A virtual reality interface to provide point interaction and constriction to the finger

Virtual reality (VR) simulation of tube thoracostomy may improve the procedural training for medical and nursing students. Current VR simulators, however, do not provide tactile feedback, which is essential for enabling certain tasks (e.g., surface palpation to identify rib location, blunt dissection for access to pleural space surrounding the lungs, and finger sweep to confirm location in the pleural space). This work develops a physical apparatus that provides users with point feedback at the fingertip when palpating an external surface and a sensation of constriction around the finger during insertion into a body. The physical apparatus is composed of two components that separately control the constriction on the tip and middle of the finger. Each constriction component is made of two nylon casings coated with a silicone-elastomer that enclose about the top and bottom of the finger. DC gearhead motors control the magnitude of pressure in proportion to feedback from force transducers embedded in the silicone-elastomer. The device is intended to communicate with a virtual environment (written in H3D). The apparatus augments traditional stick-based force feedback and should enhance the learning of tactile tasks in tube thoracostomy.