Tool orientation and motion error in microsurgical parallel manipulator

Abstract

Positioning error is inherent in normal human hand motion and limits precision in manual microsurgery. A computer-based surgery can reduce human error. This work discuss tool orientation, motion error and computer simulation of a microsurgical end effector based on a parallel spatial manipulator. Among several previously developed parallel manipulators for other applications, the selected architecture for this work is consisting of a moving platform attached to a base through three identical prismatic-revolute-spherical jointed serial linkages. The actuation is conducted through the prismatic joints while the others are passive. These prismatic actuators lie on a common plane and have radial directions of action. A surgical tool of specific length is attached to the moving platform centre. A computer-based simulation is built for the end effector by obtaining the forward and inverse kinematics solutions. The developed relation for tool tip motion with respect to actuators positioning is used to evaluate tool location and orientation. Architectural designs for two arrangements are compared for better design and positioning error.