Research On Wireless Communication Technology Of Capsule Endoscope System

The traditional diagnostic method of gastrointestinal disease is to use the mechanical intubation for detection. This method is full of pain, can easily get wounded and can cause cross-infection. The successful development of the capsule endoscope brings hope for the patients. Its advantage is a small size which is easy to be swallowed and it can check the small intestine. Now the capsule endoscope is playing a more and more important role in the gastrointestinal disease detection field. The normal life of the patient won’t be disturbed by the capsule endoscope. For some deadly disease if it can be diagnosed early the recovery rate is higher. But in the clinical case, the capsule endoscope can only move forward passively after it enters the gastrointestinal tract. The gesture & position of the capsule can’t be controlled outside the human body which leads to the randomness and blindness for the detection. The capsule endoscope has no function of treatment. So it can’t immediately cure the focus after it diagnoses disease.In response to these deficiencies of the capsule endoscope, this paper is supported by National Natural Science Foundation of China(No.31271069), National Natural Science Youth Fund of China(No.30800235) and Biomedical & Engineering Cross Fund of Shanghai Jiao Tong University(No.YG2013MS24). In this paper a capsule endoscope based on magnetism-control is developed. Whenever disease is diagnosed in the gastrointestinal tract, the capsule can be controlled by magnetism. The key content of this paper is the wireless communication module and the wireless energy supply system in the capsule endoscope. The main research for this paper is included as below:1、A special medical RF chip named ZL70102 is designed in the wireless communication module. In 2.45 GHz wake_up mode, the current of ZL70102 is only 290 nA and in TX/RX mode the current is 5mA. The communication module is designed for bidirectional transmission which guarantees that not only the image data can be transmitted to the base station but also the capsule can receive the command. The accuracy rate is high if the data is transmitted within 3 meters. It can meet the demand of a portable base receiver.2、The image capture module consists of a CMOS sensor which has the personalities of small size, low power consumption and high image performance. The resolution ratio of the colorful image is 320 × 240. Large image data need to be processed before wireless transmitting. In this paper, a chip named CX93510 is used for JPEG compression. Under a certain communication rate, the frame rate can be improved highly after data being compressed.3、To get rid of restrictions on the power consumption, this paper designs a wireless energy supply system. It consists of two parts, the energy transmission and the energy receiver. In order to obtain the maximum transmission power, the transmission frequency is adjusted to meet the intrinsic frequency of the coil for resonating. The energy receiver module is the power supply for other modules in the capsule endoscope. The experiment shows the wireless energy system can provide power as large as 200 mW. However, in normal communication the capsule consumes 175 mW to transmit image data out of the body. The validation scheme of the wireless energy supply is a practicable method for the power service.A prototype of the digital image capsule endoscope based on wireless energy supply is completed. The research combines the achievement of this paper with the effort of other members’. The diameter of the PCB is 10 mm and the whole capsule system is no longer than 15mm(without wireless energy supply module) which provides a platform for a further study of the capsule endoscope.