Preliminary development of an advanced modular pressure relief cushion: Testing and user evaluation.

STUDY AIM: Effective pressure relief cushions are identified as a core assistive technology need by the World Health Organization Global Cooperation on Assistive Technology. High quality affordable wheelchair cushions could provide effective pressure relief for many individuals with limited access to advanced assistive technology. MATERIALS: Value driven engineering (VdE) principles were employed to develop a prototype modular cushion. Low cost dynamically responsive gel balls were arranged in a close packed array and seated in bilayer foam for containment and support. Two modular cushions, one with high compliance balls and one with moderate compliance balls were compared with High Profile and Low Profile Roho® and Jay® Medical 2 cushions. METHODS: ISO 16480-2 biomechanical standardized tests were applied to assess cushion performance. A preliminary materials cost analysis was carried out. A prototype modular cushion was evaluated by 12 participants who reported satisfaction using a questionnaire based on the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) instrument. RESULTS: Overall the modular cushions performed better than, or on par with, the most widely prescribed commercially available cushions under ISO 16480-2 testing. Users rated the modular cushion highly for overall appearance, size and dimensions, comfort, safety, stability, ease of adjustment and general ease of use. Cost-analysis indicated that every modular cushion component a could be replaced several times and still maintain cost-efficacy over the complete cushion lifecycle. CONCLUSION: A VdE modular cushion has the potential provide effective pressure relief for many users at a low lifetime cost.

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Power Wheelchair Footplate Pressure and Positioning Sensor.

Power wheelchair users are at risk for severe injuries caused by foot mis-position on the footplate. This can lead to collisions or foot dragging which are severe or lifethreatening injuries for people with spinal cord injuries. The foot cannot be safely immobilized due to tilting pressure relief injuries, therefore, the foot can easily fall into a vulnerable position without the user realizing it. To reduce the likelihood of injury, we have developed a sensor for monitoring foot position in real time, as the wheelchair is driven. The sensor uses an array of force-sensing resistors and infrared distance sensors to detect the pressure and location of the foot within the immediate confines of the footplate. Sensor arrays with 23 force sensors and 14 infrared sensors per foot were fabricated on standard printed circuit boards and encapsulated in a durable thermoplastic urethane for environmental resistance. Fabricated sensors transmitted foot pressures and position data at 10 Hz using a Bluetooth Low Energy radio. An iOS app was developed to notify users of vulnerable foot position. Measured results confirmed the functionality of the system over typical foot pressures, and indicated that the device is ready for next-stage clinical trials with spinal cord injured power wheelchair users.

Interdisciplinary development of an ergonomic prone mobility cart.

Pressure ulcers remain a major source of morbidity and mortality in Veterans with neurologic impairment. Management of pressure ulcers typically involves pressure relief over skin regions containing wounds, but this can lead to loss of mobility and independence when the wounds are located in regions that receive pressure during sitting. An innovative, iterative design process was undertaken to improve prone cart design for persons with spinal cord injury and pressure ulceration. Further investigation of ways to improve prone carts is warranted to enhance the quality of life of persons with pressure ulcers.