A Markeless Augmented Reality Tracking for Enhancing the User Interaction during Virtual Rehabilitation

Virtual Rehabilitation provides a range of technological and clinical developments in the field of virtual reality and augmented reality applied to rehabilitation. In this context, a system for upper-limb motor rehabilitation of stroke patients based on augmented reality was developed. This system aimed providing the motor imagery using a virtual three-dimensional arm that replaces the paralyzed arm in a real-time image of the patient. During the task execution in the augmented reality environment, the physiotherapist had guided the patients while they saw themselves and surroundings, as in a mirror. Although not achieving statistical significance, the Fugl-Meyer results of these case studies suggested that the participants were able to use the technology and they had larger shoulder range of motion of the affected hand post-training using the augmented reality system. However, many faults in the detection and recognition of physical markers were occurred whenever there was partial obfuscation or imperfect capture of the marker´s image. For this reason, a new version of the system was developed to provide an augmented reality system without markers, and thus, aiming to improve the usability of next clinical trials.