Dexterity Analysis of an Colonoscopy Surgical Manipulator Combined with Spherical Joint and Cable-Driven Mechanism

The current endoscopic surgical manipulator exhibits limited freedom and flexibility, which poses challenges for medical procedures. To address these issues, a segmented cable-driven manipulator prototype with six bending degrees of freedom (DOF) was designed and analyzed for colonoscopy procedures. The manipulator’s dexterity was assessed by establishing a cables model using a combination of geometric analysis and the constant curvature method. The relationship between the bending angle of the joint and the cable length was derived. The Monte Carlo method was utilized to calculate the working space of the manipulator, and the dexterity distribution in axial, radial, and circumferential directions was evaluated using the flexibility index concept. The model was validated by simulation experiments, and the optimal working space and spatial dexterity parameters of the manipulator were determined, indicating that the manipulator's dexterity was suitable for colonoscopy surgical applications. The entire analytical process demonstrated feasibility and effectiveness, highlighting the potential application of this manipulator in endoscopic surgery.