Catheter is a thin tube inserted into a human body for treatments in various medical procedures because of accurate access to the disease area, small amount of blood loss and patients’ fast recovery. A catheter is manipulated by a doctor watching images acquired through a camera at the tip of the endoscope or CT (computerized tomography). Medical simulations have been studied to provide novice doctors with training of catheter manipulation. Catheter haptic interface is essential in the simulation, which provides crucial information and cues.
A catheter haptic interface is proposed in this research. The designed haptic interface provides two degrees-of freedom of translational and rotation motions by the pneumatic module made of silicon rubber. The pneumatic module has cylindrical shape with a hollow space inside. The space inside of the module can be filled with air supplied by the syringe pump, and grasp the catheter traveling through the module. The syringe pump is designed with a ball screw and a motor. The catheter position is detected by rubber-coated rotary encoder and passive roller.
Experiment is conducted to identify the force and torque capacity of the haptic module. The measured force and torque have a linear relation with the pressure. The force range is 3.61N, and the error between the measured data and calibrated equation is 8.02%. The torque range is 3.494mNm, and the error between the measured data and calibrated equation is 10.79%. Assessment of the haptic module is conducted by a medical surgeon. The proposed haptic interface is expected to provide necessary haptic sensations during simulation of catheter operation.