Multimodal Cues for Gait Rehabilitation With Smart Glasses in Persons With Parkinson’s Disease (PD): A Methodology for the Selection of Effective Design Solutions

Introduction: Persons with PD are affected by motor impairments that compromise their autonomy. Recent advances in wearable systems showed that sensory biofeedback (BF) can improve gait in PD. Through verbal BF, an existing smartphone-based gait rehabilitation system (CuPiD-system) makes PD subjects better aware of their gait performance. Thanks to Smart Glasses (SG), real-time visual and haptic cues are also feasible: this study describes strategies to design an innovative mHealth system obtained by integrating the smartphone-based CuPiD-system with SG. The aim is to rehabilitate postural and transient gait disturbances and to provide gait training at home for persons with PD. Methods: We performed a pilot trial on five subjects not belonging to a particular category of users, following a Human-Centered design research approach. We proposed sensory BF suggesting a rhythm to be followed: auditory by wireless earphones, visual and haptic by the SG. We analyzed the subjects’ qualitative and quantitative responses through an interview and a specific gait analysis protocol. Results: This testing phase investigated how sensory BF influences the user’s gait, the most efficient cues to improve user’s performance, and acceptance of the mHealth system. We applied an ad-hoc redesigned version of the Quality-Function-Deployment (QFD) design tool to manage the complexity of the collected data, Figure 33. Discussion: While visual BF improves spatial gait parameters, auditory and somatosensory BF improve temporal gait features (cadence). QFD’s results confirm the role of sensory BF on gait rehabilitation: auditory and haptic BF reach a higher efficacy than the visual one. Some critical aspects emerged: the gap between the user’s cadence and the target one; the subjects’ sensory preferences. In the next phase on PD subjects, the target cadence will be subject-specific, and questionnaires should be used to evaluate subjects’ sensory preferences and integrate them into the QFD matrix.