Design of planar spiral coil in transcutaneous energy transmission system

This paper studies transcutaneous energy transmission system (TETS) for artificial anal sphincter (AAS). The AAS is a solution to treat the severe fecal incontinence. It is designed to be implanted in the body of a patient who lose his anal sphincter. The AAS helps the patient to consciously open or close his anus to prevent fetal incontinence. The TETS is an optimal choice to provide energy for the implanted AAS without wire connections. It can provide large scale energy for the implanted AAS ideally. In order to get minimal invasions during implantation, this paper proposes a thin planar spiral shape for the secondary coil and the primary coil of the TETS. Parameters which affect the efficiency of the TETS are investigated thoroughly using Ansoft Maxwell software. The efficiency of different diameters of the primary coil and the secondary coil is discussed carefully. The experiment results show that the efficiency of the TETS can reach to 68.9% while the secondary coil is only 25 mm in diameter and 1.5 mm in thickness under the distance of 18mm to the primary coil. This shape and size of the secondary coil enable minimal invasions during the implantation of the AAS.