Smart seat cushion feasibility pilot study: automated interface pressure modulation of individuals with spinal cord Injury

This study investigates the functionality and feasibility of a novel smart seat cushion system designed for wheelchair users with spinal cord injuries. The cushion, equipped with air cells that serve as both sensors and actuators, was tested on 24 participants for its real-time pressure mapping, automated pressure redistribution, and pressure offloading functions. A commercial pressure mat was concurrently used to validate the cushion's pressure modulation functions. Additionally, the perceived comfort of the cushion was evaluated using General Discomfort Assessment (GDA) and Discomfort Intensity (DIS) scores, which provided insights into participants' overall comfort and discomfort levels. Real-time pressure profiles generated by the cushion resembled commercial pressure mat readings. During tests with individuals with spinal cord injury, the cushion was able to dynamically generate and display the real-time pressure profile of a seated individual with strong precision (correlation to commercial pressure mat: r ranging from 0.76 to 0.88), providing effective input into pressure modulation functions. Pressure redistribution algorithms eliminated peak pressure and reduced the overall pressure at the interface. Pressure offloading algorithms automatically identified the regions with the highest interface pressure and subsequently relieved the pressure from those areas. User feedback showed that the cushion was comfortable after redistribution and offloading. This work demonstrated the feasibility of an advanced smart seat cushion system for wheelchair users with spinal cord injuries. The cushion was capable of redistributing pressure evenly across the seating surface, ensuring user's comfort. Additionally, it identifies and eliminates high-pressure points, further improving comfort and reducing the risk of pressure injuries.

Evaluating bottoming-out of bariatric sized wheelchair cushions

In the United States, wheelchair cushions are classified using HCPCS codes. Cushions classified as Skin Protection cushions are provided for wheelchair users who are at risk of tissue damage. Cushions designed for bariatric users fall into a category of cushions with width of 22 inches or greater. Current coding procedures require tests that are designed for 41-43-cm-wide cushion so cannot evaluate wider cushions. The objective of this study was to evaluate the performance of heavy-duty or bariatric wheelchair cushions using an anthropometrically appropriate buttock model and loading profile. A rigid buttock model, designed to reflect the anthropometry of persons using cushions over 55 cm in width was loaded onto six bariatric-sized wheelchair cushions. Two applied loads, 75 and 88 kg, represented the 50th and 80th percentile of persons who would be expected to use a 55-cm-wide cushion. None of the cushions indicated a bottomed-out state at the 88 kg load, suggesting that they could adequately support users weighing 135 kg. However, when evaluating cushions at their maximum rated loads, two of the six cushions were approaching or had bottomed-out. This study indicates that a more valid approach to classify Skin Protection bariatric cushions is needed.

OFF-LOADING PRESSURE RELIEF WITH FOAM CUT OUT CUSHIONS: EXPERIENCES FROM RANCHO LOS AMIGOS NATIONAL REHABILITATION CENTER

This paper explores the efficacy of the cushion fitting technique using foam cut out cushions for off-loading bony prominences in the sitting position, with a particular focus on reducing the high risk of developing pressure injuries among aging wheelchair users. This technique, historically employed at Rancho Los Amigos National Rehabilitation Center, has shown promising results in reducing pressure injuries for patients with spinal cord injuries. However, its widespread adoption remains limited. This manuscript aims to raise awareness about foam cut out cushions, its historical context, and its contemporary relevance by presenting customized solutions for individual patients with specific deformities. Key clinical points are highlighted, emphasizing the importance of skilled clinicians in the fitting process and the need to consider foam cut out cushions alongside other preventive measures. Case examples illustrate successful outcomes, demonstrating improved pelvic stability, posture, and off-loading of bony prominences. By promoting foam cut out cushions as a valuable cushioning option, this manuscript equips clinicians with knowledge to utilize this technique effectively.

The design of a family of parametric anatomically-based compliant buttock models to evaluate wheelchair cushion performance

The evaluation of wheelchair cushion performance is of interest to a variety of stakeholders, including standards organizations, cushion manufacturers, clinicians, users and payers. The objective of this project was to develop a family of compliant buttock models that are based upon the anatomical parameters of persons with varying body sizes. The models are parametrically designed so can be scaled to evaluate different sized cushions. This paper will detail the designs, describe the anatomical basis for the design and provide the rationale for the design decisions. The manuscript also serves a secondary purpose to illustrate how anthropometric data can be applied to the design of anatomical phantoms that reflect both soft tissue and skeletal anthropometry. Supplemental material includes greater detail and the full CAD files and model fabrication instructions are available in an open access repository for persons who wish to fabricate the models.

Decisions and Dilemmas in Everyday Life: Daily Use of Wheelchairs by Individuals with Spinal Cord Injury and the Impact on Pressure Ulcer Risk

Individuals with spinal cord injury (SCI) use wheelchairs for mobility and for full participation in their daily activities. The use of wheelchairs, however, can increase the risk of pressure ulcers. This study focused on wheelchair users' perceptions of the interplay between their wheeled mobility and the development of pressure ulcers by performing a secondary analysis of data gathered during a 2-year ethnographic study of 20 community-dwelling adults with SCI. Data from a subset of these individuals are described; each of these stories contains a pressure ulcer risk episode related to wheeled mobility or cushion use. Identified risk episodes were associated with wheelchair selection, wheelchair adjustment, habituation to new equipment, lifestyle choices, and challenging life contexts. Examples highlighted the crucial relationship between individuals' minute-to-minute decision-making and pressure ulcer risk.