Ergonomic Design Process of Minimally Invasive Surgery Instrument hand-held manipulator with kinematic, psychologic analysis

This paper presents a design process for 6 degrees of freedom surgical instrument based on the psychological and kinematic analysis. Design requirement for an ideal mapping system for the hand-held instrument is deduced by psychological analysis. To realize the ideal mapping system, Virtual Center mechanism on the handle is proposed. Continuum rolling joint mechanism was used on the end-effector to implement two way bending in 5 mm diameter. A mechanism for compensating asymmetric displacements of the wire pairs bending the end effector is designed by kinematic analysis. The mechanism maintains equal wire tension wherever the end-effector bends to an arbitrary direction. And the mechanical design of handle that implements Virtual Center mechanism is demonstrated by Kutzbach Grübler formula. The performance of the prototype demonstrates intuitive control of the end-effector by human wrist motion.