An Innovative Device Based on Human-Machine Interface (HMI) for Powered Wheelchair Control for Neurodegenerative Disease: A Proof-of-Concept.

In the global context, advancements in technology and science have rendered virtual, augmented, and mixed-reality technologies capable of transforming clinical care and medical environments by offering enhanced features and improved healthcare services. This paper aims to present a mixed reality-based system to control a robotic wheelchair for people with limited mobility. The test group comprised 11 healthy subjects (six male, five female, mean age 35.2 ± 11.7 years). A novel platform that integrates a smart wheelchair and an eye-tracking-enabled head-mounted display was proposed to reduce the cognitive requirements needed for wheelchair movement and control. The approach's effectiveness was demonstrated by evaluating our system in realistic scenarios. The demonstration of the proposed AR head-mounted display user interface for controlling a smart wheelchair and the results provided in this paper could highlight the potential of the HoloLens 2-based innovative solutions and bring focus to emerging research topics, such as remote control, cognitive rehabilitation, the implementation of patient autonomy with severe disabilities, and telemedicine.

Influence of Visual Stimulus Changes in a Virtual Environment on Postural Control: Focusing on a Hallway Walking Simulation.

The purpose of this study was to clarify the effects of the standing center of gravity sway by providing visual stimulus information as if the subjects were walking in virtual reality (VR) and by monitoring conditions with different corridor widths. We included 25 healthy young individuals in our study. The center of gravity sway was measured during open- and closed-eye static standing using images of walking in corridors of different widths (780 and 1600 mm) presented on a VR and personal computer monitor (Monitor). The parameters measured for the center of gravity sway were swing path length (SPL), height of excursion (HoE), and width of excursion (WoE). The results showed that the SPL and HoE values were significantly greater in the VR group than those in the Monitor group. The greater center of gravity sway in the VR compared with the Monitor group can be attributed to the ability of the head-mounted VR display to cover the entire field of vision and its head-tracking function. There was no change in the center of gravity sway with respect to the corridor width, which may be because the width of the corridor alone did not provide sufficient visual stimulation to affect physical function. This research could lead to further studies which could impact the motivation of patients for rehabilitation therapies.

Effectiveness and satisfaction with virtual and donor dissections: A randomized controlled trial.

In recent years, human anatomy education has faced challenges with traditional donor dissection, leading to the emergence of virtual dissection as an alternative. This study aims to investigate the academic performance and satisfaction of medical students by comparing the virtual and donor dissections. An open-labeled crossover randomized controlled trial was conducted with 154 first-year medical students in Human Anatomy and Neuroanatomy laboratories, which were divided into three classes. Students were randomly assigned to either the virtual (virtual dissection followed by donor dissection) or donor (donor dissection followed by virtual dissection) groups in each class. A curriculum, incorporating head-mounted displays (HMDs), a life-sized touchscreen, and tablets, was developed. Data was evaluated through quizzes and surveys. In the Human Anatomy laboratory, each class of the donor group conducted heart extraction, dissection and observation. In observation class, the virtual group had a significantly higher mean quiz score than the donor group (p < 0.05). Compared to the donor, satisfaction was significantly higher for the HMD (understanding of concept and immersion), life-size touchscreen (esthetics, understanding of the concept, and spatial ability), and tablet (esthetics, understanding of the concept, spatial ability, and continuous use intention). In the Neuroanatomy laboratory, the virtual group showed significantly higher mean quiz scores than the donor group (p < 0.05), and tablet showed a significantly higher satisfaction than donor in terms of esthetics, understanding of the concept, and spatial ability. These results suggest that virtual dissection has the potential to supplement or replace donor dissection in anatomy education. This study is innovative in that it successfully delivered scenario-based virtual content and validated the efficacy in academic performance and satisfaction when using virtual devices compared to donor.Trial registration: This research has been registered in the Clinical Research Information Service (CRIS, https://cris.nih.go.kr/cris/search/detailSearch.do?search_lang=E&focus=reset_12&search_page=L&pageSize=10&page=undefined&seq=26002&status=5&seq_group=26002 ) with registration number "KCT0009075" and registration date "27/12/2023".

Perioperative use of immersive head-mounted virtual reality display enhances patient satisfaction in great saphenous vein surgery: a single-center clinical observation study.

OBJECTIVE: To explore the application effect of head-mounted virtual reality display immersive experience in improving the perioperative satisfaction of patients undergoing great saphenous vein surgery. METHODS: A total of 158 patients undergoing saphenous vein surgery at the First Affiliated Hospital, Jiangxi Medical College, Nanchang University from January 2020 to January 2023 were randomly divided into an observation group and a control group in a 1:1 ratio, with 79 cases in each group. The observation group received head-mounted display virtual reality immersive experience, whereas the control group received midazolam. The study compared the perioperative satisfaction, changes in preoperative and postoperative anxiety and depression scores, intraoperative blood pressure and heart rate, postoperative visual analog scale (VAS) score, and the incidence of postoperative nausea and vomiting between the two groups. Additionally, the satisfaction of patients, anesthesiologists, and chief surgeons was compared. RESULTS: All surgeries were completed successfully. Patients in the observation group exhibited higher perioperative satisfaction compared to those in the control group (P<0.001). There were no significant differences in anxiety or depression scores between the two groups before surgery (P>0.05). However, both groups showed a reduction in anxiety and depression scores postoperatively, with the observation group demonstrating lower scores than the control group (both P<0.05). The observation group also had lower intraoperative blood pressure, heart rate, postoperative VAS scores, and incidence of nausea and vomiting compared to the control group (all P<0.05). Furthermore, the satisfaction levels of the anesthesiologists and chief surgeons were higher in the observation group than in the control group (P=0.043, 0.012). CONCLUSION: Head-mounted display virtual reality immersive experience can enhance perioperative satisfaction among patients undergoing great saphenous vein surgery, reduce anxiety and depression scores, and contribute to the stabilization of hemodynamics during surgery, thereby decreasing postoperative nausea and vomiting.

Alone but not isolated: social presence and cognitive load in learning with 360 virtual reality videos.

Introduction: This study aimed to identify any differences in social presence and cognitive load among three types of 360 virtual reality (VR)-based videos lectures. We hypothesized that social presence would be higher when interactions among peers are visible in a 360 VR video lectures while the cognitive load would be also increased. Methods: A total of 48 college students were randomly assigned to one of the three study groups to view an assigned 360 VR video lecture. The three groups were: (1) an instructor-only video viewing group, (2) a classroom lecture video viewing group, and (3) a classroom lecture and activity video viewing group. The video lectures were differently designed depending on the levels of peer visibility and the interactions between the instructor and peers. The participants watched one of the three types of assigned video lecture and subsequently completed two sets of questionnaires regarding social presence and cognitive load. A multivariate analysis of variance (MANOVA) was conducted with a planned contrast analysis for the type of video lectures. Results: We found that, contrary to the hypotheses, students in the group 1 (instructor-only video) showed higher social presence scores than students in the groups 2 and 3. However, no significant differences were found in the cognitive load scores. Discussion: The results show that 360 VR video lectures with an instructor-only are more effective at enhancing users' social presence than 360 VR video lectures with both the instructor and class-peers. We suggest creating 360 VR video lectures with the presence of the course instructor to offer learners the sense of actually participating in a lecture.

The Effectiveness of Virtual Reality-Based Training on Cognitive, Social, and Physical Functioning in High-Functioning Older Adults (CoSoPhy FX): 2-Arm, Parallel-Group Randomized Controlled Trial.

BACKGROUND: Virtual reality (VR) has emerged as a promising technology for enhancing the health care of older individuals, particularly in the domains of cognition, physical activity, and social engagement. However, existing VR products and services have limited availability and affordability; hence, there is a need for a scientifically validated and personalized VR service to be used by older adults in their homes, which can improve their overall physical, cognitive, and social well-being. OBJECTIVE: The main purpose of the CoSoPhy FX (Cognitive, Social, and Physical Effects) study was to analyze the effects of a VR-based digital therapeutics app on the cognitive, social, and physical performance abilities of healthy (high-functioning) older adults. This paper presents the study protocol and the results from the recruitment phase. METHODS: A group of 188 healthy older adults aged 65-85 years, recruited at the Medical University of Lodz, Poland, were randomly allocated to the experimental group (VR dual-task training program) or to the control group (using a VR headset app showing nature videos). A total of 3 cognitive exercises were performed in various 360° nature environments delivered via a VR head-mounted display; the participants listened to their preferred music genre. Each patient received 3 sessions of 12 minutes per week for 12 weeks, totaling a minimum of 36 sessions per participant. Attention and working memory (Central Nervous System Vital Signs computerized cognitive battery) were used as primary outcomes, while other cognitive domains in the Central Nervous System Vital Signs battery, quality of life (World Health Organization-5 Well-Being Index), health-related quality of life (EQ-5D-5L), and anxiety (General Anxiety Disorder 7-item questionnaire) were the secondary outcomes. The group-by-time interaction was determined using linear mixed models with participants' individual slopes. RESULTS: In total, 122 (39%) of the initial 310 participants failed to meet the inclusion criteria, resulting in a recruitment rate of 61% (188/310). Among the participants, 68 successfully completed the intervention and 62 completed the control treatment. The data are currently being analyzed, and we plan to publish the results by the end of September 2024. CONCLUSIONS: VR interventions have significant potential among healthy older individuals. VR can address various aspects of well-being by stimulating cognitive functions, promoting physical activity, and facilitating social interaction. However, challenges such as physical discomfort, technology acceptance, safety concerns, and cost must be considered when implementing them for older adults. Further research is needed to determine the long-term effects of VR-based interventions, optimal intervention designs, and the specific populations that would benefit most. TRIAL REGISTRATION: ClinicalTrials.gov NCT05369897; https://clinicaltrials.gov/study/NCT05369897. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53261.

The Use of Head-Mounted Display Systems for Upper Limb Kinematic Analysis in Post-Stroke Patients: A Perspective Review on Benefits, Challenges and Other Solutions.

In recent years, there has been a notable increase in the clinical adoption of instrumental upper limb kinematic assessment. This trend aligns with the rising prevalence of cerebrovascular impairments, one of the most prevalent neurological disorders. Indeed, there is a growing need for more objective outcomes to facilitate tailored rehabilitation interventions following stroke. Emerging technologies, like head-mounted virtual reality (HMD-VR) platforms, have responded to this demand by integrating diverse tracking methodologies. Specifically, HMD-VR technology enables the comprehensive tracking of body posture, encompassing hand position and gesture, facilitated either through specific tracker placements or via integrated cameras coupled with sophisticated computer graphics algorithms embedded within the helmet. This review aims to present the state-of-the-art applications of HMD-VR platforms for kinematic analysis of the upper limb in post-stroke patients, comparing them with conventional tracking systems. Additionally, we address the potential benefits and challenges associated with these platforms. These systems might represent a promising avenue for safe, cost-effective, and portable objective motor assessment within the field of neurorehabilitation, although other systems, including robots, should be taken into consideration.

Virtual reality-based training may improve visual memory and some aspects of sustained attention among healthy older adults - preliminary results of a randomized controlled study.

BACKGROUND/AIMS: Older age and cognitive inactivity have been associated with cognitive impairment, which in turn is linked to economic and societal burdens due to the high costs of care, especially for care homes and informal care. Emerging non-pharmacological interventions using new technologies, such as virtual reality (VR) delivered on a head-mounted display (HMD), might offer an alternative to maintain or improve cognition. The study aimed to evaluate the efficacy and safety of a VR-based Digital Therapeutics application for improving cognitive functions among healthy older adults. METHODS: Seventy-two healthy seniors (experimental group N = 35, control group N = 37), aged 65-85 years, were recruited by the Medical University of Lodz (Poland). Participants were randomly allocated to the experimental group (a VR-based cognitive training which consists of a warm-up module and three tasks, including one-back and dual-N-back) or to the control group (a regular VR headset app only showing nature videos). The exercises are performed in different 360-degree natural environments while listening to a preferred music genre and delivered on a head-mounted display (HMD). The 12-week intervention of 12 min was delivered at least three times per week (36 sessions). Compliance and performance were followed through a web-based application. Primary outcomes included attention and working memory (CNS-Vital Signs computerized cognitive battery). Secondary outcomes comprised other cognitive domains. Mixed linear models were constructed to elucidate the difference in pre- and post-intervention measures between the experimental and control groups. RESULTS: The users performed, on average, 39.8 sessions (range 1-100), and 60% performed more than 36 sessions. The experimental group achieved higher scores in the visual memory module (B = 7.767, p = 0.011) and in the one-back continuous performance test (in terms of correct responses: B = 2.057, p = 0.003 and omission errors: B = -1.950, p = 0.007) than the control group in the post-test assessment. The results were independent of participants' sex, age, and years of education. The differences in CNS Vital Signs' global score, working memory, executive function, reaction time, processing speed, simple and complex attention, verbal memory, cognitive flexibility, motor speed, and psychomotor speed were not statistically significant. CONCLUSIONS: VR-based cognitive training may prove to be a valuable, efficacious, and well-received tool in terms of improving visual memory and some aspect of sustainability of attention among healthy older adults. This is a preliminary analysis based on part of the obtained results to that point. Final conclusions will be drawn after the analysis of the target sample size. TRIAL REGISTRATION: Clinicaltrials.gov ID NCT05369897.

Implementation and Evaluation of Walk-in-Place Using a Low-Cost Motion-Capture Device for Virtual Reality Applications.

Virtual reality (VR) is used in many fields, including entertainment, education, training, and healthcare, because it allows users to experience challenging and dangerous situations that may be impossible in real life. Advances in head-mounted display technology have enhanced visual immersion, offering content that closely resembles reality. However, several factors can reduce VR immersion, particularly issues with the interactions in the virtual world, such as locomotion. Additionally, the development of locomotion technology is occurring at a moderate pace. Continuous research is being conducted using hardware such as treadmills, and motion tracking using depth cameras, but they are costly and space-intensive. This paper presents a walk-in-place (WIP) algorithm that uses Mocopi, a low-cost motion-capture device, to track user movements in real time. Additionally, its feasibility for VR applications was evaluated by comparing its performance with that of a treadmill using the absolute trajectory error metric and survey data collected from human participants. The proposed WIP algorithm with low-cost Mocopi exhibited performance similar to that of the high-cost treadmill, with significantly positive results for spatial awareness. This study is expected to contribute to solving the issue of spatial constraints when experiencing infinite virtual spaces.

Forming a view: a human factors case study of augmented reality collaboration in assembly.

Industry 4.0 technology is promoted as improving manufacturing flexibility, and competitiveness; though Australia has been slow to adopt. The Australian Navy shipbuilding program provides opportunities for accelerating technology adoption, revitalising manufacturing productivity and competitiveness. Adopting a sociotechnical systems lens, our research sought to identify usability, workload, and user experience of an augmented reality head-mounted display (AR-HMD) deployed to complete multiple work tasks in a workflow (electrical assembly, collaborative robot (cobot) mediated inspection, and remote troubleshooting using video call). Usability was rated 'average' (System Usability Scale mean = 69.8) and workload 'acceptable' (NASA Task Load Index mean = 25.8) for the AR-HMD alone, with usability of the integrated work system (IWS) rated 'good' (SUS mean = 79.2). Results suggest software interfaces, tracking, and gesturing methods for the AR-HMD require improvement. This trial shows the AR-HMD provides a versatile platform for integrating multiple digital technologies without hindering effectiveness of end-user performance, potentially benefiting productivity and quality.

Using an augmented reality head-mounted display (AR-HMD) to reduce and correct errors in electrical assembly identified factors influencing technology adoption in shipbuilding. Mental workload, interface design, tracking, and gesturing most hindered successful performance. AR-HMDs can facilitate the use of more complex integrated technologies (i.e. cobot), improving usability and acceptance.

iVR-fNIRS: studying brain functions in a fully immersive virtual environment.

Immersive virtual reality (iVR) employs head-mounted displays or cave-like environments to create a sensory-rich virtual experience that simulates the physical presence of a user in a digital space. The technology holds immense promise in neuroscience research and therapy. In particular, virtual reality (VR) technologies facilitate the development of diverse tasks and scenarios closely mirroring real-life situations to stimulate the brain within a controlled and secure setting. It also offers a cost-effective solution in providing a similar sense of interaction to users when conventional stimulation methods are limited or unfeasible. Although combining iVR with traditional brain imaging techniques may be difficult due to signal interference or instrumental issues, recent work has proposed the use of functional near infrared spectroscopy (fNIRS) in conjunction with iVR for versatile brain stimulation paradigms and flexible examination of brain responses. We present a comprehensive review of current research studies employing an iVR-fNIRS setup, covering device types, stimulation approaches, data analysis methods, and major scientific findings. The literature demonstrates a high potential for iVR-fNIRS to explore various types of cognitive, behavioral, and motor functions in a fully immersive VR (iVR) environment. Such studies should set a foundation for adaptive iVR programs for both training (e.g., in novel environments) and clinical therapeutics (e.g., pain, motor and sensory disorders and other psychiatric conditions).

A System for Mixed-Reality Holographic Overlays of Real-Time Rendered 3D-Reconstructed Imaging Using a Video Pass-through Head-Mounted Display-A Pathway to Future Navigation in Chest Wall Surgery.

Background: Three-dimensional reconstructions of state-of-the-art high-resolution imaging are progressively being used more for preprocedural assessment in thoracic surgery. It is a promising tool that aims to improve patient-specific treatment planning, for example, for minimally invasive or robotic-assisted lung resections. Increasingly available mixed-reality hardware based on video pass-through technology enables the projection of image data as a hologram onto the patient. We describe the novel method of real-time 3D surgical planning in a mixed-reality setting by presenting three representative cases utilizing volume rendering. Materials: A mixed-reality system was set up using a high-performance workstation running a video pass-through-based head-mounted display. Image data from computer tomography were imported and volume-rendered in real-time to be customized through live editing. The image-based hologram was projected onto the patient, highlighting the regions of interest. Results: Three oncological cases were selected to explore the potentials of the mixed-reality system. Two of them presented large tumor masses in the thoracic cavity, while a third case presented an unclear lesion of the chest wall. We aligned real-time rendered 3D holographic image data onto the patient allowing us to investigate the relationship between anatomical structures and their respective body position. Conclusions: The exploration of holographic overlay has proven to be promising in improving preprocedural surgical planning, particularly for complex oncological tasks in the thoracic surgical field. Further studies on outcome-related surgical planning and navigation should therefore be conducted. Ongoing technological progress of extended reality hardware and intelligent software features will most likely enhance applicability and the range of use in surgical fields within the near future.

Virtual reality perceptual training can improve the temporal discrimination ability of swinging during softball batting.

Perception and action uncoupling in fastball sports anticipatory training is often criticized. Nevertheless, perception-only training offers distinct advantages, such as flexibility concerning time, place, and injury limitations. Therefore, the effectiveness of this training approach warrants evaluation. This study developed a virtual reality (VR) training system based on the idea that the two visual pathways in the brain are associated with visual information attributes, rather than perception or action. A key feature of this study's perception-only training was its presentation of not only the opponent's kinematics but also the ball's flight information (the attributes that guide hitting) to train the visual system necessary for real situations. Seventeen female softball batters were assigned to two groups: a training group (N = 9) and a control group (N = 8). Only the training group underwent the VR anticipatory skill training to discriminate the different ball speeds. Both groups completed a perception test and an action test on the VR during the pre- and post-training periods. The perception test assessed response accuracy (RA) in discriminating ball speed, and the action test assessed the temporal difference in swing onset (delta onset). Comparison of these two outcome variables between groups revealed that perception-only training improved both perceptual and action responses. This study demonstrated the effectiveness of perception-only training and emphasized the need for its thoughtful utilization and design.

Teaching empathy: comparison of a virtual reality experience using head-mounted display versus group streaming.

Empathy, an integral component of bedside manners, correlates with good healthcare provision. Training physician assistant (PA) students using Head-Mounted Display (HMD) virtual reality (VR) contributed to significant empathy increases. This pilot study, which relied on a retrospective analysis, compared a VR experience using HMD to a streamed modality (due to COVID safety) with PA students to measure empathy. We hypothesized that fully immersive and interactive HMD VR would lead to a statistically significant increase in empathy versus the streaming modality. The "Alfred Lab" VR allows viewers to "embody" a 74-year-old African American man with vision and hearing loss. The University of New England PA class of 2021 (n = 47) completed the HMD lab while the class of 2022 (n = 50) viewed the streaming modality as a group. Identical pre/post surveys were completed by each cohort. The analysis utilized paired sample t-tests, ANOVA, frequency analysis (quantitative), and content analysis with thematic coding (qualitative). The results for each cohort revealed a statistically significant increase in empathy (p < 0.05) after completing the VR lab (pre- to post-test results). The comparison of both cohorts (HMD versus group streaming) revealed no noteworthy difference. Streaming VR could improve access to PA programs unable to acquire expensive VR equipment yet still allow for the development of empathy.

Comparing Walking-Related Everyday Life Tasks of Children with Gait Disorders in a Virtual Reality Setup With a Physical Setup: Cross-Sectional Noninferiority Study.

BACKGROUND: A frequent rehabilitation goal for children with gait disorders is to practice daily-life walking activities. Unfortunately, these are often difficult to practice in a conventional therapeutic setting. Virtual reality (VR) with head-mounted displays (HMDs) could be a promising approach in neurorehabilitation to train such activities in a safe environment. First, however, we must know whether obstacles in VR are indeed mastered as obstacles. OBJECTIVE: This study aimed to provide information on whether VR is feasible and motivating to induce and practice movements needed to master real obstacles in children and adolescents with gait disorders. Furthermore, this project aims to evaluate which kinds of everyday walking activities are appropriate to be practiced in VR. METHODS: In this cross-sectional study, participants stepped over a bar, crossed a gap, balanced over a beam, and circumvented stationary obstructions arranged in a course under real physical and virtual conditions wearing a VR HMD. We recorded the respective primary outcomes (step height, step length, step width, and minimal shoulder-obstacle distance) with motion capture. We then calculated the mean differences and 95% CI of the spatiotemporal parameters between the VR and physical setup and later compared them using noninferiority analysis with margins defined a priori by a clinical expert panel. Additionally, the participants responded to a standardized questionnaire while the therapists observed and evaluated their movement performance. RESULTS: We recruited 20 participants (mean age 12.0, range 6.6-17.8 years) with various diagnoses affecting their walking ability. At 3.77 (95% CI 1.28 to 6.26) cm, the mean difference in step height of the leading foot in the overstepping task did not exceed the predefined margin of -2 cm, thus signifying noninferiority of the VR condition compared to mastering the physical obstacles. The same was true for step length (-1.75, 95% CI -4.91 to 1.41 cm; margin -10 cm), step width (1.05, 95% CI 0.20 to -1.90 cm; margin 3 cm), and the minimal shoulder-obstacle distance (0.25, 95% CI -0.85 to 0.35 cm; margin -2 cm) in the other tasks. Only the trailing foot in the overstepping task yielded inconclusive results. CONCLUSIONS: Children with gait disorders perform everyday walking tasks like overstepping, crossing, balancing, or circumventing similarly in physical and VR environments, suggesting that VR could be a feasible therapeutic tool to practice everyday walking tasks.

Real-time ultrasound-guided thoracentesis simulation using an optical see-through head-mounted display: a proof-of-concept study.

Aim: This study aimed to examine the feasibility and potential benefits of an optical see-through head-mounted display (OST-HMD) during real-time ultrasound-guided thoracentesis simulations. Material and methods: Six physicians performed a thoracentesis simulation using an OST-HMD and a wireless image transmission system. The time required, puncture needle visibility, pleural fluid collection success rate, and head movement during the procedure using a smart glass equipped with an inertial measurement unit were all recorded and compared with and without the HMD. Results: Study participants successfully extracted effusions in all procedures. The use of OST-HMD did not significantly affect the time of the procedure, but notably decreased the horizontal and vertical head movements during the procedure. Conclusions: The study demonstrated the feasibility of using an OST-HMD in a simulated real-time ultrasound-guided thoracentesis procedure and showed the potential of HMD in thoracentesis to improve ergonomics and accuracy. Further research is necessary to confirm these findings.

Attentional Tunneling in Pilots During a Visual Tracking Task With a Head Mounted Display.

OBJECTIVE: We examined whether active head aiming with a Helmet Mounted Display (HMD) can draw the pilot's attention away from a primary flight task. Furthermore, we examined whether visual clutter increases this effect. BACKGROUND: Head up display symbology can result in attentional tunneling, and clutter makes it difficult to identify objects. METHOD: Eighteen military pilots had to simultaneously perform an attitude control task while flying in clouds and a head aiming task in a fixed-base flight simulator. The former consisted of manual compensation for roll disturbances of the aircraft, while the latter consisted of keeping a moving visual target inside a small or large head-referenced circle. A "no head aiming" condition served as a baseline. Furthermore, all conditions were performed with or without visual clutter. RESULTS: Head aiming led to deterioration of the attitude control task performance and an increase of the amount of roll-reversal errors (RREs). This was even the case when head aiming required minimal effort. Head aiming accuracy was significantly lower when the roll disturbances in the attitude control task were large compared to when they were small. Visual clutter had no effect on both tasks. CONCLUSION: We suggest that active head aiming of HMD symbology can cause attentional tunneling, as expressed by an increased number of RREs and less accuracy on a simultaneously performed attitude control task. APPLICATION: This study improves our understanding in the perceptual and cognitive effects of (military) HMDs, and has implications for operational use and possibly (re)design of HMDs.

Comparing a virtual reality head-mounted display to on-screen three-dimensional visualization and two-dimensional computed tomography data for training in decision making in hepatic surgery: a randomized controlled study.

OBJECTIVE: Evaluation of the benefits of a virtual reality (VR) environment with a head-mounted display (HMD) for decision-making in liver surgery. BACKGROUND: Training in liver surgery involves appraising radiologic images and considering the patient's clinical information. Accurate assessment of 2D-tomography images is complex and requires considerable experience, and often the images are divorced from the clinical information. We present a comprehensive and interactive tool for visualizing operation planning data in a VR environment using a head-mounted-display and compare it to 3D visualization and 2D-tomography. METHODS: Ninety medical students were randomized into three groups (1:1:1 ratio). All participants analyzed three liver surgery patient cases with increasing difficulty. The cases were analyzed using 2D-tomography data (group "2D"), a 3D visualization on a 2D display (group "3D") or within a VR environment (group "VR"). The VR environment was displayed using the "Oculus Rift ™" HMD technology. Participants answered 11 questions on anatomy, tumor involvement and surgical decision-making and 18 evaluative questions (Likert scale). RESULTS: Sum of correct answers were significantly higher in the 3D (7.1 ± 1.4, p < 0.001) and VR (7.1 ± 1.4, p < 0.001) groups than the 2D group (5.4 ± 1.4) while there was no difference between 3D and VR (p = 0.987). Times to answer in the 3D (6:44 ± 02:22 min, p < 0.001) and VR (6:24 ± 02:43 min, p < 0.001) groups were significantly faster than the 2D group (09:13 ± 03:10 min) while there was no difference between 3D and VR (p = 0.419). The VR environment was evaluated as most useful for identification of anatomic anomalies, risk and target structures and for the transfer of anatomical and pathological information to the intraoperative situation in the questionnaire. CONCLUSIONS: A VR environment with 3D visualization using a HMD is useful as a surgical training tool to accurately and quickly determine liver anatomy and tumor involvement in surgery.

Pilot Study Assessing the Safety and Acceptance of a Novel Virtual Reality System to Improve Visual Function.

PURPOSE: To assess the feasibility of the clinical use of a novel Virtual Reality (VR) training software designed to be used for active vision therapy in amblyopic patients by determining its preliminary safety and acceptance on the visual function of healthy adults. METHODS: Pilot study enrolling 10 individuals (3 men, 7 women, mean age: 31.8 ± 6.5 years) with a best-corrected visual acuity (BCVA) of ≥ .90 (decimal) in both eyes were evaluated before and after 20 minutes of exposure to the NEIVATECH VR system using the HTC Vive Pro Eye head mounted display. Visual function assessment included near (40 cm) and distance (6 m) cover test (CT), stereopsis, binocular accommodative facility (BAF), near point of convergence (NPC), near point of accommodation (NPA), accommodative-convergence over accommodation (AC/A) ratio and positive and negative fusional vergences. Safety was assessed using the VR Sickness Questionnaire (VRSQ) and acceptance using the Technology Acceptance Model ;(TAM). Changes in all these variables after VR exposure were analyzed. RESULTS: Short-term exposure to the NEIVATECH VR system only induced statistically significant changes in distance phoria (p = .016), but these changes were not clinically relevant. No significant changes were observed in VRSQ oculo-motricity and disorientation scores after exposure (p = .197 and .317, respectively). TAM scores showed a good acceptance of the system in terms of perceived enjoyment and perceived ease of use, although some concerns were raised in relation to the intention-to-use domain. CONCLUSION: Exposure to the NEIVATECH VR system does not seem to adversely affect the visual function in healthy adults and its safety and acceptance profile seems to be adequate for supporting its potential use in other populations, such as amblyopic patients.