Miniature Telemetry Capsule vitro magnetic tracking technology

Interventional medical devices in order to solve the positioning of the body , the paper 863 projects ( No. : 2006AA04Z368) funding and support to Shanghai Jiaotong University for the detection of gastrointestinal pH, temperature , pressure and other physiological parameters and the development of the human gastrointestinal tract noninvasive treatment system for the technical background , based on the Hall effect magnetic field detection methods are compared in vitro depth research , trying to find a workable principle , to meet the practical requirements , easy to use and reliable magnetic positioning method . Compare the current existence of various positioning methods and found that based on the Hall effect magnetic positioning with non-contact, fast , easy application characteristics. This paper analyzes the spatial distribution of magnetic field of permanent magnets on a regular basis , we propose a new field based on permanent magnets and Hall sensor array in vitro magnetic tracking technology, and designed a magnetic tracking system in vitro . The system workflow as follows : First, in the human gastrointestinal tract for detecting micro- treatment device placed within a particular permanent magnets as the magnetic source ; Then , place the patient in vitro using a linear Hall sensor module array of sensors to detect the human body after the micro- device field information ; after detection information via the microcontroller, programmable amplifier (PGA), AD converter control module for processing composition ; finally, by the master computer to solve the magnetic dipole model equations to calculate the position of the permanent magnet , to determine the spatial position of the micro-device body coordinates purposes. Hall sensor array based on the development of in vitro magnetic tracking system and experimental optimization of the system , the system performance simulation and experimental intestinal plane experiment . Experimental results show that the positioning accuracy in the millimeter level , the absolute control error range of 18mm or less , about 95 % of the point of the error is in the range of ± 15mm , fully meet the application requirements . This system can accurately determine the spatial position of the permanent magnet is located , has a non- contact measurement , simple operation, high precision , as a valid observation in the human gut micro medical devices provided. But how will the human gut micro- device location visually effective expressed, still need further study.