None listed
Conditions
Brief summary
After a vestibular disorder, some people report persistent symptoms of motion sensitivity such as nausea, dizziness and imbalance when exposed to moving visual surroundings such as supermarkets (Zur, Schoen et al. 2015, Chin 2018). However, the causes and consequences of motion sensitivity have not been well investigated to date. This research aims to explore visual fixation and body sway that occur in response to complex visual scenes, in healthy adults and people with motion sensitivity after a vestibular disorder. The major hypothesis of the study is that complex visual environments will lead to higher variability in visual fixation and increased body sway in people with motion sensitivity as compared to healthy adults. Participants will stand on a force plate wearing a mobile eye tracker device (SMI Eye tracking glasses 2W; ETG-2.5-1520-129; iView ETG 2.7) on which retroreflective markers have been placed. The participant will be asked to look at letters projected onto a screen. The background behind the letters will be progressed in complexity, from neutral to a highly patterned, and finally a moving background. Eye movement, head position and body sway will be recorded using the eye tracker, body sway using an AMTI forceplate, and kinematics of the sway using 3D motion analysis (Qualisys). This will then be repeated in a virtual reality environment and allow comparison between a laboratory environment and a virtual reality environment.
Interventions
Each participant will attend the Motion Analysis laboratory for a single session. The session will last for 1.5 hours. The experimental set up consists of letters projected on a screen with different backgrounds with the screen 3.5 metres in front of the participant. Participants
will be standing with feet 20 cm apart on a force plate to estimate centre of pressure. Each participant will wear a mobile eye tracker device with markers attached to determine eye movements and head kinematics respect
Each participant will attend the Motion Analysis laboratory for a single session. The session will last for 1.5 hours. The experimental set up consists of letters projected on a screen with different backgrounds with the screen 3.5 metres in front of the participant. Participants will be standing with feet 20 cm apart on a force plate to estimate centre of pressure. Each participant will wear a mobile eye tracker device with markers attached to determine eye movements and head kinematics respectively. This will then be repeated in a virtual reality environment. The experimental programs for lab setup and Virtual Reality environment will be developed by an engineer. For Lab programs are supported through Python and Qualysis software. For developing Virtual Reality environment UNITY will be used as game engine and C# as language of development. Intervention will be delivered by coordinating investigator currently pursuing her doctoral degree in field of clinical sciences. She has received her Master of Physiotherapy qualification in the field of rehabilitation from India and has hands-on experience in working with people with neurological disorder. During her master's research she gained experience in conducting research adhering to clear ethical guidelines. She has also undergone consultation with the Matauranga Maori Research Committee and is familiar with the cultural considerations and the three Treaty of Waitangi principles of participation, protection and partnership. Experimental session includes following steps: 1.Lab and technical set up prior to participant arriving 2.Static calibration procedure for 3D kinematics 3.Participant Introduction and consent process 4.Preparing participant 5.Data collection Experimental Protocol: There are 6 tasks, each task lasting approximately 100 seconds. The letters on the screen will appear for 7 seconds each at different position each time. Participants will be asked to focus on the letters as they appear. Task 1: Random letters with no background: Random letters will be projected with no background. Task 2: Random letters with busy background: Random letters will be projected on busy background. Task 3: Multiple letters with no background: Random multiple letters will be projected on the screen. Participants will be asked to find and focus on letter E each time. Task 4: Multiple letters on busy background: Random multiple letters will be projected with busy background on the screen. The participant will be asked to focus on letter E each time. Task 5: Random letters on complex background: Random letters will be projected on a complex 2d moving background. Task 6: Random letters on moving background: Random letters on a moving background will be projected. After completing the session, eye tracker glasses, markers will be taken off the participant. The study will be using moving background/moving images. In some participants there are chances of feeling of dizziness or imbalance and nausea. An assistant will be standing near the participant for any assistance and to prevent fall in case of imbalance. Appropriate rest intervals will be provided.
Sponsors
Auckland University of Technology
Study design
Allocation
Non-randomised trial
Primary purpose
Diagnosis
Eligibility
Sex/Gender
All
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
1. Healthy adults Participants will be included in the healthy control group if they are aged between 18-60 years with independent level of mobility. However, people having reading glasses will be included in the study, as the design of the study require focusing on a letter at a distance. Also, the size of the letter has been chosen after piloting initial work with fellow research team members. 2. Motion sensitivity after vestibular disorder • 18-60 years of age (Agrawal, Carey et al. 2009, Bisdorff, Bosser et al. 2013) • History of Vestibular disorder • No signs of deficits of vestibular system • History of motion sensitivity symptoms as reported by situational characteristics questionnaire (score >5) (Dannenbaum, Chilingaryan et al. 2011, Sharon and Hullar 2014, Silva, Ferreira et al. 2016) • Level of dizziness as recorded by Dizziness Handicap Inventory. (Score >40)(Silva, Ferreira et al. 2016)
Exclusion criteria
- History neurological conditions that could interfere with eye movements. - History of any previous eye surgery - Medical condition which may influence the eye movements results such as sarcoidosis, Lyme disease, diabetes mellitus.
Outcome results
None listed