Stereoscopic 3D entertainment and its effect on viewing comfort: comparison of children and adults

Comparison of surgical outcomes between 3-dimensional and 2-dimensional laparoscopy of ovarian cyst (LOOC): a randomised controlled trial

The purpose of this study was to compare the surgical outcomes and efficacy of 3-dimensional (3D) versus 2-dimensional (2D) imaging systems for the treatment of ovarian cyst. A total of 46 patients undergoing a laparoscopic ovarian cystectomy were randomly assigned to either the 3D or 2D laparoscopy group. The primary outcome measure was the operative blood loss. The secondary outcome measure was visually induced motion sickness (VIMS), task efficacy during laparoscopy, and postoperative complication. There were no differences in baseline demographics between the two groups. The operative blood loss was significantly smaller in the 3D groups (28.7 ± 11.6 mL) than in the 2D groups (46.5 ± 24.4 mL) (p = .012). VIMS score was significantly higher in the 3D groups than the 2D groups (p < .001). 3D laparoscopy was superior to 2D in terms of the task efficacy of ovarian cyst enucleation (p < .001), adhesiolysis or dissection (p < .001), and ovarian suturing (p = .008). None of the patients in both groups developed operative complications. In conclusion, a 3D imaging system showed a more favourable surgical outcome and improved task efficacy than 2D in laparoscopic ovarian cystectomy. However, 3D laparoscopy tends to cause more frequent VIMS in surgeons.Impact statementWhat is already known on this subject? Several studies examining the possible benefits and drawbacks of a 3D imaging system versus 2D in laparoscopic surgery have brought about conflicting results. However, there have been few studies comparing the surgical outcomes of 3D and 2D laparoscopic ovarian cystectomy.What do the results of this study add? 3D laparoscopy showed favourable surgical outcomes and improved task efficacy than 2D laparoscopy in ovarian cystectomy.What are the implications of these findings for clinical practice and/or further research? More complex procedures, such as suturing and adhesiolysis, might be easier to perform with 3D laparoscopy than with 2D laparoscopy. Therefore, further large studies of 3D gynaecologic laparoscopy with different complexities and for surgeons with different surgical skills are needed.

Myopia-correcting lenses decrease eye fatigue in a visual search task for both adolescents and adults

The steady, world-wide increase in myopia prevalence in children over the past decades has raised concerns. As an early intervention for axial-length-related myopia, correcting lenses have been developed (such as Defocus Incorporated Multiple Segment (DIMS) lenses), which have been shown to be effective in slowing myopia progression. Beyond this direct effect, however, it is not known whether such lenses also affect other aspects important to the wearer, such as eye fatigue, and how such effects may differ across age, as these lenses so far are typically only tested with adolescents. In the present work, we therefore investigated perceived fatigue levels according to lens type (normal vs DIMS) and age (adolescents vs adults) in a demanding visual search task ("Finding Wally") at two difficulty levels (easy vs difficult). Whereas age and difficulty did not result in significant differences in eye fatigue, we found a clear reduction of fatigue levels in both age groups when wearing the correcting lenses. Hence, the additional accommodation of these lens types may result in less strain in a task requiring sustained eye movements at near viewing distances.

Mixture Kernel Density Estimation and Remedied Correlation Matrix on the EEG-Based Copula Model for the Assessment of Visual Discomfort

Since electroencephalogram (EEG) signals can directly provide information on changes in brain activity due to behaviour changes, how to assess visual discomfort through EEG signals attracts researchers’ attention. However, previous assessments based on time-domain EEG features lack sufficient consideration of the dependence among EEG signals, which may affect the discrimination to visual discomfort. Although the copula model can explore the dependence among variables, the EEG-based copula models still have the following deficiencies: (1) the methods ignoring the fine-grained information hidden in EEG signals could make the estimated marginal density function improper, and (2) the approaches neglecting the pseudo-correlation among data may inappropriately estimate the correlation matrix parameter of the copula density function. The mixture kernel density estimation (MKDE) and remedied correlation matrix (RCM) on the EEG-based copula model are proposed to mitigate the mentioned shortcomings. The simulation experiments show that MKDE can not only better estimate the marginal density function but also explore fine-grained information. The RCM can be closer to the real correlation matrix parameter. With the favourable quality of the proposed EEG-based model, it is used to extract time-domain EEG features to assess visual discomfort further. To our best knowledge, the extracted features present better discrimination to visual discomfort compared with the features extracted by the state-of-the-art method.

Incidence and severity of Visually Induced motion Sickness during 3D laparoscopy In Operators who had No experience with it (VISION)

Aim

The aim of the study was to evaluate the incidence and severity of visually induced motion sickness (VIMS) during 3D laparoscopy, in operators without prior experience.

Material and methods

Design: A retrospective comparative study (Canadian Task Force classification II-2). Setting: A university hospital. Intervention: Gynecologic surgery. Main outcome measure: This is a prospective observational study, which enrolled 9 surgeons as participants. None of these surgeons had any prior experience with 3D laparoscopy. Each participant performed 10 consecutive cases of 3D laparoscopy in patients with benign or premalignant gynecological diseases. The primary outcome measure was the incidence and severity of VIMS, which was evaluated using the validated Simulator Sickness Questionnaire. Personal preferences, discomfort, and ease of 3D laparoscopy were also evaluated.

Results

Sixty-seven percent of surgeons experienced VIMS during their first 3D laparoscopy case. The incidence and severity of VIMS dramatically decreased from the second case onward. However, in some surgeons (22-44%), VIMS did not completely disappear until the tenth case. With respect to the discomfort using 3D laparoscopy, 84 self-reported responses after each surgery were "favor 3D laparoscopy," and "no" in 61 (72.6%) and 47 (55.9%) participants, respectively. Most participants found it easier to perform 3D laparoscopy than 2D laparoscopy.

Conclusions

The occurrence of visually induced symptoms in susceptible individuals during 3D laparoscopy is high, particularly during their first case. This suggests the need for increasing surgeons' awareness regarding the possibility of discomfort.

Curved TVs improved watching experience when display curvature radii approached viewing distances: Effects of display curvature radius, viewing distance, and lateral viewing position on TV watching experience

Although watching TV often involves multiple viewing distances and viewers, less attention has been paid to the effects of display curvature radius, viewing distance, and lateral viewing position on TV watching experience. This study examined the effects of four display curvature radii (2300R, 4000R, 6000R, and flat), two viewing distances (2.3 m and 4 m), and five lateral viewing positions (P₁-P₅; 0, 35, 70, 105, and 140 cm off-center) on seven TV watching experience elements (spatial presence, engagement, ecological validity, negative effects, visual comfort, image quality, and user satisfaction). Fifty-six individuals (14 per display curvature radius) were seated in pairs to watch videos, each time at a different viewing position (2 viewing distances × 5 paired lateral viewing positions). The spatial presence and engagement increased when display curvature radius approached a viewing distance and lateral viewing position approached P₁, with 4000R-4m-P₁ (display curvature radius-viewing distance-lateral viewing position) providing the best results. Lateral viewing position alone significantly affected five TV watching experience elements; the spatial presence and engagement decreased at P₃-P₅, and ecological validity, image quality, and user satisfaction decreased at P₄-P₅. However, display curvature radius alone did not appreciably affect TV watching experience, and viewing distance alone significantly affected visual comfort only, with a 4-m viewing distance increasing visual comfort. This study demonstrated that effective display curvature radii for watching TV are viewing distance-dependent, and less off-center lateral viewing positions (P₁-P₂) are recommended for TV watching experience. Finally, among the TV watching experience elements, engagement explained user satisfaction to the greatest degree.

Effects of Immersive Virtual Reality Headset Viewing on Young Children: Visuomotor Function, Postural Stability, and Motion Sickness

PURPOSE

To assess the safety of VR 3D headset (virtual reality 3-dimensional binocular-stereoscopic near-eye display) use in young children. Product safety warnings that accompany VR headsets ban their use in children under age 13 years.

DESIGN

Prospective, interventional, before-and-after study.

METHODS

Recordings were obtained in 50 children (29 boys) aged 4-10 years (mean 7.2 ± 1.8 years). Minimum binocular corrected distance visual acuity (CDVA) was 20/50 (logarithm of the minimum angle of resolution [logMAR] 0.4) and stereoacuity 800 seconds of an arc or better. A Sony PlayStation VR headset was worn for 2 sequential play sessions (of 30 minutes each) of a first-person 3D flying game (Eagle Flight) requiring head movement to control flight direction (pitch, yaw, and roll axes). Baseline testing preceded VR exposure, and each VR session was followed by post-VR testing of binocular CDVA, refractive error, binocular eye alignment (strabismus), stereoacuity, and postural stability (imbalance). Visually induced motion sickness was probed using the Simulator Sickness Questionnaire modified for pediatric use (Peds SSQ). Visual-vestibulo-ocular reflex (V-VOR) adaptation was also tested pre- vs post-trial in 5 of the children. Safety was gauged as a decline or change from baseline in any visuomotor measure.

RESULTS

Forty-six of 50 children (94%) completed both VR play sessions with no significant change from baseline in measures of binocular CDVA (P = .89), refractive error (P = .36), binocular eye alignment (P = .90), or stereoacuity (P = .45). Postural stability degraded an average 9% from baseline after 60 minutes of VR exposure (P = .06). Peds SSQ scores increased a mean 4.7%-comparing pretrial to post-trial-for each of 4 symptom categories: eye discomfort (P = .02), head/neck discomfort (P = .03), fatigue (P = .03), and motion sickness (P = .01). None of the children who finished both trial sessions (94%) asked to end the play, and the majority were disappointed when play was halted. V-VOR gain remained unaltered in the 5 children tested. Three children (6% of participants) discontinued the trial during the first 10 minutes of the first session of VR play, 2 girls (aged 5 and 6 years) and 1 boy (aged 7 years). The girls reported discomfort consistent with mild motion sickness; the boy said he was bored and the headset was uncomfortable. No child manifested aftereffects ("flashbacks") in the days following the VR exposure.

CONCLUSION

Young children tolerate fully immersive 3D virtual reality game play without noteworthy effects on visuomotor functions. VR play did not induce significant post-VR postural instability or maladaption of the vestibulo-ocular reflex. The prevalence of discomfort and aftereffects may be less than that reported for adults.

Virtual reality games on accommodation and convergence

Increasing popularity of virtual reality (VR) gaming is causing increased concern, as prolonged use induces visual adaptation effects which disturbs normal vision. Effects of VR gaming on accommodation and convergence of young adults by measuring accommodative response and phoria before and after experiencing virtual reality were measured. An increase in accommodative response and a decrease in convergence was observed after immersion in VR games. It was found that visual symptoms were apparent among the subjects post VR exposure.

Effectiveness of three-dimensional visualisation on undergraduate nursing and midwifery students' knowledge and achievement in pharmacology: A mixed methods study

BACKGROUND

Historically nursing and midwifery students have reported difficulty understanding the concept-based science underpinning the interactions between drugs and their targets. This knowledge is crucial for the administration and monitoring of the therapeutic and adverse effects of medications. Immersive three-dimensional technology is reported to enhance understanding of complex scientific concepts but the physical effects of motion sickness may limit its use.

OBJECTIVES

This project compared the effectiveness of three-dimensional immersive visualisation technology with two-dimensional visualisation technology as a teaching method to improve student understanding of a pharmacological concept, and to assess levels of student discomfort and satisfaction associated with the experience.

DESIGN

Traditional lecture content and presentation about drug-receptor binding was followed by exposure to either a two- or three-dimensional artifact visualising β-adrenoceptor binding. Two student groups were compared by type of exposure: Group 1 watched the artifact via a three-dimensional immersive facility and Group 2 on a wide, two-dimensional screen.

SETTINGS

School of Nursing and Midwifery in a regional university in Southeast Queensland, Australia.

PARTICIPANTS

Two hundred and two second year undergraduate nursing and midwifery students.

METHODS

The study used mixed methods methodology. Pre- and post- testing of student knowledge was collected using five multiple-choice questions. A post-intervention survey elicited students' self-assessed perceptions of discomfort and satisfaction with the learning experience.

RESULTS

The three-dimensional immersive learning experience was comparable to the two-dimensional experience in terms of satisfaction and comfort but resulted in statistically significant improvements in post-test scores.

CONCLUSIONS

The three-dimensional experience improved understanding when compared to two-dimensional viewing, satisfied students leaning needs, and caused minimal discomfort. The results are encouraging in terms of using three-dimensional technology to enhance student knowledge of pharmacological concepts necessary for competency in medication management.

Usability evaluation of an instructional application based on Google Glass for mobile phone disassembly tasks

This study aims at comparing a Google Glass-based instructional application with a printed manual in mobile phone disassembly tasks. Thirty participants (15 males and 15 females) were recruited to perform tasks via three types of instructional methods (Google Glass-based augmented reality, Google Glass-based video, and a printed manual). The objective measures of performance (task completion time, error counts), and the subjective measures (NASA-Task Load Index, system usability scale) were considered. Additionally, visual fatigue was assessed by critical flicker fusion frequency and near point accommodation. According to the findings, although the printed manual method produced better results regarding mental workload and system usability, the augmented reality method improved error reduction and efficiency. Furthermore, the participants indicated that the displayed animations were helpful in locating the exact work-pieces. The augmented reality method is believed to be a potential alternative to printed manuals in mobile disassembly tasks.

Viewing 3D TV over two months produces no discernible effects on balance, coordination or eyesight

With the rise in stereoscopic 3D media, there has been concern that viewing stereoscopic 3D (S3D) content could have long-term adverse effects, but little data are available. In the first study to address this, 28 households who did not currently own a 3D TV were given a new TV set, either S3D or 2D. The 116 members of these households all underwent tests of balance, coordination and eyesight, both before they received their new TV set, and after they had owned it for 2 months. We did not detect any changes which appeared to be associated with viewing 3D TV. We conclude that viewing 3D TV does not produce detectable effects on balance, coordination or eyesight over the timescale studied. Practitioner Summary: Concern has been expressed over possible long-term effects of stereoscopic 3D (S3D). We looked for any changes in vision, balance and coordination associated with normal home S3D TV viewing in the 2 months after first acquiring a 3D TV. We find no evidence of any changes over this timescale.

Motion sickness

Over 2000 years ago the Greek physician Hippocrates wrote, "sailing on the sea proves that motion disorders the body." Indeed, the word "nausea" derives from the Greek root word naus, hence "nautical," meaning a ship. The primary signs and symptoms of motion sickness are nausea and vomiting. Motion sickness can be provoked by a wide variety of transport environments, including land, sea, air, and space. The recent introduction of new visual technologies may expose more of the population to visually induced motion sickness. This chapter describes the signs and symptoms of motion sickness and different types of provocative stimuli. The "how" of motion sickness (i.e., the mechanism) is generally accepted to involve sensory conflict, for which the evidence is reviewed. New observations concern the identification of putative "sensory conflict" neurons and the underlying brain mechanisms. But what reason or purpose does motion sickness serve, if any? This is the "why" of motion sickness, which is analyzed from both evolutionary and nonfunctional maladaptive theoretic perspectives. Individual differences in susceptibility are great in the normal population and predictors are reviewed. Motion sickness susceptibility also varies dramatically between special groups of patients, including those with different types of vestibular disease and in migraineurs. Finally, the efficacy and relative advantages and disadvantages of various behavioral and pharmacologic countermeasures are evaluated.

Heart rate variability (HRV) during virtual reality immersion

The goal of the study was assessment of the hour-long training involving handling virtual environment (sVR) and watching a stereoscopic 3D movie on the mechanisms of autonomic heart rate (HR) regulation among the subjects who were not predisposed to motion sickness. In order to exclude predispositions to motion sickness, all the participants (n=19) underwent a Coriolis test. During an exposure to 3D and sVR the ECG signal was continuously recorded using the Holter method. For the twelve consecutive 5-min epochs of ECG signal, the analysis of heart rate variability (HRV) in time and frequency domains was conducted. After 30 min from the beginning of the training in handling the virtual workstation a significant increase in LF spectral power was noted. The values of the sympathovagal LF/HF index while sVR indicated a significant increase in sympathetic predominance in four time intervals, namely between the 5th and the 10th minute, between the 15th and the 20th minute, between the 35th and 40th minute and between the 55th and the 60th minute of exposure.

Does 3D produce more symptoms of visually induced motion sickness?

3D stereoscopy technology with high quality images and depth perception provides entertainment to its viewers. However, the technology is not mature yet and sometimes may have adverse effects on viewers. Some viewers have reported discomfort in watching videos with 3D technology. In this research we performed an experiment showing a movie in 2D and 3D environments to participants. Subjective and objective data are recorded and compared in both conditions. Results from subjective reporting shows that Visually Induced Motion Sickness (VIMS) is significantly higher in 3D condition. For objective measurement, ECG data is recorded to find the Heart Rate Variability (HRV), where the LF/HF ratio, which is the index of sympathetic nerve activity, is analyzed to find the changes in the participants' feelings over time. The average scores of nausea, disorientation and total score of SSQ show that there is a significant difference in the 3D condition from 2D. However, LF/HF ratio is not showing significant difference throughout the experiment.

Pathophysiology and treatment of motion sickness

PURPOSE OF REVIEW

Motion sickness remains bothersome in conventional transport and is an emerging hazard in visual information technologies. Treatment remains unsatisfactory but advances in brain imaging, neurophysiology, and neuropharmacology may provide insights into more effective drug and behavioural management. We review these major developments.

RECENT FINDINGS

Recent progress has been in identifying brain mechanisms and loci associated with motion sickness and nausea per se. The techniques have included conventional neurophysiology, pathway mapping, and functional MRI, implicating multiple brain regions including cortex, brainstem, and cerebellum. Understanding of the environmental and behavioural conditions provocative of and protective against motion sickness and how vestibular disease may sensitize to motion sickness has increased. The problem of nauseogenic information technology has emerged as a target for research, motivated by its ubiquitous applications. Increased understanding of the neurophysiology and brain regions associated with motion sickness may provide for more effective medication in the future. However, the polysymptomatic nature of motion sickness, high interindividual variability, and the extensive brain regions involved may preclude a single, decisive treatment.

SUMMARY

Motion sickness is an emerging hazard in information technologies. Adaptation remains the most effective countermeasure together with established medications, notably scopolamine and antihistamines. Neuropharmacological investigations may provide more effective medication in the foreseeable future.

An investigation of pointing postures in a 3D stereoscopic environment

Many object pointing and selecting techniques for large screens have been proposed in the literature. There is a lack of quantitative evidence suggesting proper pointing postures for interacting with stereoscopic targets in immersive virtual environments. The objective of this study was to explore users' performances and experiences of using different postures while interacting with 3D targets remotely in an immersive stereoscopic environment. Two postures, hand-directed and gaze-directed pointing methods, were compared in order to investigate the postural influences. Two stereo parallaxes, negative and positive parallaxes, were compared for exploring how target depth variances would impact users' performances and experiences. Fifteen participants were recruited to perform two interactive tasks, tapping and tracking tasks, to simulate interaction behaviors in the stereoscopic environment. Hand-directed pointing is suggested for both tapping and tracking tasks due to its significantly better overall performance, less muscle fatigue, and better usability. However, a gaze-directed posture is probably a better alternative than hand-directed pointing for tasks with high accuracy requirements in home-in phases. Additionally, it is easier for users to interact with targets with negative parallax than with targets with positive parallax. Based on the findings of this research, future applications involving different pointing techniques should consider both pointing performances and postural effects as a result of pointing task precision requirements and potential postural fatigue.

Impact of the motion and visual complexity of the background on players' performance in video game-like displays

The visual interfaces of virtual environments such as video games often show scenes where objects are superimposed on a moving background. Three experiments were designed to better understand the impact of the complexity and/or overall motion of two types of visual backgrounds often used in video games on the detection and use of superimposed, stationary items. The impact of background complexity and motion was assessed during two typical video game tasks: a relatively complex visual search task and a classic, less demanding shooting task. Background motion impaired participants' performance only when they performed the shooting game task, and only when the simplest of the two backgrounds was used. In contrast, and independently of background motion, performance on both tasks was impaired when the complexity of the background increased. Eye movement recordings demonstrated that most of the findings reflected the impact of low-level features of the two backgrounds on gaze control.

Cinerama sickness and postural instability

Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly larger right after the movie than before, and in a lesser extent still so after 45 min. The average standard deviation of the lateral centre of pressure excursions was significantly larger only right afterwards. When low-pass filtered at 0.1 Hz, lateral and for-aft excursions were both significantly larger right after the movie, while for-aft excursions then remained larger even after 45 min. Speculating on previous findings, we predict more sickness and postural instability in 3D than in 2D movies, also suggesting a possible, but yet unknown risk for work-related activities and vehicle operation.

PRACTITIONER SUMMARY

Watching motion pictures may be sickening and posturally destabilising, but effects in a cinema are unknown. We, therefore, carried out an observational study showing that sickness then is mainly an issue during the exposure while postural instability is an issue afterwards.