Development Of Online Detecting System Base On Pressure Artificial Denture

Using the removable dentures to repair the bad natural teeth,the health of the patient is impacted by the force of oral below in the dental clinic.Therefore,the oral medicine researchers hope to accurately understand the oral beneath the force of dentures.An online detecting system based on pressure artificial denture is presented in this paper.The system consists of microcontroller and PC.The microcontroller is the core of system and the PC performs real-time display,analysis and process for data. The primary works in this thesis are listed as follow:1,Express the measurement on the change of resistive weak signal which was no more than 1Ω,the bridge circuit with error compensation is designed to reduce errors produced by lead resistor and unbalanced bridge;Integrated device with high-precision inside resistance is used for amplifying the weak signal,the circuit reduces the gain error and improve the common mode rejection ratio;The active second-order low-pass filter(anti-aliasing filter) is designed to restrain noise signal and improve the signal to noise ratio.2,A data acquisition system must boast its marked features,such as strong real-time property,high reliability,good generality and easy to extend.According to it, a data acquisition system with the core of microcontroller is designed,it collect the 12-site data with the conversion accuracy of 10 and the sampling frequency of 50Hz; The microcontroller controls the USB chip to realize the transfer protocol between parallel I/O and USB interface conversing automatically,thereby,the microcontroller can transfer with PC in a higher rate which is up to 1 Mbps.3,Acordding to the practicality and economy,the PC software is developed by Visual C++,whose interface is visual and easy to use.The digital filtering algorithm and least squares method is used to inhibit the impact of random error and rectify nonlinearity.The dynamic data curve which is display by double buffering technology has a good animation effect and brings convenience to doctors.4,The sensor embedded in the denture had been tested,the result showed that the system of good linearity and repeatability.The testing of the system had been finished.The test results showed that the sensor had good and stable relations between the input and output.The ehanges to the external pressure can be aeeurately measured. In the dental clinic,implant denture can be buried sensors distributed.The force and its distribution beneath the bottom of mucosa and sub mucosa of the bone tissue exposure can be accurately measured by the detecting system.