Vibrotactile feedback: Effect of wearable sensors on balance

Introduction and Objective: Bilateral Vestibular Hypofunction (BVH) is the complete loss of vestibular function in both internal ears. Persons with BVH have difficulty maintaining balance, especially when walking in the dark or on uneven surfaces. This leads to an increased risk of falls, visual blurring, dizziness, unsteadiness and impaired general physical condition. This study aims to investigate the effects of a balance belt on activities of daily living (ADL) and quality of life (QoL). Method: The study includes 22 persons aged between 18-65 and diagnosed to have bilateral vestibulopathy as per Barany criteria. Participants were tested by high-speed video-oculography (prototype used for vHIT - ICS Impulse Type 1085) to assess their vestibular system before the study. Pre-assessment and final assessment on the participants were performed through; Visual Analogue Scale (VAS) to assess the severity and frequency of vertigo and dizziness, SF-36 Quality of Life Questionnaire (SF-36), Dizziness Handicap Inventory (DHI) for emotional, physical and functional outcomes of vestibular system disorders, HUR Smart Balance device to assess static balance and postural stability. Static balance, proprioception score, visual score, vestibular score and limit of stability (LOS) results were analysed with HUR Static Smart Balance device. Persons were briefly informed about how the balance belt was used. The balance belt provided vibratory feedback by stimulating the body position by sensing the direction of the user's tilt. The persons used the balance belt for 4 weeks during their daily life activities (sitting, standing, moving) and during vestibular rehabilitation. The vestibular rehabilitation programme was completed with the use of balance belt for a total of 8 sessions - 2 days a week for 4 weeks. Objective and subjective balance scores obtained through the vestibular rehabilitation programme were compared with the results obtained before the use of balance belt. Findings: A total of 22 persons with a mean age of 48.59±9y were included in the study. The gender distribution was 15 (68.2%) female and 7 (31.8%) male. When we look at the comparison of Balance Scores after using the balance belt; while a statistically significant increase was observed in Proprioception Scores (p=0.040*), Visual Scores (p=0.014*), Vestibular Scores (p=0.002**), no statistically significant difference was observed in terms of Static Balance Score (p>0.05). When we look at the comparison of the Limits of Stability Test Scores after the use of the balance belt; While a statistically significant increase was observed in LOS Backward Test Score (p=0.001**) and in LOS Leftward Test Score (p=0.001**), there was no statistically significant difference in LOS Forward and Rightward Test Scores (p>0.05). VAS vertigo frequency (p=0.001**), VAS vertigo severity (p=0.001**), Dizziness frequency (p=0.001**), Dizziness severity (p=0.001**) scores after balance belt use were observed to have a significant statistical decrease; while a significant increase was observed in the SF-36 (p=0.001**). A statistically significant decrease was observed in the Dizziness Disability Inventory scores (p=0.001**). (**The comparison is significant for p<0.01. *The comparison is significant for p<0.05) Conclusion and Recommendations: The balance belt contributed to vestibular rehabilitation by increasing somatosensory input and vibrotactile feedback and improved quality of life. As a result of this study, there were significant differences in balance scores in persons with bilateral vestibulopathy using balance belt. Using a balance belt, persons with bilateral vestibulopathy could move freely without the need of assistance or walking aids. The balance belt, providing tactile feedback on body position and balance, ensured mobility independence and an active and social lifestyle for persons with BVH. It is thought that the approaches to increase the physical activity level of persons with bilateral vestibulopathy should be adopted.