Serious game development for Ankle rehabilitation aiming at user experience

Abstract

This article proposes an approach to adapt a game to ankle movement for a rehabilitation mechanism. Thus, a game was developed for ankle rehabilitation, which is inspired in the commercial version, already used with the AnkleBot (by Interactive Motion Technologies - IMT), changing both aesthetics and gameplay characteristics aiming a more intuitive and softer gameplay, improving the game experience. The movement underwent a transformation from elliptical motion, performed by the ankle, to game's rectangular workspace, better exploiting subject's movement features. For the assistance-resistance behavior the robot imposes to the user, a similar change was implemented converting a rectangular constraint to an elliptical one. These changes avoided motion discontinuity sensations to the user and provided a consistent motion for the ankle movement. Initial tests with a healthy subject showed that it is possible to adapt the game drive to the ankle movement through this mathematical transformation, better exploiting the player movement space and a smooth robot cooperation behavior, with movements more intuitive. System calibration is performed runtime, which allows not only the game to adjust itself for each patient, but also to adjust for every new achievement in patient's movement.