Assessment of control techniques for lower limb exoskeletons for physiotherapy with virtual reality

Abstract

Worldwide, as the average life expectancy increases, the number of people in need of physiotherapy rises. Besides, it is noted that not only stroke survivors and individuals with spinal cord injury demand for these services, but also SARS-CoV-2 patients, after long bed rest periods, need some gait therapy sessions. In order to turn physiotherapy more efficient, virtual reality and robotic devices have been employed. While virtual reality can place patients in an engaging environment, increasing pain tolerance by distracting them, robotic systems, such as wearable exoskeletons, can provide the patients support, assisting them during the execution of movements. Virtual reality systems and robotic exoskeletons altogether can provide visual, auditory and haptic feedback. When this happens, the user can interact with virtual environments as well as feel them by means of the robotic exoskeleton. Haptic feedback is known to improve motor learning, however, it is still an overlooked feature up to these days, due to its complexity and cost. Having this in mind, this work proposes the study of the influence of haptic stimulus in conjunction with visual and auditory stimuli on the human gait, comparing it with other control strategies that do not consider the haptic cue from the virtual environment. Tests will be performed on healthy individuals considering different exoskeleton behaviors; the data obtained through the sensors will be analyzed, as well as the information regarding the user's subjective perception during the experience, which will be assessed through questionnaires. Hence, this seeks to study the influence of different stimuli and different control architectures, considering the patient experience, which is oftentimes underestimated or even neglected during the development of robotic orthosis and control arquitectures.