Design and assessment of novel artificial anal sphincter with adaptive transcutaneous energy transfer system

This paper presents the in vitro assessment of a novel elastic scaling artificial anal sphincter system (ES-AASS) with an adaptive transcutaneous energy transfer system (TETS) for treatment of severe faecal incontinence (FI). The proposed adaptive TETS has a phase control, which can maintain the output voltage at ∼7 V across the full range of the coupling coefficient variation (from 0.09-0.31) during the whole process of charging with a phase shift of 177.5° to 79.1°. A maximum surface temperature of 42.2 °C was measured above the secondary coil during an energy transmission of 3.5 W in air. The specific absorption rate (SAR) and current density analysis of the biological three-layers structure, including the skin, fat and muscle) surrounding the coil pair were analysed and the results of simulation analysis showed that the value of SAR and current density were very small at any given transmission condition compared with the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). In conclusion, in vitro experimental results showed that the ES-AASS can control simulated faecal behaviour effectively and the performance of TETS was validated.