Abstract

Info

Author(s):: LI Ruixing1; ZHANG Laixi1; CHEN Huixian1; SONG Mingtao2; LEI Wule1; ZHANG Peng1; 1. School of Mechanical and Electrical Engineering, Lanzhou University of Technology, Lanzhou 730050, China 2. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China

Keywords:: Keywords: target position biomechanics deformation error feed-forward correction

Abstract:: Abstract: Objective To analyze the deformation rules of the organ and tumor under the effects of biomechanics on target position in the second positioning, and to compensate for the error by controlling the position of mechanical arm. Methods According to anatomy and biomechanics, a finite element model of the lung and tumor was established by Mimics v17.0 software, and then the established finite element model was imported into ANSYS15.0. Finally, the deformation errors of the lung and tumor were analyzed using the biomechanical parameters summarized by predecessors. Results In the second positioning, the maximum deformations of the lung and tumor were 21.24 mm and 3.17 mm, respectively, and an error model was obtained by a quadratic polynomial fitting. After position verification, the error deformations were within the range, of which the deformation in the head and foot direction was the largest. Conclusion Based on the self-designed 6-degree-of-freedom positioning mechanical arm, a method for position control through feed-forward correction is proposed. The proposed method can compensate the displacement error of tumor in advance during the second positioning, thereby improving the accuracy and efficiency of radiotherapy, and reducing the damages to the normal tissues around the treatment target.