Universal Access in Human-Computer Interaction. Design Methods, Tools, and Interaction Techniques for eInclusion 7th International Conference, UAHCI 2013, Held as Part of HCI International 2013, Las Vegas, NV, USA, July 21-26, 2013, Proceedings, Part I

Symptoms of three-dimensional (3D) sickness, such as intoxication and eye fatigue, have been observed in subjects viewing 3D films and vary according to the image quality and visual environment. In addition, the influence of stereoscopic vision on the incidence of 3D sickness has not been explored sufficiently. Therefore, it is important to examine the safety of viewing virtual 3D content. The present study examines the effects of peripheral vision on reported motion sickness during exposure to 2D/3D video clips for 1 min and for 1 min afterwards in human subjects. Stabilograms were recorded during exposure to video clips with or without visual pursuit of a 3D object and compared, and subjects were administered the simulator sickness questionnaire after stabilometry. There were no significant main effects of solidity of the visual stimulous (2D/3D) and the vision method (visual pursuit/peripheral viewing) in accordance with the two-way analysis of variance of the sway values, although the sway values during the 2D/3D video clips were higher than in control subjects. A consistent trend in the main effect of stability was observed. Further, the sway values changed remarkably after the 3D video clip was viewed peripherally and produced a persistent instability in equilibrium function. The questionnaire findings also significantly changed after the subjects viewed the video clips peripherally. Subjective exacerbation and deterioration of equilibrium function were observed after peripheral viewing of 3D video clips. This persistent influence may result when subjects view a poorly depicted background element peripherally, which generates depth perception that contradicts daily experience.

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Peripheral viewing during exposure to a 2D/3D video clip: effects on the human body

It has been shown that it is possible to induce a strong illusion that a virtual body (VB) is one's own body. However, the relative influence of a first-person-perspective (1PP) view of the VB and spatial coincidence of the real body and VB remains unclear. We demonstrate a method that permits separation of these two factors. It provides a 1PP view of a VB, supporting visuomotor synchrony between real body and VB movements, but where the entire scene including the body is rotated 15 degrees upwards through the axis connecting the eyes, so that the VB and real body are coincident only through this axis. In a within-subjects study that compared this 15 degrees rotation with a 0 degrees rotation condition, participants reported only slightly diminished levels of perceived ownership of the VB in the rotated condition and did not detect the rotation of the scene. These results indicate that strong spatial coincidence of the virtual and real bodies is not necessary for a full-body ownership illusion. The rotation method used, similar to the effects of vertical prisms, did not produce significant negative side-effects, thus providing a useful methodology for further investigations of body ownership.

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The effects of rotating the self out of the body in the full virtual body ownership illusion.

Differences in autonomic responses between subjects with and without nausea while watching an irregularly oscillating video

By relaxing the contracted focus-adjustment muscles around the eyeball, such as the ciliary and extraocular muscles, improvement of the pseudo-myopia is expected. This understanding has led to the accommodation training in which the visual target is given by stereoscopic video clips. In this study, we verify short-term effects of the apparatus on eyesight of visual inspection workers (22 females) suffering from eye fatigue and 12 middle-aged persons. In the Measurement 1, the workers were trained in 3 days. Moreover, the middle-aged were investigated on several trials of the eyesight recovering apparatus in the Measurement 2. As a result, the visual acuity was statistically improved by continuous accommodation training which will promote a ciliary muscle-stretching effect.

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Effect of Accommodation Training on Visual Function of Visual Inspection Workers and Middle-Aged People

Effect of strategic accommodation training by wide stereoscopic movie presentation on myopic young people of visual acuity and asthenopia

By relaxing the contracted focus-adjustment muscles around the eyeball, such as the ciliary and extraocular muscles, improvement of the pseudo-myopia is expected. This understanding has led to the development of an eyesight recovering apparatus called Dr.REX, which uses stereoscopic video. In this study, we verify effects of the apparatus on eyesight of myopic young persons (16M & 16F) and 12 middle-aged persons. In the Measurement 1, the young were examined in the medium-range (>10 days) effect. Moreover, the middle-aged were investigated on several trials of the eyesight recovering apparatus in the Measurement 2. As a result, the visual acuity was statistically improved by continuous DR.REX treatment. We considered that the effect of the visual acuity recovery device is temporary, but the findings suggested that the continuous use of DR.REX will promote a ciliary muscle-stretching effect, leading to the improvement of visual acuity.

Effect of an Eyesight Recovering Stereoscopic Movie System on Visual Acuity of middle-aged and Myopic Young People

Visually induced motion sickness (VIMS) is caused by sensory conflict, the disagreement between vergence and visual accommodation while observing stereoscopic images. VIMS can be measured by psychological and physiological methods. We quantitatively measured the head acceleration and body sway before and during exposure to a conventional 3D movie. The subjects wore a head mount display and maintained the Romberg posture for the first 60 s and a wide stance (midlines of the heels 20 cm apart) for the next 60 s. Head acceleration was measured using an Active Tracer with 50 Hz sampling. The Simulator Sickness Questioner (SSQ) was completed immediately afterward. For the SSQ sub-scores and each index for stabilograms, we employed two-way ANOVA with leg postures and presence/absence of stereoscopic images as factors. Moreover, we assumed that the input signal was the head acceleration in the transfer system to control the body sway and estimate the transfer function.

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Effect of a Stereoscopic Movie on the Correlation between Head Acceleration and Body Sway

In general, gastrointestinal motility tests cause pain; therefore, the establishment of noninvasive methods is desired. Noninvasive methods facilitate the measurement of motility close to the normal physiological state, can provide new findings, and may contribute to the development of associated fields. Electrogastrography (EGG) is a gastrointestinal motility test in which gastrointestinal electric activity is measured. Compared with other gastrointestinal motility measurement methods such as the gastric emptying and internal pressure measurement methods, EGG is noninvasive and allows measurement under minimum restriction; therefore, measurement for a long time is also possible. In addition, since gastrointestinal electric activity, which cannot be quantified using other methods, can be measured, EGG is applicable to the evaluation of the state of the body and pathological conditions, and may provide new findings such as those useful for the prevention of gastrointestinal dysfunction associated with various disorders. EGG is also useful for preventing disorders associated with abnormal gastrointestinal activity such as functional dyspepsia, which has been more frequently observed in recent years, and constipation, which is an extremely frequent complaint in the elderly. Thus, EGG is of marked importance in public health. However, the range of EGG utilizations and applications is still limited at present. Therefore, we outlined the measurement/analysis methods, the advantages and problems of EGG and electrogastroenterography (EGEG), described their clinical importance, and also commented on forefront studies on EGG and evaluated its prospects.

Application of electrogastrography to public health

Relaxing the contracted muscles involved in focus-adjustment around the eyeball, such as the ciliary body and extraocular muscles, is expected to improve pseudomyopia. This hypothesis has led to the development of Dr.REX--an apparatus for recovering eyesight by using a stereoscopic video. In this study, we verified the effects of this apparatus on visual acuity and asthenopia in the short and medium terms. Thirty-two myopic Japanese students participated in this study. We compared the severity of asthenopia in subjects who used Dr.REX and in those who performed close work on video display terminals (VDTs). We determined that the use of the apparatus improved visual acuity in both the short and medium terms. In addition, asthenopia seemed to be less severe in subjects who used Dr.Rex than in those who performed close work on VDTs.

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Tetsuya Yamamoto

Papers

Effect of strategic accommodation training by wide stereoscopic movie presentation on myopic young people of visual acuity and asthenopia

Effect of an Eyesight Recovering Stereoscopic Movie System on Visual Acuity of middle-aged and Myopic Young People

Effect of a Stereoscopic Movie on the Correlation between Head Acceleration and Body Sway

Application of electrogastrography to public health

Effect of an Eyesight Recovering Stereoscopic Movie System on Visual Acuity and Asthenopia