Research on wireless power transmission for gastrointestinal microsystems based on inductive coupling / 生物医学工程学杂志

A wireless power transmission method based on electromagnetic coupling was proposed for gastrointestinal microsystems. We analyzed the coupling coefficient, taking coils' misalignments into account by calculating mutual inductance. A power transmission model was built up. And based on this model, the electric parameters of maximizing the received power were deducted under weakly coupling condition. From the transmitting efficiency formula, we found two ways to enhance the efficiency. The transmission power was more than 200mW in our experiments when the receiving coil was located at the center of transmitting coil. This validated the method feasibility.

Power transmission for gastrointestinal microsystems using inductive coupling.

Much research on the development of a robotic capsule and microrobot for the diagnosis of gastrointestinal diseases has been carried out. The powering of these microsystems is becoming very important as the implementation of such systems is becoming more feasible by advances in relevant technologies. A wireless power transmission system employing two coils, based on inductive coupling, is discussed in this note. The coupling coefficient between the two coils was measured on axial, lateral and pitch misalignment. The power transmission efficiency was deduced and optimized by selecting proper tuning capacitors and transmission frequency. A serial resonant circuit (SRC) on a receiving side is more adaptive by comparison with parallel resonant circuit (PRC) topology. A multi-receiving coil structure was proposed and examined in an attempt to resolve the orientation indetermination problem of a receiving coil. Experiments show that a dc power level up to 170 mW, with an efficiency of 1.3%, could be steadily received when the receiving coil was placed at the center of the transmitting coil, which can meet the requirement for electric power of some microsystems.