François Routhier

Mobility of wheelchair users: a proposed performance assessment framework.

Purpose : Few standardized outcome measures used in the clinical assessment of wheelchair user performance assess or document all the factors that influence mobility. This article presents a conceptual framework that suggests a more all-encompassing view of wheelchair mobility performance assessment. Method : After determining, through a survey of the literature, which factors influence wheelchair mobility, a conceptual framework was proposed. Outcome measures of wheelchair mobility were then surveyed. An analysis of these assessment tools allowed factors to be determined that were considered in the clinical assessment of wheelchair mobility performance. A comparison of these led to observations being drawn, which could allow the development of a valid and reliable standardized outcome measure to be used in clinics. Results and Conclusion : Future improvements to the clinical assessment of wheelchair mobility performance should focus on developing an assessment tool considering all categories of factors influencing wheelchair mobility. These categories are the users profile, the wheelchair, the environment, the daily activities and social roles and the assessment and training received. A controlled-environment outcome measure using a standardized obstacle course with fundamental situations would allow rehabilitation therapists to evaluate clients for the selection of a wheelchair and to document their progress during training. This tool should make it possible to extrapolate the results and thereby apply them to daily activities and social roles.

Evaluation of the JACO robotic arm: Clinico-economic study for powered wheelchair users with upper-extremity disabilities

Many activities of daily living, such as picking up glasses, holding a fork or opening a door, which most people do without thinking, can become insurmountable for people who have upper extremity disabilities. The alternative to asking for human help is to use some assistive devices to compensate their loss of mobility; however, many of those devices are limited in terms of functionality. Robotics may provide a better approach for the development of assistive devices, by allowing greater functionality. In this paper, we present results of a study (n=31) which objectives were to evaluate the efficacy of a new joystick-controlled seven-degree of freedom robotic manipulator and assess its potential economic benefits. Results show that JACO is easy to use as the majority of the participants were able to accomplish the testing tasks on their first attempt. The economic model results inferred that the use of the JACO arm system could potentially reduce caregiving time by 41%. These study results are expected to provide valuable data for interested parties, such as individuals with disabilities, their family or caregivers.

Quantitative accelerated degradation testing: Practical approaches

The concept of accelerated testing by tracking degradation of samples over test time needs to be developed for reliability estimation. This paper aims at proposing practical approaches to conduct accelerated degradation testing on new and available used samples. For this purpose, product failure is related to a suitable physical property. Then, its failure time is defined as the expected time in which its property reaches the critical level. Degradation model of field samples returned from service due to a degrading failure mode has been estimated based on the least square method, and available gap between manufacturer criterion and users claim (to report a failure) has also been discussed. For a product under some stresses, a general formula has been proposed by the superposition principle in order to estimate its degradation for independent and dependent failure modes. If used samples are available, and acceleration factor of the related test is unknown, partial aging method has been presented to considerably shorten the test time.

Efficacy and Retention of the French-Canadian Version of the Wheelchair Skills Training Program for Manual Wheelchair Users: A Randomized Controlled Trial

OBJECTIVES To test the hypotheses that, in comparison with a control group that received standard care, users of manual wheelchairs who also received the French-Canadian version of the Wheelchair Skills Training Program (WSTP) would significantly improve their wheelchair-skills capacity and that these improvements would be retained at 3 months. DESIGN Multicenter, single-blind, randomized controlled trial. SETTING Three rehabilitation centers in Montréal, Quebec, Canada. PARTICIPANTS Manual wheelchair users (N=39), a sample of convenience. INTERVENTION Participants were randomly allocated to the WSTP or control groups. Participants in both groups received standard care. Participants in the WSTP group also received a mean of 5.9 training sessions (a mean total duration of 5h and 36min). MAIN OUTCOME MEASURES The French-Canadian version of the Wheelchair Skills Test (WST) (Version 3.2) was administered at evaluation at first time period (baseline) (t1), evaluation at second time period (posttraining) (t2) (a mean of 47d after t1), and at evaluation at third time period (follow-up) (t3) (a mean of 101d after t2). RESULTS At t2, the mean ± SD total percentage WST capacity scores were 77.4%±13.8% for the WSTP group and 69.8%±18.4% for the control group (P=.030). Most of this difference was due to the community-level skills (P=.002). The total and subtotal Wheelchair Skills Test scores at t3 decreased by ≤0.5% from the t2 values, but differences between groups at t3, adjusting for t1, did not reach statistical significance (P≥.017 at a Bonferroni-adjusted α level of .005). CONCLUSION WSTP training improves wheelchair skills immediately after training, particularly at the community-skills level, but this study did not show statistically significant differences between the groups at 3 months.

Development of a French-Canadian version of the Life-Space Assessment (LSA-F): content validity, reliability and applicability for power mobility device users

Purpose. To examine the measurement properties of the French-Canadian version of the Life-Space Assessment questionnaire (LSA-F) for power mobility device (PMD) users. Methods. Content validity, test–retest reliability of telephone interviews (2-week interval) and applicability were examined with PMD users presenting neurological, orthopedic or medically complex conditions. Translation/back-translation from English to French and cultural adaptation was performed and pretested with five bilingual users. Test–retest reliability was examined with 40 French-speaking users, age 50 and over, who had been using a subsidised PMD for 2–15 months. Audio-taped interviews were coded to judge content validity and applicability. Results. Content validity results confirmed equivalent meaning for most questions. The test–retest reliability was excellent for the composite score (intra-class correlation coefficient = 0.87) and revealed moderate to substantial concordance for 18/20 items (k = 0.47–0.73; Pa > 57.5%). The applicability of the LSA-F is satisfactory considering an acceptable burden of assessment, low refusal of the telephone interview format (8%; n = 4), reasonable administration time (9.2 ± 3.9 min) and a normally distributed composite score. Conclusions. The LSA-F is a valid measure with regards to its content, stable over a period of 2 weeks and applicable for a population of middle-aged and older French-Canadian speaking adults who use PMDs.

On the Design of a Mechanically Programmable Underactuated Anthropomorphic Prosthetic Gripper

This paper introduces a novel underactuated anthropomorphic gripper for prosthetic applications. In order to extend the grasping capabilities of underactuated prosthetic grippers and improve the force transmission ratio, a mechanical lever is mounted inside the palm that allows a proper distribution of the forces and provides mechanical advantage. A static model is developed and the possibilities offered by the lever transmission are investigated. Also, a compact mechanism is introduced to synchronize the motion of the four fingers. Additionally, a mechanical selector is designed that functions as a means of mechanically programming the motion of the fingers by selectively blocking their closing motion. Finally, a prototype, including all the above features, is described and experimental validation is briefly reported. [DOI: 10.1115/1.4025493]

The role of self-efficacy in the wheelchair skills-physical activity relationship among manual wheelchair users with spinal cord injury

Purpose: The purpose of this study was to determine whether self-efficacy can account for the relationship between wheelchair skills and leisure-time physical activity (LTPA) in people with spinal cord injury (SCI). Method: Fifty-four manual wheelchair users with SCI participated in this cross-sectional study. Participants completed a wheelchair skills test, and self-report measures of wheelchair-use self-efficacy, LTPA barrier self-efficacy, and LTPA. It was hypothesized that a positive wheelchair skills-LTPA relationship would be mediated by wheelchair-use self-efficacy and LTPA barrier self-efficacy. Results: Using linear regression models, a positive association between wheelchair skills and LTPA was established (β = 0.27, p < 0.05). LTPA barrier self-efficacy was a significant partial mediator, explaining 47.7% of the variance of the total relationship between skills and LTPA. Wheelchair-use self-efficacy was not a significant mediator of the wheelchair skills-LTPA relationship. Conclusions: Wheelchair skills play a modest role in LTPA participation and may facilitate LTPA, if skills help people feel more self-efficacious in their abilities to overcome LTPA barriers. The results have implications for understanding and improving LTPA participation. Improvements in wheelchair skills may facilitate LTPA, if people are taught the skills needed to increase their self-efficacy to overcome barriers to LTPA participation. Implications for Rehabilitation Many Canadians with spinal cord injury (SCI) do not participate in leisure-time physical activities (LTPAs). Lack of LTPA participation is associated with increased health risks in people with SCI, who are already at higher risk for health problems when compared to the able-bodied population. The belief in one’s ability to overcome barriers (barrier self-efficacy) to LTPA plays a significant role in LTPA participation for people with SCI. People with SCI may benefit from a formal wheelchair skills training program to improve their barrier self-efficacy which can lead to more participation in LTPA and decreased health risks.

Design and validation of an intelligent wheelchair towards a clinically-functional outcome

BackgroundMany people with mobility impairments, who require the use of powered wheelchairs, have difficulty completing basic maneuvering tasks during their activities of daily living (ADL). In order to provide assistance to this population, robotic and intelligent system technologies have been used to design an intelligent powered wheelchair (IPW). This paper provides a comprehensive overview of the design and validation of the IPW.MethodsThe main contributions of this work are three-fold. First, we present a software architecture for robot navigation and control in constrained spaces. Second, we describe a decision-theoretic approach for achieving robust speech-based control of the intelligent wheelchair. Third, we present an evaluation protocol motivated by a meaningful clinical outcome, in the form of the Robotic Wheelchair Skills Test (RWST). This allows us to perform a thorough characterization of the performance and safety of the system, involving 17 test subjects (8 non-PW users, 9 regular PW users), 32 complete RWST sessions, 25 total hours of testing, and 9 kilometers of total running distance.ResultsUser tests with the RWST show that the navigation architecture reduced collisions by more than 60% compared to other recent intelligent wheelchair platforms. On the tasks of the RWST, we measured an average decrease of 4% in performance score and 3% in safety score (not statistically significant), compared to the scores obtained with conventional driving model. This analysis was performed with regular users that had over 6 years of wheelchair driving experience, compared to approximately one half-hour of training with the autonomous mode.ConclusionsThe platform tested in these experiments is among the most experimentally validated robotic wheelchairs in realistic contexts. The results establish that proficient powered wheelchair users can achieve the same level of performance with the intelligent command mode, as with the conventional command mode.

Exoskeletons' design and usefulness evidence according to a systematic review of lower limb exoskeletons used for functional mobility by people with spinal cord injury

Abstract Purpose: Rehabilitation professionals have little information concerning lower limb exoskeletons for people with paraplegia. This study has four objectives: (1) Outline the characteristics of the exoskeletons’ design and their usefulness evidence as assistive mobility devices in the community for the Rewalk™, Mina, Indego®, Ekso™ (previously known as the eLEGS™) and Rex®; (2) document functional mobility outcomes of using these exoskeletons; (3) document secondary skills and benefits achieved with these exoskeletons, safety, user satisfaction and applicability in the community; and (4) establish level of scientific evidence of the selected studies. Method: A systematic review of the literature (January 2004 to April 2014) was done using the databases PubMed, CINAHL and Embase and groups of keywords associated with “exoskeleton”, “lower limb” and “paraplegia”. Results: Seven articles were selected. Exoskeleton use is effective for walking in a laboratory but there are no training protocols to modify identified outcomes over the term usage (ReWalk™: 3 months, Mina: 2 months and Indego®: 1 session). Levels of evidence of selected papers are low. Conclusions: The applicability and effectiveness of lower limb exoskeletons as assistive devices in the community have not been demonstrated. More research is needed on walking performance with these exoskeletons compared to other mobility devices and other training contexts in the community. Implications for rehabilitation Characteristics of the exoskeletons’ design and their usefulness evidence as assistive mobility devices in the community are addressed for the Rewalk™, Mina, Indego®, Ekso™ and Rex® ReWalk™, Indego® and Mina lower limb exoskeletons are effective for walking in a laboratory for individuals with complete lower-level SCI. The ReWalk™ has the best results for walking, with a maximum speed of 0.51 m/s after 45 sessions lasting 60 to 120 min; it is comparable to the average speed per day or per week in a manual wheelchair. The level of scientific evidence is low. Other studies are needed to provide more information about performance over the longer term when walking with an exoskeleton, compared to wheelchair mobility, the user’s usual locomotion, the use of different exoskeletons or the training context in which the exoskeleton is used.

Driving performance in a power wheelchair simulator

Purpose: A power wheelchair simulator can allow users to safely experience various driving tasks. For such training to be efficient, it is important that driving performance be equivalent to that in a real wheelchair. This study aimed at comparing driving performance in a real and in a simulated environment. Method: Two groups of healthy young adults performed different driving tasks, either in a real power wheelchair or in a simulator. Smoothness of joystick control as well as the time necessary to complete each task were recorded and compared between the two groups. Driving strategies were analysed from video recordings. The sense of presence, of really being in the virtual environment, was assessed through a questionnaire. Results: Smoothness of joystick control was the same in the real and virtual groups. Task completion time was higher in the simulator for the more difficult tasks. Both groups showed similar strategies and difficulties. The simulator generated a good sense of presence, which is important for motivation. Conclusions: Performance was very similar for power wheelchair driving in the simulator or in real life. Thus, the simulator could potentially be used to complement training of individuals who require a power wheelchair and use a regular joystick. Implications for Rehabilitation Individuals who require a power wheelchair for mobility often lack sufficient training, which may be supplemented through the use of a simulator. For such training to be efficient, it is important that performance in the simulator and in a real wheelchair be equivalent. This study showed that driving performance, strategies used and difficulties encountered were very similar, for groups of healthy adults driving in the simulator or in a real power wheelchair.