Study And Application On Dynamic Balance In Computed Tomography System

CT(Computed Tomography)is an imaging technology which measures from different angles of the X-ray projection of a specific object,to obtain the cross-sectional information.Especially in medical industry,it provides a quick and non-destructive way for auxiliary diagnosis and treatment.With the issuance of “Health China 2030”,the need for CT is growing as the popular medical imaging devices.At present,CT has been widely used in basic clinical diagnosis;the rotation speed of the CT gantry has reached the sub-second level along with a high image time resolution.In the current situation of scanning speed and coverage,the application capability and scope of CT can be significantly improved.With the continuous improvement of the requirements of scan time,higher requirements for CT hardware design are also presented.In addition to the pursuit of more sophisticated detectors,X-ray tubes and advanced algorithms,the acceleration and stability of the rotation speed has become a basic requirement for high-speed CT design.For general CT device for cardiac diagnosis,the rotation speed of less than 0.5s has become standard.However,to control the vibration during high-speed rotation is the problem when design the gantry.Improve the stability and accuracy of the frame rotation,and other impacts come along with the high-speed rotation,is also the important guarantee to sustain the service life of CT and stability.The impact of unbalanced rotating frame is one of the problems to be solved.Based on the basic principle of CT,this paper studies and solves the shaking of the frame caused by the non-equilibrium state of the rigid non-uniform rotor under the high-speed rotation of the CT system.The study object model of the unbalance rotor of the CT frame is established to analyze and study the cause of rotor imbalance,and the theoretical analysis of the unbalanced control of the rigid rotor is carried out.Double dynamic balancing technology as the main method,the key to solve the dynamic balance testing vibration signal acquisition,processing,analysis and accurate extraction,calculation of unbalanced vector key problems,such as proposed in this paper the unbalance vibration extraction algorithm based on DFT is the implementation scheme.Combined with the theory and method of dynamic balance,using VIBXpertII tool,in this paper,the design and implementation of application in the CT system double dynamic balance debugging system,based on influence coefficient method and DFT to extract the signal,the system design,hardware selection,process design.The system realizes the dynamic balance calculation and adjustment of the rotor system of the two-sided disc on the CT prototype.Select the CT prototyping to validate and test the designed system.Through the verification of the design system,the test results meet the design requirements,indicating that the design scheme is normal and feasible,and the design requirements is met.