An autonomous wheelchair with health monitoring system based on Internet of Thing.

Assistive powered wheelchairs will bring patients and elderly the ability of remain mobile without the direct intervention from caregivers. Vital signs from users can be collected and analyzed remotely to allow better disease prevention and proactive management of health and chronic conditions. This research proposes an autonomous wheelchair prototype system integrated with biophysical sensors based on Internet of Thing (IoT). A powered wheelchair system was developed with three biophysical sensors to collect, transmit and analysis users' four vital signs to provide real-time feedback to users and clinicians. A user interface software embedded with the cloud artificial intelligence (AI) algorithms was developed for the data visualization and analysis. An improved data compression algorithm Minimalist, Adaptive and Streaming R-bit (O-MAS-R) was proposed to achieve a higher compression ratio with minimum 7.1%, maximum 45.25% compared with MAS algorithm during the data transmission. At the same time, the prototype wheelchair, accompanied with a smart-chair app, assimilates data from the onboard sensors and characteristics features within the surroundings in real-time to achieve the functions including obstruct laser scanning, autonomous localization, and point-to-point route planning and moving within a predefined area. In conclusion, the wheelchair prototype uses AI algorithms and navigation technology to help patients and elderly maintain their independent mobility and monitor their healthcare information in real-time.

2024 Wheelchair Compendium of Physical Activities: An update of activity codes and energy expenditure values.

PURPOSE: This paper presents an update of the 2011 Wheelchair Compendium of Physical Activities designed for wheelchair users and is referred to as the 2024 Wheelchair Compendium. The Wheelchair Compendium aims to curate existing knowledge of the energy expenditure for wheelchair physical activities (PAs). METHODS: A systematic review of the published energy expenditure of PA for wheelchair users was completed between 2011 and May 2023. We added these data to the 2011 Wheelchair Compendium data that was compiled previously in a systematic review through 2011. RESULTS: A total of 47 studies were included, and 124 different wheelchair PA reported energy expenditure values ranging from 0.8 metabolic equivalents for wheelchair users (filing papers, light effort) to 11.8 metabolic equivalents for wheelchair users (Nordic sit skiing). CONCLUSION: In introducing the updated 2024 Wheelchair Compendium, we hope to bridge the resource gap and challenge the prevailing narratives that inadvertently exclude wheelchair users from physical fitness and health PAs.

Understanding Wheelchair Use in Older Adults From the National Health and Aging Trends Study.

OBJECTIVE: To identify the trends of wheelchair use and physical characteristics among older people who used wheelchairs relative to those who did not. DESIGN: Cohort and survey. SETTING: General community. PARTICIPANTS: 7026 participants (N=7026) were selected from the 2011 cohort of the National Health and Aging Trends Study (NHATS), which is made up of Medicare beneficiaries over the age of 65. Repeated observations among participants in the 2011 cohort were analyzed in the 4 following rounds: 2013 (N=4454), 2015 (N=3327), 2017 (N=2623), and 2019 (N=2091). Participants were divided into 2 groups: those who used and did not use wheelchairs. INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Physical characteristics, including pain, strength limitation, balance problems, mobility disability, as well as the frequency of going outside. RESULTS: The number of older adults who use wheelchairs had increased significantly from 4.7 per 100 people in 2011 to 7.1 in 2019 (P<.001). The logistic regression analysis indicated that participants who reported less frequently going out were at least 4.27 times more likely to be wheelchair users than non-wheelchair users (P<.01). Participants who reported health and physical problems were at least 2.48 times more likely to be wheelchair users than non-wheelchair users from 2011 to 2017 (P<.0001). Balance or coordination problems increased (24%-38%) significantly among non-wheelchair users from 2011 to 2019 (all P<.05). CONCLUSIONS: Current wheelchair users reported more physical difficulties and were much less likely to go outside. This lower outdoor mobility could be due to physical difficulties or potential barriers in physical and socio-cultural environments. In addition, older adults who do not use wheelchairs showed increasing physical problems over time (including balance or coordination problems). Clinicians should consider older wheelchair users' health and physical limitations when prescribing wheelchairs.

Reliability and validity of the T-shirt test for the assessment of unsupported sitting in manual wheelchair users with spinal cord injury.

This study aimed to evaluate the validity and reliability of the T-shirt test (TST) in assessing sitting stability under three thigh support conditions and with timed outcomes derived in six ways among individuals with a spinal cord injury (SCI). The TST was performed five times under three thigh support conditions (85%, 55% and 25% of total thigh length) in two evaluations spaced between 7-14 days. For each thigh condition, six different outcomes were derived (average or best time from 2, 3, and 5 trial). All outcomes derivation showed excellent reliability on test day (intraclass correlation coefficient; ICC  ≥ 0.997) and excellent test-retest reliability (ICC ≥ 0.874) for each thigh support condition. The TST showed high inverse correlations with the Spinal Cord Independence Measure III (SCIM)-mobility score for all outcomes and support conditions (ρ≥-0.706), except for Best-5; moderate inverse correlations with total SCIM-total scores for most outcome derivations and support conditions (ρ≥-0.636); and a moderate inverse correlation with confidence and capacity domains of Wheelchair Skills Test-Questionnaire for most outcome derivation and support conditions (ρ≥-0.504). The TST could discriminate cervical from high and low thoracic levels of injuries under minimal thigh support condition. Overall, all the TST-derived outcomes and support conditions showed adequate validity and test-retest reliability, but Best-5 had inconsistency. Under the minimal thigh support condition, all outcome derivations except Best-3 could discriminate cervical from other injury-level groups. Although all outcome derivations and thigh support conditions provided reliable results, we recommend using the average of 3 trials under the maximal thigh support condition.

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.

Development of a Portable Low-Cost System for the Metrological Verification of Wheelchair Roller Ergometers.

Wheelchair ergometers are widely used in research, clinical practice, and sports environments. The majority of wheelchair ergometers are roller systems that allow for wheelchair propulsion in the personal wheelchair on one or two (instrumented) rollers. Oftentimes these systems are only statically calibrated. However, wheelchair propulsion is dynamic by nature, requiring a dynamic validation process. The aim of the current project was to present a low-cost portable system for the dynamic metrological verification of wheelchair roller ergometers, based on an instrumented reference wheel. The tangential force on the roller is determined, along with its uncertainty, from the reference wheel properties, and compared with the force measured by the ergometer. Uncertainty of this reference wheel system was found to be lower than the one of the ergometer used, indicating that this novel approach can be used for the metrological verification of ergometers.

Reliability of home-based remote and self-assessment of transfers using the Transfer Assessment Instrument among wheelchair users with spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To evaluate the reliability of home-based remote and self-assessment of transfer quality using the Transfer Assessment Instrument (TAI) among wheelchair users with spinal cord injury (SCI). SETTING: Participant's home environment. METHODS: Eighteen wheelchair users with SCI transferred from their wheelchair to a surface of their choice (bed, sofa, or bench) in their homes. During a live video conference, the transfer was recorded and evaluated live using the TAI (rater 1). Participants completed a self-assessment of their transfer using the TAI- questionnaire (TAI-Q). Two additional raters (raters 2 & 3) completed asynchronous assessments by watching recorded videos. Interrater reliability was assessed using Intraclass Coefficient Correlations (ICC) to compare rater 1 with the average of raters 2 & 3 and TAI-Q. Intrarater reliability was assessed by rater 1 completing another TAI by watching the recorded videos after a 4-week delay. Assessments were compared using paired sample t-tests and level of agreement between TAI scores was evaluated using Bland-Altman plots. RESULTS: Moderate to good interrater and good intrarater reliability were found for the total TAI score with ICCs: 0.57-0.90 and 0.90, respectively. Moderate to good intrarater and interrater reliability were found for all TAI subscores (ICC: 0.60-0.94) except for interrater reliability of flight/landing which was poor (ICC: 0.20). Bland-Altman plots indicate no systematic bias related to the measurement of error. CONCLUSIONS: The TAI is a reliable outcome measure for assessing the wheelchair and body setup phases of home-based transfers remotely and through self-assessment among individuals with SCI.

Low Cost Magnetic Field Control for Disabled People.

Our research presents a cost-effective navigation system for electric wheelchairs that utilizes the tongue as a human-machine interface (HMI) for disabled individuals. The user controls the movement of the wheelchair by wearing a small neodymium magnet on their tongue, which is held in place by a suction pad. The system uses low-cost electronics and sensors, including two electronic compasses, to detect the position of the magnet in the mouth. One compass estimates the magnet's position while the other is used as a reference to compensate for static magnetic fields. A microcontroller processes the data using a computational algorithm that takes the mathematical formulations of the magnetic fields as input in real time. The system has been tested using real data to control an electric wheelchair, and it has been shown that a trained user can effectively use tongue movements as an interface for the wheelchair or a computer.

Development of a metric to evaluate the ergonomic principles of assistive systems, based on the DIN 92419.

The DIN 92419 defines six principles for assistive systems' ergonomic design. There is, however, a lack of measurement tools to evaluate assistive systems considering these principles. Consequently, this study developed a measurement tool for the quantitative evaluation of the fulfilment of each principle for assistive systems. A systematic literature review was performed to identify dimensions belonging to the principles, identify how previous research evaluated these dimensions, and develop a measurement tool for assistive systems. Findings show that scales commonly used for evaluating assistive systems disregard several aspects highlighted as relevant by research, implying the need for considering the DIN 92419 principles. Based on established scales and theoretical findings, a questionnaire, and a checklist for evaluating assistive systems were developed. The work provides a grounding for measuring relevant aspects of assistive systems. Further development is needed to substantiate the reliability and validity of the proposed questionnaire scales and items. Practitioner Summary: Responding to the gap of a holistic measurement tool to evaluate assistive systems, a systematic literature review was performed considering the DIN 92419 principles. This resulted in a comprehensive summary of relevant aspects of assistive systems that were made numerically measurable, which proposes better criteria to assess assistive systems. Abbreviations: IoT: internet of things; RQ: research question; TAM: technology acceptance model; UTAUT: unified theory of acceptance and use of technology; AaaS: adaptivity as a service; SAR: socially assistive robots; SEEV: salience, effort, expectancy, and value; PRISMA: preferred reporting items for systematic reviews and meta-analyses; HMI: human-machine interaction; HRI: human-robot interaction; BCI: brain-computer interface; QUEST: Quebec user evaluation of satisfaction with assistive technology; SUS: system usability scale; NASA-TLX: NASA task load index; ATD PA: assistive technology device predisposition assessment; Wheel Con: wheelchair use confidence scale; CATOM: caregiver assistive technology outcome measure; CBI: caregiver burden inventory; RoSAS: robotic social attributes scale; WheelCon: wheelchair use confidence scale; IMI: intrinsic motivation inventory; ATD PA: assistive technology device predisposition assessment; UEQ: User experience questionnaire; USEUQ: usefulness satisfaction and ease of use questionnaire; USPW: usability scale for power wheelchairs; UES: user engagement scale; SUTAQ: service user technology acceptability questionnaire; QUEAD: questionnaire for the evaluation of physical assistive devices; FATCAT: functional assessment tool for cognitive assistive technology; SE-HRI: human-robot interaction scale; SART: situation awareness rating technique; TSQ;WT: tele-healthcare satisfaction questionnaire-wearable technology; PAIF: participants' assessment of the intervention's feasibility; SWAT: subjective workload assessment technique; MARS-HA: measure of audiologic rehabilitation self-efficacy for hearing aids; IOI-HA: International outcome inventory for hearing aids; FMA: functional mobility assessment; FBIS: familiarity and behavioural intention survey; CSQ: client satisfaction questionnaire; COPM: canadian occupational performance measure; ATCS: assistive technology confidence scale; ACC: acceptance; SSP: safety, security and privacy; OPT: optimisation of resultant internal load; CTRL: controllability; ADAPT: adaptability; P&I: perceptibility and identifiability; AAL: ambient assisted living; VR: virtual reality; AS: assistive system; WEIRD: Western, educated, industrialised, rich, and democratic; HEART: horizontal european activities of rehabilitation technology; AAATE: advancement of assistive technology in Europe's; GATE: global collaboration on assistive technology; ATA-C: assistive technology assessment toolkit.

Design of a low-cost, reconfigurable, standing wheelchair with easy and stable sit-stand-sit transition capability.

PURPOSE: Assistive devices like Standing Wheelchairs (SWC) have remained out of reach of the economically underprivileged even before the pandemic-induced financial downturn, and more so now. This paper describes the mechanical design of a manual user-actuated SWC that is cost-effective (equivalent of USD 210 in India, ex-factory) and has special features that minimise user effort and accommodates varying body weights (50-110 kg) and dimensions (1.52-1.83 m height). METHODS: The design includes a six-bar mechanism and spring balancing to optimise user effort during operation. The optimised gas spring incorporates adjustability to minimise each user's force for sit-stand-sit transitions. The handle shape is ergonomically designed using kinematic analysis to provide convenient gripping positions for actuation. The design has been customised based on parametric studies to suit varying body weights. RESULTS: Overall, the SWC design provides standing functionality with ease of operation, safety locks, customisability, affordability, outdoor mobility and is aesthetically pleasing. CONCLUSIONS: Customisability and the low cost of the device would enhance the accessibility of the SWC to a larger group of eligible users.Implications for rehabilitationManual user-operated standing wheelchair design using a six-bar mechanismSpring balancing used to reduce user effort to self-lift to the standing positionKinematic analysis used to determine convenient handle location for user easeCustomisability for wide range of users to ensure correct posture, optimal effortDesign refined through multiple iterations using inputs from users and cliniciansDesign commercialised at an affordable cost, making it accessible to a larger population.

Economic evaluation of wheelchairs interventions: a systematic review.

OBJECTIVE: The overall aim of this systematic review was to identify and synthesise the best available evidence on effectiveness, resource use and costs involved in wheelchair interventions of adults with mobility limitations. METHODOLOGY: This systematic review was undertaken in accordance with the Centre for Reviews and Dissemination Guidelines. The protocol for this systematic review was registered with PROSPERO International Prospective Register of Systematic reviews. The following PICOS eligibility criteria were considered: (P) Population was individuals with mobility limitations that live in their community (e.g., non-institutionalized), with aged 18 or older; (I) Intervention was mobility assistive technologies (MAT), such as manual and powered wheelchairs; (C) Comparators (Not Applied); (O) Outcome, the primary outcome of interest, was established as the cost-effectiveness of wheelchair interventions. Direct and indirect costs per unit of effect were expressed in terms of clinical outcome units, quality-adjusted life years gained, utility scores, quality of life measures and incremental cost-effectiveness ratios to inform the economic outcomes. (S) Study design was considered as a health economic evaluation (i.e., including cost-effectiveness analysis, cost-utility analysis and cost benefit analysis as well as partial economic evaluations). The Consolidated Health Economic Evaluation Reporting Standards - CHEERS, checklist was used for summarising and interpreting the results of economic evaluations. RESULTS: Sixteen studies were included, two were identified as full health economic evaluations and 14 were considered partial health economic evaluations. CONCLUSION: Only two full health economic analyses of wheelchair interventions have been conducted and both focussed on powered wheelchair provision. There are important gaps in current knowledge regarding wheelchair health economic methods and available outcome measures, which there is a great need for further research.Implication for RehabilitationSystematic reviews of health economic evaluation studies are useful for synthesising economic evidence about health interventions and provide insight in new research development.Organisations involved in the provision of wheelchairs should apply cost-effectiveness outcome measures to help raise the standard of provision, to support evidence-based practice, and to improve resource utilisation.

Preliminary evaluation of an automated robotic transfer assist device in the home setting.

PURPOSE: The purpose of this study was to examine the effects of six weeks of routine use of a novel robotic transfer device, the AgileLife Patient Transfer System, on mobility-related health outcomes, task demand, and satisfaction relative to previous transfer methods. MATERIALS AND METHODS: Six end users and five caregivers used the system in their homes for six weeks. Participants completed several surveys examining perceived demands related to preparing and performing a transfer and mobility-related health outcomes pre and post intervention. Participants were also asked about their satisfaction with using the technology compared to previous transfer methods. RESULTS: Both end users and caregivers reported reduction in perceived physical demand (p = 0.007) and work (p ≤ 0.038) when preparing for and performing a transfer. End users indicated that the device intervention had a positive impact, indicating some improvements to health-related quality of life as well as improved competence, adaptability, and self-esteem post-intervention. All participants were highly likely to recommend the technology to others. CONCLUSION: The AgileLife Patient Transfer System is a promising new form of transfer technology that may improve the mobility and mobility-related health of individuals with disabilities and their caregivers in home settings.Implications for rehabilitationRobotic transfer assistance reduced physical demand and work among end users and caregivers.The robotic device had a positive impact on some quality of life outcomes after 6 weeks of use.Users were highly likely to recommend the robotic transfer device to others.

Effects of wheels and tires on high-strength lightweight wheelchair propulsion cost using a robotic wheelchair tester.

PURPOSE: This study was designed to investigate the effect of wheel and tire selections on the propulsion characteristics of a high-strength lightweight manual wheelchair using robotic wheelchair propulsion. MATERIALS AND METHODS: Four configurations were compared with differing combinations of drive wheel tires and casters, with the baseline reflecting the manufacturer configuration of a solid mag drive wheel and 8"×1" caster. The robotic wheelchair tester propelled the chair using pre-generated straight and curvilinear manoeuvres using repeatable and reliable cyclic torque profiles. Additionally, energy loss of the components was measured using coast-down deceleration tests to approximate the system-level rolling resistance of each configuration. RESULTS: Results indicate a significant decrease in propulsion cost, increased distance travelled and increased manoeuvrability across all configurations, with upgraded casters and tires. CONCLUSIONS: These results indicated that with better casters and drive wheel tires, the performance of high strength lightweight wheelchairs can be improved and better meet the mobility needs of users.Implications for rehabilitationWheel and tire selection can have a demonstrable impact on the propulsion efficiency of manual wheelchairsCoast-down test protocols can be used as a simple and cost-effective means of assessing representative energy losses across various surfacesWheelchair configurations can be optimized with proper knowledge of the main energetic loss contributions and the environments and contexts of use.

Family challenges in personal transportation of children with medical complexity.

PURPOSE: This study aimed to explore the family experience and associated challenges of transporting children with medical complexity (CMC) in personal vehicles. METHODS: Parents/guardians of CMC in Maryland were recruited to participate in an audiotaped, semi-structured interview. Conventional content analysis was applied to transcripts. RESULTS: Data from 29 participants who indicated use of personal vehicles to transport their CMC were included in the analysis. Transportation challenges were common, and analysis revealed the following themes: 1) challenges transitioning in/out of the vehicle: excess planning time, child factors (e.g., weight), equipment factors (e.g., wheelchair), physical and environmental factors, 2) safety and comfort: CMC positioning/restraints, driver distraction, 3) financial challenges: travel costs related to medical care, accessible modification costs, transportation equipment costs, insurance delays in equipment coverage, 4) adverse family repercussions: parental physical health, isolation, and 5) evolving and unpredictable transportation needs. CONCLUSION: Families with CMC experience multifactorial challenges that impact all phases of travel in personal vehicles and negatively impact child and family safety, access to community and medical care, family finances, and overall well-being. Health care providers can support families by identifying transportation challenges that contribute to health inequities, tailoring solutions to the family's unique needs, and advocating at a policy level to promote change.

Metabolic Cost and Mechanical Efficiency of a Novel Handle-Based Device for Wheelchair Propulsion.

OBJECTIVE: To investigate differences in metabolic cost and gross mechanical efficiency of a novel handlebased wheelchair propulsion device and to compare its performance with conventional push-rim propulsion. DESIGN: Double-group comparative study between 2 different propulsion methods. PARTICIPANTS: Eight paraplegic individuals and 10 non-disabled persons. METHODS: Participants performed the same exercise using a push-rim device and the novel handle-based device on a wheelchair- based test rig. The exercise consisted of a combined submaximal and maximal test. Power output, oxygen uptake, ventilation, respiratory exchange ratio and heart rate were recorded continuously during the tests. Analysis of variance was performed to determine the effects of group, mode and on power output. RESULTS: Submaximal exercise resulted in a higher efficiency for the novel device and significant main effects of propulsion mode on all investigated parameters, except heart rate. On the respiratory exchange ratio, a significant interaction effect was found for both mode and group. The maximal exercise resulted in a higher peak power output and lower peak heart rate during propulsion using the handle-based device. A significant main effect on mode for mean peak power output, ventilation and heart rate was also observed. CONCLUSION: Wheelchair propulsion using the handle-based device resulted in lower physical responses and higher mechanical efficiency, suggesting that this novel design may be well suited for indoor use, thereby offering an attractive alternative to pushrim wheelchairs.

Self-Assessment of Physical Fitness and Health versus Motivational Value of Physical Activity Goals in People Practicing Fitness, Football, Martial Arts and Wheelchair Rugby.

The aim of the study was to determine the relationship between self-assessment of physical fitness and health, and the motivational role of physical activity goals in people, depending on their sports discipline. The study included 470 men and 218 women, aged 18-45, from western and southern Poland. The respondents practiced sports recreationally (fitness-F), competitively (football-FB, martial arts-MA), and for rehabilitation and sports purposes (wheelchair rugby-R). The standardized questionnaire for the motivational role of physical activity goals (Inventory of Physical Activity Objectives, IPAO) by Lipowski and Zaleski and the authors' questionnaire on lifestyle were used. In the statistical analyses, non-parametric statistics were used. Individuals with very high and high self-assessment of their physical fitness and very good self-assessment of health achieved higher scores on the motivational value scale, time management, motivational conflict and multidimensionality of physical activity goals (p < 0.05). Respondents who assessed their health as very good achieved lower results on the perseverance scale, compared to those who assessed their health as good or poor. Self-assessment of physical fitness had a positive, high and moderate correlation with the self-assessment of health in people practicing wheelchair rugby, fitness, football and martial arts (r = 0.61; r = 0.52; r = 0.41; r = 0.40, respectively). Correlations were found between the motivational role and time management in people practicing fitness (r = 0.81), football (r = 0.66) and martial arts (r = 0.45), and multidimensionality of goals in those practicing fitness (r = 0.65) and martial arts (r = 0.42) Wheelchair rugby players scored the highest on all KCAF scales (except for motivational conflict). Self-assessment of physical fitness of wheelchair rugby players and fitness practitioners was negatively correlated with time management (r = -0.68; r = -0.49), multidimensionality of goals (r = -0.51; r = -0.49) and motivational values (r = -0.43; r = -0.43). The demonstrated relationships indicated that there was a need to strengthen the self-esteem and motivation for physical activity, promoting perseverance, the ability to focus on the implementation of one's goals and prioritizing the goals among people practicing various sports disciplines.

Effect of Wheels, Casters and Forks on Vibration Attenuation and Propulsion Cost of Manual Wheelchairs.

Manual wheelchair users are exposed to whole-body vibrations as a direct result of using their wheelchair. Wheels, tires, and caster forks have been developed to reduce or attenuate the vibration that transmits through the frame and reaches the user. Five of these components with energy-absorbing characteristics were compared to standard pneumatic drive wheels and casters. This study used a robotic wheelchair propulsion system to repeatedly drive an ultra-lightweight wheelchair over four common indoor and outdoor surfaces: linoleum tile, decorative brick, poured concrete sidewalk, and expanded aluminum grates. Data from the propulsion system and a seat-mounted accelerometer were used to evaluate the energetic efficiency and vibration exposure of each configuration. Equivalence test results identified meaningful differences in both propulsion cost and seat vibration. LoopWheels and SoftWheels both increased propulsion costs by 12-16% over the default configuration without reducing vibration at the seat. Frog Legs suspension caster forks increased vibration exposure by 16-97% across all four surfaces. Softroll casters reduced vibration by 11% over metal grates. Wide pneumatic 'mountain' tires showed no difference from the default configuration. All vibration measurements were within acceptable ranges compared to health guidance standards. Out of the component options, softroll casters show the most promising results for ease of efficiency and effectiveness at reducing vibrations through the wheelchair frame and seat cushion. These results suggest some components with built-in suspension systems are ineffective at reducing vibration exposure beyond standard components, and often introduce mechanical inefficiencies that the user would have to overcome with every propulsion stroke.

Applying Machine Learning for Intelligent Assessment of Wheelchair Cushions from Pressure Mapping Images.

Pressure ulcers are skin and underlying tissue injuries caused by the cells' lack of oxygen and nutrition due to blood flow obstruction from constant pressure on the skin. It is prevalent in people with motion disabilities, such as wheelchair users. For both prevention and healing, wheelchair users should occasionally change their sitting posture, use cushions that evenly distribute the pressure, or relieve pressure from the sensitive areas. Occupational therapists (OTs) often use pressure mapping systems (PMS) to assess their clients and recommend them a cushion. A cushion with more uniform pressure distribution and fewer pressure concentration points is ranked the highest. This paper offers a novel approach to enhance the objectivity of PMS readings and rankings for OTs. Our method relies on image segmentation techniques to generate quantifiable measures for cushions assessment. We implemented a sequential process to generate a score representing a cushion's suitability for an individual, which begins with PMS image segmentation using machine learning, followed by a deep learning algorithm for identifying high-risk pressure points. We introduced a Cushion Index for quantifying and ranking the cushions. Clinical Relevance- By selecting proper cushions for wheelchair users, the risk of developing PUs is reduced.

Policy Analysis on Power Seat Elevation Systems.

In the early 2000s the Centers for Medicare and Medicaid Services determined that power seat elevation systems did not meet the definition of durable medical equipment, and therefore are non-covered items. Yet, power seat elevation systems are covered by other funding sources, and many power wheelchair users utilize these systems regularly when performing tasks such as transferring, reaching, and looking at objects in environments designed for ambulatory people. Adjusting for height when performing these tasks may reduce the onset of pain and comorbidities. To improve access to power seat elevation systems, a clinical team of 4 Clinician Task Force members investigated applicable literature, compiled evidence, and evaluated existing policies to explain the medical nature of power seat elevation systems as a part of a greater interprofessional effort. This manuscript aims to analyze Medicare's policy decision that power seat elevation systems are not primarily medical in nature using Bardach's 8-step framework. As a special communication, this will inform health care professionals of the medical nature of power seat elevation systems and the evidence-based conditions under which power wheelchair users may need power seat elevation systems, as well as empower clinicians to engage in policy directives to affect greater change.

A novel push-pull central-lever mechanism reduces peak forces and energy-cost compared to hand-rim wheelchair propulsion during a controlled lab-based experiment.

BACKGROUND: Hand-rim wheelchair propulsion is straining and mechanically inefficient, often leading to upper limb complaints. Previous push-pull lever propulsion mechanisms have shown to perform better or equal in efficiency and physiological strain. Propulsion biomechanics have not been evaluated thus far. A novel push-pull central-lever propulsion mechanism is compared to conventional hand-rim wheelchair propulsion, using both physiological and biomechanical outcomes under low-intensity steady-state conditions on a motor driven treadmill. METHODS: In this 5 day (distributed over a maximum of 21 days) between-group experiment, 30 able-bodied novices performed 60 min (5 × 3 × 4 min) of practice in either the push-pull central lever wheelchair (n = 15) or the hand-rim wheelchair (n = 15). At the first and final sessions cardiopulmonary strain, propulsion kinematics and force production were determined in both instrumented propulsion mechanisms. Repeated measures ANOVA evaluated between (propulsion mechanism type), within (over practice) and interaction effects. RESULTS: Over practice, both groups significantly improved on all outcome measures. After practice the peak forces during the push and pull phase of lever propulsion were considerably lower compared to those in the handrim push phase (42 ± 10 & 46 ± 10 vs 63 ± 21N). Concomitantly, energy expenditure was found to be lower as well (263 ± 45 vs 298 ± 59W), on the other hand gross mechanical efficiency (6.4 ± 1.5 vs 5.9 ± 1.3%), heart-rate (97 ± 10 vs 98 ± 10 bpm) and perceived exertion (9 ± 2 vs 10 ± 1) were not significantly different between modes. CONCLUSION: The current study shows the potential benefits of the newly designed push-pull central-lever propulsion mechanism over regular hand rim wheelchair propulsion. The much lower forces and energy expenditure might help to reduce the strain on the upper extremities and thus prevent the development of overuse injury. This proof of concept in a controlled laboratory experiment warrants continued experimental research in wheelchair-users during daily life.