Study on three-dimensional energy receiving system for capsule endoscope

A wireless capsule endoscope for diagnosing human gastrointestinal tract is a great break-through. The system overcomes some disadvantages of the traditional push endoscope and causes less comfortlessness for patients. At present, the efficiency and stability of the energy receiving system of MEMS are still handicaps in practical applications and need improving. In this paper, a detailed analysis of three-dimensional energy receiving system for the endoscope is presented. Energy receiving performances of the three-dimensional secondary coil in the wireless energy transmission system for MEMS are studied. The coupling coefficient between the transmitting coil and one of the three windings of the receiving coil are actually measured under different working conditions such as different angles, by a self-made measuring circuit. The experimental results confirm that three orthometric windings of the receiving coil can compensate each other effectively for different attitudes. Afterwards a rectifying circuit is designed and fabricated in order to make use of the voltages generated from the three windings to power the MEMS. After measuring the output voltage of each rectifying circuit, the actual power consumption is calculated at different spatial attitudes. The experimental results prove that the efficiency and stability of the three-dimensional receiving system represented in this paper can meet practical requirements.