Experimental telemanipulation in endoscopic surgery.

Today's rigid endoscopic instruments limit the intracorporeal mobility of the surgical tool and are a severe impediment for the further spread of endoscopic techniques in operative medicine. Since 1992 flexible, steerable instruments with additional links for pivoting and rotating the tip have been developed and experimentally evaluated. The latest versions of this series of instruments are equipped with electromotors for better handling. The next aim in this development is a fully mobile telemanipulator with six motion axes dedicated to use in endoscopic surgery. Its first tests are planned for 1995. For successful operation of an electric telemanipulator, the man-machine interface (MMI) is of cardinal importance. For the definition of surgical requirements for the MMI, a conventional master-slave manipulator designed for technical application was modified for use in guiding a laparoscopic instrument. Master and slave sites of the system were 1.3 km apart and linked by means of a fiber-optic cable. Using this modified telepresence system, remote laparoscopic cholecystectomy was feasible in a phantom model. In a standardized test series using a test parcours, different parameters of the control system were modified, and their influence on the execution time of the parcours tasks was recorded. Well-suited parameter configurations were found and allowed experimental verification and completion of the important aspects of our concepts for development of an endoscopic manipulator MMI.