A New Laparoscopic Tool with In-Hand Rolling Capabilities for Needle Reorientation

In laparoscopic Minimally Invasive Robotic Surgery a teleoperated robot is interposed between the patient and the surgeon. Despite the robot aid, the manipulation capabilities of surgical instruments are far from those of the human hand. In this work we want to make a step forward towards robotic solutions that can improve the manipulation capabilities of the surgical instruments. A new concept of needle-driver tool is presented which takes inspiration from the human hand model. The idea is to modify a standard laparoscopic tool by introducing an additional degree of freedom which allows in-hand reorientation of the suturing needle. A 3D printed prototype was built to validate the tool's design. The improved manipulation capabilities have been assessed quantitatively by evaluating a weighted dexterity index along a single stitch trajectory. Moreover, a comparison between our tool and a standard needle driver has been done in terms of time required for the execution of a complete suturing sequence.