Optimization Design for Receiving Coil with Novel Structure Based on Mutual Coupling Model in Wireless Power Transmission for Capsule Endoscope

Wireless capsule endoscope (WCE) is a promising technology for noninvasive and painless imaging detection on gastrointestinal (GI) diseases. On the other hand, conventional endoscopes with wires could discomfort patients and cause them to vomit and aerosolize coronavirus if the patients are infected with COVID-19. However, there stands a technical bottleneck on power supply for the WCE. With the help of wireless power transmission technology, a hollow receiving coil (RC) is proposed to supply sufficient power and also minimize the size of WCE. A model on mutual inductance between transmitting and receiving coils is proposed to evaluate receiving power when the RC is in a different position and direction of patient's GI tract. Based on the model, an optimal RC is built to obtain sufficient and stable power. Measurement of mutual inductance with the optimal RC validates high accuracy of the proposed model. The standard deviation of receiving power is very low. WCE with optimum RC gets sufficient power and captures images stably in live pig's intestine tract. Additionally, the model is little affected by biological tissues. It ensures reliable performance of WCE and makes popular clinical application of WCE possible, which is also a relief to reduce epidemics like COVID-19.