Research on a novel artificial anal sphincter for human incontinence

Abstract

This paper discusses a novel artificial anal sphincter with sensor feedback for controlling anal incontinence. The artificial anal sphincter system is a novel hydraulic-electric muscle which mainly comprises an artificial anal sphincter, a wireless power supply subsystem, and a communication subsystem. High integration of all functional components and no wire linking to the outer device make surgical implantation easier and lower risk. The wireless power supply subsystem employs a Class-E power amplifier based on adaptive control technique, and the electromagnetic compatibility in biological tissue is analysed. With the goal of designing a reliable and safe instrument, the models of human colonic blood flow and rectum motion are developed, the biomechanical material properties of human rectum and tissue ischaemia are analysed. The results show that the deformation of the artificial anal sphincter can be controlled by the press of reservoir below the upper limit of human tissue ischaemia. In vitro experiments demonstrate the artificial anal sphincter system is a good cure for human anal incontinence problems.

Keywords:

• Human incontinence
• Artificial anal sphincter
• Electromagnetic compatibility
• Ischaemia

Acknowledgment

This work was supported by “Shanghai University, ‘11th Five-Year Plan’ 211 Construction Project”, Innovation Fund of Shanghai University, Scientific Special Research Fund for Training Excellent Young Teachers in Higher Education Institutions of Shanghai (No. shu10052), and National Natural Science Foundation of China (No. 60975079).