Common Wheelchair Research Articles

Wheelchair assistive system with EMG

In this technological development work, the design and construction of a device is presented which will operate a system of electric motors to support the movement of a wheelchair through the reading of signals by means of an electromyograph (EMG) in order to detect the effort made during displacement in a common wheelchair, the signal is conditioned in such a way that it detects only the effort made during this action, when closing the hand to hold the wheel and drive the rotation, without detecting movements such as simple muscle tension or normal arm movements. Considering that people with motor disabilities who use wheelchairs have to move for long distances and during the whole day, with this system the effort is reduced and it supports on paths with steep slopes when going up.

Classification of wheelchair pressure relief maneuvers using changes in center of pressure and weight on the seat

Background Pressure injuries from prolonged sitting are a significant problem for wheelchair users incurring high costs in healthcare expenditures and reducing quality-of-life. There is a need to improve pressure relief training and adherence in a variety of settings. Objective To identify effective common wheelchair pressure relief (PR) manoeuvres based on changes to users’ seated centre of pressure (CoP) and seated weight. Participants 20 individuals who use manual wheelchairs as their primary means of mobility Methods Participants performed 5 types of PR including seated push-ups, leftward, rightward, forward, and backward leans—while sitting in a wheelchair equipped with a custom instrumented seat pan support. Data were analysed using both clustering and decision tree approaches to identify types of PR. Results Both clustering and decision tree approaches were able to identify and classify PR though neither could accurately distinguish between forward and backward PR. Conclusion Changes in the centre of pressure and the total weight on the wheelchair’s seat can be used to automatically characterise type, amplitude and duration of pressure relief manoeuvres. Building such a classification and quality assessment scheme into an algorithm could enable a virtual coaching system to track users’ pressure relief behaviour and make suggestions to improve adherence with clinical recommendations. IMPLICATIONS FOR REHABILITATION Multiple bending beam load cells can be used to measure wheelchair users’ seated centre of pressure independent of type of cushion used. Both cluster analysis and decision tree algorithms can classify commonly practiced pressure reliefs by measuring changes to the centre of pressure and total weight on the wheelchair’s seat. The combination of force sensing for centre of pressure determination and either algorithm could serve as the basis for an application to coach wheelchair users to do effective pressure reliefs.

Mind Controlled Wheelchair

The paper deals with engineering an electric wheelchair from a common wheelchair and the development of a BCI system (Brain-Computer Interface) between the electric wheelchair and the human brain. The target populations for the mind controlled wheelchair are the patients who are paralyzed below the neck and are unable to use conventional wheelchair interfaces. A portable EEG headset, MCU and fi rmware signal processing together facilitate the movement of the wheelchair by processing the user’s brain activity and eye blinks’ frequency. This paper reports the creation of a cost effi cient solution, later intended to be distributed as an add-on conversion kit for a common manual wheelchair. A Neurosky Mind wave headset is used to pick up EEG signals from the brain. This is a commercialized version of the Open-EEG Project. The signal obtained from EEG sensor is processed by the ARM microcontroller FRDM KL-25Z, a Freescale board. The microcontroller takes decision for determining the direction of motion of wheelchair based on floor detection and obstacle avoidance sensors mounted on wheelchair’s footplate. The MCU shows real time information on a color LCD interfaced to it. Joystick control of the wheelchair is also provided as an additional interface option that can be chosen from the menu system of the project.

Measurement of rolling resistance and scrub torque of manual wheelchair drive wheels and casters

ABSTRACT The effort needed to maneuver a manual wheelchair is a function of the occupied wheelchair’s inertia and energy loss. The primary source of energy loss is due to the resistance of the drive wheels and casters on the ground. Specifically, manual wheelchairs have two major sources of frictional energy loss: rolling resistance and scrub torque. The objective of this study was to develop and validate component-level test methods to evaluate the energy loss properties of drive wheels and casters on different surfaces and with different applied loads. Rolling resistance is measured using a weighted coast-down cart and scrub torque is calculated by measuring the force required to rotate a plate that is loaded onto the tire’s surface. Each test method was iterated and then applied to a cohort of drive wheels and casters. Both test methods demonstrated acceptable repeatability and the ability to distinguish energy loss parameters between common wheelchair components. The results show that caster and drive wheel energy losses can vary significantly across surfaces and with increased load on the casters. However, the findings also illuminate complex relationships between rolling resistance and scrub torque performance that embody a tradeoff in performance as applied to mobility during everyday life.

The inter-rater reliability of the Wheelchair Interface Questionnaire

Purpose Wheelchair outcomes measures are useful to support evidence-based practice in wheelchair provision, especially in low- and middle-income countries (LMIC). The Wheelchair Interface Questionnaire (WIQ) was developed to provide a professional perspective on the quality of the interface between a wheelchair and its user. Studies conducted during the development of the WIQ indicated it has face validity and content validity. The objective of this field study was to conduct a subsequent investigation of the inter-rater reliability of the WIQ at a school for children with disabilities in Kenya. Materials and methods Eight practitioners with wheelchair experience from disparate cultural backgrounds participated in the study. They evaluated eight wheelchairs and the interface with their users. The interclass correlation coefficient (ICC) of the mean rating for the eight-item dataset was computed using SPSS. Results The ICC was found to be 0.911, indicating that the WIQ possesses inter-rater reliability. Common comment topics indicated that the qualitative data yielded by the WIQ is meaningful. Informal timing indicated that the WIQ is a brief measure. Conclusion The WIQ is a reliable tool that can meet the need for a professional assessment of the wheelchair-user interface. The reliability of this questionnaire is important because the tool can be used to evaluate the interface between a wheelchair user and their wheelchair, strengthening evidence-based practice in wheelchair provision. Implications for Rehabilitation Based on the score of a specific wheelchair interface, a rehabilitation professional could recommend more assessment, seating modification, or wheelchair replacement in order to maximize rehabilitation benefit for a client The WIQ could provide evidence-based information to support the need for wheelchair repair or replacement to funders. In large-scale studies involving many of the same wheelchair type in the same setting, the WIQ could be used to identify problems with the interface between that wheelchair type and its intended user population so that manufacturers can make responsive design changes. The WIQ could be used in a clinical setting over time to identify the most common wheelchair interface issues for that setting.

Compressive radial neuropathy induced by ‘hooking’ manoeuvre in a tetraplegic person

Case report. To describe a case of radial nerve compression neuropathy caused by a common wheelchair technique (hooking manoeuvre) used by a tetraplegic person to maintain truncal stability on a wheelchair. Department of Rehabilitation Medicine, University of Malaya Medical Centre, Kuala Lumpur, Malaysia. A 45-year-old man with American Spinal Injury Association Impairment Scale A C6 for the last 32 years developed progressive weakness of the right upper limb that was associated with pain in the shoulder and arm. Serial physical examinations demonstrated motor and sensory deterioration. Magnetic resonance imaging of the spinal cord showed no evidence of syringomyelia. Electrodiagnostic study showed motor and sensory neuropathy of the right radial nerve in the axillary region. The act of hooking the arm behind the wheelchair push handle causes trauma leading to radial nerve compression neuropathy. Because this technique is used frequently by wheelchair users, future studies should examine the prevalence of radial neuropathy in this population and develop alternative methods to maintain balance on the wheelchair.

WC19: A wheelchair transportation safety standard—Experience to date and future directions

ANSI/RESNA WC19 (i.e., WC19) is a voluntary standard that specifies design and performance requirements for wheelchairs that are suitable for use as seats in motor vehicles. The guiding principles for the standard originate from automotive crash-protection principles that are effective in reducing occupant injuries and fatalities. In addition to frontal-impact testing of wheelchairs, the standard includes tests for securement-point accessibility, tiedown-strap clear paths, lateral stability, and accommodation of vehicle-anchored belt restraints. Results from testing wheelchairs to WC19 reveal that the most common wheelchair problems include: a lack of structural integrity during frontal-impact loading; sharp rigid edges; and wheelchair structures that interfere with achieving proper positioning of vehicle-anchored belt restraints. Data from 8 years of experience with WC19 indicate where changes are needed to further improve transportation safety for wheelchair-seated travelers. These include expanding WC19 to include wheelchairs for smaller children who require a five-point harness restraint, and requiring wheelchairs to achieve a minimal rating for the ease of achieving proper positioning of vehicle-anchored belt restraints.

Wheelchair Tiedown and Occupant Restraint System Issues in the Real World and the Virtual World: Combining Qualitative and Quantitative Research Approaches

The Americans with Disabilities Act requires that transit providers accommodate passengers who use “common wheelchairs” when traveling in a motor vehicle. Wheelchair tiedown and occupant restraint systems are commonly used to secure wheelchairs and restrain occupants in fixed-route and demand route transit vehicles. Throughout the 17 years since the Americans with Disabilities Act has been in effect, transit providers have complained about the usability of wheelchair tiedown and occupant restraint systems, and improper securement has been linked to injuries among wheelchair users during “nonimpact incidents.” This research study explored the use of wheelchair tiedown and occupant restraint systems in actual practice and the potential risks of misuse to wheelchair-seated individuals. The qualitative research conducted in this study revealed that improper wheelchair securement (i.e. using less than four tiedown straps) can be fairly common practice in fixed-route transit. In addition, preliminary computer simulations show that improper wheelchair securement in emergency driving conditions may place wheelchair occupants at a greater risk of injury. It should be noted, however, that this is a pilot study and has its limitations. For example, qualitative data were gathered from one metropolitan area transit provider across a limited range of vehicle and wheelchair types. Additionally, the computer simulation model used in this study was originally validated for impact situations.