Stiffness Augmentation using an Electromagnetic-based Haptic Interface

In this study, we develop an impedance-type algorithm for an electromagnetic-based haptic interface to provide a stiffness augmentation for a three-dimensional(3D) Virtual objects. A wearable haptic device is used and contains a magnetic dipole, the capability of the system is evaluated to render 3D virtual objects in mid-air using magnetic force in excess of 2 N within a workspace of 150 mm × 150 mm × 60 mm. As a target for rendering soft medical tissues for surgical training applications, our system is capable of rendering low range values of stiffness (0-500 N/m). We combine our system with an augmented reality (AR) tool to provide a combination of haptic perception and 3D visual representation. In order to show the effect of this combination, we conduct an experiment to evaluate the accuracy of stiffness perception with/without using an AR tool. Participants experimentally demonstrate an average success rate -% and -% in distinguishing between six values of stiffness with/without using an AR tool, our statistical analysis shows that effect of integrating an AR tool on the average success rate is statistically significant/ not significant, for 95% confidence level.