Static And Kinematic Analysis Of A Planar Cable-Driven Flexible Endoscope

Flexible endoscopes are mainly used for diagnostics and performing simple therapeutic tasks inside human cavities but are now becoming the key instrument for the incisionless surgery known as natural orifice transluminal endoscopic surgery (NOTES). Since the current endoscope technology gives limited maneuverability, dexterity, and functionality, a number of new endoscope designs have been proposed. Due to miniaturization, conduit, and actuation simplicity, many of the new designs rely on cable-actuating mechanisms similar to the current technology. Basic kinematical and static analyses for this device have not appeared in the literature. In this paper the articulated section of a planar cable-driven endoscope is modeled as a serial robot. The kinematic and static analyses for single-jointed and multi-jointed endoscope structures are performed to relate tip motion to the controlling inputs. Pre-tensioning cables increases the endoscope stiffness and extends its range of operation.