In the rail environment, Lookouts protect workers on track by visually monitoring the environment and detecting approaching trains. It is therefore critically important that trains are easily detected by Lookouts. The specificity of standards regarding front-of-train colour designs are varied and ambiguous. As well, limited guidance is found in the body of literature on conspicuity regarding how it applies to the rail and broader transport industry. In visual perception research, conflicting views exist on whether colour is important in determining object conspicuity. The present study seeks to address this research gap by employing a novel use of virtual reality (VR) technology, to simulate a train detection task for Lookouts. The experiments investigated (1) whether train conspicuity differs for varying train types under different ambient conditions, and (2) whether colour is important for improving train conspicuity. We found differences in the time taken to detect different train types, providing evidence that train conspicuity is affected by front-of-train design. However, the observed conspicuity differences between train types were not due to chromatic colour differences. The study findings raise interesting questions regarding the role of colour in visual detection tasks and demonstrates a novel application of empirical research to address rail industry issues.

A group of highly experienced pilots performed full-motion, simulated T-38 landings before and after extended missions aboard the International Space Station (ISS). On the day of return from the ISS pilots’ performance was degraded on the initial landing attempt, with difficulty maintaining altitude during banking turns and navigational errors, which affected touchdown parameters such as touchdown speed, height over runway threshold and touchdown distance from the runway threshold. A positive result was that all pilots successfully completed a second landing attempt on the same day, suggesting a rapid recovery of performance once exposed to the task at hand. These results are consistent with a previous study that demonstrated significant deficits in post-flight driving performance, and both the pilot and driver subjects’ performance recovered to pre-flight levels within four days of return from the ISS. We propose that the primary factors underlying the post-flight performance deficits were the inability to respond appropriately to gravitational and visual tilts and a reduction in multitasking ability.

IntroductionThe non-intoxicating plant-derived cannabinoid, cannabidiol (CBD), has demonstrated therapeutic potential in a number of clinical conditions. Most successful clinical trials have used relatively high (≥300 mg) oral doses of CBD. Relatively few studies have investigated the efficacy of lower (<300 mg) oral doses, typical of those available in over-the-counter CBD products.MethodsWe present a protocol for a randomised, double-blind, placebo-controlled, parallel-group clinical trial investigating the effects of a low oral dose (150 mg) of CBD on acute psychosocial stress, situational anxiety, motion sickness and cybersickness in healthy individuals. Participants (n=74) will receive 150 mg of CBD or a matched placebo 90 min before completing three virtual reality (VR) challenges (tasks) designed to induce transient stress and motion sickness: (a) a 15 min ‘Public Speaking’ task; (b) a 5 min ‘Walk the Plank’ task (above a sheer drop); and (c) a 5 min ‘Rollercoaster Ride’ task. The primary outcomes will be self-reported stress and nausea measured on 100 mm Visual Analogue Scales. Secondary outcomes will include salivary cortisol concentrations, skin conductance, heart rate and vomiting episodes (if any). Statistical analyses will test the hypothesis that CBD reduces nausea and attenuates subjective, endocrine and physiological responses to stress compared with placebo. This study will indicate whether low-dose oral CBD has positive effects in reducing acute psychosocial stress, situational anxiety, motion sickness and cybersickness.Ethics and disseminationThe University of Sydney Human Research Ethics Committee has granted approval (2023/307, version 1.6, 16 February 2024). Study findings will be disseminated in a peer-reviewed journal and at academic conferences.Trial registration numberAustralian New Zealand Clinical Trials Registry (ACTRN12623000872639).

BACKGROUND:Digital surgical planning (DSP) has revolutionized the preparation and execution of the management of complex head and neck pathologies. The addition of virtual reality (VR) allows the surgeon to have a three-dimensional experience with six degrees of freedom for visualizing and manipulating objects. This pilot study describes the participants experience with the first head and neck reconstructive VR-DSP platform.METHODS:An original VR-DSP platform has been developed for planning the ablation and reconstruction of head and neck pathologies. A prospective trial utilizing this platform involving reconstructive surgeons was performed. Participants conducted a simulated VR-DSP planning session, pre- and post-questionnaire as well as audio recordings allowing for qualitative analysis.RESULTS:Thirteen consultant reconstructive surgeons representing three surgical backgrounds with varied experience were recruited. The majority of surgeons had no previous experience with VR. Based on the system usability score, the VR-DSP platform was found to have above average usability. The qualitative analysis demonstrated the majority had a positive experience. Participants identified some perceived barriers to implementing the VR-DSP platform.CONCLUSIONS:Virtual reality-digital surgical planning is usable and acceptable to reconstructive surgeons. Surgeons were able to perform the steps in an efficient time despite limited experience. The addition of VR offers additional benefits to current VSP platforms. Based on the results of this pilot study, it is likely that VR-DSP will be of benefit to the reconstructive surgeon.

Background: For almost a decade, virtual reality (VR) has been employed in otology simulation. The realism and accuracy of traditional three-dimensional (3D) mesh models of the middle ear from clinical CT have suffered because of their low resolution. Although micro-computed tomography (micro-CT) imaging overcomes resolution issues, its usage in virtual reality platforms has been limited due to the high computational requirements. The aim of this study was to optimize a high-resolution 3D human middle ear mesh model suitable for viewing and manipulation in an immersive VR environment using an HTC VIVE VR headset (HTC and Valve Corporation, USA) to enable a seamless middle ear anatomical visualisation viewing experience in VR while preserving anatomical accuracy. Methods: A high-resolution 3D mesh model of the human middle ear was reconstructed using micro-CT data with 28 μm voxel resolution. The models were optimised by tailoring the surface model polygon counts, file size, loading time, and frame rate. Results: The optimized middle ear model and its surrounding structures (polygon counts reduced from 21 million polygons to 2.5 million) could be uploaded and visualised in immersive VR at 82 frames per second with no VR-related motion sickness reported. Conclusion: High-resolution micro-CT data can be visualized in an immersive VR environment after optimisation. To our knowledge, this is the first report on overcoming the translational hurdle in middle ear applications of VR.

INTRODUCTION:Patient education is a critical component of healthcare delivery. However, medical information and knowledge are complex and can be difficult for patients and families to comprehend when delivered verbally. The use of virtual reality (VR) to convey medical information to patients may bridge this communication gap and lead to more effective patient education. It may be of increased value to those with low health literacy and levels of patient activation, in rural and regional settings. The objective of this randomised, single-centre pilot study is to examine the feasibility and preliminary effectiveness of VR as an education tool for people with cancer. The results will provide data to inform the feasibility of a future randomised controlled trial, including sample size calculations.METHODS AND ANALYSIS:Patients with cancer undergoing immunotherapy will be recruited. A total of 36 patients will be recruited and randomised to one of three trial arms. Participants will be randomised 1:1:1 to receive VR, a two-dimensional video or standard care (ie, verbal communication and information leaflets). Feasibility will be assessed by recruitment rate, practicality, acceptability, usability and related adverse events. The potential impact of VR on patient-reported outcomes (ie, perceived information provision quality, knowledge about immunotherapy and patient activation) will be assessed and stratified by information coping style (ie, monitors vs blunters) whenever statistical analyses are significant. The patient-reported outcomes will be measured at baseline, post-intervention and 2 weeks post-intervention. In addition, semistructured interviews will be conducted with health professionals and participants randomised to the VR trial arm, to further explore acceptability and feasibility.ETHICS AND DISSEMINATION:Ethics approval was obtained from the Greater Western Human Research Ethics Committee, New South Wales Local Health District (2022/ETH01760). Informed consent will be obtained from all participants. Findings will be disseminated via relevant conference presentations and publications in peer-reviewed journals.TRIAL REGISTRATION NUMBER:ACTRN12622001473752.

This paper is concerned mainly with the assumptions underpinning the actual testing procedure, measurement, and interpretation of the video head impulse test-vHIT. Other papers have reported in detail the artifacts which can interfere with obtaining accurate eye movement results, but here we focus not on artifacts, but on the basic questions about the assumptions and geometrical considerations by which vHIT works. These matters are crucial in understanding and appropriately interpreting the results obtained, especially as vHIT is now being applied to central disorders. The interpretation of the eye velocity responses relies on thorough knowledge of the factors which can affect the response-for example the orientation of the goggles on the head, the head pitch, and the contribution of vertical canals to the horizontal canal response. We highlight some of these issues and point to future developments and improvements. The paper assumes knowledge of how vHIT testing is conducted.

BACKGROUND:Dizziness is a common perioperative complication after cochlear implantation (CI). To date, the exact cause behind this phenomenon remains unclear. There is recent evidence to suggest that otolith function, specifically utricular, may be affected shortly after CI surgery, however whether these changes are related to patient symptoms has not yet been investigated. OBJECTIVE:To determine whether CI surgery and perioperative dizziness is associated with changes in utricular function. METHODS:We performed an observational study on patients undergoing routine CI surgery. Utricular function was assessed using the Subjective Visual Vertical (SVV), and perioperative dizziness was determined using a questionnaire. The study followed patients before surgery and then again 1-day, 1-week and 6-weeks after implantation. RESULTS:Forty-one adult CI recipients participated in the study. The SVV deviated away from the operated ear by an average of 2.17° a day after implantation, 0.889° 1 week and -0.25° 6 weeks after surgery. Dizziness contributed to a tilt of 0.5° away from the implanted ear. These deviations were statistically significant. CONCLUSIONS:CI surgery causes utricular hyperfunction in the operated ear that resolves over 6 weeks. SVV tilts were greater in participants experiencing dizziness, suggesting that utricular hyperfunction may contribute to the dizziness.

BACKGROUND:Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting toxicity for people treated for cancer. Impaired balance and falls are functional consequences of CIPN. Virtual reality (VR) technology may be able to assess balance and identify patients at risk of falls.AIMS:To assess the impact of potentially neurotoxic chemotherapy on balance using VR, and explore associations between VR balance assessment, falls and CIPN.METHODS:This prospective, repeated measures longitudinal study was conducted at two Australian cancer centres. Eligible participants were commencing adjuvant chemotherapy containing a taxane for breast cancer, or oxaliplatin for colorectal cancer (CRC), per institutional guidelines. Balance assessments using VR were conducted at baseline, end of chemotherapy and 3 and 6 months after completion of chemotherapy. Participants also completed a comprehensive CIPN assessment comprising clinical and patient-reported outcomes, and recorded falls or near falls.RESULTS:Out of 34 participants consented, 24 (71%) had breast cancer and 10 (29%) had CRC. Compared to baseline, balance threshold was reduced in 10/28 (36%) evaluable participants assessed at the end of chemotherapy, and persistent in 7/22 (32%) at 6 months. CIPN was identified in 86% at end of chemotherapy and persisted to 6 months after chemotherapy completion in 73%. Falls or near falls were reported by 12/34 (35%) participants, and were associated with impaired VR balance threshold (P = 0.002).CONCLUSIONS:While VR balance assessment was no better at identifying CIPN than existing measures, it is a potential surrogate method to assess patients at risk of falls from CIPN.

Otoliths are the primary gravity sensors of the vestibular system and are responsible for the ocular counter-roll (OCR). This compensatory eye torsion ensures gaze stabilization and is sensitive to a head roll with respect to gravity and the Gravito-Inertial Acceleration vector during, e.g., centrifugation. To measure the effect of prolonged spaceflight on the otoliths, we quantified the OCR induced by off-axis centrifugation in a group of 27 cosmonauts in an upright position before and after their 6-month space mission to the International Space Station. We observed a significant decrease in OCR early postflight, larger for first-time compared to experienced flyers. We also found a significantly larger torsion for the inner eye, the eye closest to the rotation axis. Our results suggest that experienced cosmonauts have acquired the ability to adapt faster after G-transitions. These data provide a scientific basis for sending experienced cosmonauts on challenging missions that include multiple g-level transitions.

BACKGROUND:Previous research has established that anxiety is associated with freezing of gait (FOG) in Parkinson's disease (PD). Although providing body-related visual feedback has been previously suggested to improve FOG, it remains unclear whether anxiety-induced FOG might be improved.RESEARCH QUESTION:The current study aimed to evaluate whether body-related visual feedback (VF) improves FOG consistently across low and high threat conditions.METHODS:Sixteen PD patients with FOG were instructed to walk across a plank in a virtual environment that was either located on the ground (low threat) or elevated above a deep pit (high threat). Additionally, visual feedback (VF) was either provided (+) or omitted (-) using an avatar that was synchronised in real-time with the participants movements.RESULTS:revealed that in the low threat condition (i.e., ground), %FOG was significantly reduced when VF was provided (VF+) compared to when VF was absent (VF-). In contrast, during the elevated high threat condition, there were no differences in %FOG regardless of whether VF was provided or not.SIGNIFICANCE:These findings confirm that although VF can aid in the reduction of FOG, anxiety may interfere with freezers' ability to use sensory feedback to improve FOG and hence, in high threat conditions, VF was unable to aid in the reduction of FOG. Future studies should direct efforts towards the treatment of anxiety to determine whether better management of anxiety may improve FOG.

The otoliths of the vestibular system are seen as the primary gravitational sensors and are responsible for a compensatory eye torsion called the ocular counter-roll (OCR). The OCR ensures gaze stabilization and is sensitive to a lateral head roll with respect to gravity and the Gravito-Inertial Acceleration (GIA) vector during e.g., centrifugation. This otolith-mediated reflex will make sure you will still be able to maintain gaze stabilization and postural stability when making sharp turns during locomotion. To measure the effect of prolonged spaceflight on the otoliths, we measured the OCR induced by off-axis centrifugation in a group of 27 cosmonauts before and after their 6-month space mission to the International Space Station (ISS). We observed a significant decrease in OCR early post-flight, with first- time flyers being more strongly affected compared to frequent or experienced flyers. Our results strongly suggest that experienced space crew have acquired the ability to adapt faster after G-transitions and should therefore be sent for more challenging space missions, e.g., Moon or Mars, because they are noticeably less affected by microgravity regarding their vestibular system.

BACKGROUND: Parkinson’s disease (PD) is a common multi-system neurodegenerative disorder with possible vestibular system dysfunction, but prior vestibular function test findings are equivocal. OBJECTIVE: To report and compare vestibulo-ocular reflex (VOR) gain as measured by the video head impulse test (vHIT) in participants with PD, including tremor dominant and postural instability/gait dysfunction phenotypes, with healthy controls (HC). METHODS: Forty participants with PD and 40 age- and gender-matched HC had their vestibular function assessed. Lateral and vertical semicircular canal VOR gains were measured with vHIT. VOR canal gains between PD participants and HC were compared with independent samples t-tests. Two distinct PD phenotypes were compared to HC using Tukey’s ANOVA. The relationship of VOR gain with PD duration, phenotype, severity and age were investigated using logistic regression. RESULTS: There were no significant differences between groups in vHIT VOR gain for lateral or vertical canals. There was no evidence of an effect of PD severity, phenotype or age on VOR gains in the PD group. CONCLUSION: The impulsive angular VOR pathways are not significantly affected by the pathophysiological changes associated with mild to moderate PD.

OBJECTIVE:To explore what is currently known about the use of virtual reality (VR) as a patient education tool in healthcare. METHODS:Arksey and O'Malley's scoping review method and the PRISMA-ScR Checklist were employed. Four peer-reviewed databases were searched (Medline, Embase, PsychINFO, the Cochrane library). Pre-defined selection criteria identified 18 studies for inclusion. Results were synthesized using a narrative approach. RESULTS:VR as an educational tool in healthcare is feasible and acceptable, and may improve patient's knowledge about their illness and satisfaction with treatment. Most studies used the Oculus VR glasses or headset, educated patients though the use of 3D 360° VR anatomical models, and were conducted with people affected with cancer. Opportunities exist for exploring unintended consequences, and the role of VR in educating populations with lower health literacy. CONCLUSION:VR could assist in communicating medical information and knowledge to patients, but more research is needed, particularly to identify for whom and in what situations this method is most useful and to improve understanding about the potential unintended consequences. PRACTICE IMPLICATIONS:Health professionals should consider using VR to educate their patients, and researchers can use this as a road map on how to address knowledge gaps in this field.

Subjective visual vertical (SVV) assesses the ability to perceive verticality, which is a measure of vestibular otolithic function. Vestibular lesions influence this perception of verticality. We developed a method using virtual reality (VR) display and an Android software application named ‘Curator SVV’. The virtual reality SVV (Curator SVV) consisted of ten readily identifiable artworks projected by a Samsung phone S6 which is inserted into a virtual reality headset. In the first study, 20 patients had there SVV assessed with two devices: (1) a commercially available SVV measurement device (VestiTest®) and (2) a virtual reality SVV using the Curator SVV application. In a second study, 32 healthy subjects had their SVV assessed by the Curator SVV application whilst sitting in a chair. In the first study, there was no significant difference (p = 0.44, paired t test and p = 0.01, test of equivalence) between results obtained by Curator SVV and the commercially available device. In the second study, the average angle measured for healthy subjects was 0.00° ± 0.85°. The normal range (mean ± 2 SD) was ± 2° in standard upright position. We were able to demonstrate that the Curator SVV can be readily employed as an objective, non-invasive and affordable means of assessing otolith function in the clinical context. We validated this novel methodology by finding strong quantitative parity between a standard commercial SVV unit and the VR Curator SVV method. Our very lightweight and mobile device can be employed in clinical contexts including at the bedside and in different head and body positions.

Background: Freezing of gait (FOG) in Parkinson’s disease (PD) has been shown to be more frequent in stressful situations, implicating anxiety. Heart rate (HR) has been shown to increase prior to a FOG episode supporting the notion that elevated stress levels may trigger FOG. However, no studies to date have investigated whether elevated HR precedes all subtypes of FOG or only those episodes that are driven by anxiety. Objective: The present study sought to investigate whether 1) HR increases prior to FOG episodes in nonspecific environments (Experiment 1), and if 2) HR increases prior to FOG when provoked in high but not low threat environments using a virtual reality paradigm (Experiment 2). Methods: In Experiment 1, 10 of 19 participants with PD and FOG (PD + FOG) experienced FOG during a series of walking trials. In Experiment 2, 12 of 23 participants with PD + FOG experienced FOG while walking across an elevated and ground level narrow plank in virtual reality. HR was collected throughout the duration of both experiments, while FOG was quantified by experts using video review and tagging. Results: HR significantly increased 2–3 seconds prior to a FOG episode during Experiment 1. In Experiment 2, HR significantly increased 4–6 seconds prior to a FOG episode, specifically while navigating the elevated plank. However, there were no significant increases in HR prior to FOG episodes when participants navigated the ground plank. Conclusion: This study extends previous work further demonstrating that increases in HR prior to FOG episodes appear linked to elevated anxiety levels.

The suppression head impulse test paradigm (SHIMP) is a newly described indicator of vestibular function which yields two measures: vestibulo-ocular reflex (VOR) gain and a saccadic response. It is an alternative and complementary test to the head impulse test paradigm (HIMP). Parkinson’s disease (PD) has known saccadic and central vestibular pathway dysfunction. This paper is the first description of SHIMP VOR gain and saccade characteristic in this population. This prospective observational study measured the SHIMP VOR gain and saccade characteristics in 39 participants with idiopathic PD and compared this to 40 healthy controls (HC). The effect of group, demographic variables and SHIMP characteristics were evaluated. SHIMP VOR gains were not significantly different between groups (p = 0.10). Compared to HC, the PD group mean SHIMP peak saccade velocity was significantly reduced by an average of 77.07°/sec (p < 0.001), and SHIMP saccade response latency was longer, with an average delay of 23.5 ms (p = 0.003). SHIMP saccade peak velocity was also associated with both head impulse velocity (p = 0.002) and SHIMP VOR gain (p = 0.004) variables, but there was no significant influence of these variables when SHIMP saccade peak velocity was considered as a predictor of PD (p = 0.52–0.91). VOR gains were unaffected by PD. PD-specific saccadic dysfunction, namely reduced peak saccade velocities and prolonged response latencies, were observed in the SHIMP-induced saccade responses. VOR gain using slow phase eye velocity is preferred as the indicator of vestibular function in the SHIMPs paradigm as non-vestibular factors affected saccade peak velocity.

Background Superior Canal Dehiscence is classically diagnosed with typical abnormalities on Vestibular Evoked Myogenic Potentials (VEMPs) and Computed Tomography (CT) scans. Aim This paper discusses the utility of the video Head Impulse Test (vHIT) in SCD. Methods Data from 11 ears (8 patients) with SCD were retrospectively reviewed. Results from vHIT, VEMPs and CT and when possible, MRI scans were correlated. An audit of 300 vHIT from patients undergoing routine testing for any neurotological complaint was also conducted to look at the incidence of isolated abnormal superior canal function. Results 82% of patients (9 ears) with SCD showed abnormal vHIT (reduced gain and catch-up saccades) isolated to the affected superior semicircular canal. Conclusion Correlation of the CT and VEMPs are important in forming a diagnosis of SCD. However, if isolated superior canal vHIT abnormalities are demonstrated, it is suggestive of SCD and such patients should be referred for further investigations.

PurposeChemotherapy-induced peripheral neuropathy (CIPN) commonly affects people treated for cancer, with functional consequences of impaired balance and falls. Virtual reality technology (VR) may be able to assess balance, identifying patients at increased risk of falls. We aimed to assess the impact of neurotoxic chemotherapy on balance and falls risk using VR, and explore whether changes in balance threshold were associated with falls or validated CIPN measures. MethodsWe conducted a prospective, longitudinal cohort study at two Australian oncology centres. Eligible participants were commencing adjuvant chemotherapy containing a taxane for breast cancer, or oxaliplatin for colon cancer. Excluded: insufficient English to complete assessments, VR intolerance, or pre-existing balance disorder. VR balance threshold was recorded at baseline, intervals during chemotherapy, and 3- and 6-months after chemotherapy completion. Additional measures: 1) clinician-graded peripheral sensory neuropathy (Common Terminology Criteria for Adverse Events), 2) Total Neuropathy Score-clinical, 3) patient-reported neuropathy, 4) ‘Timed Up-and-Go’ test, 5) participant-reported falls/near-falls. ResultsOf 34 participants consented, 24 (71%) had breast cancer and 10 (29%) had colon cancer. Compared to baseline, balance threshold worsened in 10/28 (36%) evaluable participants assessed at the end-of-chemotherapy; this persisted in 7/22 (32%) at 6 months. CIPN affected 86% at end of chemotherapy, and 73% at 6-months post-chemotherapy . Falls/near-falls were reported by 12/34 (35%), and associated with impaired balance (p = 0.002). ConclusionVR balance assessment warrants further investigation as a surrogate method to objectively identify patients at risk of falls from CIPN, however was no better at diagnosing CIPN than existing tools. Trial Registration: N/A