Effect of Control Design on Task Performance in Endoscopic Tele-Operation

Ori-Ben Porat, Industrial Design Program, Dept. of Architecture and Town Planning, Technion - IIT
Moshe Shoham, Faculty of Mechanical Engineering, Technion - IIT, Israel
Joachim Meyer, Dept. of Industrial Engineering and Management, Ben-Gurion University, Israel

Abstract:
    Endoscopic surgery, while offering considerable gains for the patient, has created new difficulties for the surgeon. One problem is the fulcrum effect, which causes the movement of a surgical instrument, as seen on the monitor, to be in the opposite direction to the movement of the surgeon's hand. The problem has been shown to impede endoscopic skill acquisition. Tele-operated robotic arms may circumvent this problem by allowing different control-response relations. Four alternative control designs of a tele-operated device were compared in a simulated endoscopic task. A rigid tele-operated robotic arm with 2 degrees-of-freedom, that represented a surgical tool, was coupled to a joystick in a position control mode. Feedback was provided through a video display. Participants without prior experience in endoscopy performed a target acquisition task, first by pointing the robotic arm at the targets, and later by maneuvering an object. Performance was measured under 4 different combinations of visual-motor mapping (normal / reversed), and the joystick's orientation (upwards / downwards). Task completion time under normal visual-motor mapping was found to be significantly shorter then under reversed visual-motor mapping, emphasizing the potential advantage of a tele-operated endoscopic system. The joystick's orientation only affected the maneuvering of an object under the reversed visual-motor mapping, implying that the positioning of a surgical tool and the manipulation of tissues or objects with the tool may be differentially affected by the control design.

Endoscopic Tele-Operation

ori1.jpg (38367 bytes)

The system :

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Full paper:Effect of Control Design on Task Performance in Endoscopic Tele-Operation