Participatory Action Design and Engineering of Powered Personal Transfer System for Wheelchair Users: Initial Design and Assessment.

Caregivers that assist with wheelchair transfers are susceptible to back pain and occupational injuries. The study describes a prototype of the powered personal transfer system (PPTS) consisting of a novel powered hospital bed and a customized Medicare Group 2 electric powered wheelchair (EPW) working together to provide a no-lift solution for transfers. The study follows a participatory action design and engineering (PADE) process and describes the design, kinematics, and control system of the PPTS and end-users' perception to provide qualitative guidance and feedback about the PPTS. Thirty-six participants (wheelchair users (n = 18) and caregivers (n = 18)) included in the focus groups reported an overall positive impression of the system. Caregivers reported that the PPTS would reduce the risk of injuries and make transfers easier. Feedback revealed limitations and unmet needs of mobility device users, including a lack of power seat functions in the Group-2 wheelchair, a need for no-caregiver assistance/capability for independent transfers, and a need for a more ergonomic touchscreen. These limitations may be mitigated with design modifications in future prototypes. The PPTS is a promising robotic transfer system that may aid in the higher independence of powered wheelchair users and provide a safer solution for transfers.

Comparing the performance of ultralight folding manual wheelchairs using standardized tests.

OBJECTIVE: To evaluate ultralight folding manual wheelchairs (UFMWs) in order to produce comparative data on their strength, durability, stability and cost-benefit, and to determine progress of wheelchairs by comparing these results to results of past studies. DESIGN: Engineering testing using American National Standards Institute (ANSI) and Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) standards. SETTING: Laboratory testing of UFMW stability, and static, impact and fatigue strength performance with three devices using ANSI/RESNA standardized tests. PARTICIPANTS: The three wheelchair models were the TiLite Aero X (Permobil, Lebanon, TN), Sunrise Medical Quickie 2 (Fresno, CA) and Ki Mobility Catalyst 5 (Stevens Point, WI). INTERVENTIONS: ANSI/RESNA standardized tests. MAIN OUTCOME MEASURES: Mass and critical measurements, static stability, static strength, impact strength, fatigue strength and cost analysis. RESULTS: The ultralight folding wheelchairs continued to outperform their lightweight and rigid framed counterparts. According to these data, the quality of ultralight wheelchairs has not declined over the past 10 years. The Ki Catalyst did not pass strength and durability testing, while the TiLite Aero X and Sunrise Medical Quickie 2 surpassed these tests. CONCLUSIONS: This result exemplifies the need for ongoing research to identify whether wheelchairs satisfy ANSI/RESNA testing requirements and highlights the importance of creating a resource data set. This is particularly important when numerous other wheelchairs fail to meet minimum ANSI/RESNA requirements.Implications for RehabilitationFolding frame wheelchairs offer benefits such as transportability and convenience that may benefit certain wheelchair users, assuming their durability is sufficient and they provide similar benefits vs. other wheelchair construction.Previous studies have shown that folding wheelchairs perform meet the minimum requirements of standardized testing, and it is important to see if durability has increased, decreased or remained the same over the years. Other wheelchair types have remained stagnant with respect to durability and are less likely to meet the minimum durability requirements.Durable devices will improve a wheelchair user's quality of life by reducing downtime while waiting for repairs, and also reduce the likelihood of injury due to component failure.

Mini-review: Rehabilitation engineering: Research priorities and trends.

Rehabilitation Engineering is the use of engineering principles applied to rehabilitation, disability, and independent living. Google Scholar is a searchable resource that allows people from around the world to create profiles of their interests and collaborations, and it provides a means to search the broad scientific and technical literature. Google Scholar was used to identify the 150 most cited people who listed Rehabilitation Engineering in their profile. Research impact, characteristics, and areas of research of the most cited rehabilitation engineers were examined. Furthermore, gender and geographical differences in research metrics of the highest citied rehabilitation engineers were investigated. Consumer priorities in rehabilitation engineering were identified using a voice of consumer (VoC) survey and recent literature based on VoC studies. Gaps between research publication and activities and consumer priorities were identified to recommend seven areas of research with high demand and opportunity for growth and innovation. Implications.

Assessment of Muscle Activation of Caregivers Performing Dependent Transfers With a Novel Robotic-Assisted Transfer Device Compared With the Hoyer Advance.

OBJECTIVE: The purpose of this study was to compare muscle activity in caregivers while using a novel robotic-assisted transfer device (Strong Arm) to a clinical standard of care (Hoyer Advance). DESIGN: A quasi-experimental design was used in which 20 caregivers (33 ± 15 yrs old) performed transfers with three surfaces (toilet, bench, and shower chair) with the Strong Arm and Hoyer Advance. Transfer completion time (seconds), peak percentage surface electromyography (EMG), and integrated EMG of the bilateral erector spinae, latissimus dorsi, pectoralis major and anterior deltoid were measured. RESULTS: Caregivers required less transfer time when transferring from wheelchair to surface using the Hoyer Advance (P = 0.011, f = 0.39). For the lower back, significantly lower peak percentage EMGs were found using Strong Arm in 50% and for the integrated EMG in 25% of the cases, with the remaining cases showing no significant differences. For the shoulder, significantly lower peak percentage EMG values were found using Strong Arm in 19% of transfers and lower integrated EMG was found in 25% of transfers when using the Hoyer Advance, with the remaining cases showing no significant differences. CONCLUSION: Although back muscle activation during Strong Arm transfers is statistically, but not clinically, lower, additional features that couple with significantly lower muscle activation make it an alternative to the clinical standard for further research and possible clinical applicability.

Comparison of carbon fibre and aluminium materials in the construction of ultralight wheelchairs.

Carbon fibre-reinforced polymers have been used in the sporting goods industry for decades, and wheelchairs have incorporated the material since the late 1980s. There is no independently collected data available on carbon fibre-reinforced polymer wheelchairs' performance on the ANSI/RESNA testing standards, however. This study evaluated three full carbon fibre wheelchair specimens to determine their performance versus similar wheelchairs. Testing determined that while the frames survived more testing cycles than any other wheelchair, the casters and rear tires failed similarly to other devices. Overall, due to the purchase cost, the cost benefit of the tested wheelchair model was similar to aluminium wheelchairs.Implications for rehabilitationCarbon fibre wheelchair construction is a viable alternative to aluminium, titanium, or steel construction, and decreasing costs will continue to improve the benefits of carbon fibre over these modelsCarbon fibre wheelchair found to be more durable than aluminium models, but are also much more expensive. The additional cost may be justified for some users that need the increased durability, howeverIncreased durability will reduce the number of repairs and warranty claims, potentially reducing the burden on a wheelchair user, and also improving their ability to travel and participate in their communityThe low weight of carbon fibre wheelchairs may increase the mobility of some users by allowing them to transfer more easily into and out of vehicles and manoeuvre throughout the environment.

Test-retest reliability of the functional mobility assessment (FMA): a pilot study.

PURPOSE: Functional mobility is necessary to perform activities of daily living and for community participation for everyone, but especially important for persons with disabilities (PWD). Therefore, functional mobility requires reliable measurement of consumer satisfaction and functional changes. The functional mobility assessment (FMA) instrument is a self-report outcomes tool designed to measure effectiveness of wheeled mobility and seating (WMS) interventions for PWD. This study examined the test-retest reliability of the FMA, and the stability of self-reported performance items. METHOD: A repeated-measures cohort study was conducted at the Center for Assistive Technology, at the University of Pittsburgh Medical Center. Participants (n = 41) completed an initial FMA questionnaire, and were re-administered the questionnaire within 7-21 days of the first questionnaire completion. The study sample included 20 participants who were non-WMS users but in the process of being evaluated for a device and 21 participants who were existing WMS users. Intra-Class Correlation coefficients (ICC) were computed to determine agreement between the two scores. RESULTS: Test-retest reliability scores for all items and participants were above the acceptable value for a clinical assessment tool (≥0.80). Responses on the FMA of Existing WMS users and non-WMS users did not differ significantly at test or retest. CONCLUSIONS: Results indicate that the FMA was a reliable and stable tool for assessing the functional performance of individuals who use or need WMS interventions.

Pilot study for quantifying driving characteristics during power wheelchair soccer.

This study determined the driving characteristics of wheelchair users during power wheelchair soccer games. Data for this study were collected at the 28th and 29th National Veterans Wheelchair Games. Nineteen veterans who were 18 years or older and power wheelchair soccer players completed a brief demographic survey and provided information about their power wheelchairs. A customized data-logging device was placed on each participant's wheelchair before power soccer game participation. The data logger was removed at the end of the final game for each participant. The average distance traveled during the games was 899.5 +/- 592.5 m, and the average maximum continuous distance traveled was 256.0 +/- 209.4 m. The average wheelchair speed was 0.8 +/- 0.2 m/s, and the average duration of driving time was 17.6 +/- 8.3 min. Average proportion of time spent at a speed >1 m/s was 30.7% +/- 33.8%, between 0.5 and 1 m/s was 16.2% +/- 34.4%, and <0.5 m/s was 21.4% +/- 24.3%. The information from this descriptive study provides insight for future research in the field of adapted sports for people with high levels of impairments who use power wheelchairs for their mobility.

Development and qualitative assessment of the GAME(Cycle) exercise system.

Increased physical activity is important for reducing the risk of cardiovascular disease. However, among people with disabilities, inactivity is prevalent. In order to encourage exercise among members of this group, an exercise system combining arm ergometry with video gaming, called the GAME(Cycle) was previously developed. User input was received through an arm crank ergometer on a swivel, with the angular velocity of the ergometer resistance wheel controlling one axis and rotation of ergometer about the swivel controlling the other. The purpose of this study was to detail the algorithms used in this device and present novel features included in a second generation of the GAME(Cycle). The features include a wheel on base, a steering return mechanism, and wireless fire buttons. A focus group of clinicians (n = 8), wheelchair users (n = 8), and clinician wheelchair users (n = 2) was conducted to evaluate the features of the GAME(Cycle). The focus group suggested improvements to the steering mechanism and to reduce vibration in the system. However, the focus group enjoyed the GAME(Cycle) and felt that it would encourage exercise among persons with disabilities.

Towards the development of an effective technology transfer model of wheelchairs to developing countries.

PURPOSE: And estimated 20-100 million wheelchairs are needed in developing countries. Efforts to provide wheelchairs either through donations or by starting small-scale workshops have been made for decades, but estimates suggest that less than 1 million wheelchairs have been provided. We undertook this study to better understand why these efforts have not met the need, and to investigate if other technology transfer models may be successful for wheelchair provision. METHODS: We performed a literature review, discussed our own experiences with wheelchair technology transfer, and used our expertise to develop a model for wheelchair technology transfer. RESULTS: Previous efforts have not met the need because: (1) donated wheelchairs were typically inappropriate for the user, and (2) small-scale workshops are not easily scalable for the large-scale production needed. Three additional technology transfer models exist-manufacturing, globalization, and multi-modal-that have not been widely demonstrated or discussed in the literature. Our experience with the manufacturing model suggests that it could potentially provide the large volumes of appropriate wheelchairs needed in certain regions. Lastly, we present a framework comparing the important characteristics of each model: required input, sustainability, appropriateness, and the potential impact. CONCLUSIONS: While most efforts to provide wheelchairs to developing countries are helpful, we show that expansion of the manufacturing and globalization model to provide wheelchairs may be necessary if the supply will meet the demand.

Evaluation of the safety and durability of low-cost nonprogrammable electric powered wheelchairs.

OBJECTIVE: To evaluate whether a selection of low-cost, nonprogrammable electric-powered wheelchairs (EPWs) meets the American National Standards Institute (ANSI)/Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) Wheelchair Standards requirements. DESIGN: Objective comparison tests of various aspects of power wheelchair design and performance of 4 EPW types. SPECIMENS: Three of each of the following EPWs: Pride Mobility Jet 10 (Pride), Invacare Pronto M50 (Invacare), Electric Mobility Rascal 250PC (Electric Mobility), and the Golden Technologies Alanté GP-201-F (Golden). SETTING: Rehabilitation engineering research center. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Static tipping angle; dynamic tipping score; braking distance; energy consumption; climatic conditioning; power and control systems integrity and safety; and static, impact, and fatigue life (equivalent cycles). RESULTS: Static tipping angle and dynamic tipping score were significantly different across manufacturers for each tipping direction (range, 6.6 degrees-35.6 degrees). Braking distances were significantly different across manufacturers (range, 7.4-117.3 cm). Significant differences among groups were found with analysis of variance (ANOVA). Energy consumption results show that all EPWs can travel over 17 km before the battery is expected to be exhausted under idealized conditions (range, 18.2-32.0 km). Significant differences among groups were found with ANOVA. All EPWs passed the climatic conditioning tests. Several adverse responses were found during the power and control systems testing, including motors smoking during the stalling condition (Electric Mobility), charger safety issues (Electric Mobility, Invacare), and controller failures (Golden). All EPWs passed static and impact testing; 9 of 12 failed fatigue testing (3 Invacare, 3 Golden, 1 Electric Mobility, 2 Pride). Equivalent cycles did not differ statistically across manufacturers (range, 9759-824,628 cycles). CONCLUSIONS: Large variability in the results, especially with respect to static tipping, power and control system failures, and fatigue life suggest design improvements must be made to make these low-cost, nonprogrammable EPWs safe and reliable for the consumer. Based on our results, these EPWs do not, in general, meet the ANSI/RESNA Wheelchair Standards requirements.

Fatigue testing of selected suspension manual wheelchairs using ANSI/RESNA standards.

OBJECTIVES: To evaluate the durability and value of 3 common suspension manual wheelchairs and to compare the results with those of previously tested lightweight and ultra-lightweight folding-frame wheelchairs. DESIGN: Standardized fatigue testing and cost analysis of 3 suspension manual wheelchairs from 3 different manufacturers. SETTING: A rehabilitation engineering center. SPECIMENS: Nine suspension manual wheelchairs. INTERVENTIONS: Wheelchairs were fitted with a standardized wheelchair test dummy and tested on a series of fatigue tests, consistent with those developed by the International Organization for Standardization. Main outcome measures Fatigue life (measured as the number of equivalent cycles completed) and value (equivalent cycles divided by cost) were compared among all wheelchairs. RESULTS: Analysis of variance revealed significant differences (P< or =.05) in the number of equivalent cycles among the suspension wheelchairs tested. When compared with previously tested ultra-lightweight and lightweight wheelchairs, the suspension wheelchairs failed to show significant improvements; however, significant improvements were found between individual suspension and lightweight wheelchairs. CONCLUSIONS: We found little evidence to suggest that suspension manual wheelchairs provide advantages in terms of durability or value over standard lightweight and ultra-lightweight folding-frame wheelchairs.

Preliminary assessment of a prototype advanced mobility device in the work environment of veterans with spinal cord injury.

The INDEPENDENCE 3000 IBOT Transporter (IBOT) is an electronically stabilizing device for people with disabilities. The purpose of this study was to collect qualitative data on the potential for the IBOT to improve employment satisfaction of veterans who use wheelchairs to work. This study was based upon observations by trained clinicians, and responses to a survey completed by four men with traumatic spinal cord injury, who worked in an office environment. The mean age of the subjects was 52 +/- 8.8 years. The subjects used the devices to hold eye-level discussions with colleagues, climb stairs, ascend steep ramps, and negotiate curbs. When subjects were asked to rate the ease of getting around in the IBOT compared to their personal wheelchairs, they responded with a mean of 6.7 +/- 1.8 on a 10-point visual analog scale. The response to rating the overall function of the IBOT within their working environment yielded a rating of 6.0 +/- 2.8. Half of the users felt that the IBOT would help them at work and all thought it should be made available to veterans who use wheelchairs. A larger study should be conducted to determine if the IBOT affects work performance and the ability to return to work.

Investigating neck pain in wheelchair users.

OBJECTIVE: Despite the fact that wheelchair users are exposed to risk factors for neck and upper back pain (NP), little is known about the impact and possible diagnoses associated with NP. The purpose of this study was to examine the significance of NP in wheelchair users and to determine if a portion of the NP may be myofascial in origin. DESIGN: Cross-sectional cohort study using questionnaires and physical exams to evaluate NP in a convenience sample of wheelchair users from the National Veteran's Wheelchair Games. Main outcome measures included reported NP, visual analog scale of neck complaints, Neck Disability Index, and physical examination findings of trigger points. RESULTS: Sixty-six percent of subjects reported NP since becoming a wheelchair user and, 60% reported pain during the past month. Neither age nor length of time in a wheelchair was significantly different between those subjects who did and those subjects who did not report pain. Of those respondents who reported NP, 60% visited the doctor about the pain and 40% limited their daily activities due to the pain. Trigger-point palpation reproduced pain in 54% of those respondents who experienced pain in the past month (n = 34). CONCLUSION: This study provides a first step in defining the prevalence and significance of NP among wheelchair users. Clinicians who work with this population need to ask subjects about symptoms and consider a myofascial origin for that pain when considering treatment.