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.