Design of a 3D motion simulator for respiration compensation study in stereotactic radiosurgery

Human respiration hinders accurate tumor localization during stereotactic radiosurgery. Localization error makes the treatment unsatisfactory, such as inadequate irradiation to the tumor, and damages to the normal tissues near the tumor. To track the tumor motion caused by respiration, surrogates are used instead of real-time directly X ray imaging. However, this still can´t avoid X-ray examination on human. For the sake of research on the relationship of surrogates and the tumor motion, we developed a 3D motion simulator which imitates the motions of surrogate and tumor. The motion of surrogate is provided by a 3D slide motion platform. The surrogate and “tumor” are connected by a spring-based mechanism, to satisfy the nonlinear and latency relationship. Force analysis has been done with the spring-based mechanism, and open motion data of the surrogate and tumor have been used to test the design´s validity.