Johanne L. Mattie

A survey of stakeholder perspectives on exoskeleton technology

BackgroundExoskeleton technology has potential benefits for wheelchair users’ health and mobility. However, there are practical barriers to their everyday use as a mobility device. To further understand potential exoskeleton use, and facilitate the development of new technologies, a study was undertaken to explore perspectives of wheelchair users and healthcare professionals on reasons for use of exoskeleton technology, and the importance of a variety of device characteristics.MethodsAn online survey with quantitative and qualitative components was conducted with wheelchair users and healthcare professionals working directly with individuals with mobility impairments. Respondents rated whether they would use or recommend an exoskeleton for four potential reasons. Seventeen design features were rated and compared in terms of their importance. An exploratory factor analysis was conducted to categorize the 17 design features into meaningful groupings. Content analysis was used to identify themes for the open ended questions regarding reasons for use of an exoskeleton.Results481 survey responses were analyzed, 354 from wheelchair users and 127 from healthcare professionals. The most highly rated reason for potential use or recommendation of an exoskeleton was health benefits. Of the design features, 4 had a median rating of very important: minimization of falls risk, comfort, putting on/taking off the device, and purchase cost. Factor analysis identified two main categories of design features: Functional Activities and Technology Characteristics. Qualitative findings indicated that health and physical benefits, use for activity and access reasons, and psychosocial benefits were important considerations in whether to use or recommend an exoskeleton.ConclusionsThis study emphasizes the importance of developing future exoskeletons that are comfortable, affordable, minimize fall risk, and enable functional activities. Findings from this study can be utilized to inform the priorities for future development of this technology.

Biomechanical characteristics, patient preference and activity level with different prosthetic feet: a randomized double blind trial with laboratory and community testing.

Providing appropriate prosthetic feet to those with limb loss is a complex and subjective process influenced by professional judgment and payer guidelines. This study used a small load cell (Europa™) at the base of the socket to measure the sagittal moments during walking with three objective categories of prosthetic feet in eleven individuals with transtibial limb loss with MFCL K2, K3 and K4 functional levels. Forefoot stiffness and hysteresis characteristics defined the three foot categories: Stiff, Intermediate, and Compliant. Prosthetic feet were randomly assigned and blinded from participants and investigators. After laboratory testing, participants completed one week community wear tests followed by a modified prosthetics evaluation questionnaire to determine if a specific category of prosthetic feet was preferred. The Compliant category of prosthetic feet was preferred by the participants (P=0.025) over the Stiff and Intermediate prosthetic feet, and the Compliant and Intermediate feet had 15% lower maximum sagittal moments during walking in the laboratory (P=0.0011) compared to the Stiff feet. The activity level of the participants did not change significantly with any of the wear tests in the community, suggesting that each foot was evaluated over a similar number of steps, but did not inherently increase activity. This is the first randomized double blind study in which prosthetic users have expressed a preference for a specific biomechanical characteristic of prosthetic feet: those with lower peak sagittal moments were preferred, and specifically preferred on slopes, stairs, uneven terrain, and during turns and maneuvering during real world use.

Concept proposal for a detachable exoskeleton-wheelchair to improve mobility and health

Wheelchair use has consequences to quality of life in at least two areas: 1) health issues such as pressure sores and chronic overuse injury; and 2) access problems due to the inaccessible nature of the built and natural environments that are most amenable to upright postures. Even with these concerns, wheelchairs are still the best form of mobility for many people (e.g. they are relatively easy to transfer into and propel). However, wheelchairs are simply not transformative, i.e. they do not allow a person with a disability to attain a level of mobility performance that approaches that of their non-disabled peers, nor do they typically allow for face to face interactions and full participation in the community. Wheelchairs also do not typically support ongoing therapeutic benefits for the user. To address the inadequacy of existing wheelchairs, we are merging two evolving technologies into a coherent new mobility device. The first is dynamic wheeled mobility, which adds significant functionality to conventional wheelchairs through the use of on-the-fly adjustable positioning. The second is powered walking exoskeletons, which enable highly desired standing and walking functions, as well as therapeutic benefits associated with rehabilitation gait training. Unfortunately, exoskeletons have significant usability concerns such as slow speed, limited range, potential to cause skin issues, and difficult transfers. A new concept of docking a detachable exoskeleton to a wheeled frame has been developed to address these issues. The design goal is a single mobility device that not only optimizes daily activities (i.e. wheelchair seating and propulsion with dynamic positioning), but also serves as an easy-to-use rehabilitation tool for therapeutic benefits (i.e. a detachable powered exoskeleton for walking sojourns). This has significant potential benefits for the lives of people with mobility impairments.

Characterizing the community use of an ultralight wheelchair with “on the fly” adjustable seating functions: A pilot study

An ultralight manual wheelchair that allows users to independently adjust rear seat height and backrest angle during normal everyday usage was recently commercialized. Prior research has been performed on wheelchair tilt, recline, and seat elevation use in the community, however no such research has been done on this new class of manual ultralight wheelchair with “on the fly” adjustments. The objective of this pilot study was to investigate and characterize the use of the two adjustable seating functions available on the Elevation™ ultralight dynamic wheelchair during its use in the community. Eight participants had data loggers installed onto their own wheelchair for seven days to measure rear seat height, backrest angle position, occupied sitting time, and distance traveled. Analysis of rear seat height and backrest adjustment data revealed considerable variability in the frequency of use and positions used by participants. There was a wide spread of mean daily rear seat heights among participants, from 34.1 cm to 46.7 cm. Two sub-groups of users were further identified: those who sat habitually at a single typical rear seat height, and those who varied their rear seat height more continuously. Findings also showed that participants used the rear seat height adjustment feature significantly more often than the backrest adjustment feature. This obvious contrast in feature use may indicate that new users of this class of wheelchair may benefit from specific training. While the small sample size and exploratory nature of this study limit the generalizability of our results, our findings offer a first look at how active wheelchairs users are using a new class of ultralight wheelchair with “on the fly” seating adjustments in their communities. Further studies are recommended to better understand the impact of dynamic seating and positioning on activity, participation and quality of life.

Development of an integrated staircase lift for home access

Purpose Stairways into buildings present a significant environmental barrier for those with mobility impairments. A number of home access solutions that allow users to safely enter and exit the home exist; however, these all have some limitations. The purpose of this work was to develop a novel, inclusive home access solution that integrates a staircase and a lift into one device. Method We developed an integrated staircase lift following a structured protocol with stakeholders providing feedback at various stages in the design process, consistent with rehabilitation engineering design methods. Results A novel home access device was developed. The integrated staircase-lift has the following features: inclusivity, by a design that provides an option for either use of stairs or a lift; constant availability, with a lift platform always ready for use on either level; and potential aesthetic advantages when integrating the device into an existing home. The potential also exists for emergency descent during a power outage, and self-powered versions. Conclusions By engaging stakeholders in a user-centred design process, we were able to gain insight into the limitations of existing home access solutions and get specific feedback on our lift concept. This information strengthened the development of a novel home access device.

Experiences with and perceptions of an adaptive hiking program

Abstract Purpose: Outdoor activities in natural settings have been found to be beneficial for overall health and well-being. However, people with disabilities may have different experiences accessing outdoor activities in natural settings. This research explored the experiences of users, volunteers, and staff, and perspectives of non-users about an adapted hiking program that uses a specialized mobility device called a TrailRider. The research had three objectives: 1. Describe the experiences of users, volunteers, and staff; 2. Identify perceived barriers to or limitations of participating for users, volunteers, staff, and non-users; and 3. Explore the impact of participation for users, volunteers, and staff. Method: This ethnographic study used a combination of observations and in-depth interviews as a means of data collection. Results: Researchers accompanied 38 participants on five hikes and conducted semi-structured interviews with 20 participants. Analysis identified three themes: “Let the Good Times Roll” described how TrailRider users and volunteers enjoyed the opportunity to explore the great outdoors. “An Uphill Battle” acknowledged perceived physical and psychological barriers to participation. “Clearing the Path” addressed potential areas for program improvement. Conclusions: This study emphasized how volunteers and users appreciated the outdoor and social opportunities the program afforded. The study identified a number of potential improvements that could be implemented to improve access to the program. Implications for Rehabilitation Outdoor recreation programs create positive experiences, as well as unique social opportunities for users and volunteers. Identifying and considering physical and psychological barriers would improve wilderness access for individuals with disabilities. Despite the fact that outdoor recreation programs, like the adaptive hiking program, are in place, deficient marketing and promotion limit users and volunteers from taking part.

Development and pilot testing of a kneeling ultralight wheelchair design.

“Dynamic wheeled mobility” offers “on the fly” seating adjustments for wheelchair users such that various activities performed throughout the day can be matched by an appropriate seat position. While this has benefits for user participation and health, the added weight in existing dynamic wheelchairs may impact the users ability to transport the frame, e.g. into cars. Other dynamic features to enable more participation avenues are also desirable. This paper outlines the development of a “kneeling” ultralight wheelchair design that offers dynamic wheeled mobility functionality at a weight that is comparable to many existing ultralight wheelchairs. In addition, the wheelchairs kneeling function allows a lowered seat position to facilitate low-to-the-ground tasks such as floor transfers and other activities where sustained low level reaching may be required (e.g. playing with children, changing a tire, etc.). This paper also describes the development and pilot testing of an end user evaluation protocol designed to validate the wheelchairs functionality and performance. Successful realization and commercialization of the technology would offer a novel product choice for people with mobility disabilities, and that may support daily activities, health, improved quality of life, and greater participation in the community.

End user evaluation of a Kneeling Wheelchair with “on the fly” adjustable seating functions

Abstract A “kneeling” ultralight wheelchair prototype has been developed that allows users to adjust seat position “on the fly” for different activities throughout the day. The wheelchair includes independent adjustment functions for rear seat height, front seat height (“kneeling”) and backrest angle. Aim: This work aimed to gather feedback about the wheelchair’s functionality and performance through end user evaluation trials. Methods: Eight manual wheelchair users evaluated the prototype Kneeling Wheelchair for a range of activities. User perspectives on parameters such as usability, comfort, stability and effectiveness were obtained through both open-ended and Likert-scale rating questions. Results: Results indicate several potential benefits of the adjustment functions of the Kneeling Wheelchair. Rear seat height adjustment may facilitate a number of activities of daily living, as well as provide benefits for comfort and social interactions. Back rest adjustment may increase comfort and stability on slopes. Front seat height adjustment may be beneficial for transfers and conducting sustained low-to-the-ground activities. While benefits of this adjustment function were described by many participants, some struggled with usability of the kneeling mechanism and rated this function less favourably than the other two. Conclusion: The findings of this study will inform future iterations of the Kneeling Wheelchair design and may spur future developments in wheeled mobility. In the long-term, it is anticipated that novel wheelchair solutions, such as the one described in this paper, may support improved health, quality of life and community participation for people with mobility impairments. Implications for rehabilitation Wheelchairs that allow users to easily adjust seat and backrest position “on the fly” to better suit different tasks throughout the day may provide benefits such as facilitating activities of daily living. A front seat height adjustment feature on a new wheelchair prototype may be beneficial for transfers and conducting sustained low-to-the ground activities. End user evaluations can provide valuable insight to direct future design modifications and innovation.