Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation

BACKGROUND: Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. METHODS: Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. RESULTS: The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. CONCLUSION: The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation

The effect of virtual reality on visual vertigo symptoms in patients with peripheral vestibular dysfunction: a pilot study

Individuals with vestibular dysfunction may experience visual vertigo (VV), in which symptoms are provoked or exacerbated by excessive or disorientating visual stimuli (e.g. supermarkets). VV can significantly improve when customized vestibular rehabilitation exercises are combined with exposure to optokinetic stimuli. Virtual reality (VR), which immerses patients in realistic, visually challenging environments, has also been suggested as an adjunct to VR to improve VV symptoms. This pilot study compared the responses of sixteen patients with unilateral peripheral vestibular disorder randomly allocated to a VR regime incorporating exposure to a static (Group S) or dynamic (Group D) VR environment. Participants practiced vestibular exercises, twice weekly for four weeks, inside a static (Group S) or dynamic (Group D) virtual crowded square environment, presented in an immersive projection theatre (IPT), and received a vestibular exercise program to practice on days not attending clinic. A third Group D1 completed both the static and dynamic VR training. Treatment response was assessed with the Dynamic Gait Index and questionnaires concerning symptom triggers and psychological state. At final assessment, significant betweengroup differences were noted between Groups D (p = 0.001) and D1 (p = 0.03) compared to Group S for VV symptoms with the former two showing a significant 59.2% and 25.8% improvement respectively compared to 1.6% for the latter. Depression scores improved only for Group S (p = 0.01) while a trend towards significance was noted for Group D regarding anxiety scores (p = 0.07). Conclusion: Exposure to dynamic VR environments should be considered as a useful adjunct to vestibular rehabilitation programs for patients with peripheral vestibular disorders and VV symptoms

The Use of Technology in Vestibular Rehabilitation and Balance Assessment

Background study 1: Individuals with vestibular disorders usually complain of dizziness and visual vertigo in visually complex environments. Habituation exercises using visually provocative stimuli have been shown to be useful during vestibular rehabilitation. Virtual reality based therapy (VRBT) is an emerging technology that can be used in vestibular rehabilitation to provide visual habituation exercises for individuals with vestibular disorders. The purpose of the study was to explore the use of VRBT in the treatment of individuals with vestibular disorders and to examine the difference in self report and performance measures between VRBT and customized physical therapy (PT). Methods: Forty subjects with vestibular disorders participated in the study; subjects were assigned into two groups (VRBT or PT). Both groups had six treatment sessions for six weeks, and were assessed using self-report and performance measures. Results: Both groups improved similarly in most of self-report and performance measures and maintained improvements for six months after the intervention ended. Background study 2: Falling is a risk factor associated with vestibular disorders that can impact quality of life and reduce participation in daily life. Falling can be caused by a decline in function of sensory inputs associated with aging. Measuring sensory control during standing may help to investigate age and vestibular disease effects on balance. The Balance Rehabilitation Unit (BRU) utilizes high technology in balance assessment. The psychometric properties of the BRU including the reliability and validity have not been studied. The purpose of study 2 was to examine the reliability and validity of the BRU in the assessment of people with and without vestibular disorders. Methods: Ninety subjects (30 young healthy, 30 older healthy over 60 years of age, 30 individuals with vestibular disorders) participated in this study. Results: The BRU provided a reliable and valid measure for measuring the sensory contributions to postural control for healthy persons and people with vestibular disorders and was able to discriminate age and disease effect on balance

Effectiveness of conventional versus virtual reality based vestibular rehabilitation in the treatment of dizziness, gait and balance impairment in adults with unilateral peripheral vestibular loss: a randomised controlled trial.

BACKGROUND: Unilateral peripheral vestibular loss results in gait and balance impairment, dizziness and oscillopsia. Vestibular rehabilitation benefits patients but optimal treatment remains unkown. Virtual reality is an emerging tool in rehabilitation and provides opportunities to improve both outcomes and patient satisfaction with treatment. The Nintendo Wii Fit Plus (R) (NWFP) is a low cost virtual reality system that challenges balance and provides visual and auditory feedback. It may augment the motor learning that is required to improve balance and gait, but no trials to date have investigated efficacy. METHODS: In a single (assessor) blind, two centre randomised controlled superiority trial, 80 patients with unilateral peripheral vestibular loss will be randomised to either conventional or virtual reality based (NWFP) vestibular rehabilitation for 6 weeks. The primary outcome measure is gait speed (measured with three dimensional gait analysis). Secondary outcomes include computerised posturography, dynamic visual acuity, and validated questionnaires on dizziness, confidence and anxiety/depression. Outcome will be assessed post treatment (8 weeks) and at 6 months. DISCUSSION: Advances in the gaming industry have allowed mass production of highly sophisticated low cost virtual reality systems that incorporate technology previously not accessible to most therapists and patients. Importantly, they are not confined to rehabilitation departments, can be used at home and provide an accurate record of adherence to exercise. The benefits of providing augmented feedback, increasing intensity of exercise and accurately measuring adherence may improve conventional vestibular rehabilitation but efficacy must first be demonstrated. Trial registration Clinical trials.gov identifier: NCT01442623

Effectiveness of virtual reality-based vestibular rehabilitation in patients with peripheral vestibular hypofunction

Indexed keywords Metrics Abstract Background/aim: The rehabilitation of classical peripheral vestibular disorders is long and costly. Recently, interactive systems based on virtual reality (VR) technology have reduced the cost of vestibular rehabilitation therapy (VRT) and made the process more enjoyable. This study aims to investigate the effects of VR-based VRT in patients diagnosed with peripheral vestibular hypofunction (PVH). Materials and methods: In this study, a VR-based VRT program that utilized Sony Playstation®4 VR Head Mounted Display was applied to 25 patients (between 18–60) diagnosed with PVH. PVH was diagnosed by evaluating the patients’ clinical histories, the findings in the “Micromedical Technologies VisualEyes Spectrum” videonystagmography (VNG) and the “Micromedical Aqua Stim” model bithermal water caloric tests. VR-based VRT program was applied to the patients for 4 weeks, 2 sessions per week, 8 sessions in total. Each session lasted around 30 to 40 min. All patients underwent the Dizziness Handicap Inventory (DHI), Sensory Organization Test (SOT), Adaptation Test (ADT), Limits of Stability (LOS), and Rhythmic Weight Shift (RWS) before, after, and 8-week follow-up of the VRT program. In addition, the Cybersickness Survey was applied to the patients at the end of the VR-based VRT session every week. Results: The DHI mean scores of the patients were 54.60, 19.20, and 16.84, respectively, before, just after, and at the 8-week follow-up VRT (p < 0.001). The mean SOT composite score of the patients was obtained as 58.08 before VRT; 77.16 after VRT and 76.40 at 8-week after VRT (p < 0.000). On the other hand, the values in the ‘movement velocity’ and “direction control” parameters of the patients in LOS and RWS showed a significant improvement after VRT compared to before VRT (p < 0.000). From before VRT to 8 weeks after VRT, the patient’s oscillation averages in the ‘toes up’ and ‘toes down’ positions in ADT reduced progressively (p < 0.000). Conclusion: This study demonstrates that implementing a VR-based VRT protocol may be an efficient option to improve posture stability and the quality of life in patients with PVH. In addition, VR-based vestibular rehabilitation therapy has shown to be effective for PVH patients in the mid-term

Efficacy of a Computerized Sensor System for Evaluation and Training of Dizzy Patients

Patients with vestibular hypofunction often experience dizziness and unsteadiness while moving their heads. Appropriate sensors can effectively detect a patient’s dynamic visual acuity and associated body balance control. Forty-one vestibular-deficit patients and 10 normal individuals were invited to participate in this study. Questionnaires, clinical assessment scales and objective measures were evaluated on participants’ first visits. After 12 sessions of training, all scales were evaluated again on vestibular-deficit patients. The computerized system was composed of sensors, including a gyro and strain gauges, data acquisition accessories and LabVIEW software. Results revealed that the system could effectively distinguish normal subjects from subjects with vestibular deficits. In addition, after a rehabilitation program, subjects’ subjective and objective performances were significantly improved. Based on our results, we concluded that the present system, which uses a gyro and strain gauges, may provide an effective method for assessing and treating vestibular-deficit patients

Why do retail customers hesitate for shopping grocery online?

Considering a relatively slow adoption of online grocery shopping in the vast majority of the world markets, the main objective of this study was to uncover any new reasons why customers hesitate to shop groceries online. Moreover, we were not looking for undiscovered discouraging reasons only but also intended to validate previously researched reasons in published studies. Thus, we have first used a systematic literature review to cover all relevant previous studies on online grocery non-buyers. Even though this process is time-consuming, it provides a coherent overview of the published material on the topic. Further, we designed a web-based survey of 670 respondents from the general internet population. The data in open-ended questions related to online grocery attitudes and opinions were analysed by the content analysis. 14 thematic units emerged from the process from which the majority confirmed previously researched negative attitudes toward online grocery shopping. Non-buyers prefer to see grocery in person before buying it, there is a distrust in e-tailers to choose the best and freshest grocery, non-buyers prefer personal contact with the seller and behave habitually. Moreover, they tend to shop offline also because of hedonic reasons and pleasure from the shopping experience. Novel reasons why people hesitate to shop online in this category were the time consumption where consumers perceived online shopping slow regarding order-delivery time gap and were reluctant to pay for the delivery service, to mention just a few. We conclude with a summary of our results and a handful of recommendation for e-tail companies

Physical therapy in unilateral and bilateral vestibular hypofunction

[ES] Introducción: La rehabilitación vestibular (RV) basada en la terapia física, tiene el objetivo, en el caso de patología vestibular, de inducir la compensación del sistema nervioso central (SNC) a nivel de núcleos vestibulares y de otros niveles del SNC. Incluye ejercicios de habituación, adaptación y sustitución vestibular, ejercicios para mejorar el equilibrio y el control postural dinámico y ejercicios para el acondicionamiento general. En este capítulo discutimos los recientes avances sobre el adiestramiento del equilibrio y de la marcha, la estabilidad de la mirada y la habituación, en el contexto de los trastornos vestibulares uni y bilaterales. Método: Revisión narrativa. Resultados: Los ejercicios se prescriben para mejorar la función; fortaleciendo, y favoreciendo la flexibilidad y la resistencia, a través de la adaptación del RVO, la habituación, la sustitución sensorial, la marcha y el equilibrio postural. Son más eficaces los programas personalizados que los genéricos. El cumplimiento mejora con la personalización y las visitas de seguimiento a un fisioterapeuta. Discusión/Conclusiones: La RV permite mejorar el déficit funcional y los síntomas subjetivos derivados de la hipofunción vestibular periférica uni y bilateral, así como las alteraciones del equilibrio de origen central. Los objetivos de la RV consisten en reducir los síntomas para mejorar la estabilidad postural y de la mirada (particularmente durante los movimientos de la cabeza) y devolver al individuo a sus actividades normales, incluyendo la actividad física, la conducción y el trabajo habitual. Los médicos deben ofrecer la RV a quienes muestren limitaciones funcionales relacionadas con un déficit vestibular, pues actualmente se considera el tratamiento estándar en la disfunción vestibular periférica

Virtual Reality for Enhanced Ecological Validity and Experimental Control in the Clinical, Affective and Social Neurosciences

This article highlights the potential of virtual reality environments for enhanced ecological validity in the clinical, affective, and social neurosciences