Preliminary Research On A Capsule Type Of PH Monitoring System For Gastro Esophageal Reflux Disease Diagnosis

In recent years, the changes of people's diet structure have caused the incidence rate of Gastro Esophageal Reflux Disease(GERD) increasing year by year. In clinical medicine, doctor inserts a pH monitor electrode through the patient's nasal cavity to the upper 5 cm on the Lower Esophageal Sphincter(LES), pH monitoring electrode is connected to the extracorporeal data recorder to monitor pH value of esophageal for diagnosis of GERD. However, this method will not only affect the patient's life and bring discomfort to the patient's esophagus wall, but also due to the movement of the electrode leads to measurement results is not accurate enough.This paper combined with the status of the diagnosis of GERD, based on the concept of Swallow Electronic Capsule(SEC), and preliminarily designed A GERD diagnostic assistant system based on wireless pH monitoring. This paper contained mainly four parts. First, I compared the performance of various electrodes used to measure the value of pH synthetically and chose glass electrode as pH sensor. A series of experiments have been carried out on the glass electrode, the experimental results show that the glass electrode has good stability and high accuracy. Second, TI micro control chip CC2540 is selected based on the function of data acquisition and processing and wireless transmission. It is the core of the data processing system with above function. This system can achieve accurate pH monitoring, real-time data processing and synchronization of wireless data transmission. Third, based on the concept of portable medicine, I designed a mobile phone application program based on Android system. The application receives data from the CC2450 and then displays and saves the data, and through the wireless transmission test, proved that the design of the application can achieve the data accurately. Fourth, I designed the sensor calibration scheme and verified the stability and accuracy of the pH measurement. Finally, I designed and completed the New Zealand rabbit in vivo experiment, suggesting that the GERD diagnostic assistance system based on the wireless pH monitoring is feasible.This topic has a unique application value in aspects of diagnosis and treatment of GERD. It is expected to be applied to clinical by gradual improvement. In addition, this technology can also provide a new way for pH monitoring in non-medical field.