Pressure injuries are a significant secondary complications for many individuals with reduced mobility, including elderly Veterans and those with spinal cord injury (SCI). Core assistive technology for persons with limited mobility includes a wheelchair seating system, comprising both a wheelchair and an effective pressure relief cushion. All wheelchair users are at some increased risk of pelvic region pressure injuries while sitting. Numerous studies have shown that although no one cushion can meet every user's needs, pressure relieving cushions are a critical component in all wheelchair seating systems to maximize function for individuals with mobility restrictions and decrease the risk of pressure injury development. An effective cushion prevents tissue breakdown, promotes postural stability and increases overall sitting tolerance. Preliminary work investigated a range of novel low-cost dynamically responsive materials developed for the non-medical market and which showed potential for use in seating design. A key aspect of the modular cushion's design is its ability to be fitted and customized for each user using a cushion fitting algorithm (CFA). The modular array thus optimizes pressure distribution over the cushion surface while the user is sitting. Using the CFA, each cushion can be personalized for the user to optimize interface pressure distribution and maintain seated tissue health. The current project will provide next-generation development and user evaluation of a low-cost advanced modular pressure relief cushion and fitting algorithm, building on the previous support from VA. The first generation modular cushion was designed for power wheelchair users, the second generation will be lower weight and also suitable for manual wheelchair users. Low cost compressible SquishINS inserts will be additively manufactured using commercially available silicon by modified desktop Makerbot Replicator printers (StrataSys, Brooklyn, NY). Pre-clinical benchmark evaluation will be carried out using ISO 16840-2 testing standards. Cost analysis will ensure that the next- generation modular cushion continues to apply value-driven principles. A clinical pilot study of 30 Veterans who are full-time wheelchair users will be carried out using a repeated measures clinical study design, with study participants as their own controls. `Pre-baseline' seated interface pressures will be assessed with study participants sitting on their own cushions and pelvic region skin checks carried out by the study Research Nurse. All participants will then receive customized modular cushions fit to the user using the CFA to create a personalized cushion insert layouts. Participants will be randomly assigned to Group A or Group B using a modified randomization scheme. Group A participants will first use a gel ball fitted cushion for 2 weeks during all daily living activities while seated in their wheelchair followed by use of a SquishINS fitted cushion for 2 weeks. Group B will first use the SquishINS fitted cushion then a gel ball fitted cushion. Seated interface pressure distribution will be obtained with the fitted cushion at the beginning and end of each test period. A dual temperature and humidity sensor placed in the cushion will enable continuous monitoring of microenvironmental status during use for download at the end of each test period. The study Research Nurse will also repeat the pelvic region skin check and participants will complete a questionnaire based on the QUEST 2.0 user satisfaction instrument. All responses will be documented as part of the QS/DC program. Our pre-clinical development and user evaluation will provide a strong foundation for translation of personalized low-cost high-performance modular cushions for effective seated pressure redistribution in wheelchair users.
Many elderly Veterans and those with spinal cord injury rely on a wheelchair seating system, made up of a wheelchair and an effective pressure relief cushion. Used together these provide mobility and sitting stability while decreasing skin breakdown risk and increasing overall sitting tolerance. This project will develop the next-generation low-cost high-performance customizable modular pressure relief cushion. 3D printing will be used to build cushions with SquishINS inserts that combine lightness and variable stiffness. 30 Veterans who are full-time wheelchair users will use personalized modular cushions for two weeks each. Personalized cushions will be created using a cushion fitting process we have already developed and tested. Microenvironmental conditions will be monitored during use. A cost analysis will ensure the customized modular cushion applies value-driven principles. User satisfaction will be measured along with the effects on daily function, skin status and seated tissue health.
