Simulations of temperature rise on transcutaneous energy transmission by non-contact energy transmitting coils

The authors describe simulation of steady-state temperature rise on transcutaneous energy transmission by non-contact energy transmitting coils. Electrical energy can be transmitted transcutaneously by means of the inductive coupling between two coils, one of which is located on the skin and the other of which is implanted inside the body. Temperature rise is calculated by the finite element method (FEM), considering the cooling effect of blood flow. Spacing the two coils farther apart increases the transmitting loss, i.e., the heating value of the coils, and raises the heat radiation effect around the coils. By simulating with various values of coil spacing, the optimum coil spacing which minimizes the temperature rise has been estimated. The results indicate that the optimum spacing depends on the thickness of a layer of subcutaneous tissues in which the cooling effect is expected to be less than in normal tissues. In a typical case the optimum spacing is in the range of 9-13 mm