Effectiveness of head-mounted ultrasound display for radial arterial catheterisation in paediatric patients by anaesthesiology trainees: A randomised clinical trial.

BACKGROUND: The effectiveness of head mounted real-time ultrasound displays (hereafter referred to as 'smart glasses') in improving hand-eye coordination in less experienced individuals, such as trainees in anaesthesia, is unclear. OBJECTIVES: To compare the first-attempt success rate of smart glasses-assisted ultrasound-guided paediatric radial artery catheterisation with conventional ultrasound guided catheterisation performed by anaesthesiology trainees. DESIGN: Prospective randomised controlled trial. SETTINGS: Tertiary university hospital from September 2021 to February 2023. PATIENTS: One hundred and twenty-two paediatric patients (age <7 years, weight ≥3 kg) who required radial artery cannulation during general anaesthesia. INTERVENTIONS: The participants were randomly assigned to either the ultrasound screen group (control) or the smart glasses group prior to radial artery catheterisation. MAIN OUTCOME MEASURES: The primary outcome was the first attempt success rate. Secondary outcomes included the number of attempts, use of transfixion technique, overall complication rate, and clinical anaesthesiology (CA) year of the operators. RESULTS: A total of 119 paediatric patients were included in the analysis. The smart glasses group exhibited higher first-attempt success rate than did the control group (89.8% [53/59] vs. 71.7% [43/60]; P  = 0.023; odds ratio (OR) 3.49; (95% confidence interval (CI) 1.27-9.6). The overall number of attempts [median, 1; interquartile range (IQR), 1-1; range, 1-3 vs. median, 1; IQR, 1-2; range, 1-4; P   =  0.006], use of transfixion technique (12/59 [20.3%] vs. 28/60 [46.7%]; P  = 0.002), and overall complication rate (6.8% [4/59] vs. 30.0% [18/60]; P  = 0.002) were lower in the smart glasses group than in the control group. However, among paediatric anaesthesiology fellows (CA 5 years), the first- (89.3% [25/28] vs. 80.8% [21/26]; P  = 0.619) and second-attempt success rates (96.4% [27/28] vs. 80.8% [21/26]; P  = 0.163) did not differ between the two groups. CONCLUSIONS: Smart glasses-assisted ultrasound guided radial artery catheterisation improved the first attempt success rate among anaesthesiology trainees, reducing the number of attempts and overall complication rates in small paediatric patients. Smart glasses were more effective for anaesthesia residents (CA 2-4 years) but were not effective for paediatric anaesthesiology fellows (CA 5 years). TRIAL REGISTRATION: ClinicalTrials.gov (NCT05030649) ( https://classic.clinicaltrials.gov/ct2/show/NCT05030649 ).

A Comparison of Head Movement Classification Methods.

To understand human behavior, it is essential to study it in the context of natural movement in immersive, three-dimensional environments. Virtual reality (VR), with head-mounted displays, offers an unprecedented compromise between ecological validity and experimental control. However, such technological advancements mean that new data streams will become more widely available, and therefore, a need arises to standardize methodologies by which these streams are analyzed. One such data stream is that of head position and rotation tracking, now made easily available from head-mounted systems. The current study presents five candidate algorithms of varying complexity for classifying head movements. Each algorithm is compared against human rater classifications and graded based on the overall agreement as well as biases in metrics such as movement onset/offset time and movement amplitude. Finally, we conclude this article by offering recommendations for the best practices and considerations for VR researchers looking to incorporate head movement analysis in their future studies.

Slim and robust eye tracker on eyeglass temples with NIR patterned mirrors.

Eye trackers play a crucial role in the development of future display systems, such as head-mounted displays and augmented reality glasses. However, ensuring robustness and accuracy in gaze estimation poses challenges, particularly with limited space available for the transmitter and receiver components within these devices. To address the issues, we propose what we believe is a novel eye tracker design mounted on foldable temples, which not only supports accurate gaze estimation but also provides slim form-factor and unobstructed vision. Our temple-mounted eye tracker utilizes a near-infrared imaging system and incorporates a patterned near-infrared mirror for calibration markers. We present wearable prototypes of the eye tracker and introduce a unique calibration and gaze extraction algorithm by considering the mirror's spatial reflectance distribution. The accuracy of gaze extraction is evaluated through tests involving multiple users with realistic scenarios. We conclude with an evaluation of the results and a comprehensive discussion on the applicability of the temple-mounted eye tracker.

Using augmented reality to cue obstacles for people with low vision.

Detecting and avoiding obstacles while navigating can pose a challenge for people with low vision, but augmented reality (AR) has the potential to assist by enhancing obstacle visibility. Perceptual and user experience research is needed to understand how to craft effective AR visuals for this purpose. We developed a prototype AR application capable of displaying multiple kinds of visual cues for obstacles on an optical see-through head-mounted display. We assessed the usability of these cues via a study in which participants with low vision navigated an obstacle course. The results suggest that 3D world-locked AR cues were superior to directional heads-up cues for most participants during this activity.

Dispatcher-assisted BLS for lay bystanders: A pilot study comparing video streaming via smart glasses and telephone instructions.

OBJECTIVE: To determine whether dispatcher assistance via smart glasses improves bystander basic life support (BLS) performance compared with standard telephone assistance in a simulated out-of-hospital cardiac arrest (OHCA) scenario. METHODS: Pilot study in which 28 lay people randomly assigned to a smart glasses-video assistance (SG-VA) intervention group or a smartphone-audio assistance (SP-AA) control group received dispatcher guidance from a dispatcher to provide BLS in an OHCA simulation. SG-VA rescuers received assistance via a video call with smart glasses (Vuzix, Blade) connected to a wireless network, while SP-AA rescuers received instructions over a smartphone with the speaker function activated. BLS protocol steps, quality of chest compressions, and performance times were compared. RESULTS: Nine of the 14 SG-VA rescuers correctly completed the BLS protocol compared with none of the SP-AA rescuers (p = 0.01). A significantly higher number of SG-VA rescuers successfully opened the airway (13 vs. 5, p = 0.002), checked breathing (13 vs. 8, p = 0.03), correctly positioned the automatic external defibrillator pads (14 vs.6, p = 0.001), and warned bystanders to stay clear before delivering the shock (12 vs. 0, p < 0.001). No significant differences were observed for performance times or chest compression quality. The mean compression rate was 104 compressions per minute in the SG-VA group and 98 compressions per minute in the SP-AA group (p = 0.46); mean depth of compression was 4.5 cm and 4.4 cm (p = 0.49), respectively. CONCLUSIONS: Smart glasses could significantly improve dispatcher-assisted bystander performance in an OHCA event. Their potential in real-life situations should be evaluated.

Laser guidance for ultrasound-guided radial artery catheterization using smart glasses: a randomized trial.

PURPOSE: The use of smart glasses during ultrasound-guided needle procedures may reduce operators' head movements but has not been shown to improve procedural performance. Laser guidance has been shown to decrease the time required for ultrasound-guided procedures in phantom models but has not been tested clinically. We hypothesized that adding laser guidance to the use of smart glasses for ultrasound-guided radial artery catheterization using the long axis approach would improve performance by relatively inexperienced users unfamilar with these techniques. METHODS: In an unblinded controlled trial, we enrolled 52 patients requiring radial artery catheterization under anesthesia, randomized into two groups: smart glasses only (SO) (control; N = 26) or smart glasses with laser guidance group (SL) (N = 26). We assessed catheterization time (primary outcome), the number of needle redirections, first-pass success rate, and operator satisfaction (100 = most satisfactory; 0 = unsatisfactory). RESULTS: Comparing the SL with the SO group, catheterization time was shorter (median [interquartile range], 13 [9-20] sec vs 24 [18-46] sec, P < 0.001) and the number of needle redirections was lower (0 [0-1] vs 3 [1-3], P < 0.001) while the first-pass success rate (50% vs 12%, P = 0.007) and operator satisfaction score (85 [76-95] vs 52 [44-74], P < 0.001) were higher. CONCLUSION: Laser guidance improved the performance of ultrasound-guided radial artery catheterization using smart glasses in users inexperienced in the long axis in-plane approach. Nevertheless, it is unclear whether these findings are clinically significant. STUDY REGISTRATION DATE: CRIS.nih.go.kr (KCT0007168); registered 8 April 2022.

RéSUMé: OBJECTIF: L'utilisation de lunettes intelligentes pendant les procédures de ponctions échoguidées peut réduire les mouvements de la tête des opérateurs et opératrices, mais il n'a pas été démontré qu'elle améliorait les performances procédurales. Il a été démontré que le guidage laser réduisait le temps requis pour les interventions échoguidées sur des modèles fantômes, mais cette modalité n'a pas été testée cliniquement. Nous avons émis l'hypothèse que l'ajout d'un guidage laser à l'utilisation de lunettes intelligentes pour le cathétérisme échoguidé de l'artère radiale en utilisant une approche longitudinale (long axe) améliorerait les performances d'utilisateurs et utilisatrices relativement inexpérimenté·es et peu familier·ères avec ces techniques. MéTHODE: Dans une étude contrôlée sans insu, nous avons recruté et randomisé en deux groupes 52 patient·es nécessitant un cathétérisme de l'artère radiale sous anesthésie : lunettes intelligentes uniquement (LIU) (témoin N = 26) ou lunettes intelligentes avec guidage laser (LIL) (N = 26). Nous avons évalué le temps de cathétérisme (critère d'évaluation principal), le nombre de réorientation d'aiguilles, le taux de réussite au premier passage et la satisfaction de l'opérateur·trice (100 = le plus satisfaisant; 0 = insatisfaisant). RéSULTATS: En comparant le groupe LIL au groupe LIU, le temps de cathétérisme était plus court (médiane [écart interquartile], 13 [9-20] sec vs 24 [18­46] sec, P < 0,001) et le nombre de réorientations d'aiguilles était plus faible (0 [0­1] vs 3 [1­3], P < 0,001), tandis que le taux de réussite au premier passage (50 % vs 12 %, P = 0,007) et le score de satisfaction des opératrices et opérateurs (85 [76­95] vs 52 [44­74], P < 0,001) étaient plus élevés. CONCLUSION: Le guidage laser à l'aide de lunettes intelligentes a amélioré les performances du cathétérisme échoguidé de l'artère radiale chez des utilisateurs et utilisatrices inexpérimenté·es en approche longitudinale. Nous ne pouvons toutefois pas déterminer si ces résultats sont cliniquement significatifs. DATE D'ENREGISTREMENT DE L'éTUDE: CRIS.nih.go.kr (KCT0007168); enregistré le 8 avril 2022.

Real Time, Remote, and Recorded: Medical Student Experiences with Smart Glasses in Obstetrical Simulation.

OBJECTIVES: The coronavirus disease 2019 pandemic generated the need for a teaching tool for enhancing remote education and evaluation of medical trainees. Smart glasses are being explored as a hands-free teaching tool for teleconferencing with hands-on demonstrations in addition to livestreaming capability. We wanted to understand the efficacy of such virtual teaching techniques in teaching procedural and surgical skills. METHODS: Medical students in their Obstetrics and Gynecology clerkship at our medical school were recruited to participate in a virtual demonstration of normal vaginal delivery. A birthing simulator and smart glasses were used to livestream the simulated delivery, and a previously published checklist was used to show the steps for conducting routine vaginal delivery. A follow-up electronic survey assessed the clarity of the video and audio feed, level of satisfaction, positive and constructive feedback, and an error-identification exercise with a smart glass-recorded video. RESULTS: A total of 62 students participated; 98% of them reported that the audio and video feeds were clear and 95% of the students reported being extremely satisfied or satisfied with the teaching tool. Students could identify on average three out of four errors. Students believed the streaming to be "interactive" and a "most effective remote learning" tool, but expressed that it did not "take the place of clinical skills learning." CONCLUSIONS: The combination of smart glass technology and simulation can be a useful new tool for clinical faculty who simultaneously deliver care to patients and teach. Continued research is needed to explore the use of smart glass technology into livestreaming or surgeries and examinations, with consideration for patient privacy concerns and remote assessment of students.

Calibration of head mounted displays for vision research with virtual reality.

Immersion in virtual environments is an important analog for scientists. Situations that cannot be safely organized in the real world are being simulated virtually to observe, evaluate, and train aspects of human behavior for psychology, therapy, and assessment. However, creating an immersive environment using traditional graphics practices may create conflict with a researcher's goal of evaluating user response to well-defined visual stimuli. Standard computer monitors may display color-accurate stimuli, but it is generally viewed from a seating position, where the participant can see real-world visual context. In this article, we propose a novel means to allow vision scientists to exert finer control over the participants visual stimuli and context. We propose and verify a device-agnostic approach to color calibration by analyzing display properties such as luminance, spectral distribution, and chromaticity. We evaluated five different head-mounted displays from different manufacturers and showed how our approach produces conforming visual outputs.

Augmented reality during parotid surgery: real-life evaluation of voice control of a head mounted display.

PURPOSE: Augmented Reality can improve surgical planning and performance in parotid surgery. For easier application we implemented a voice control manual for our augmented reality system. The aim of the study was to evaluate the feasibility of the voice control in real-life situations. METHODS: We used the HoloLens 1® (Microsoft Corporation) with a special speech recognition software for parotid surgery. The evaluation took place in a audiometry cubicle and during real surgical procedures. Voice commands were used to display various 3D structures of the patient with the HoloLens 1®. Commands had different variations (male/female, 65 dB SPL)/louder, various structures). RESULTS: In silence, 100% of commands were recognized. If the volume of the operation room (OR) background noise exceeds 42 dB, the recognition rate decreases significantly, and it drops below 40% at > 60 dB SPL. With constant speech volume at 65 dB SPL male speakers had a significant better recognition rate than female speakers (p = 0.046). Higher speech volumes can compensate this effect. The recognition rate depends on the type of background noise. Mixed OR noise (52 dB(A)) reduced the detection rate significantly compared to single suction noise at 52 dB(A) (p ≤ 0.00001). The recognition rate was significantly better in the OR than in the audio cubicle (p = 0.00013 both genders, 0.0086 female, and 0.0036 male). CONCLUSIONS: The recognition rate of voice commands can be enhanced by increasing the speech volume and by singularizing ambient noises. The detection rate depends on the loudness of the OR noise. Male voices are understood significantly better than female voices.

Photoplethysmogram Biometric Authentication Using a 1D Siamese Network.

In the head-mounted display environment for experiencing metaverse or virtual reality, conventional input devices cannot be used, so a new type of nonintrusive and continuous biometric authentication technology is required. Since the wrist wearable device is equipped with a photoplethysmogram sensor, it is very suitable for use for nonintrusive and continuous biometric authentication purposes. In this study, we propose a one-dimensional Siamese network biometric identification model using a photoplethysmogram. To maintain the unique characteristics of each person and reduce noise in preprocessing, we adopted a multicycle averaging method without using a bandpass or low-pass filter. In addition, to verify the effectiveness of the multicycle averaging method, the number of cycles was changed and the results were compared. Genuine and impostor data were used to verify the biometric identification. We used the one-dimensional Siamese network to verify the similarity between the classes and found that the method with five overlapping cycles was the most effective. Tests were conducted on the overlapping data of five single-cycle signals and excellent identification results were observed, with an AUC score of 0.988 and an accuracy of 0.9723. Thus, the proposed biometric identification model is time-efficient and shows excellent security performance, even in devices with limited computational capabilities, such as wearable devices. Consequently, our proposed method has the following advantages compared with previous works. First, the effect of noise reduction and information preservation through multicycle averaging was experimentally verified by varying the number of photoplethysmogram cycles. Second, by analyzing authentication performance through genuine and impostor matching analysis based on a one-dimensional Siamese network, the accuracy that is not affected by the number of enrolled subjects was derived.

Interface Design of Head-Worn Display Application on Condition Monitoring in Aviation.

Head-worn displays (HWDs) as timely condition monitoring are increasingly used in aviation. However, interface design characteristics that mainly affect HWD use have not been fully investigated. The aim of this study was to examine the effects of several important interface design characteristics (i.e., the distance between calibration lines and the layouts of vertical and horizontal scale belts) on task performance and user preference between different conditions of display, i.e., HWD or head-up display (HUD). Thirty participants joined an experiment in which they performed flight tasks. In the experiment, the calibration lines' distance was set to three different levels (7, 9 and 11 mrad), and the scale belt layouts included horizontal and vertical scale belt layouts. The scale belts were set as follows: the original vertical scale belt width was set as L, and the horizontal scale belt height as H. The three layouts of the vertical calibration scale belt used were 3/4H, H and 3H/2. Three layouts of horizontal calibration scale belts were selected as 3L/4, L and 3L/2. The results indicated that participants did better with the HWD compared to the HUD. Both layouts of vertical and horizontal scale belts yielded significant effects on the users' task performance and preference. Users showed the best task performance while the vertical calibration scale belts were set as H and horizontal calibration scale belts were set as L, and users generally preferred interface design characteristics that could yield an optimal performance. These findings could facilitate the optimal design of usable head-worn-display technology.

Augmenting Image-Guided Procedures through In Situ Visualization of 3D Ultrasound via a Head-Mounted Display.

Medical ultrasound (US) is a commonly used modality for image-guided procedures. Recent research systems providing an in situ visualization of 2D US images via an augmented reality (AR) head-mounted display (HMD) were shown to be advantageous over conventional imaging through reduced task completion times and improved accuracy. In this work, we continue in the direction of recent developments by describing the first AR HMD application visualizing real-time volumetric (3D) US in situ for guiding vascular punctures. We evaluated the application on a technical level as well as in a mixed-methods user study with a qualitative prestudy and a quantitative main study, simulating a vascular puncture. Participants completed the puncture task significantly faster when using 3D US AR mode compared to 2D US AR, with a decrease of 28.4% in time. However, no significant differences were observed regarding the success rate of vascular puncture (2D US AR-50% vs. 3D US AR-72%). On the technical side, the system offers a low latency of 49.90 ± 12.92 ms and a satisfactory frame rate of 60 Hz. Our work shows the feasibility of a system that visualizes real-time 3D US data via an AR HMD, and our experiments show, furthermore, that this may offer additional benefits in US-guided tasks (i.e., reduced task completion time) over 2D US images viewed in AR by offering a vividly volumetric visualization.

Head-Mounted Display for Clinical Evaluation of Neck Movement Validation with Meta Quest 2.

Neck disorders have a significant impact on people because of their high incidence. The head-mounted display (HMD) systems, such as Meta Quest 2, grant access to immersive virtual reality (iRV) experiences. This study aims to validate the Meta Quest 2 HMD system as an alternative for screening neck movement in healthy people. The device provides data about the position and orientation of the head and, thus, the neck mobility around the three anatomical axes. The authors develop a VR application that solicits participants to perform six neck movements (rotation, flexion, and lateralization on both sides), which allows the collection of corresponding angles. An InertiaCube3 inertial measurement unit (IMU) is also attached to the HMD to compare the criterion to a standard. The mean absolute error (MAE), the percentage of error (%MAE), and the criterion validity and agreement are calculated. The study shows that the average absolute errors do not exceed 1° (average = 0.48 ± 0.09°). The rotational movement's average %MAE is 1.61 ± 0.82%. The head orientations obtain a correlation between 0.70 and 0.96. The Bland-Altman study reveals good agreement between the HMD and IMU systems. Overall, the study shows that the angles provided by the Meta Quest 2 HMD system are valid to calculate the rotational angles of the neck in each of the three axes. The obtained results demonstrate an acceptable error percentage and a very minimal absolute error when measuring the degrees of neck rotation; therefore, the sensor can be used for screening neck disorders in healthy people.

Effects of the Loss of Binocular and Motion Parallax on Static Postural Stability.

Depth information is important for postural stability and is generated by two visual systems: binocular and motion parallax. The effect of each type of parallax on postural stability remains unclear. We investigated the effects of binocular and motion parallax loss on static postural stability using a virtual reality (VR) system with a head-mounted display (HMD). A total of 24 healthy young adults were asked to stand still on a foam surface fixed on a force plate. They wore an HMD and faced a visual background in the VR system under four visual test conditions: normal vision (Control), absence of motion parallax (Non-MP)/binocular parallax (Non-BP), and absence of both motion and binocular parallax (Non-P). The sway area and velocity in the anteroposterior and mediolateral directions of the center-of-pressure displacements were measured. All postural stability measurements were significantly higher under the Non-MP and Non-P conditions than those under the Control and Non-BP conditions, with no significant differences in the postural stability measurements between the Control and Non-BP conditions. In conclusion, motion parallax has a more prominent effect on static postural stability than binocular parallax, which clarifies the underlying mechanisms of postural instability and informs the development of rehabilitation methods for people with visual impairments.

Multisensory Cues for Gait Rehabilitation with Smart Glasses: Methodology, Design, and Results of a Preliminary Pilot.

Recent advances in mobile technology have shown that augmented unisensory feedback can be leveraged to improve gait using wearable systems, but less is known about the possible benefits and usability of multisensory (i.e., multimodal) feedback. This paper introduces the preliminary results of an innovative research project aiming to develop an mHealth system including Android smart glasses, and providing multisensory cues for gait rehabilitation of people affected by Parkinson's disease in and out of the medical context. In particular, the paper describes a preliminary pilot focusing on the design of visual, auditory, and haptic cues, and testing the design methodologies to be used in further developments of the project. Considered research questions were: Which kinds of images, sounds, and vibrations mostly influence gait speed, stride length, and cadence? Which are the ones stressing the user the least? Which ones induce the most immediate reaction? Thus, in this starting part of the research project, different typologies of sensory cues were designed, tested, and evaluated considering quantitative and qualitative parameters to properly answer the research questions.

Mitigating the Costs of Spatial Transformations With a Situation Awareness Augmented Reality Display: Assistance for the Joint Terminal Attack Controller 3-17.

OBJECTIVE: Evaluate and model the advantage of a situation awareness (SA) supported by an augmented reality (AR) display for the ground-based joint terminal attack Controller (JTAC), in judging and describing the spatial relations between objects in a hostile zone. BACKGROUND: The accurate world-referenced description of relative locations of surface objects, when viewed from an oblique slant angle (aircraft, observation post) is hindered by (1) the compression of the visual scene, amplified at a lower slang angle, (2) the need for mental rotation, when viewed from a non-northerly orientation. APPROACH: Participants viewed a virtual reality (VR)-simulated four-object scene from either of two slant angles, at each of four compass orientations, either unaided, or aided by an AR head-mounted display (AR-HMD), depicting the scene from a top-down (avoiding compression) and north-up (avoiding mental rotation) perspective. They described the geographical layout of four objects within the display. RESULTS: Compared with the control condition, that condition supported by the north-up SA display shortened the description time, particularly on non-northerly orientations (9 s, 30% benefit), and improved the accuracy of description, particularly for the more compressed scene (lower slant angle), as fit by a simple computational model. CONCLUSION: The SA display provides large, significant benefits to this critical phase of ground-air communications in managing an attack-as predicted by the task analysis of the JTAC. APPLICATION: Results impact the design of the AR-HMD to support combat ground-air communications and illustrate the magnitude by which basic cognitive principles "scale up" to realistically simulated real-world tasks such as search and rescue.

Can a Wireless Full-HD Head Mounted Display System Improve Knee Arthroscopy Performance? - A Randomized Study Using a Knee Simulator.

INTRODUCTION: Our prototype wireless full-HD Augmented Reality Head-Mounted Display (AR-HMD) aims to eliminate surgeon head turning and reduce theater clutter. Learning and performance versus TV Monitors (TVM) is evaluated in simulated knee arthroscopy. METHODS: 19 surgeons and 19 novices were randomized into either the control group (A) or intervention group (B) and tasked to perform 5 simulated loose-body retrieval procedures on a bench-top knee arthroscopy simulator. A cross-over study design was adopted whereby subjects alternated between devices during trials 1-3, deemed the "Unfamiliar" phase, and then used the same device consecutively in trials 4-5, to assess performance in a more "Familiarized" state. Measured outcomes were time-to-completion and incidence of bead drops. RESULTS: In the unfamiliar phase, HMD had 67% longer mean time-to-completion than TVM (194.7 ± 152.6s vs 116.7 ± 78.7s, P < .001). Once familiarized, HMD remained inferior to TVM, with 48% longer completion times (133.8 ± 123.3s vs 90.6 ± 55s, P = .052). Cox regression revealed device type (OR = 0.526, CI 0.391-0.709, P < .001) and number of procedure repetitions (OR = 1.186, CI 1.072-1.311, P = .001) are significantly and independently related to faster time-to-completion. However, experience is not a significant factor (OR = 1.301, CI 0.971-1.741, P = .078). Bead drops were similar between the groups in both unfamiliar (HMD: 27 vs TVM: 22, P = .65) and familiarized phases (HMD: 11 vs TVM: 17, P = .97). CONCLUSION: Arthroscopic procedures continue to be better performed under conventional TVM. However, similar quality levels can be reached by HMD when given more time. Given the theoretical advantages, further research into improving HMD designs is advocated.

The effects of dual-task interference on visual search and verbal memory.

The operational costs of multitasking are more pressing given the increase in wearable technologies (head-up displays; HUDs) that facilitate multitasking. Often multitasking comes with performance costs, where the addition of more tasks impairs the performance of the tasks. The current study explored the extent to which multitasking interference can be characterised in simulated environments, as opposed to risky and harsh environments in real operational contexts. Forty-eight participants completed several trials where they performed a visual search task while navigating a simulated environment. There were three conditions: a standalone memory task, a standalone search task, and both tasks simultaneously. Results revealed significant dual-task interference when comparing the dual-task to each of the single-tasks. Results were corroborated by subjective workload and stress metrics. The results could prove useful for designing systems for individuals who routinely multitask in operational environments. Specifically, by furthering the understanding of their performance capabilities and trade-offs due to multitasking.Practitioner summary: Due to the demands of multitasking in operational environments, quantifying the degree of information lost on each task individually will aid in the understanding of the deficits of multitasking performance. This study shows that deficits in multi-tasking (via a HUD) can be understood in simulated environments to a similar degree as real-world tasks.

Visions of Control: The Head-Up Display, Perceptual Labor, and a Lesson for Augmented Reality.

Traditional workplace studies focus on the bodily integration of familiar technologies like the desktop computer and smartphone. To better understand augmented reality (AR) technologies that provide new ways to perform daily tasks, this article turns to an overlooked yet critical forerunner of AR: the head-up display (HUD). Extensive archival research and oral histories show that the HUD caused pilots to depend on a single interface, curtailing their autonomy for integrating disparate information that could inform critical, often lethal decision-making processes. This history provides evidence that once a single device subsumes many functions of a work environment, adaptive articulation work can drive information workers to undertake increasingly insulated information practices. The HUD's isolating and insulating perceptual legacy suggests that AR will similarly train users in many contexts how to trust interactive data overlays in ways that preclude cross-checking alternative data sources that could inform decision-making processes.

Optical design and pupil swim analysis of a compact, large EPD and immersive VR head mounted display.

Virtual reality head-mounted displays (VR-HMDs) are crucial to Metaverse which appears to be one of the most popular terms to have been adopted over the internet recently. It provides basic infrastructure and entrance to cater for the next evolution of social interaction, and it has already been widely used in many fields. The VR-HMDs with traditional aspherical or Fresnel optics are not suitable for long-term usage because of the image quality, system size, and weight. In this study, we designed and developed a large exit pupil diameter (EPD), compact, and lightweight VR-HMD with catadioptric optics. The mathematical formula for designing the catadioptric VR optics is derived. The reason why this kind of immersive VR optics could achieve a compact size and large EPD simultaneously is answered. Various catadioptric forms are systematically proposed and compared. The design can achieve a diagonal field of view (FOV) of 96° at -1 diopter, with an EPD of 10 mm at 11 mm eye relief (ERF). The overall length (OAL) of the system was less than 20 mm. A prototype of a compact catadioptric VR-HMD system was successfully developed.