Synthesis and Design of a 2-DOF Haptic Device for Simulating Epidural Injection

This work demonstrates the synthesis and design of a 2-DOF (Degrees Of Freedom) parallel haptic device intended for use in virtual simulation of medical procedures, e.g., epidural injection. The process involved choosing a right kinematic architecture of the mechanism, calculation of the end-effector forces, CAD modeling, stress analysis and a rapid prototyping of the device. We chose a pantograph mechanism with congruent joints i.e., effective base link length equal to zero. Maximum forces that can be exerted at the endeffector over the usable workspace were calculated from the stall torque of the actuators. The enhancement in the actuator torque was achieved by employing a capstan torque-amplifying transmission mechanism.