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.

Blind spot sensor systems for power wheelchairs: obstacle detection accuracy, cognitive task load, and perceived usefulness among older adults

PURPOSE

Blind spot sensor systems can improve power wheelchair (PWC) safety. This research (1) compared accuracy of obstacle detection in the rear of a wheelchair with and without a sensor system, and (2) explored cognitive task load and perceived usability, safety, confidence and awareness in a laboratory setting, and (3) PWC users' perceptions in real-world settings.

MATERIALS AND METHODS

A mixed-method design was used. PWC users were provided with the sensor system. In laboratory accuracy of obstacle detection with and without a sensor system, cognitive task load and perceived usability, safety, confidence and awareness were evaluated. Participants then used the sensor system at home for two-months before completing semi-structured interviews. Statistical and thematic analyses were conducted.

RESULTS

Among 11 PWC users (age = 67.5 ± 7.5y), obstacles were detected more accurately with sensor system than without (p < 0.001). Using the sensor system required lower cognitive task loads (p = 0.005). The system was perceived by most users as easy to use (9/11) and its capabilities meeting their requirements (8/11). Most users did not perceive safety (9/11), confidence (9/11) or increased awareness (10/11) in the laboratory. Three themes emerged in the follow-ups: perceived usefulness, barriers to use, and recommendations. Four participants reported continued use after 2 months, reporting perceived increased awareness, convenience, and independence using the system. Those who discontinued use reported perceived lack of usefulness and technical issues. Recommendations included types of users who can benefit and sensor improvements.

CONCLUSIONS

Sensor systems may improve obstacle detection accuracy while reducing cognitive task load. However, larger scale implementation should consider recommendations for PWC service provision.IMPLICATIONS FOR REHABILITATIONBlind spot sensors systems increased speed and accuracy of obstacle detection when using a power wheelchair.Technical and hardware issues encountered by PWC users highlight the need for training and support services.Technical support was out of scope for the current research project and will be explored in future research given the critical role it might play in the usability and adoption of assistive technologies.PWC users perceived there to be practical uses for blind spot sensor systems.

Policy Analysis on Power Seat Elevation Systems

In the early 2000s the Centers for Medicare and Medicaid Services determined that power seat elevation systems did not meet the definition of durable medical equipment, and therefore are non-covered items. Yet, power seat elevation systems are covered by other funding sources, and many power wheelchair users utilize these systems regularly when performing tasks such as transferring, reaching, and looking at objects in environments designed for ambulatory people. Adjusting for height when performing these tasks may reduce the onset of pain and comorbidities. To improve access to power seat elevation systems, a clinical team of 4 Clinician Task Force members investigated applicable literature, compiled evidence, and evaluated existing policies to explain the medical nature of power seat elevation systems as a part of a greater interprofessional effort. This manuscript aims to analyze Medicare's policy decision that power seat elevation systems are not primarily medical in nature using Bardach's 8-step framework. As a special communication, this will inform health care professionals of the medical nature of power seat elevation systems and the evidence-based conditions under which power wheelchair users may need power seat elevation systems, as well as empower clinicians to engage in policy directives to affect greater change.

Virtual community centre for power wheelchair training: Experience of children and clinicians

PURPOSE

To: 1) characterize the overall experience in using the McGill immersive wheelchair - community centre (miWe-CC) simulator; and 2) investigate the experience of presence (i.e., sense of being in the virtual rather than in the real, physical environment) while driving a PW in the miWe-CC.

METHOD

A qualitative research design with structured interviews was used. Fifteen clinicians and 11 children were interviewed after driving a power wheelchair (PW) in the miWe-CC simulator. Data were analyzed using the conventional and directed content analysis approaches.

RESULTS

Overall, participants enjoyed using the simulator and experienced a sense of presence in the virtual space. They felt a sense of being in the virtual environment, involved and focused on driving the virtual PW rather than on the surroundings of the actual room where they were. Participants reported several similarities between the virtual community centre layout and activities of the miWe-CC and the day-to-day reality of paediatric PW users.

CONCLUSION

The simulator replicated participants' expectations of real-life PW use and promises to have an effect on improving the driving skills of new PW users. Implications for rehabilitation Among young users, the McGill immersive wheelchair (miWe) simulator provides an experience of presence within the virtual environment. This experience of presence is generated by a sense of being in the virtual scene, a sense of being involved, engaged, and focused on interacting within the virtual environment, and by the perception that the virtual environment is consistent with the real world. The miWe is a relevant and accessible approach, complementary to real world power wheelchair training for young users.

Intelligent power wheelchair use in long-term care: potential users' experiences and perceptions

PURPOSE

Long-term care (LTC) residents with cognitive impairments frequently experience limited mobility and participation in preferred activities. Although a power wheelchair could mitigate some of these mobility and participation challenges, this technology is often not prescribed for this population due to safety concerns. An intelligent power wheelchair (IPW) system represents a potential intervention that could help to overcome these concerns. The purpose of this study was to explore a) how residents experienced an IPW that used three different modes of control and b) what perceived effect the IPW would have on their daily lives.

MATERIALS AND METHODS

We interviewed 10 LTC residents with mild or moderate cognitive impairment twice, once before and once after testing the IPW. Interviews were conducted using a semi-structured interview guide, audio recorded and transcribed verbatim for thematic analyses.

RESULTS

Our analyses identified three overarching themes: (1) the difference an IPW would make, (2) the potential impact of the IPW on others and (3) IPW-related concerns.

CONCLUSIONS

Findings from this study confirm the need for and potential benefits of IPW use in LTC. Future studies will involve testing IPW improvements based on feedback and insights from this study. Implications for rehabilitation Intelligent power wheelchairs may enhance participation and improve safety and feelings of well-being for long-term care residents with cognitive impairments. Intelligent power wheelchairs could potentially have an equally positive impact on facility staff, other residents, and family and friends by decreasing workload and increasing safety.

Joystick-controlled video console game practice for developing power wheelchairs users' indoor driving skills

[Purpose] This study aimed to determine the effectiveness of joystick-controlled video console games in enhancing subjects’ ability to control power wheelchairs. [Subjects and Methods] Twenty healthy young adults without prior experience of driving power wheelchairs were recruited. Four commercially available video games were used as training programs to practice joystick control in catching falling objects, crossing a river, tracing the route while floating on a river, and navigating through a garden maze. An indoor power wheelchair driving test, including straight lines, and right and left turns, was completed before and after the video game practice, during which electromyographic signals of the upper limbs were recorded. The paired t-test was used to compare the differences in driving performance and muscle activities before and after the intervention. [Results] Following the video game intervention, participants took significantly less time to complete the course, with less lateral deviation when turning the indoor power wheelchair. However, muscle activation in the upper limbs was not significantly affected. [Conclusion] This study demonstrates the feasibility of using joystick-controlled commercial video games to train individuals in the control of indoor power wheelchairs.

Voice controlled wheelchairs: fine control by humming

People without disabilities seamlessly control devices with their hands. Interestingly, their hands can perform coarse and fine control. Implementing smooth control for computerized systems is not straightforward and most of the time it is not intuitive either. Here we offer a solution to that problem: smooth control through humming. Voice commands have become ubiquitous in modern technology. Speech-to-text applications abound. Smooth control, on the other hand, has not been tackled yet. Here we design and implement a humming control technique, and demonstrate a hardware implementation with a powered wheelchair. Once actuated, the speed with which the chair moves will depend on the subtle variation on the fundamental frequency of the user's humming, acquired through an accelerometer measuring vocal cord vibration. We also discuss two signal processing techniques that handle commonly encountered issues when trying to resolve frequencies in real time data. The hardware implementation shows performance of 80% and higher in speech recognition for signal-to-noise ratio (SNR) higher than 8dB and 100% in smooth control and frequency detection for all tested SNRs. We also discuss potential applications of smooth humming control to other assistive technology.