changes are used to perform two basic functions when the SMA artificial sphincter was fitted around intestines, i.e.. an occlusion body temperature and a release function upon heating. For reducing the potential of infection, a transcutaneous energy transmission (TET) system was incorporated into the artificial anal sphincter, facilitating the complete implantation of the device. Investigation on the thermomechanical responses of the artificial sphincter has been conducted, with both the in vitro and in vivo experiments, showing great potential of practical uses.