The MUSHA Hand II:A Multifunctional Hand for Robot-Assisted Laparoscopic Surgery

Although substantial progresses have been made in robot-assisted laparoscopic surgery, the graspers for existing surgical systems generally remain nonsensorized forceps design with limited functions. This article presents the design, development, and preliminary evaluation of the MUSHA Hand II, a multifunctional hand with force sensors for robot-assisted laparoscopic surgery. The proposed hand has three snake-like underactuated fingers that can be folded into a $phi$12 mm cylindrical form. Each finger has a three-axis force sensor, to provide force information. After been deployed into an abdominal cavity, the hand can be configured to either grasper mode, retractor mode, or palpation mode for different tasks. Underactuated finger design enhances the adaptivity in grasping and the compliance in interaction with the environment. In addition, fingertip force sensors can be utilized for palpation to obtain a real-time stiffness map of organs. Using the da Vinci Research Kit as a robotic testbed, the functionality of the hand has been demonstrated and experiments have been conducted, including robotic palpation and organ manipulation. The results suggest that the hand can effectively enhance the functionality of a robotic surgical system and overcome the limits on force sensing introduced by the use of robots in laparoscopic surgery.