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Evaluation of an intelligent wheelchair system for older adults with cognitive impairments.

How TV, Wang RH, Mihailidis A - J Neuroeng Rehabil (2013)

Bottom Line: Measurements of safety and usability were taken and compared between the two phases.However, the objective performance (time to complete course) of users navigating their environment did not improve with the IWS.This study shows the efficacy of the IWS in performing with a potential environment of use, and benefiting members of its desired user population to increase safety and lower perceived demands of powered wheelchair driving.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto ON, Canada.

ABSTRACT

Background: Older adults are the most prevalent wheelchair users in Canada. Yet, cognitive impairments may prevent an older adult from being allowed to use a powered wheelchair due to safety and usability concerns. To address this issue, an add-on Intelligent Wheelchair System (IWS) was developed to help older adults with cognitive impairments drive a powered wheelchair safely and effectively. When attached to a powered wheelchair, the IWS adds a vision-based anti-collision feature that prevents the wheelchair from hitting obstacles and a navigation assistance feature that plays audio prompts to help users manoeuvre around obstacles.

Methods: A two stage evaluation was conducted to test the efficacy of the IWS. Stage One: Environment of Use - the IWS's anti-collision and navigation features were evaluated against objects found in a long-term care facility. Six different collision scenarios (wall, walker, cane, no object, moving and stationary person) and three different navigation scenarios (object on left, object on right, and no object) were performed. Signal detection theory was used to categorize the response of the system in each scenario. Stage Two: User Trials - single-subject research design was used to evaluate the impact of the IWS on older adults with cognitive impairment. Participants were asked to drive a powered wheelchair through a structured obstacle course in two phases: 1) with the IWS and 2) without the IWS. Measurements of safety and usability were taken and compared between the two phases. Visual analysis and phase averages were used to analyze the single-subject data.

Results: Stage One: The IWS performed correctly for all environmental anti-collision and navigation scenarios. Stage Two: Two participants completed the trials. The IWS was able to limit the number of collisions that occurred with a powered wheelchair and lower the perceived workload for driving a powered wheelchair. However, the objective performance (time to complete course) of users navigating their environment did not improve with the IWS.

Conclusions: This study shows the efficacy of the IWS in performing with a potential environment of use, and benefiting members of its desired user population to increase safety and lower perceived demands of powered wheelchair driving.

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Related in: MedlinePlus

Sample obstacle course for user trials. Each grid square represents a 1 m × 1 m zone. All obstacles, except the 180° turn (no walls), were built using 5 cm thick and 1.2 m high foam walls. For the stopping block the participant had to stop within 0.5 m of the obstacle before it was removed from their path. The ideal path for the participant is marked by the dotted line. Participants performed a 180° turn at the turnaround location to re-enter the course and manoeuvre back to the start.
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Figure 5: Sample obstacle course for user trials. Each grid square represents a 1 m × 1 m zone. All obstacles, except the 180° turn (no walls), were built using 5 cm thick and 1.2 m high foam walls. For the stopping block the participant had to stop within 0.5 m of the obstacle before it was removed from their path. The ideal path for the participant is marked by the dotted line. Participants performed a 180° turn at the turnaround location to re-enter the course and manoeuvre back to the start.

Mentions: For this evaluation, participants were asked to drive a powered wheelchair (Pride Mobility™ Quantum 6000z) through an obstacle course (Figure 5) under two phases: Phase A) driving without the IWS, and Phase B) driving with the IWS. The ordering of the phases was randomized in order to negate any learning or fatigue effects. In each phase the participants completed the course (or runs) five times, with one run occurring once a day (that is, the total phase lasted five days). The obstacle course was composed of six essential movements related to powered wheelchair use. These movements were derived from the Wheelchair Skills Test (WST) [24] and the Power-Indoor Mobility Driving Assessment (PIDA) [25]. Both are clinical assessments for powered wheelchair mobility. The movements in the obstacle course included: 1) 90° left turn, 2) 90° right turn, 3) 3 m straight path, 4) weaving around obstacles, 5) 180° turn, and 6) stopping. All movements were driven through twice per run, with the exception of the 180° turn, which was driven through once per run (Figure 5). To further minimize the effects of testing bias, the order of the movements within the course was randomized for each run in the study.


Evaluation of an intelligent wheelchair system for older adults with cognitive impairments.

How TV, Wang RH, Mihailidis A - J Neuroeng Rehabil (2013)

Sample obstacle course for user trials. Each grid square represents a 1 m × 1 m zone. All obstacles, except the 180° turn (no walls), were built using 5 cm thick and 1.2 m high foam walls. For the stopping block the participant had to stop within 0.5 m of the obstacle before it was removed from their path. The ideal path for the participant is marked by the dotted line. Participants performed a 180° turn at the turnaround location to re-enter the course and manoeuvre back to the start.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750699&req=5

Figure 5: Sample obstacle course for user trials. Each grid square represents a 1 m × 1 m zone. All obstacles, except the 180° turn (no walls), were built using 5 cm thick and 1.2 m high foam walls. For the stopping block the participant had to stop within 0.5 m of the obstacle before it was removed from their path. The ideal path for the participant is marked by the dotted line. Participants performed a 180° turn at the turnaround location to re-enter the course and manoeuvre back to the start.
Mentions: For this evaluation, participants were asked to drive a powered wheelchair (Pride Mobility™ Quantum 6000z) through an obstacle course (Figure 5) under two phases: Phase A) driving without the IWS, and Phase B) driving with the IWS. The ordering of the phases was randomized in order to negate any learning or fatigue effects. In each phase the participants completed the course (or runs) five times, with one run occurring once a day (that is, the total phase lasted five days). The obstacle course was composed of six essential movements related to powered wheelchair use. These movements were derived from the Wheelchair Skills Test (WST) [24] and the Power-Indoor Mobility Driving Assessment (PIDA) [25]. Both are clinical assessments for powered wheelchair mobility. The movements in the obstacle course included: 1) 90° left turn, 2) 90° right turn, 3) 3 m straight path, 4) weaving around obstacles, 5) 180° turn, and 6) stopping. All movements were driven through twice per run, with the exception of the 180° turn, which was driven through once per run (Figure 5). To further minimize the effects of testing bias, the order of the movements within the course was randomized for each run in the study.

Bottom Line: Measurements of safety and usability were taken and compared between the two phases.However, the objective performance (time to complete course) of users navigating their environment did not improve with the IWS.This study shows the efficacy of the IWS in performing with a potential environment of use, and benefiting members of its desired user population to increase safety and lower perceived demands of powered wheelchair driving.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto ON, Canada.

ABSTRACT

Background: Older adults are the most prevalent wheelchair users in Canada. Yet, cognitive impairments may prevent an older adult from being allowed to use a powered wheelchair due to safety and usability concerns. To address this issue, an add-on Intelligent Wheelchair System (IWS) was developed to help older adults with cognitive impairments drive a powered wheelchair safely and effectively. When attached to a powered wheelchair, the IWS adds a vision-based anti-collision feature that prevents the wheelchair from hitting obstacles and a navigation assistance feature that plays audio prompts to help users manoeuvre around obstacles.

Methods: A two stage evaluation was conducted to test the efficacy of the IWS. Stage One: Environment of Use - the IWS's anti-collision and navigation features were evaluated against objects found in a long-term care facility. Six different collision scenarios (wall, walker, cane, no object, moving and stationary person) and three different navigation scenarios (object on left, object on right, and no object) were performed. Signal detection theory was used to categorize the response of the system in each scenario. Stage Two: User Trials - single-subject research design was used to evaluate the impact of the IWS on older adults with cognitive impairment. Participants were asked to drive a powered wheelchair through a structured obstacle course in two phases: 1) with the IWS and 2) without the IWS. Measurements of safety and usability were taken and compared between the two phases. Visual analysis and phase averages were used to analyze the single-subject data.

Results: Stage One: The IWS performed correctly for all environmental anti-collision and navigation scenarios. Stage Two: Two participants completed the trials. The IWS was able to limit the number of collisions that occurred with a powered wheelchair and lower the perceived workload for driving a powered wheelchair. However, the objective performance (time to complete course) of users navigating their environment did not improve with the IWS.

Conclusions: This study shows the efficacy of the IWS in performing with a potential environment of use, and benefiting members of its desired user population to increase safety and lower perceived demands of powered wheelchair driving.

Show MeSH
Related in: MedlinePlus