INTRODUCTION

Independent mobility is an important milestone in a child's development [1,2]. Mobility provides children with opportunities for self-exploration and participation, to learn about spatial relationships, size, cause and effect and to develop the muscles needed to move efficiently in their environment. Children with severe motor impairments (SMI) have limited opportunities of mobility, hence they are at risk for developing secondary impairments such as decreased curiosity and initiative, learned helplessness, passivity and dependency. Introducing powered mobility at a young age has been shown to facilitate the development of important milestones and to provide these children with opportunities to interact with their family and friends [3-11].

Since powered wheelchairs can be unsafe for both the wheelchair driver and others in the environment, it is important to have ample practice time to develop the core skills of powered mobility [4]. When access to powered mobility training opportunities is inadequate due to limited availability of chairs and practice time, simulators for powered mobility have been used as a feasible option by adults [12].

Simulation-based learning is a technique to enable learning and practice of activities normally performed in functional life situations [13]. It allows the user to experience real life scenarios in a safe, controlled environment, to spend time on a specific task until mastery is achieved, and to learn via structured visual and auditory feedback of results and performance during and after task completion [14].  During simulation–based learning the user engages in an interactive experience that may be immersive (e.g., via a Head mounted display (HMD), or non-immersive (e.g., viewed on a flat screen) [15]. 

Simulation based learning has been demonstrated to be effective in a number of related fields of clinical practice. Cheng, Lang, Starr, Pusic, & Cook's (2014) [16] meta-analysis on the use of simulation in pediatric education reviewed 57 studies with 3666 participants. Knowledge, skills, behavior and patient outcomes increased after using simulation-based learning.  Nurses, for example, used simulation-based learning to practice and gain proficiency in core skills (patient safety, communication, hand hygiene and medication safety [17-18]. Physicians used simulation-based learning to practice specific skills, communication, surgery and evaluation [19]. Simulators have also been used to support the practicing of manual and powered mobility skills, primarily evaluating virtual simulator prototypes for powered wheelchairs during simulated daily routes and free driving. In a systematic review [20] of 17 wheelchair simulators (eight for powered wheelchairs, four for manual wheelchairs and five for both) studied between 1985-2008, only two studied children with special needs. Results showed that the inexperienced drivers significantly improved in driving performance, but did not reach that of experienced drivers; in addition, children were able to interact with the simulator and showed interest in the activities [21,22, 23].  

In 2012, Archambault et al. [24] developed the McGill Immersive Wheelchair Simulator (MiWe), to enable wheelchair practice via a simulator. It was further tested in 2017 [25] to determine the extent to which the virtual simulator was useful for training six daily tasks performed by powered mobility users (elevator use, shopping at supermarket and at mall, street crossing, entering and exiting accessible van and entering and exiting a bathroom). Seventeen participants (18-75 years) who had three months or less experience with powered mobility participated in the study. A significant reduction in the number of collisions was recorded at the end of the two-week period. The participants who experienced multiple collisions were interested in continuing to use the simulation in order to improve their skills.

Despite the encouraging evidence, especially for the training of adult users, to date, there is not yet sufficient data to conclude the extent to which training of powered mobility in simulated settings is effective as a practice tool for children with physical disabilities. The goal of the study was to validate a modified version of the MiWe simulator for children, by investigating the relationship between driving and simulator performance. Driving performance was evaluated through two powered mobility tests. It was hypothesized that the powered mobility and simulator driving performance would not significantly differ.

METHODS

Participants

Data from 12 participants (of an eventual total of 30 children), aged 5-18 years, with a physical disability (Cerebral Palsy, Spinal Cord Lesion, Neuro Muscular Conditions) are presented. All children use a joystick to drive their own powered wheelchair, provided to them by the Ministry of Health, after being recognized as proficient drivers. They all had at least three months of driving experience at the time of testing. Children using switches or a scanning device to drive their powered wheelchair were excluded. The goals of the study were explained to parents and children, prior to commencement. Children were told that they could stop at any given moment. The study took place in ALYN Hospital, Jerusalem Israel. The study was approved by the Research Ethics Committee of ALYN Hospital.  Informed written consent was obtained from all parents and participants.

Instruments

Powered Wheelchairs- Each child was tested on his or her own personal powered wheelchairs including an adapted seating system and access devices when necessary.

Computer and Joystick-  A laptop computer with a hybrid joystick were used with a simulator program.

McGill Immersive Wheelchair Simulator- Modified version (MiWe-C)- the MiWe simulator has six practice environments including driving in elevator, bathroom, accessible van, shopping mall, supermarket and crossing the street. The program was modified for research studies done in ALYN hospital. The Hebrew language was added and two additional environments were added by Illogika (http://illogika.com/) for training and for testing. These environments simulate specific routes within ALYN Hospital with high fidelity. Data regarding the time and number of collisions were collected automatically by the simulator program and used as an indication of the child’s skill level.

Physical and Virtual Routes- Two different virtual routes were developed, based on two physical routes within the hospital. The children drove one of two predefined routes in their powered wheelchair and while using the simulator. The routes have segments that are both indoor and outdoor and were designed to correspond to the distances and levels of difficulty required by the physical driving tests. A photo (Fig. 1) and a screenshot (Fig. 2) show segments of the physical and virtual environments.   

The Powered Mobility Program (PMP) [26] is an outcome measure entailing up to 34 tasks that is used to evaluate powered mobility driving skills. The tasks consist of skills needed for indoor and outdoor driving. The Assessment for Learning Powered Mobility (ALP) [27] is an outcome measure that assesses the user’s emotional, intellectual and behavior elements of power mobility.

Procedure

A demographic questionnaire was filled out by a parent prior to commencement of the study and consent forms were signed. Data were collected during a single 60-minute evaluation where children drove their powered wheelchair through one of the hospital routes and then drove the same route via the MiWe-C simulator (order was counterbalanced). The children were evaluated using the PMP and the ALP.  The PMP was performed twice, once for the powered wheelchair and once for the simulator whereas, the ALP was performed once at end of session and was based on performance in both conditions.  

Statistical Analysis

All data were analyzed using non-parametric statistics in SPSS version 25 (SPSS, Inc., Chicago, Illinois). The Wilcoxon Signed-rank test was used to compare differences in the PMP scores between the two conditions (driving a powered wheelchair and the MiWe-C simulator).

Results

Participants’ mean (SD) age was 14.9 years (3.0). The mean (SD) driving experience was 3.7 years (2.0) and the mean (SD) ALP score was 7.75/8.0 (.34). The mean (SD) powered wheelchair and simulator PMP scores were 4.94/5.0 (.15) and 4.91/5.0 (.12), respectively. The high scores demonstrate that the participants were extremely proficient in both powered wheelchair driving and in navigating the simulated tasks, with no significant differences between them (Z=1.47, p=.14). The conference presentation will include results from all 30 participants.

Discussion and conclusions

Although there is growing data on the use of simulators and its benefits in many applications, few studies have examined their use by children under field conditions with simulators that have been validated for use by this age group. The initial results from the current study demonstrate the validity of the MiWe-C in comparison to driving a powered wheelchair using the PMP, a well-accepted evaluation outcome measure of powered mobility driving skills [26]. This validation process supports the original validation study done on the MiWe [24] where driving and simulator-based tasks were performed and compared. They also showed that there were no differences in how seven tasks were performed (including time, movement strategies and joystick deflection) while driving the powered wheelchair or the simulator. These seven tasks are part of the PMP outcome measure. 

The overall high scores on the PMP and ALP outcome measures and small standard deviations demonstrate the excellent proficiency level achieved by the study participants who had at least three months of driving experience at the time of testing with many having much more experience than that (mean = 3.7 years). Such results are not surprising for experienced drivers since both the PMP and ALP were designed to monitor children who are engaged in the process of learning powered mobility and have not yet become proficient drivers. In order to differentiate between higher levels of proficient driving in a powered wheelchair it is important to consider additional aspects of the powered mobility experience including participation, perceived independence, and enhanced social relationships. A child can be a proficient driver, yet, for example, not use the chair out-of-doors, or use it while taking part in social activities. A next step would be to examine ways in which powered wheelchair proficiency impacts on participation [28].   

This study is the first stage in a longer intervention study where children practice either on a powered wheelchair or on the modified MiWe-C simulator and their driving performance is compared. The goal of the intervention study is to prove that simulator based practice is as good as powered wheelchair based practice and to provide a viable alternative for practicing independent powered mobility.