Research On Wireless Capsule Endoscope System With Electrical Stimulation

The traditional diagnostic method of digestive track is to use the interpolating endoscope for inner detection.This method could make patient ausea and vomitting.Moreover,it may hurt the digestive track.With the birth of the capsule endoscope,the diagnostic method with no pain nor risk could be possible.However,the capsule endoscopes that we are using often have images with low resolution,low transmission rate and limited working time.They have only detection function and can't deal with the disease at the same time.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 JiaoTong University(No.YG2013MS24).In this paper a wireless capsule endoscope with electrical stimulation function is developed.The system could be controlled by doctors wirelessly,transmit the images outside the body.It can execute the electrical stimulation while detecting the disease powered by wireless power transmitting.The main research for this paper include image collection and compression,wireless data transmitting,electrical stimulation and wireless power transmitting.The image collection and compression unit include the CMOS sensor OV7740 and JPEG-compression chip CX93510 ? The frame buffer in CX93510 is well developed and we could use difference frame mode to increase the compression rate.The wireless data transmitting unit use the medical RF chip ZL70102,which has small size and low power with current of 5mA in working time.The protocol in ZL70102 is designed for the implanted medical system with excellent CCA,data transmitting,data checking and retransmission.Electrical stimulation is designed using constant flow source with 2 amplifiers.The function of DAC is achieved by PWM wave to meet the low power and small size.The wireless power supply unit measure the transmission power to adjust the transmission wave for a higher efficiency.The experiment results show that the diameter of capsule endoscope is 11 mm.In the distance of 2m,the images could be transmitted fluently and the electrical stimulation could be controlled well.In image captured mode,the system power consumption is about 180 mW.With electrical stimulation,the system power consumption is about 230 mW.The wireless power supply unit is related to the capsule's position.It could offer over 300 mW at most of the time which is sufficient for the capsule endoscope system.