Mechatronic design of a hand-held instrument with active trocar for laparoscopy

Instruments used in many types of minimally invasive procedures, in particular laparoscopy, are rigid or only limitedly flexible and some tasks like suturing are difficult to perform with them. A novel hand-held, lightweight and ergonomic mechatronic instrument is presented in this paper. The instrument has a 3-DOF roll-pitch-roll end-effector controlled using an easy to use handle that provides the surgeon with a 6-DOF movement, including a distal circular movement which resembles the circular movement of stitching. The design of the instrument is based on a global study involving control, dexterity and ergonomic aspects, with the aim of developing an instrument that enhances the dexterity of the surgeon while having an intuitive and ergonomic interface. A proof of concept prototype was built and tested in vitro and in vivo.