US Patent 8342853 System for displaying and interacting with palpatable feature

A training aid for of a medical procedure where a substance is injected under the skin is disclosed that provides a user with the sensation of “pushing” the substance under the skin to smooth out raised areas. The training apparatus includes an artificial skin area with a raised feature protruding there from that is provided by cam-driven lifters positioned under the artificial skin area. The raised feature simulates the injected substance and may be touched and manipulated by the user.