Wheelchair Design Research Articles

A novel ergonomic wheelchair reduces bacterial hand contamination

Objective To determine whether bacterial contamination of rider’s hands is less with a novel ergonomic wheelchair (EW) than a standard wheelchair (SW). Experimental design After wheelchair hand rims were disinfected, volunteers wearing nitrile gloves propelled each wheelchair through a standardised “run” in hospital. Post-run cultures were obtained from riders' gloved hands. Bacterial hand counts were compared between runs matched by rider (same rider, different chairs) or time (different riders in each chair, running concurrently), and overall. Setting Minneapolis Veterans Affairs Health Care System (MVAHCS), a large tertiary care facility. Participants Eleven employee volunteers. Intervention EW, as compared with SW. With SW, co-location of hand rims and tyres potentially exposes the user’s hands to tyres, which risks contaminating the user’s hands with ground-source bacteria. Our novel ergonomic wheelchair (EW) separates drive wheel and hand rims, potentially reducing hand contamination. Main outcome measure Bacterial hand counts. Results Post-run bacterial hand counts were over 10-fold lower with the EW than the SW. This was true (i) when the same rider tested both chairs sequentially (n = 8 pairs) (median counts, 40 vs. 1030; p = 0.008), (ii) when different riders tested the two chairs concurrently (n = 9 pairs) (median counts, 40 vs. 660; p = 0.004), and (iii) overall (median counts, 40 [n = 9 runs] vs. 550 [n = 10 runs]; p < 0.001). Conclusion Separation of wheelchair hand rims from tyres significantly reduces bacterial hand contamination. Reduced hand contamination could decrease bacterial infections and dissemination of resistant bacteria, warranting further study. Implications for rehabilitation The novel design of the ergonomic wheelchair, removing the push rim from proximity to the wheelchair tyre, keeps the hands of wheelchair users cleaner. The re-design of the standard manual wheelchair was implemented initially to improve shoulder ergonomics during manual wheelchair propulsion and has the added benefit of reduction in the transfer of bacteria from floors to hands for manual wheelchair users. Since the ergonomic wheelchair has the potential to decrease rates of bacterial infection in manual wheelchair users, further testing is warranted.

Psychological Test System and Signal Processing Algorithm for Intelligent Wheelchair

Intelligent wheelchair based on BCI is a hot spot in recent research, and brain activity is actually a reflection of psychological activity. Completing the design of psychological test system is the key to BCI. ERP reflects the psychological activity of the brain, is a psychological test good tools such as cognitive neuroscience research. And there is psychological test system is mostly based on the traditional theory of external behavior inference, unable to objectively evaluate people’s psychological activity. In the study of psychological tests and event related potential theory, the article improved FastICA algorithm, and applied to feature extraction of ERP. Eventually set up a complete set of psychological test system. Experiments show that the system can effectively detect the ERP feature extraction, and faster, better than other conventional psychological test system. So as to lay the foundation for the completion of the design of Intelligent wheelchair.

A Novel Approach to Wheelchair Design and Operation Using Multi-Function Controller

An electric multi-function controlled wheelchair is designed and fully tested. This wheelchair is controlled by several physiological variables namely; voice, head movement, finger bending, breathing pressure and Electrooculography (EOG). The patient has the choice to use any of these variables to control the wheelchair. The voice command is recorded by a voice recognition module with its microphone, whereas, the head and finger motion operate through the gyro accelerometer and flex sensors. A pressure sensor is used to determine the force of breathing and EOG signals are used to control the wheelchair movement. All of the inputs are processed using a microcontroller. Testing of the wheel chair using the mentioned variables is carried out successfully with accuracy between 88 to 96% for various control modules and safety consideration as a primary goal.

Modeling manual wheelchair propulsion cost during straight and curvilinear trajectories.

Minimizing the effort to propel a manual wheelchair is important to all users in order to optimize the efficiency of maneuvering throughout the day. Assessing the propulsion cost of wheelchairs as a mechanical system is a key aspect of understanding the influences of wheelchair design and configuration. The objective of this study was to model the relationships between inertial and energy-loss parameters to the mechanical propulsion cost across different wheelchair configurations during straight and curvilinear trajectories. Inertial parameters of an occupied wheelchair and energy loss parameters of drive wheels and casters were entered into regression models representing three different maneuvers. A wheelchair-propelling robot was used to measure propulsion cost. General linear models showed strong relationships (R2 > 0.84) between the system-level costs of propulsion and the selected predictor variables representing sources of energy loss and inertial influences. System energy loss parameters were significant predictors in all three maneuvers. Yaw inertia was also a significant predictor during zero-radius turns. The results indicate that simple energy loss measurements can predict system-level performance, and inertial influences are mostly overshadowed by the increased resistive losses caused by added mass, though weight distribution can mitigate some of this added cost.

Design and Implementation of Sign Language Interpretation System and Wireless Enabled Wheel Chair

Design and Implementation of Sign Language Interpretation System and Wireless Enabled Wheel Chair

Automatic Controlled Wheel Chair Using Multi-Intelligence Technique

Tremendous magnification in medical technology is incrementing day by day with excellent remedying methodologies and making persons to be salubrious, but paralysis disease is unable to remedy perpetually whereas partial remedying is possible. Peoples are affected with plenarily and/or quarterly paralyzed persons were unable to survive themselves, even though with felicitous medication is available. Paralyzed persons need an opportune conveyance to move themselves independently for their personal needs. Now a day’s advancement of automation in electric conveyance designs is predicated on the desideratum of application. In this paper, a new wheelchair design methodology was presented with multi controlled schemes for the fully or partially paralyzed persons to move independently without help of any caretaker. Three controlling schemes were developed and integrated to make the robust of the wheelchair design. A prototype model is developed and presents in the paper, it was tested rigorously to analyze the performance of the proposed methodology. Results show the efficacy of the method.

Wheelchair Mobility-Related Injuries Due to Inadvertent Lower Extremity Displacement on Footplates: Analysis of the FDA MAUDE Database From 2014 to 2018.

The aims of the study were to assess reports of wheelchair mobility-related injuries from inadvertent lower extremity displacement (ILED) on footplates, which were submitted to the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database during 2014-2018, characterize injury types, and evaluate MAUDE data quality. A systematic MAUDE database review was performed. Annual reports were searched using keywords: (a) "power wheelchair" and "injury" and (b) "mechanical (also known as manual) wheelchair" and "injury." Reports related to injuries from ILED on the footplate were reviewed. Reports of 1075 wheelchair injuries were found across the review period. Twenty nine (3%) met our inclusion criteria. The most common source of reports was "manufacturer." The wheelchair was unavailable for evaluation in 55.17% of reports. Manufacturers' submission dates (number of days that passed after they were notified) ranged from 3 to 159. Reported injuries decreased by 60% from 2014 to 2018. The end user used a power wheelchair for all but one report. The most common injuries were single fractures, multiple fractures, wounds/cuts/infections, and amputations (in order of incidence). The most common mechanism was the foot slipping off the footplate during wheelchair mobility. We observed inherent weaknesses in the MAUDE database reporting process and a concerning level of reporting bias. Although there were limited reports of injuries related to ILED on the footplate during wheelchair mobility, the injuries reported were significant. More standardized reporting of the mechanism and impact of these injuries is needed to better inform wheelchair design, prescription, and patient/family education.

An integration of a QFD model with Fuzzy-ANP approach for determining the importance weights for engineering characteristics of the proposed wheelchair design

A wheelchair design with a nested seat back and hand-rest was proposed and ergonomically analyzed, with the objective of decreasing the likelihood of poor and awkward body postures for both the disabled user and his/her companion. The proposed design was validated by integrating a Quality Function Deployment (QFD) framework with a Fuzzy Analytic Network Process (FANP) to determine the degree of importance of the engineering characteristics. In this study, the influence of this integration on determining weights that prioritize engineering characteristics (ECs) was highlighted by taking into consideration the mutual dependence between customer needs (CNs) and ECs and the inner dependence amongst them. This study focused on utilizing FANP methodology, in which triangular fuzzy numbers (TFNs) were used to represent the degree of importance of CNs and ECs, since human judgments of the intensity of preference for these attributes are subjective, vague, and uncertain. Regarding the importance weights for engineering characteristics of the proposed wheelchair design, it has been found that the quality of material scores the highest weight compared to other ECs, with an overall importance weight of 0.43. This result differed from that one obtained using the QFD model without integration, in which the method of design came in first position. The integrated approach proved to be a promising tool in solving fuzzy decision-making problems in different fields and in several applications such as product development and design for ergonomics. As the FANP approach is not popular in the product development/selection field, this study will expand its employment by decision makers in facilitating the evaluation process where there are interrelated factors under an uncertain environment.

TRIZ and AHP in Early Design Stage of a Novel Reconfigurable Wheelchair

The Reconfigurable wheelchair incorporated with sit-to-stand and sit-to-sleep capabilities is the technological solution for extensive wheelchair users to promote their quality of life (QoL), safety and comfort. This paper presents the conceptual design of a reconfigurable wheelchair using the TRIZ and AHP integrated approach. The objective of this study was to develop optimal conceptual designs of a reconfigurable wheelchair by overcoming identified design conflicts. The TRIZ contradiction toolkit was employed in the early conceptual design phase. Based on the TRIZ inventive principles and developed design strategy, new reconfigurable wheelchair mechanism was modelled in SolidWorks environment, using a top-down modelling approach. Dimensions of a wheelchair were kept within the dimensions of a standard wheelchair. The newly modelled mechanism was refined using motion simulation capabilities of the SolidWorks software. The new mechanism was further integrated with different wheelchair design features by means of the morphological chart in order to get innovative conceptual designs. Further, Analytical Hierarchy Process (AHP) was utilized as a multi-criteria decision making technique for optimal conceptual design selection. Conceptual design-I (joystick controller with electric drive) received highest weight among all conceptual designs, hence selected as the optimal conceptual design. Consistency ratio (CR) for the pair-wise comparisons made throughout the AHP method was found less than 0.10. All AHP calculations were supported by Microsoft Excel Add-in for multi-criteria decision problems. For the purpose of functionality testing of newly modelled wheelchair, 3D printed wheelchair parts have been fabricated (using ABS material) and tested for desired mechanical movements. The methodology implemented in the present work can be utilized for upcoming applications in design of new assistive devices.

A Sociotechnical History of the Ultralightweight Wheelchair: A Vehicle of Social Change

The emergence of the ultralightweight wheelchair has transformed the lives of millions of disabled people. It has radically changed the principles and practices of wheelchair design, manufacture, and prescription and redefined wheelchair users and wheelchair use. Designed and built largely by wheelchair users themselves, it was driven initially by a desire to improve sport performance and later by a wish for improved access to the community and built environment. In this paper, we draw on oral histories and documentary sources to reconstruct its sociotechnical history. We employ the analytical concept of “boundary object” to illuminate how the wheelchair as a technological artifact is implicated in relations of social change and show the role of wheelchair users in the development and emergence of the ultralightweight wheelchair. We highlight the tensions and negotiations within this history and the push and pull between different social groups. The emergence of the ultralightweight wheelchair helped to reconfigure ideas about wheelchairs and their users and allowed wheelchairs to gain a foothold within broader social and technological infrastructures. What makes this account powerful is that this is a success story for a group who have historically been excluded from design processes.

Optimal parameters and tolerances in concurrent product and process design using simulation and fuzzy goal programming

PurposeThe purpose of this paper is to propose an approach to determine the optimal parameters and tolerances in concurrent product and process design in the early design stages utilizing fuzzy goal programming. A wheelchair design is provided for illustration.Design/methodology/approachThe product design is developed on the basis of both customer and functionality requirements. The critical product components are then determined. The design and analysis of experiments are performed by using simulation, and then the probability distributions are adopted to determine the values of desired responses under each combination of critical product parameters and tolerances. Regression nonlinear models are then developed and inserted as constraints in the complete optimization model. Preferences on product specifications and process settings, as well as process capability index ranges, are also set as model constraints. The combined objective functions are finally formulated to minimize the sum of positive and negative deviations from desired targets and maximize process capability. The optimization model is applied to determine the optimal wheelchair design.FindingsThe results showed that the proposed approach is effective in determining the optimal values of the design parameters and tolerances of the critical components of the wheelchair with their related process means and standard deviations that enhance desired multiple quality responses under uncertainty.Practical implicationsThis work provides a general methodology that can be applied for concurrent optimization of product design and process design in a wide range of business applications. Moreover, the methodology is beneficial when uncertainty exists in quality responses and the parameters and tolerances of product design and its critical processes.Originality/valueThe fuzziness is rarely considered in research and development stage. This research considers membership functions for parameters and tolerances of a product and its related processes rather than crisp values. Moreover, presented optimization model considers multiple objective functions, sum of deviations and process capability. Finally, the indirect quality responses are calculated from the best-fit probability distributions rather than assuming a normal distribution.

Face and content validity for the Wheelchair Satisfaction Questionnaire

Purpose Because outcomes studies are known to facilitate effective use of funds, economic realities in lower-resource countries increase the need for outcome measures for wheelchair effectiveness in these areas. Effective use of funds based on evidence is especially needed since the level of wheelchair provision is low, and many wheelchairs are inappropriate for their intended users. There are very few existing wheelchair specific assistive technology outcome measures. The Wheelchair Satisfaction Questionnaire (WSQ) was designed to be a snapshot of a wheelchair user’s level of satisfaction with their wheelchair. The current studies examined the development of the WSQ and its initial face and content validity. Materials and Methods The WSQ is comprised of 16 visual analogue scale questions; each question includes a qualitative explanatory comment. In study 1, 15 adult users of manual wheelchairs completed the WSQ and then the completed a follow-up questionnaire which collected feedback on each question. In study 2, 15 secondary school student users of manual wheelchairs in Kenya completed the same procedure used in study 1. Results High mean satisfaction scores on the follow-up questionnaire support face and content validity in both studies. Conclusion The WSQ has the potential to give wheelchair users a quantifiable voice on wheelchair function. Data obtained from the WSQ also has the potential to provide data from wheelchair users to wheelchair manufacturers and providers, leading to better design and provision. Implications for Rehabilitation Based upon the score of a specific item, manufacturers could improve design of wheelchairs for use in lower-and-middle-income countries, and providers could be better-informed as to models sent to specific environments. The WSQ could provide evidence-based information to support improved provision and design. The WSQ could be used in a clinical setting over time to identify the most common interface problems in that particular setting.

Innovative Design of Ergonomic Wheelchair For Disabled People

For disabled people, difficulties in daily activities still become a major problem, especially for those who do not have normal legs. This condition requires an appliance to ease them in moving that is wheelchair. However, the use of the existing wheelchair still gives problems such as pain in buttock (90%), waist (93%), hands (86%), thigh (90%), and back (93%). Furthermore, the chair is easily damaged (83%), difficult to manoeuvre and move (83%), as well as expensive (67%). Thus, it is crucial to improve wheelchair. The objective of this study was to propose an ergonomic and innovative redesign of wheelchair in order to be able to satisfy users’ need. The QFD method was used to determine the design specification of the wheelchair. Survey was done to identify user requirements of the design. Statistical analysis was implemented to test hypothesis. The result of this study showed that the proposed design of the wheelchair is valid to satisfy user criteria at 5% significance level since it is more comfortable, stronger, affordable, easier to use, easier to repair and easier to move.

Prototyping of manual wheelchair with alternative propulsion system

Aim: This paper presents the study, design and prototyping of a manual wheelchair, named handwheelchair.q, with an innovative propulsion's system. The research is based on a novel system of propulsion that is more efficient and ergonomic than the hand rim one. The main goal of the designed prototype is to facilitate the mobility and to extend the reachable areas while reducing the required time.Methods: The propulsion is realised through a rowing-inspired gesture.Results: This gesture avoids the damages caused on shoulders by the compressive force of the hand rim and lever systems.Conclusion: The prototyping allowed the analysis of the project parameters and their influence on the kinematic characteristics of the prototype and the biomechanical characteristics of the gesture. The same propulsion's system can be adopted on wheelchairs devoted to sport activities, representing the starting point for a future prototype of racing wheelchairs. In this regard, the wheelchair's braking system has been redesigned in order to improve efficiency and safety.Implication for rehabilitationThe use of the Handwheelchair.q may have positive impacts in terms of the quality of life, in order to reduce the shoulder pain caused by the handrim and lever system.In addition, it can be a good tool for rehabilitation because the activity can be performed outdoor.

An exploration of the experiences of Brazilian hemiplegic manual wheelchair users

Purpose: The objective of this research was to explore the experiences of 11 hemiplegic users with their manual wheelchairs.Method: The phenomenological approach explored the subjective experiences of Brazilian hemiplegic manual wheelchair users in order to identify and describe the factors that affected their relationship with their wheelchair. Using in depth semistructured interviews. The data were analysed using thematic analysis. The health records from the physiotherapy service of the Health Department of Itajaí were reviewed to identify hemiplegic wheelchair users.Results: The results identified 4 key themes: heteronomy, inadequate/inappropriateness of wheelchair design, poor state of the pavements and roads prohibiting wheelchair use and lack of suitable wheelchair provision.Conclusion: The findings confirm that current manual wheelchair provision, both new and secondhand, for this group of users is inadequate and they highlighted the issues and problems arising from the current provision. A novel finding was the identification of heteronomy that resulted from the provision of unsuitable equipment.Implication for rehabilitationAdding into physiotherapy and occupational therapy education, the importance of matching technology to the user in their environment.The importance of involving the user in decisions made about wheelchair provision.Sharing findings with wheelchair manufacturers to improve manual wheelchair design for hemiplegic users.

Design of a modular wheelchair with posture transformation capabilities from sitting to standing

A significant part of world’s population is handicap, with majority suffering from lower body disabilities – the body waist down is paralysed or weak. In many of such cases, upper body of the affected person was found to be deemed fit and was able to perform all tasks, if feasible. Being able to transform posture from sitting to standing position independently, helps perform routine jobs with ease, increases employment prospects and improves blood circulation to name a few. Most of the existing wheelchair designs are expensive because of the electrical and electronics involved requiring added maintenance, or contain a variety of subsystems thus decreasing reliability. The objective is to further increase the posture transformation capabilities in terms of cost, user effort, maintenance and life. The modular wheelchair allows the user to use his/her own energy and bodyweight to shift from sitting to standing position and back, in single smooth movement with zero dependency on electrical/electronic parts. Detailed design of links, mechanisms and load calculations were performed as per standard requirements. Prototype of the proposed design was also made and successfully tested for all its design features and capabilities as per the design standards and conditions of physically challenged people.Implications for rehabilitationFive bar link mechanism helps to reduce manual effort.There is no dependency on auxiliary power source.It is a low cost rehabilitation solution with increased posture transformation capabilities.Increased body movements will help to increase self-confidence of disabled person.Easy sitting and standing capabilities will improve overall bodily functions and remove psychological barriers.

Design and Fabrication of Efficient Wheelchair

Design and Fabrication of Efficient Wheelchair

The Design of a New Manual Wheelchair for Sport

In this paper, an innovative system of propulsion inspired by a rowing gesture for manual wheelchairs is shown. The innovative system of propulsion, named Handwheelchair.q, can be applied to wheelchairs employed in everyday life and to sports wheelchairs for speed races, such as Handbike and Wheelchair racing. The general features of the innovative system of propulsion and the functional designs of the different solutions are described in detail. In addition, the design of the mechanism for the transmission of motion, employed in a second prototype, Handwheelchair.q02, is presented and analysed. Finally, the dynamic model of the Handwheelchair.q has been developed in order to obtain important results for the executive design of Handwheelchair.q.

Design and Analysis of A Multifunctional Wheelchair

Based on existing designs of multifunctional wheelchairs, a new wheelchair designed with body posture adjustment function is proposed to satisfy the needs of the elderly and the disabled. This paper shows the overall design of the wheelchair and the establishment of its 3D model at first; then, the kinematics analysis of the wheelchair’s backrest adjustment mechanism, and verifying the smoothness of its reclining process with establishing a virtual wheelchair prototype for motion simulation in ADAMS; finally, finite element analysis of key components of the wheelchair to make sure their requirements of structural strength.

Development of the Wheelchair Interface Questionnaire and initial face and content validity.

BackgroundBecause resources are limited in low- and middle-income countries (LMIC), the development of outcome measures is of interest. Wheelchair outcome measures are useful to support evidence-based practice in wheelchair provision.ObjectivesThe Wheelchair Interface Questionnaire (WIQ) is being developed to provide a professional perspective on the quality of the interface between a wheelchair and its user. This article discusses the development of the WIQ and its face and content validity.MethodDuring field studies in Kenya, we sought to include professional report data on the wheelchair–user interface that could be analysed to inform design changes. None of the existing measures was focused on the interface between users and their wheelchairs. The WIQ was developed to meet this need. To investigate face and content validity, 24 experienced wheelchair professionals participated in a study that included two rounds of an online survey and a focus group in Kenya.ResultsResponses were categorised by topic and the WIQ was modified following each iteration. Participants affirmed the usefulness of a brief professional report measure to provide a snapshot of the user–wheelchair interface. Participants emphasised the importance of brevity, wide applicability and provision of specific feedback for wheelchair modification or design changes. The focus group agreed that the final version provided useful data and was applicable to virtually all wheelchair users in LMIC.ConclusionThese preliminary studies indicate initial face and content validity of the WIQ as a method for providing a professional perspective on the interface between a user and his or her wheelchair.KeywordsOutcome measure; wheelchair assessment; user–wheelchair interface; wheelchair appropriateness; professional report.