Surgeon´s third hand: An assistive robot endoscopic system with intuitive maneuverability for laparoscopic surgery

Laparoscopic surgery has to be operated with an assistant during surgery, which requires training and high cooperation work between the surgeon and assistants. The objective of this study is to develop a laparoscopic system providing intuitive maneuverability. We develop a Robotic Flexible Laparoscope System (RFLS) with compliance effect including adaptive impedance and velocity control to assist in laparoscopic surgery. The system is controlled by the surgeon´s head movements, so that the surgeon can use his/her hands to manipulate the laparoscopic instruments while maneuvering the laparoscope intuitively, and thus replace the assistant and enhance the efficiency of the surgery. The laparoscope movements are controlled by adaptive impedance control approach, the compliance effect, the impedance with the integral and derivative control design, and the reaction torque observer. We also add zero-point-correcting algorithm and singular situation elimination algorithm. Furthermore, scalable ratio adjustment of head movement with respect to laparoscope movement is also included in our system. This system makes surgeon-in-charge maneuver the laparoscope intuitively without communication and coordination with assistant needed in conventional way. As a result, it is expected to reduce manpower and time during surgery. Experimental results demonstrate that the articulated laparoscope can always follow user´s head motion in all necessary orientations.