scholarly journals Exocentric Distance Judgment and Accuracy of Head-Mounted and Stereoscopic Widescreen Displays in Frontal Planes

2020 ◽  
Vol 10 (4) ◽  
pp. 1427
Author(s):  
Chiuhsiang Joe Lin ◽  
Betsha Tizazu Abreham ◽  
Dino Caesaron ◽  
Bereket Haile Woldegiorgis
Keyword(s):  
Frontal Plane ◽  
Distance Judgment ◽  
Head Mounted Display ◽  
Position Accuracy ◽  
Significant Difference ◽  
Head Mounted Displays ◽  
Position Data ◽  
Exocentric Distance ◽  
3D Applications ◽  
Display Systems

An experiment was done to explore the effects of two virtual display systems on the accuracy of exocentric distance judgment and position. Sixteen participants viewed animated virtual targets using either a head-mounted display (HMD) or a stereoscopic widescreen display (SWD). The virtual targets have been shown, one at a time, at three depth levels and with two corresponding exocentric distances and three target sizes at each target distance and, afterward, via pointing by holding a stick to estimate the exocentric distance and position of each target. The position data were collected using an OptiTrack motion capture system. The results showed that the accuracy of exocentric distance judgment was higher with the head-mounted displays than with the stereoscopic widescreen displays. In addition, higher position accuracy in the X-direction was obtained from the stereoscopic widescreen displays, whereas no significant difference was observed in position accuracy in the Y-direction. However, it is possible that the HMD could give better accuracy in both exocentric distance and position judgments in the frontal plane, if the HMD had been perfectly mounted and flawlessly fit the participant’s eyes. The result also revealed that exocentric distance judgment was significantly higher at the farthest target distances than at the nearest distance. Similarly, the position accuracy significantly increased as exocentric distance decreased. Moreover, engineers may allude to the findings as the evidence from the study suggests that the intermediate target distances might be fitting or ideal distances to design and structure 3D applications.

Evaluation and Benefits of Head-Mounted Display Systems for HRI Research

2018 ◽  
Vol 62 (1) ◽  
pp. 1484-1488
Author(s):  
Rhyse Bendell ◽  
Gabrielle Vasquez ◽  
Andrew B. Talone ◽  
Florian Jentsch
Keyword(s):  
Human Robot Interaction ◽  
Hand Tracking ◽  
Head Tracking ◽  
Robot Interaction ◽  
Head Mounted Display ◽  
Military Research ◽  
Head Mounted Displays ◽  
Pros And Cons ◽  
Conducting Research ◽  
Display Systems

The intent of this evaluation is to describe the unique benefits that may be provided to human robot interaction (HRI) researchers by the capabilities of commercially available binocular head-mounted displays (HMDs) and associated handheld controllers. Three popular HMDs (Oculus Rift, HTC Vive, and Google Daydream) were compared across eight factors: cost, head tracking fidelity, visual resolution, user mobility, hand tracking fidelity, number of input modes, adaptability of input, and provided tracking space. Each of these elements was considered in the context of their relevance to the field of HRI, and potential importance for conducting research in immersive virtual reality (IVR). A Pugh chart was developed to succinctly compare the pros and cons of each headset alongside a description of IVR tasks for HRI military research as well as examples taken from work currently being conducted in our lab.

scholarly journals Comparison of superficial wound documentation using 2D forensic photography, 3D photogrammetry, Botscan© and VR with real-life examination

2021 ◽  
Vol 17 (3) ◽  
pp. 422-430
Author(s):  
Federico Massini ◽  
Lars Ebert ◽  
Garyfalia Ampanozi ◽  
Sabine Franckenberg ◽  
Lena Benz ◽  
...  
Keyword(s):  
Gold Standard ◽  
3D Visualization ◽  
Real Life ◽  
The Body ◽  
Whole Body ◽  
Forest Plot ◽  
Technical Documentation ◽  
Forensic Photography ◽  
Head Mounted Display ◽  
Significant Difference

AbstractEvidence acquisition, interpretation and preservation are essential parts of forensic case work that make a standardized documentation process fundamental. The most commonly used method for the documentation and interpretation of superficial wounds is a combination of two modalities: two-dimensional (2D) photography for evidence preservation and real-life examination for wound analysis. As technologies continue to develop, 2D photography is being enhanced with three-dimensional (3D) documentation technology. In our study, we compared the real-life examination of superficial wounds using four different technical documentation and visualization methods.To test the different methods, a mannequin was equipped with several injury stickers, and then the different methods were applied. A total of 42 artificial injury stickers were documented in regard to orientation, form, color, size, wound borders, wound corners and suspected mechanism of injury for the injury mechanism. As the gold standard, superficial wounds were visually examined by two board-certified forensic pathologists directly on the mannequin. These results were compared to an examination using standard 2D forensic photography; 2D photography using the multicamera system Botscan©, which included predefined viewing positions all around the body; and 3D photogrammetric reconstruction based on images visualized both on screen and in a virtual reality (VR) using a head-mounted display (HMD).The results of the gold standard examination showed that the two forensic pathologists had an inter-reader agreement ranging from 69% for the orientation and 11% for the size of the wounds. A substantial portion of the direct visual documentation showed only a partial overlap, especially for the items of size and color, thereby prohibiting the statistical comparison of these two items. A forest plot analysis of the remaining six items showed no significant difference between the methods. We found that among the forensic pathologists, there was high variability regarding the vocabulary used for the description of wound morphology, which complicated the exact comparison of the two documentations of the same wound.There were no significant differences for any of the four methods compared to the gold standard, thereby challenging the role of real-life examination and 2D photography as the most reliable documentation approaches. Further studies with real injuries are necessary to support our evaluation that technical examination methods involving multicamera systems and 3D visualization for whole-body examination might be a valid alternative in future forensic documentation.

scholarly journals The Pilot Study of the Hazard Perception Test for Evaluation of the Driver’s Skill Using Virtual Reality

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1114
Author(s):  
Tatsunori Sawada ◽  
Hiroki Uda ◽  
Akira Suzuki ◽  
Kounosuke Tomori ◽  
Kanta Ohno ◽  
...  
Keyword(s):  
Limited Range ◽  
Chi Square ◽  
Hazard Perception ◽  
Novice Drivers ◽  
Head Mounted Display ◽  
Road Users ◽  
Driving Skill ◽  
Significant Difference ◽  
Chi Square Test ◽  
Gender Groups

Background: Although various technologies are used to evaluate driving skill, there are some limitations such as the limited range of the monitor and the possible risk of causing cybersickness. The purpose of this study is to investigate differences in the hazard perception and cybersickness experienced between novice and experienced drivers measured in a VR hazard perception test with a head-mounted display (HMD). Methods: The novice (n = 32) and the experienced drivers (n = 36) participated in the hazard perception test through the VR of an HMD. Results: The total number of identified hazards was 1071 in the novice drivers and 1376 in the experienced drivers. Two of the hazards appeared to be only identifiable through the HMD. A chi-square test revealed that experienced drivers were more likely to identify the hazards than the novice drivers (p < 0.05). The novice drivers appeared to identify “hazard prediction of the current behavior of other road users” more than other hazard types, unlike the experienced group. The Simulator Sickness Questionnaire scores indicated no significant difference in the different age or gender groups (p > 0.05). Conclusion: Our results suggest that the VR hazard perception test may be useful for evaluating patients’ driving skills.

scholarly journals Isokinetic strength of shoulder internal and external rotators in cricket bowlers

2002 ◽  
Vol 58 (2) ◽  
Author(s):  
X.M. Mabasa ◽  
A. Stewart ◽  
C. Fleishman
Keyword(s):  
External Rotation ◽  
Peak Torque ◽  
Isokinetic Strength ◽  
Neutral Position ◽  
Joint System ◽  
Rotational Strength ◽  
Significant Difference ◽  
Position Data ◽  
Torque Values ◽  
Rotation Strength

The strength of the shoulder internal and external rotators incricket bowlers, may not be sufficient to cope with the demands of bowling.As very little research has been done on cricketers, this study was done to establish the isokinetic strength profile of the shoulder internal andexternal rotators in cricket bowlers.Isokinetic, shoulder rotational strength was evaluated in thirty malecricket volunteers with a mean age of 23.9 years and mean body weight of 70.3 kgs. The Cybex 340 dynamometer multi joint system was used to collect data on shoulder rotation strength in a standing neutral position. Data were collected at four different speeds (60,90,180 and 300deg/sec) and were computed for peak torque values for internal and external ratios for both dominant and non dominant shoulders.The results showed no statistically significant difference in the mean shoulder rotational torque between the bowlingand non-bowling shoulders for external rotation (p>0.05), and indicated statistically significant differences in themean shoulder rotational torque between the bowling and non-bowling shoulders for internal rotation (p<0.05). Therewas a significant decrease in isokinetic peak torque production for the external/internal rotator muscles as the speedof contraction increased (p<0.05). The peak torque ratio for the external/internal rotator muscles of the bowling armwere significantly less than of the non-bowling arm (p<0.05). These findings suggest that the strength ratios of thebowling arm need to be considered when managing young cricketers and their injuries.

scholarly journals Viewpoint Usability for Desktop Augmented Reality

2006 ◽  
Vol 5 (3) ◽  
pp. 33-39 ◽  
Author(s):  
Seokhee Jeon ◽  
Hyeongseop Shim ◽  
Gerard J. Kim
Keyword(s):  
Augmented Reality ◽  
Task Performance ◽  
Depth Perception ◽  
Object Manipulation ◽  
Head Mounted Display ◽  
Usability Problems ◽  
Head Mounted Displays ◽  
Hand Eye Coordination ◽  
Manipulation Task ◽  
Perceived Usability

In this paper, we have investigated the comparative usability among three different viewing configurations of augmented reality (AR) system that uses a desktop monitor instead of a head mounted display. In many cases, due to operational or cost reasons, the use of head mounted displays may not be viable. Such a configuration is bound to cause usability problems because of the mismatch in the user's proprioception, scale, hand eye coordination, and the reduced 3D depth perception. We asked a pool of subjects to carry out an object manipulation task in three different desktop AR set ups. We measured the subject's task performance and surveyed for the perceived usability and preference. Our results indicated that placing a fixed camera in the back of the user was the best option for convenience and attaching a camera on the user�s head for task performance. The results should provide a valuable guide for designing desktop augmented reality systems without head mounted displays

scholarly journals A kinematics analysis of the lower limb during running with different sports shoes

2018 ◽  
Vol 233 (1) ◽  
pp. 46-52
Author(s):  
Lin Fu ◽  
Yaodong Gu ◽  
Qichang Mei ◽  
Julien S Baker ◽  
Justin Fernandez
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Statistical Significance ◽  
Frontal Plane ◽  
3D Motion Analysis ◽  
Significant Difference ◽  
Running Shoes ◽  
Knee Abduction ◽  
Analysis System ◽  
Sports Shoes

The study aimed to investigate the differences in lower limb joint angles during running with three different sports shoes: basketball shoes, football shoes, and running shoes. Fifteen male subjects (age: 25 ± 2.2 years, height: 1.79 ± 0.05 m, and mass: 70.8 ± 3.4 kg) were asked to run on a treadmill at their preferred running speed. The Vicon 3D motion analysis system was used to capture the kinematics of the lower extremity during running. A one-way analysis of variance was used to determine whether any statistical significance existed between the three types of shoes (α < 0.05). Significant differences existed in the lower limb joints between the three sports shoes, particularly at the knee joint. Running shoes presented more knee flexion than basketball shoes and football shoes. In the frontal plane, basketball shoes showed less knee abduction than running shoes and football shoes. No significant difference occurred in ankle external rotation between basketball shoes and football shoes, and both of them presented greater range of motion of the ankle and knee than running shoes.

Development of a Low-Cost Augmented Reality Head-Mounted Display Prototype

2018 ◽  
pp. 1-28
Author(s):  
Thiago D'Angelo ◽  
Saul Emanuel Delabrida Silva ◽  
Ricardo A. R. Oliveira ◽  
Antonio A. F. Loureiro
Keyword(s):  
Virtual Reality ◽  
Augmented Reality ◽  
User Experience ◽  
Low Cost ◽  
User Interaction ◽  
Daily Activities ◽  
Head Mounted Display ◽  
Time Performance ◽  
Work Tasks ◽  
Head Mounted Displays

Virtual Reality and Augmented Reality Head-Mounted Displays (HMDs) have been emerging in the last years. These technologies sound like the new hot topic for the next years. Head-Mounted Displays have been developed for many different purposes. Users have the opportunity to enjoy these technologies for entertainment, work tasks, and many other daily activities. Despite the recent release of many AR and VR HMDs, two major problems are hindering the AR HMDs from reaching the mainstream market: the extremely high costs and the user experience issues. In order to minimize these problems, we have developed an AR HMD prototype based on a smartphone and on other low-cost materials. The prototype is capable of running Eye Tracking algorithms, which can be used to improve user interaction and user experience. To assess our AR HMD prototype, we choose a state-of-the-art method for eye center location found in the literature and evaluate its real-time performance in different development boards.

scholarly journals Wired to Exit: Exploring the Effects of Wayfinding Affordances in Underground Facilities Using Virtual Reality

2020 ◽  
pp. 104687812094456
Author(s):  
Panos Kostakos ◽  
Paula Alavesa ◽  
Mikko Korkiakoski ◽  
Mario Monteiro Marques ◽  
Victor Lobo ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Control Group ◽  
Head Mounted Display ◽  
Significant Difference ◽  
Parking Lot ◽  
Biometric Measurements ◽  
Physiological Outcomes ◽  
High Level ◽  
Experimental Group ◽  
Level Effect

Background Wayfinding has been adopted in several intense evacuation and navigation simulations; however, the use of biometric measurements for characterizing physiological outcomes has been somewhat overlooked and applied only under limited laboratory conditions. Methods Twenty-four participants took part in a virtual reality (VR) experiment using a wayfinding installation with the Oculus Rift S head-mounted display (HMD). They were immersed in a simulation of a burning underground parking lot and tasked to navigate to the exit. The purpose of this research was to investigate the high-level effect of wayfinding assistive lights on behavioral, physiological, and psychological outcomes. Participants were split into two groups: the control group was exposed to a scene without assistive lights, and the experimental group was exposed to the same scene with assistive lights. Results Results indicate there was no statistically significant difference between the groups in traveled distance, pauses, turns, or game completion time. Curiously, differences between the two groups in heart rate (HR) outcomes were found to be statistically significant, with subjects in the control group displaying an increasing HR trend during simulation. Conclusions This finding, in accordance with previous studies that have shown the efficacy of landmarks and wayfinding affordances in reducing cognitive demands, suggests that assistive lights might contribute to improved brain wiring connectivity during the game. We discuss these findings in the context of a rich wayfinding affordances literature.

Spinal Curvature and Lower Extremities Kinematics of Simulated Pregnancy during Stair Ascending and Descending

2019 ◽  
Vol 41 ◽  
pp. 11-22
Author(s):  
Ihssan S. Masad ◽  
Sami Almashaqbeh ◽  
Othman Smadi ◽  
Mariam Abu Olaim ◽  
Abeer Obeid
Keyword(s):  
Knee Flexion ◽  
Lower Extremities ◽  
Ankle Dorsiflexion ◽  
Spinal Curvature ◽  
Control Group ◽  
Group Data ◽  
Significant Difference ◽  
Position Data ◽  
Infrared Cameras ◽  
Hip Flexion

The purpose of this work is to investigate the effect of anteriorly-added mass to simulate pregnancy on lower extremities kinematic and lumbar and thoracic angles during stair ascending and descending. 18 healthy females ascended and descended, with and without a pseudo-pregnancy sac of 12 kg (experimental and control groups, respectively), a costume-made wooden staircase while instrumented with 20 reflective markers placed on the lower extremities and the spine. The movements were captured by 12 infrared cameras surrounding the staircase. Tracked position data were exported to MATLAB to calculate the required joints angles. SPSS was used to compare the ascent and descent phases of control group, and to find if there are any significant differences between control and experimental groups in the ascent phase as well as in the descent phase. When comparing the ascent and descent phases of control group, data revealed a higher hip flexion during ascending and greater ankle planter-flexion and dorsiflexion, lumbar, and thoracic angles during descending; however, no significant difference was shown in the knee flexion angle between ascending and descending. Non-pregnant data showed greater maximum hip flexion and ankle dorsiflexion during stair ascending compared to simulated-pregnant group; while ankle planter-flexion, knee flexion, and lumbar angle were greater for simulated-pregnant status. During stair descending, non-pregnant group had greater minimum hip flexion and ankle dorsiflexion compared to simulated pregnant group; while ankle planter-flexion, knee flexion, and maximum hip flexion were greater for simulated-pregnant group. However, the lumbar and thoracic angles were found to be similar for simulated-pregnant and non-pregnant groups during stair descending. In conclusion, the current study revealed important kinematic modifications pregnant women adopt while ascending and descending stairs at their final stage of pregnancy to increase their stability.

Augmented Reality Text Style Readability with See-Through Head-Mounted Displays in Industrial Context

2013 ◽  
Vol 22 (2) ◽  
pp. 171-190 ◽  
Author(s):  
Michele Fiorentino ◽  
Saverio Debernardis ◽  
Antonio E. Uva ◽  
Giuseppe Monno
Keyword(s):  
Augmented Reality ◽  
Completion Time ◽  
Presentation Mode ◽  
Error Rates ◽  
Head Mounted Display ◽  
Head Mounted Displays ◽  
Specific Meaning ◽  
Industrial Environments ◽  
Effective Visualization ◽  
Effective Use

The application of augmented reality in industrial environments requires an effective visualization of text on a see-through head-mounted display (HMD). The main contribution of this work is an empirical study of text styles as viewed through a monocular optical see-through display on three real workshop backgrounds, examining four colors and four different text styles. We ran 2,520 test trials with 14 participants using a mixed design and evaluated completion time and error rates. We found that both presentation mode and background influence the readability of text, but there is no interaction effect between these two variables. Another interesting aspect is that the presentation mode differentially influences completion time and error rate. The present study allows us to draw some guidelines for an effective use of AR text visualization in industrial environments. We suggest maximum contrast when reading time is important, and the use of colors to reduce errors. We also recommend a colored billboard with transparent text where colors have a specific meaning.

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