Experimental Study on the Wireless Energy Receiving System for a Capsule Endoscope

Wireless capsule endoscopy is a novel technology that enables close examination of regions deep inside human body. Because the energy available in the battery-powered types does not suffice to achieve high-quality images for a long time, inductive powering is a solution to this dilemma. In this paper, energy receiving performances of a two-dimensional receiving coil are studied. By experiments and simulations, coupling coefficient is obtained at different working conditions, such as different positions, different attitudes and different types of cores. The results prove that the two-dimensional coil can receive energy more effectively than one-dimensional coil at different attitudes. They also prove that a ferrite core can greatly enhance transmission capability. Then, a micro rectifying circuit is designed and fabricated to power a self-made picture pick-up system. Base on this, the actual output power is measured. The experimental results verify that the two-dimensional receiving system can provide enough power for the pick-up system. It may replace chemical batteries to power the MEMS inside human body.