Integrating Haptics with Augmented Reality in a Femoral Palpation and Needle Insertion Training Simulation

This paper presents a virtual environment for training femoral palpation and needle insertion, the opening steps of many interventional radiology procedures. A novel augmented reality simulation called PalpSim has been developed that allows the trainees to feel a virtual patient using their own hands. The palpation step requires both force and tactile feedback. For the palpation haptics effect, two off-the-shelf force feedback devices have been linked together to provide a hybrid device that gives five degrees of force feedback. This is combined with a custom built hydraulic interface to provide a pulse like tactile effect. The needle interface is based on a modified PHANTOM Omni end effector that allows a real interventional radiology needle to be mounted and used during simulation. While using the virtual environment, the haptics hardware is masked from view using chroma-key techniques. The trainee sees a computer generated patient and needle, and interacts using their own hands. This simulation provides a high level of face validity and is one of the first medical simulation devices to integrate haptics with augmented reality.