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 end- effector 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.