Comparison of virtual wheelchair driving performance of people with traumatic brain injury using an isometric and a conventional joystick

Evaluation of power wheelchair driving performance in simulator compared to driving in real-life situations: the SIMADAPT (simulator ADAPT) project-a pilot study

OBJECTIVE

The objective of this study was to evaluate users' driving performances with a Power Wheelchair (PWC) driving simulator in comparison to the same driving task in real conditions with a standard power wheelchair.

METHODS

Three driving circuits of progressive difficulty levels (C1, C2, C3) that were elaborated to assess the driving performances with PWC in indoor situations, were used in this study. These circuits have been modeled in a 3D Virtual Environment to replicate the three driving task scenarios in Virtual Reality (VR). Users were asked to complete the three circuits with respect to two testing conditions during three successive sessions, i.e. in VR and on a real circuit (R). During each session, users completed the two conditions. Driving performances were evaluated using the number of collisions and time to complete the circuit. In addition, driving ability by Wheelchair Skill Test (WST) and mental load were assessed in both conditions. Cybersickness, user satisfaction and sense of presence were measured in VR. The conditions R and VR were randomized.

RESULTS

Thirty-one participants with neurological disorders and expert wheelchair drivers were included in the study. The driving performances between VR and R conditions were statistically different for the C3 circuit but were not statistically different for the two easiest circuits C1 and C2. The results of the WST was not statistically different in C1, C2 and C3. The mental load was higher in VR than in R condition. The general sense of presence was reported as acceptable (mean value of 4.6 out of 6) for all the participants, and the cybersickness was reported as acceptable (SSQ mean value of 4.25 on the three circuits in VR condition).

CONCLUSION

Driving performances were statistically different in the most complicated circuit C3 with an increased number of collisions in VR, but were not statistically different for the two easiest circuits C1 and C2 in R and VR conditions. In addition, there were no significant adverse effects such as cybersickness. The results show the value of the simulator for driving training applications. Still, the mental load was higher in VR than in R condition, thus mitigating the potential for use with people with cognitive disorders. Further studies should be conducted to assess the quality of skill transfer for novice drivers from the simulator to the real world. Trial registration Ethical approval n∘ 2019-A001306-51 from Comité de Protection des Personnes Sud Mediterranée IV. Trial registered the 19/11/2019 on ClinicalTrials.gov in ID: NCT04171973.

The effect of differences in powered wheelchair joystick shape on subjective and objective operability

Various-shaped joysticks steer electric-powered wheelchairs (EPWs); however, an operability evaluation has not been fully conducted. This study evaluated the subjective and objective operability of various-shaped joysticks in 22 younger and 22 older adults. Participants operated an EPW on an experimental course using nine different-shaped joysticks, before ranking each joystick by their operability (1 = best, 9 = worst) as a primary outcome. Movement time (MT) and driving accuracy (DA) were also measured. Despite no significant differences in the primary outcome between joysticks, the I-shaped joystick with rounded tips (neutral grip) was ranked higher than the others. MT did not differ between joysticks, but DA was higher for the thin-columnar I-shaped joystick (pinch grip) than for the U- and T-shaped joysticks (pronated grip). MT and DA scores for young adults were significantly better than those for older adults. Further studies should be conducted to clarify possible factors related to EPW operability.

Simulation System of Electric-Powered Wheelchairs for Training Purposes

For some people with severe physical disabilities, the main assistive device to improve their independence and to enhance overall well-being is an electric-powered wheelchair (EPW). However, there is a necessity to offer users EPW training. In this work, the Simcadrom is introduced, which is a virtual reality simulator for EPW driving learning purposes, testing of driving skills and performance, and testing of input interfaces. This simulator uses a joystick as the main input interface, and a virtual reality head-mounted display. However, it can also be used with an eye-tracker device as an alternative input interface and a projector to display the virtual environment (VE). Sense of presence, and user experience questionnaires were implemented to evaluate this version of the Simcadrom in addition to some statistical tests for performance parameters like: total elapsed time, path following error, and total number of commands. A test protocol was proposed and, considering the overall results, the system proved to simulate, very realistically, the usability, kinematics, and dynamics of a real EPW in a VE. Most subjects were able to improve their EPW driving performance in the training session. Furthermore, all skills learned are feasible to be transferred to a real EPW.

ViEW: A wheelchair simulator for driving analysis

The powered wheelchair (PW) has become an essential mobility assistive technology for people with motor disabilities. A critical step involved in maximizing the end-user experience is evaluating individual functional abilities. Using powered wheelchair simulation for driving analysis offers flexibility for safely evaluating the individual's driving performance in a variable environment and situations ranging in difficulty. Additionally, it makes it possible to measure numerous variables involved in the driving process. The main objectives of this pilot study were to assess PW users' outdoor driving abilities to study how the simulator can improve outdoor driving task performance, and to define new objective criteria for evaluating the overall driving process. The study presented involved a group of 12 children and young adults diagnosed with cerebral palsy. Simulations were conducted using ViEW (Virtual Electrical Wheelchair), a 3D wheelchair simulator designed in our laboratory. A customized virtual environment was designed to immerse the user in a life-like driving experience. We used the data collected on the simulator to define driving skills indicators. The acquired skills during simulations were transferable to on-road wheelchair driving. The participants' performance indicators produced positive results. Computed performance indicators can be a valuable decision-making tool for occupational therapists.

A scoping review of powered wheelchair driving tasks and performance-based outcomes

Introduction: Wheelchairs and scooters promote participation and have positive effects on quality of life. However, powered wheelchairs (PW) use can be challenging and can pose safety concerns. Adequate PW assessment and training is important. There is a wide variety of tasks and PW driving assessment measures used for training and assessing PW driving ability in the literature and little consensus as to which tasks and outcomes are the most relevant. A scoping review of the literature was performed in order to characterize this extensive variety of tasks and performance-based outcomes used for training and assessing PW skills.Methods: A search of the literature was conducted in January 2017. Four databases were searched: CINAHL, Embase, PsycInfo and Medline. Articles were included if they contained at least one PW driving task.Results: 827 articles were screened and 48 articles were retained. PW driving tasks from each article were identified and categorized in terms of the environment in which they were performed: Driving in a controlled environment, ecological driving tasks, 2D virtual environment (VE) tasks, 3D VE tasks. The assessment measures formed a separate category. Subjective and objective performance-based outcomes related to PW driving were also identified and grouped into outcomes assessing speed and outcomes assessing accuracy.Conclusion: This scoping review provides an overview of tasks and performance outcomes used in the literature when training and assessing PW skills. The results of this review could guide future research when choosing appropriate tasks and performance outcomes for PW driving ability.Implications for rehabilitationThere is wide variety of tasks and performance-based outcomes for PW driving.Results showed that available assessment measures are not commonly used in research and that tasks used often lacked consistency across studies.New methods to measure the interaction of speed and accuracy are needed.The contents of this review could be used by researchers as a starting point when designing a PW task and selecting appropriate performance-based outcomes.

Improving Target Acquisition for Computer Users With Athetosis

Prior work has highlighted the challenges faced by people with athetosis when trying to acquire on-screen targets using a mouse or trackball. The difficulty of positioning the mouse cursor within a confined area has been identified as a challenging task. We have developed a target acquisition assistance algorithm that features transition assistance via directional gain variation based on target prediction, settling assistance via gain reduction in the vicinity of a predicted target, and expansion of the predicted target as the cursor approaches it. We evaluated the algorithm on improving target acquisition efficiency among seven participants with athetoid cerebral palsy. Our results showed that the algorithm significantly reduced the overall movement time by about 20%. Considering the target acquisition occurs countless times in the course of regular computer use, the accumulative effect of such improvements can be significant for improving the efficiency of computer interaction among people with athetosis.

Advanced Joystick Algorithms for Computer Access Tasks

OBJECTIVE

To compare 2 correction algorithms and 2 joysticks (a conventional movement-sensing joystick and a custom-designed isometric joystick) in computer access tasks.

DESIGN

Repeated-measures, within-subject.

SETTING

National Veterans Wheelchair Games.

PARTICIPANTS

Fifteen participants with various diagnoses including multiple sclerosis, spinal cord injury, traumatic brain injury, Wilson disease, and Parkinson disease.

METHODS

A computer access test scenario was used to evaluate the effects of applying proportional integral derivative (PID)-based and least means-based algorithms to suppress unintentional cursor motions by users with upper extremity spasticity.

MAIN OUTCOME MEASURES

Trial completion time, reaction time, and trajectory-based measures: movement offset, movement variability, and percentage of out-of-path motion on test tracks.

RESULTS

The quantitative outcome measures showed a high correlation with clinical measures for spasticity and functional independence. On small test tracks, compared to when no correction algorithms were used, both algorithms performed equally well in suppressing unintentional cursor motions. On longer test tracks, participants navigated most accurately while using the PID algorithm. Participants moved the cursor more accurately using the isometric joystick compared to the movement-sensing joystick, with only a slight increase in the task completion times.

CONCLUSIONS

The joysticks and the advanced correction algorithms show promise for use in wide-ranging applications as control interfaces.

Assessment of wheelchair driving performance in a virtual reality-based simulator

OBJECTIVE

To develop a virtual reality (VR)-based simulator that can assist clinicians in performing standardized wheelchair driving assessments.

DESIGN

A completely within-subjects repeated measures design.

METHODS

Participants drove their wheelchairs along a virtual driving circuit modeled after the Power Mobility Road Test (PMRT) and in a hallway with decreasing width. The virtual simulator was displayed on computer screen and VR screens and participants interacted with it using a set of instrumented rollers and a wheelchair joystick. Driving performances of participants were estimated and compared using quantitative metrics from the simulator. Qualitative ratings from two experienced clinicians were used to estimate intra- and inter-rater reliability.

RESULTS

Ten regular wheelchair users (seven men, three women; mean age ± SD, 39.5 ± 15.39 years) participated. The virtual PMRT scores from the two clinicians show high inter-rater reliability (78-90%) and high intra-rater reliability (71-90%) for all test conditions. More research is required to explore user preferences and effectiveness of the two control methods (rollers and mathematical model) and the display screens.

CONCLUSIONS

The virtual driving simulator seems to be a promising tool for wheelchair driving assessment that clinicians can use to supplement their real-world evaluations.

Virtual electric power wheelchair driving performance of individuals with spastic cerebral palsy

OBJECTIVE

Upper limb spasticity may impair the use of control interfaces such as joysticks for many individuals with disabilities such as cerebral palsy (CP). The aims of this study were to compare the driving performance of those with CP to that of control participants, to identify the impact of lead time on performance, and to compare two joystick designs, a standard movement sensing joystick and a novel isometric joystick.

DESIGN

This study used a repeated-measures design to compare the performance of a group of participants with CP to that of participants without disabilities in a two-dimensional simulated driving task on a computer screen using the two control interfaces. The driving trials used varying "lead times," or the amount of warning time available to make movement decisions and turns. A total of 34 participants with CP and without disability were matched by age and sex into two groups.

RESULTS

Participants with CP had lower driving performance in most variables of interest compared with controls. However, surprisingly, reducing lead time also reduced some performance errors, possibly because of more deliberate driving. The isometric joystick outperformed the movement sensing joystick in terms of performance errors but contributed to a prolonged reaction time.

CONCLUSIONS

The isometric joystick was preferred by participants over the movement sensing joystick in this study and may be a future alternative for individuals with CP for both power mobility and computer access tasks.