首台质子治疗装置（SAPT)360°紧凑型旋转机架等中心精度研究

Background]:Shanghai Proton Therapy Device (SAPT) is the first domestic proton therapy demonstration device, and the gantry is an important part of the proton therapy device, with an isocentric accuracy of 0.275mm, which is superior to the international mainstream equipment and requires high motion positioning accuracy and reliability.[Purpose]:To provide a reference for the impact of the gantry structure on the treatment accuracy of the gantry under different rotation angle conditions.[Methods]:The development progress of the 360 gantry located in the Ruijin proton center was introduced, and the research on its isocentric accuracy was introduced, and the measured results were compared. Through the static structural analysis module of ANSYS, the deformation analysis of the center point of the gantry is carried out, and the actual deformation is measured and the error sphere is plotted using a laser tracker to find the accuracy at the center point under typical working conditions and analyze the cause.[Results]:Through the qualitative analysis of the accuracy of the equal center point in the process of gantry and the comparison between the installed measured data and the simulation results, the trend of the two is the same, but there is a certain deviation (the simulation value is generally small), indicating that the theoretical calculation is close to the measured results but not the same. However, the rationality and reliability of the simulation method are fully verified.[Conclusions]:The simulation results not only show that the stiffness, strength and stability of the gantry structure are at an excellent level, but also provide a solid theoretical support for subsequent engineering applications. The successful development of China's first 360 gantry is not only a milestone in the localization of high-end medical equipment, but also a leading international level with ultra-high precision, innovative structure and cost advantages.