Adaptive transcutaneous power delivery for an artificial anal sphincter system

For controlling anal incontinence, a novel artificial anal sphincter system with sensor feedback based on transcutaneous energy transmission was developed. The device mainly comprises an artificial anal sphincter, a wireless power supply subsystem, and a communication subsystem. A transcutaneous power delivery system employing a class-E power amplifier, based on the adaptive control technique, is discussed in this paper. Amplitude modulation of the class-E power amplifier is integrated in the system and applied for the adaptive transcutaneous power delivery. Optimization of the power transfer efficiency and the misalignment tolerance is obtained. Experiments show that the system is capable of delivering at least 150 mW, with a power transfer efficiency of 41% over a distance of 3 cm, which can meet the electric power requirements of the artificial anal sphincter system. The power transfer frequency is 760 kHz.