Analysis of Inductance in Flexible Square Coil Applied to Biotelemetry

Flexible square coils are widely applied in wearable devices, especially in wireless power transfer systems. Wearable biomedical sensors are solutions where the electronic circuits are embedded into the clothes, for long-term patient monitoring in homecare health. The determination of coil´s inductance in a situation of flexion is not trivial, and may involve complex equations. In this paper, an analysis of inductance in flexible square coil, using classical Neumann equation, is proposed. An approximation with decagonal coils was used to simplify the calculation. Two sigmoid curves were calculated for fitting with high correlation. The simplification presented an averaged error less than 4.1%. Finally, comparisons with practical data are done. This proposed procedure can help in the design of flexible coils applied in wearable biotelemetric devices.