Abstract: The Ortho-SUV frame, as an innovative parallel mechanism with variable hinge joints, can flexibly and conveniently treat limb deformities and fractures. In order to achieve orthopedic treatment, the spatial pose of the Ortho-SUV frame needs to be adjusted according to the fracture or deformity of different patients. Its kinematic analysis is therefore required. The pose of the Ortho-SUV frame was described by six spatial pose parameters, and its mathematical model was established. Based on its special structure, the nonlinear and high-coupled equations with trigonometric functions were transformed into ordinary non-linear equations without trigonometric functions, and the efficient and fast solution methods for the forward and inverse solutions of the spatial pose model were given. The correctness and the accuracy of the model were proved by checking calculation and simulated orthopedic experiment of tibial fracture, which provides a theoretical basis for the Ortho-SUV frame to be used in orthopedic treatment.

Key words: Ortho-SUV frame, parallel mechanism, forward and inverse solution, deformity correction