Hybrid Visual Servoing For Autonomous Robotic Laser Tattoo Removal

Laser tattoo removal is a standard non-invasive method for removing color pigments on the skin. Increasing number of tattooed people who want to remove their tattoo has driven the medical laser market to develop new technologies for painless, scar-free and complete tattoo removal. However, manual use of such laser systems creates post-operative complications since they do not guarantee (i) protection on non-tattooed skin from laser exposure, nor (ii) precise control of the laser focus during the operations for best performance. This paper introduces deTattoo, a robotic system to improve tattoo removal operations. A robotic arm is equipped with a RGB-D camera and a visible laser, in eye-in-end configuration. A hybrid visual servoing control is proposed to guarantee the correct pose of the laser with respect to the tattooed tissue while compensating body motions. 2D features tracked with a mass-spring-damper deformable mesh model are combined with the 3D reconstruction retrieved from a RGB-D camera in order to build the control law. Several experiments were conducted to evaluate the performance of the system with a fixed or moving tattooed surface, at different inclinations. Results showed that the proposed framework is able to fulfil the laser-based tattoo removal requirements, providing high positioning accuracy (< 1mm) orientation (< 0.2 degrees) and body motion compensation.