Evaluation of a Stair-Climbing Power Wheelchair in 25 People With Tetraplegia

Wheelchair users' perceptions of a system enabling them to traverse rough terrain controlling their own wheelchair

We recently developed a dynamic mimicking system that mounts a user's wheelchair onto a carrier platform capable of performing required manoeuvres using the wheelchair's own controls. Two wheelchair user studies were performed to evaluate users' perception of their own wheelchair and the proposed system. The first user study included ten wheelchair users who were interviewed in order to map their current perceptions toward their wheelchair and their views about its shortcomings when traversing rough terrains. In the second study, the system was explained to 33 participants who were then exposed to three simulations of its main features. Participants were interviewed and the experimenter wrote down their answers, which were analysed using IBM SPSS Statistics 27 software. The conclusions are that special consideration should be given to motorized wheelchair users, and that the designers of the system should include a user interface that explains and demonstrates the system to users.

Curb Negotiation With Dynamic Human-Robotic Wheelchair Collaboration

Wheelchair users often face architectural barriers such as curbs, limiting their accessibility, mobility, and participation in their communities. The mobility enhancement robotic (MEBot) wheelchair was developed to navigate over such architectural barriers. Its application allows wheelchair users to negotiate curbs automatically while the user remains in control. The application was optimized from a manual to a semiautomated process based on wheelchair users' feedback. The optimized application was evaluated by experienced wheelchair users who navigated over curbs of different heights. Participants evaluated MEBot in terms of effectiveness, workload demand, and usability. Ten participants successfully ascended and descended curbs of different heights at an average completion time of 55.7 ± 19.5 and 30.3 ± 9.1 s, respectively. MEBot maintained stability during the process, while participants reported low levels of effort, frustration, and overall cognitive demand to operate MEBot. Furthermore, participants were satisfied with the ease of learning and using the MEBot curb negotiation application to overcome the curbs but suggested less wheel adjustment for comfort and a faster pace to overcome curbs during real-world conditions.

RailBot: A Novel Assistive Device for Stair Climbing

For most older adults, their own homes is the overwhelmingly preferred environment for living and growing older. However, for those living in homes with stairs, the difficulty and risk of injury in stair ascent/descent is a major challenge in their daily life, which may endanger the feasibility of such choice. In this paper, the authors present a novel assistive device, namely RailBot, to help mobility-challenged individuals (including frail older adults) to climb stairs more easily. Unlike the traditional elevators and stair lifts, the RailBot is a highly compact device that can be easily installed in existing stairways, allowing it to benefit a large number of individuals living in homes with stairs. Further, by assisting the users' stair climbing instead of carrying them upstairs, the RailBot enables and encourages the users to maintain and enhance their stair-climbing capabilities, and thus contributes to their long-term physical health. The design details of the RailBot prototype are presented, including the system configuration, the actuation mechanism of the mobile platform, as well as the intuitive control interface for start-stop control and speed regulation. After mounting the prototype in a real-world use environment, a small-scale human study was conducted, with the results clearly demonstrating the effectiveness of the RailBot assistance through the significant reduction of lower-limb muscle activities.

A Heuristic Approach to Overcome Architectural Barriers Using a Robotic Wheelchair

The Mobility Enhancement roBotic (MEBot) wheelchair was developed to improve the safety and accessibility of wheelchair users when facing architectural barriers. MEBot uses pneumatic actuators attached to its frame and six wheels to provide curb ascending/descending for heights up to 20.3 cm. To improve MEBot's application, this study used a heuristic approach with power wheelchair users to evaluate and improve the MEBot application at different curb heights. Wheelchair users were trained on MEBot's features to operate its curb ascending/descending application. Three trials were carried out with wheelchair users ascending and descending three curbs of different height. Quantitative variables were analyzed to improve the sequential steps to ascend/descend curbs. Additionally, the application's effectiveness and efficiency were measured by the number of completed tasks, change in seat angle, and task completion time. Results showed that participants completed each trial and applied alternative strategies to traverse different curb heights. Furthermore, results suggested the combination and/or re-arrangement of steps to reduce task completion time. MEBot demonstrated its effectiveness to ascend/descend different curb heights with a heterogeneous participant sample. Future work will incorporate participant's most efficient strategies to improve the ascending/ascending process and the efficiency of the MEBot application.

Usability Evaluation of a Novel Robotic Power Wheelchair for Indoor and Outdoor Navigation

OBJECTIVE

To compare the Mobility Enhancement roBotic (MEBot) wheelchair's capabilities with commercial electric-powered wheelchairs (EPWs) by performing a systematic usability evaluation.

DESIGN

Usability in effectiveness, efficacy, and satisfaction was evaluated using quantitative measures. A semistructured interview was employed to gather feedback about the users' interaction with MEBot.

SETTING

Laboratory testing of EPW driving performance with 2 devices in a controlled setting simulating common EPW driving tasks.

PARTICIPANTS

A convenience sample of expert EPW users (N=12; 9 men, 3 women) with an average age of 54.7±10.9 years and 16.3± 8.1 years of EPW driving experience.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Powered mobility clinical driving assessment (PMCDA), Satisfaction Questionnaire, National Aeronautics and Space Administration's Task Load Index.

RESULTS

Participants were able to perform significantly higher number of tasks (P=.004), with significantly higher scores in both the adequacy-efficacy (P=.005) and the safety (P=.005) domains of the PMCDA while using MEBot over curbs and cross-slopes. However, participants reported significantly higher mental demand (P=.005) while using MEBot to navigate curbs and cross-slopes due to MEBot's complexity to perform its mobility applications which increased user's cognitive demands.

CONCLUSIONS

Overall, this usability evaluation demonstrated that MEBot is a promising EPW device to use indoors and outdoors with architectural barriers such as curbs and cross-slopes. Current design limitations were highlighted with recommendations for further improvement.

Step-Climbing Power Wheelchairs: A Literature Review

Background: Power wheelchairs capable of overcoming environmental barriers, such as uneven terrain, curbs, or stairs, have been under development for more than a decade. Method: We conducted a systematic review of the scientific and engineering literature to identify these devices, and we provide brief descriptions of the mechanism and method of operation for each. We also present data comparing their capabilities in terms of step climbing and standard wheelchair functions. Results: We found that all the devices presented allow for traversal of obstacles that cannot be accomplished with traditional power wheelchairs, but the slow speeds and small wheel diameters of some designs make them only moderately effective in the basic area of efficient transport over level ground and the size and configuration of some others limit maneuverability in tight spaces. Conclusion: We propose that safety and performance test methods more comprehensive than the International Organization for Standards (ISO) testing protocols be developed for measuring the capabilities of advanced wheelchairs with step-climbing and other environment-negotiating features to allow comparison of their clinical effectiveness.

Development of an advanced mobile base for personal mobility and manipulation appliance generation II robotic wheelchair

BACKGROUND

This paper describes the development of a mobile base for the Personal Mobility and Manipulation Appliance Generation II (PerMMA Gen II robotic wheelchair), an obstacle-climbing wheelchair able to move in structured and unstructured environments, and to climb over curbs as high as 8 inches. The mechanical, electrical, and software systems of the mobile base are presented in detail, and similar devices such as the iBOT mobility system, TopChair, and 6X6 Explorer are described.

FINDINGS

The mobile base of PerMMA Gen II has two operating modes: "advanced driving mode" on flat and uneven terrain, and "automatic climbing mode" during stair climbing. The different operating modes are triggered either by local and dynamic conditions or by external commands from users. A step-climbing sequence, up to 0.2 m, is under development and to be evaluated via simulation. The mathematical model of the mobile base is introduced. A feedback and a feed-forward controller have been developed to maintain the posture of the passenger when driving over uneven surfaces or slopes. The effectiveness of the controller has been evaluated by simulation using the open dynamics engine tool.

CONCLUSION

Future work for PerMMA Gen II mobile base is implementation of the simulation and control on a real system and evaluation of the system via further experimental tests.

The role of assistive robotics in the lives of persons with disability

Robotic assistive devices are used increasingly to improve the independence and quality of life of persons with disabilities. Devices as varied as robotic feeders, smart-powered wheelchairs, independent mobile robots, and socially assistive robots are becoming more clinically relevant. There is a growing importance for the rehabilitation professional to be aware of available systems and ongoing research efforts. The aim of this article is to describe the advances in assistive robotics that are relevant to professionals serving persons with disabilities. This review breaks down relevant advances into categories of Assistive Robotic Systems, User Interfaces and Control Systems, Sensory and Feedback Systems, and User Perspectives. An understanding of the direction that assistive robotics is taking is important for the clinician and researcher alike; this review is intended to address this need.