Design Of Cone-Beam Oral CT Machine And Research On Its Key Technology

With the continuous development of stomatology,cone beam CT has been widely used in oral diagnosis.Cone beam CT(Cone beam CT)is the most promising and practical diagnostic equipment in oral cranial imaging equipment.Its imaging principle is that the oral CT machine uses a cone X-ray beam to rotate around the target,using a small-sized dynamic flat panel detector.The data is collected and reconstructed by computer,and the two-dimensional projection image acquired at each angle is converted into three-dimensional volume data to display a three-dimensional image map of any direction and level.In a cone beam oral CT system,the combination of an X-ray source,an area array detector,and a scanning mechanism plays a key role in device performance.In the development of oral CT systems,high-precision mechanical devices,calibration of installation parameters,X-ray sources in scanning systems,area array detectors,and motor-assisted control are all key technical issues that need to be addressed.This paper has done some work on these key technical issues:By analyzing and exploring the principles of oral CT imaging and the current status of the current equipment,according to the requirements of mechanical accuracy in the imaging process,the overall design of the device is constructed,and the scanning imaging system transmission device is designed to improve the current transmission solution,Using Solidworks virtual prototype technology to complete the3 D modeling,and use Workbench Topology Optipizatiom to optimize the structure of the structure,so that the design structure while ensuring its safety and stability,to achieve the lightest quality,reduce related costs,and use Ansys Wokbench software performs static analysis and modal analysis on the 3D model of cone beam oral CT.The results show that the design meets the requirements of strength,stiffness and medical requirements.This design can effectively improve the force situation of the current equipment,low cost,safety and reliability.This paper analyzes the key parameters in the cone-beam CT imaging system.According to the conditions required by the FDK algorithm and the existing methods for obtaining geometric parameters,this paper proposes a method for quickly obtaining all parameters based on the four ellipses.Calibration phantom.Analyze the geometric relationship of the calibration phantom in space to accurately obtain all geometric parameters in the system.Finally,the method has been experimentally demonstrated.The experimental results show that the geometric parameters obtained by this method have high accuracy and can meet the requirements of normal medical treatment.In the oral CT system,the coordinated control of the X-ray source,the area array detector and the motor is a prerequisite to ensure the accurate quality of the scanned image.This article uses the STM32F407 series microcontroller as the main control chip to complete the X-ray source and detector.Coordinated control with the three motors,and in-depth analysis of the system’s motor start-stop and speed regulation characteristics,proposed a GA-optimized BP neural network PID control method,and conducted simulation experiments.The results indicate that the proposed control method has fast dynamic response,small amplitude of electromagnetic torque fluctuations,and strong anti-interference ability,which has certain application value.In this paper,the mechanical structure of cone beam oral CT,geometric parameter calibration method and coordinated control method of scanning imaging system are studied.The software simulation and experimental verification show that the mechanical structure,geometric parameter calibration algorithm and coordinated control method of imaging system designed in this paper are effective and feasible,and solve the practical problems faced by oral CT.However,there are still problems such as incomplete consideration of the manufacturing process of mechanical mechanisms,strict requirements for the calibration of installation parameters,and the need to optimize the human-computer interaction interface.