The Error Analysis Of The Precision Radiotherapy With The Cutting Fork Type Treatment

The shear-fork type bed for precise radiotherapy treatment is one of the most important equipment in the radiotherapy room,its high stability and precision positioning play a crucial role in the process of cancer treatment,through the heavy ion beam irradiation,effectively killing the patient's bad cells,at the same time protect the patient's normal cells from irradiation.Any actual mechanical movement has a certain deviation with theoretical position,this article take the shear-fork type bed for precise radiotherapy treatment as the research object,mainly aimed at the displacement error of loading plate in the vertical direction is analyzed,the main work is as follows:(1)When the distance of the tip of the screw nut device with cutting fork mechanism fix point is at a certain point,the overall error of the cutting fork mechanism in the vertical direction is larger when the end position is closer to the left end;when the distance of the bottom of the screw nut device with cutting fork mechanism fix point is at a certain point,the overall error of the cutting fork mechanism in the vertical direction is larger when the end position is closer to the right end;(2)In the condition of roller wear,and the advance and delay of the roller which caused by the screw nut roller transmission error are at same amount,with the k value increases,the bearing plate on the horizontal direction,the absolute error value of roller wear less than the absolute error value of roller advance and delay,the absolute error value of which caused by roller advance and delay is equal;Bearing plate at the vertical direction,the absolute error value of roller wear larger than the absolute error value of roller advance and delay,the absolute error value of which caused by roller advance and delay is equal;(3)When single side error of the cutting fork mechanism is established,to make general error model of loading plate error and the simulation verification based on Matlab,on the basis of using the homogeneous coordinate transformation,get the mathematical model of displacement of loading plate under all levers in cutting fork mechanism may have deviation,including a point on the bearing plate of vertical,horizontal movement and bearing plate Angle gamma;(4)The statics and modal analysis was carried out on the cutting fork mechanism based on ANSYS software,and comprehensive studies of roller and shearfork lever,and select different materials on roller and shear fork lever,get the biggest rigid deformation of the bearing plate will change;The dynamic performance of the structure of shear-fork type bed for precise radiotherapy treatment was satisfied.