Validity of Hololens Augmented Reality Head Mounted Display for Measuring Gait Parameters in Healthy Adults and Children with Cerebral Palsy

Augmented Reality Exergames for Upcoming Cognitive-Motor Rehabilitation: User-Centered Design Approach and User Experience of Healthy Children

BACKGROUND

Traditional rehabilitation programs for children with cerebral palsy and acquired brain injuries aim to enhance motor and cognitive abilities through repetitive exercises, which are often perceived as tedious and demotivating. Extended reality technologies, including augmented reality (AR) and virtual reality, offer more engaging methods through exergames. However, to date, no AR exergames simultaneously integrate cognitive and motor aspects within navigational tasks. Developing these exergames necessitates rigorous methodological steps, especially when using emerging technologies such as AR. The MIDE (Multidisciplinary Iterative Design of Exergames) framework advocates a participatory design approach, involving users from the outset, the objective being to optimize the interface and validate game mechanics through user experience (UX) assessment. Some researchers initially test these mechanisms on healthy children before applying them to clinical populations.

OBJECTIVE

This study aims to evaluate the UX of our AR exergames, consisting of two games (AR Corsi and AR Zoo), in typically developing children.

METHODS

Typically developing children participated in two 1.5-hour sessions. During each session, they played one of two AR games using the Microsoft HoloLens 2 headset: AR Corsi and AR Zoo, both of which are designed to engage executive functions and motor skills through navigational capabilities. UX was assessed after each session using the following measures: System Usability Scale scores for usability, AttrakDiff for attractiveness and game quality, MeCue for emotional experience, and Rating scale of Perceived Exertion for Children for pre- and postsession mental and physical fatigue.

RESULTS

A total of 27 participants (mean age 11.9, SD 1.2 years) were included in the study. Mean System Usability Scale scores were 79.9 (SD 11.4) for AR Corsi and 76.3 (SD 12.1) for AR Zoo, indicating good usability. The AttrakDiff questionnaire yielded favorable results, with scores between 1 and 3 for overall attractiveness, pragmatic quality, and stimulation for both AR games. However, the hedonic quality "identity" received neutral scores (mean 0.6, SD 0.5 for AR Corsi and mean 0.7, SD 0.8 for AR Zoo). The MeCue emotions module yielded average scores of 5.2 (SD 0.7) for AR Corsi and 5.3 (SD 0.8) for AR Zoo, significantly exceeding the theoretical mean of 4 (P<.001). We observed a significant effect of physical fatigue (P=.02) and mental fatigue (P=.002) after exposure to both games. A comparative analysis of UX between the two games showed no significant differences.

CONCLUSIONS

This study demonstrates that our exergame, comprising two AR games, is user-friendly and well-received by typically developing children, eliciting positive emotions and overall appeal. Although some children reported fatigue, favorable UX evaluation confirms the validity of the game's content and mechanisms, suggesting its suitability for use among children with cerebral palsy and acquired brain injuries.

Evaluation of Remote Surgical Hands-on Training in Veterinary Education Using a Hololens Mixed Reality Head-Mounted Display

Conferencing system-assisted online classes have been conducted worldwide since the COVID-19 pandemic, and the use of three-dimensional glasses may improve pre-clinical veterinary education. However, students' satisfaction with this technique rather than their ability to perform surgery using these items has not been assessed. This study could potentially assess students' satisfaction with technique/instruction rather than their ability to perform surgery using these items.This study aimed to evaluate the effectiveness of remote online hands-on training in veterinary education using 3D glasses. Sixty students enrolled at the Faculty of Veterinary Medicineat Yamaguchi University voluntarily participated and were randomly divided into a 3D glasses and tablet group, each with 30 students. Each student completed one orthopedic and one ophthalmological task. The orthopedic task was performing surgery on a limb model, whereas the ophthalmological task involved incising a cornea on an eye model. The 3D glasses group participated in the ophthalmology task, then the orthopedic task, at a separate venue from the instructor. The tablet group participated in the same tasks using a tablet. In the student questionnaire, orthopedic screw fixation showed significantly higher levels of satisfaction in the 3D glasses group than in the tablet group, indicating a preference for this method. By contrast, for ophthalmic corneal suturing, the tablet group showed a significantly higher level of satisfaction than the 3D glasses group. Our findings showed that 3D glasses have a high educational value in practical training requiring depth and angle information.

Effect of an augmented reality active video game for gait training in children with cerebral palsy following single-event multilevel surgery: protocol for a randomised controlled trial

INTRODUCTION

In paediatric rehabilitation, fun and motivation are also critical keys to successful therapy. A variety of interventions have shown positive effects, high level of interest, compliance and engagement with active video game (AVG).This seems to be an interesting approach for the postoperative gait rehabilitation of children with cerebral palsy (CP). In this study, we will investigate if an overground gait training (GT) delivered through an AVG can improve walking capacity and anaerobic performance.

METHODS AND ANALYSIS

This study is a randomised clinical controlled trial. A total of 14 children and adolescents in the age of 10-18 years with CP will be included. The minimum time between surgery and inclusion will be 7 weeks. The test group will participate in the GT programme with Augmented Reality Rehabilitation of Walking-Cerebral Palsy AVG, control group will receive GT on a treadmill. The primary outcome is the 6-Min Walk Test assessing walking capacity; secondary outcomes are the Muscle Power Sprint Test for anaerobic performance and Shuttle Run Test for physical fitness level. Satisfaction is tested with the Physical Activity Enjoyment Scale.

ETHICS AND DISSEMINATION

The findings will be disseminated by publications in peer-reviewed journals and conferences. This study received agreement from French ethic committee (Comité de Protection des Personnes Sud-Est VI-Number 2020-A02959-30).

TRIAL REGISTRATION NUMBER

NCT04837105.

Visual Feedback in Augmented Reality to Walk at Predefined Speed Cross-Sectional Study Including Children With Cerebral Palsy

In an augmented reality environment, the range of possible real-time visual feedback is extensive. This study aimed to compare the impact of six scenarios in augmented reality combining four visual feedback characteristics on achieving a target walking speed. The six scenarios have been developed for Microsoft Hololens augmented reality headset. The four feedback characteristics that we have varied were: Color; Spatial anchoring; Speed of the feedback, and Persistence. Each characteristic could have different values (for example, the color could be unicolor, bicolor, or gradient). Participants had to walk for two consecutive walking trials for each scenario: at their maximal speed and an intermediate speed. Mean speed, percentage of time spent above or around target speed, and time to reach target speed were compared between scenarios using mixed linear models. A total of 25 children with disabilities have been included. The feasibility and user experience were excellent. Mean speed during scenario 6, which displayed feedback with gradient color, attached to the world, with a speed relative to the player equal to his speed, and that disappeared over time, was significantly higher than other scenarios and control (p =0.003). Participants spent 80.98% of time above target speed during scenario 6. This scenario mixed the best combination of feedback characteristics to exceed the target walking speed (p=0.0058). Scenarios 5 and 6, which shared the same feedback characteristics for spatial anchoring (world-locked) and feedback speed (equal to the player speed), decreased the time to reach the target speed (p=0.019). Delivering multi-modal feedback has been recognized as more effective for improving motor performance. Therefore, our results showed that not all visual feedback had the same impact on performance. Further studies are required to test the weight of each feedback characteristic and their possible interactions inside each scenario. This study was registered in the ClinicalTrials.gov database (NCT04460833).

A Wearable Mixed Reality Platform to Augment Overground Walking: A Feasibility Study

Humans routinely modify their walking speed to adapt to functional goals and physical demands. However, damage to the central nervous system (CNS) often results in abnormal modulation of walking speed and increased risk of falls. There is considerable interest in treatment modalities that can provide safe and salient training opportunities, feedback about walking performance, and that may augment less reliable sensory feedback within the CNS after injury or disease. Fully immersive virtual reality technologies show benefits in boosting training-related gains in walking performance; however, they lack views of the real world that may limit functional carryover. Augmented reality and mixed reality head-mount displays (MR-HMD) provide partially immersive environments to extend the virtual reality benefits of interacting with virtual objects but within an unobstructed view of the real world. Despite this potential advantage, the feasibility of using MR-HMD visual feedback to promote goal-directed changes in overground walking speed remains unclear. Thus, we developed and evaluated a novel mixed reality application using the Microsoft HoloLens MR-HMD that provided real-time walking speed targets and augmented visual feedback during overground walking. We tested the application in a group of adults not living with disability and examined if they could use the targets and visual feedback to walk at 85%, 100%, and 115% of each individual’s self-selected speed. We examined whether individuals were able to meet each target gait speed and explored differences in accuracy across repeated trials and at the different speeds. Additionally, given the importance of task-specificity to therapeutic interventions, we examined if walking speed adjustment strategies were consistent with those observed during usual overground walking, and if walking with the MR-HMD resulted in increased variability in gait parameters. Overall, participants matched their overground walking speed to the target speed of the MR-HMD visual feedback conditions (all p-values > 0.05). The percent inaccuracy was approximately 5% across all speed matching conditions and remained consistent across walking trials after the first overall walking trial. Walking with the MR-HMD did not result in more variability in walking speed, however, we observed more variability in stride length and time when walking with feedback from the MR-HMD compared to walking without feedback. The findings offer support for mixed reality-based visual feedback as a method to provoke goal-specific changes in overground walking behavior. Further studies are necessary to determine the clinical safety and efficacy of this MR-HMD technology to provide extrinsic sensory feedback in combination with traditional treatments in rehabilitation.

The Microsoft HoloLens 2 Provides Accurate Measures of Gait, Turning, and Functional Mobility in Healthy Adults

Augmented-reality (AR) headsets, such as the Microsoft HoloLens 2 (HL2), have the potential to be the next generation of wearable technology as they provide interactive digital stimuli in the context of ecologically-valid daily activities while containing inertial measurement units (IMUs) to objectively quantify the movements of the user. A necessary precursor to the widespread utilization of the HL2 in the fields of movement science and rehabilitation is the rigorous validation of its capacity to generate biomechanical outcomes comparable to gold standard outcomes. This project sought to determine equivalency of kinematic outcomes characterizing lower-extremity function derived from the HL2 and three-dimensional (3D) motion capture systems (MoCap). Sixty-six healthy adults completed two lower-extremity tasks while kinematic data were collected from the HL2 and MoCap: (1) continuous walking and (2) timed up-and-go (TUG). For all the continuous walking metrics (cumulative distance, time, number of steps, step and stride length, and velocity), equivalence testing indicated that the HL2 and MoCap were statistically equivalent (error ≤ 5%). The TUG metrics, including turn duration and turn velocity, were also statistically equivalent between the two systems. The accurate quantification of gait and turning using a wearable such as the HL2 provides initial evidence for its use as a platform for the development and delivery of gait and mobility assessments, including the in-person and remote delivery of highly salient digital movement assessments and rehabilitation protocols.