System for guiding motions of a target joint

Abstract

Examples of a motion guiding device of a target joint of a target body are disclosed. The device allows three degree-of-freedom (DOF) motion about a remote center of rotation that is approximately aligned to a center of rotation of the target joint. The device comprises a base adjustably connected to the target body and three rotary joints interconnected with a network of linkages. One end of the network of linkages is connected to the base and the opposite end to an effector plate. At least one of the three rotary joints is not aligned with an axes of motion of the target joint and any of these rotary joints may be positioned under angle with respect to the others. Each of the rotary joints provides one DOF of rotary motion about the respective axes and each axis of the three rotary joints intersect at the remote center of rotation. The geometry of the network of linkages is adjustable to adjust a position of the remote center of rotation in three dimensions. The three rotary joints and the network of linkages rotate the effector plate about the remote center of rotation that is approximately align with the center of rotation of the target joint. This system may be connected with one or more parallel branches for additional actuation.