Prototype tactile feedback system for examination by skin touch

Background/purpose: Diagnosis of conditions such as psoriasis and atopic dermatitis, in the case of induration, involves palpating the infected area via hands and then selecting a ratings score. However, the score is determined based on the tester's experience and standards, making it subjective. To provide tactile feedback on the skin, we developed a prototype tactile feedback system to simulate skin wrinkles with PHANToM OMNI. Methods: To provide the user with tactile feedback on skin wrinkles, a visual and haptic Augmented Reality system was developed. First, a pair of stereo skin images obtained by a stereo camera generates a disparity map of skin wrinkles. Second, the generated disparity map is sent to an implemented tactile rendering algorithm that computes a reaction force according to the user's interaction with the skin image. Results: We first obtained a stereo image of skin wrinkles from the in vivo stereo imaging system, which has a baseline of 50.8 mu m, and obtained the disparity map with a graph cuts algorithm. The left image is displayed on the monitor to enable the user to recognize the location visually. The disparity map of the skin wrinkle image sends skin wrinkle information as a tactile response to the user through a haptic device. Conclusion: We successfully developed a tactile feedback system for virtual skin wrinkle simulation by means of a commercialized haptic device that provides the user with a single point of contact to feel the surface roughness of a virtual skin sample.