Page 25 - Mobility Management, May 2017

aging: When outdoors, the cushion is exposed to more extremes of temperature, sunlight and humidity. Bowel and bladder incon- tinence can accelerate aging by causing exposure to moisture and soiling, requiring more frequent laundering of the cover.”
That brings up another irony: Cleaning and not cleaning a cushion can cause it to age.
“Add in laundering, and even disinfecting \[the cushion\] if the person is living in a facility, and you’ll find the cushion can really be exposed to a wide variety of potentially abusive conditions,” Kopplin said. “When a cushion is not washed, or cannot be washed, biological agents accumulate that can attack the cushion materials. So this can lead to accelerated degradation...not to mention an unsanitary condition for the user. There can even
be the problem of wear and tear from foreign objects that aren’t washed away, like sand from a visit to the beach, which can grind and scrape against the cushion or cover.”
WHEN WEAR HAPPENS
As the cushion’s initial line of protection from such menaces as spilled food and drink, as well as incontinence, cushion covers also age.
“The cover can show wear and tear from these exposures as well,” Kopplin said. “Depending on the design and construction of the cushion, though, these failures may be more cosmetic in nature, with potentially less or no impact on the overall benefits of the cushion. However, in other cases one of the important functions of the cover is to protect a cushion that cannot be washed or disinfected, so the degree of effect of a cover failure can vary.”
“Cushion covers are designed not only to work with the func- tional design of the cushion, but to protect the cushion inside,” Cwiertnia said. “The covers will wear faster than the cushion and should be replaced to extend the lifetime of the cushion. Some users will have a second cover and alternate them during wash cycles. If the cushion is in use in a facility instead of a home, it may also have accelerated aging due to disinfection techniques used on equipment in facilities.”
What wear looks like depends on the media that make up the cushion: “Symptoms of aging can vary depending on the cushion materials,” Cwiertnia said.
As an example, Rogers said, “As foams and other materials are exposed to the elements, they can accelerate the wear. Foam that is starting to deteriorate or break down is one common side of excessive wear. Fabrics that are starting to become thin and see through is another.”
“Open-cell foam cushions can develop a compression set, where the spring-like nature of the cells don’t spring back to full height,” Cwiertnia said. “Open-cell foam can be moldy due to moisture and can have stains. Both open- and closed-cell foam cushions can crumble with aging and exposure to ultra- violet light. Neoprene cushion materials can also show signs of cracking, or the cells might stick together, indicating reduction in neoprene integrity.
“Most cushions use a passive system for microclimate control
that includes spacer knit material or reticulated foam as part of the cover materials for air to circulate, so inspecting the cover
is important. Viscous gel cushions might show signs of fluid leakage or fluid hardening over time. Also check for the number and location of puncture patches on cushions, because too many patches on the surface will decrease how the cushion functions.”
TESTING & STANDARDS FOR CUSHION WEAR
Theoretically, subjecting seat cushions to standards regarding wear could help clinicians to better understand the anticipated performance of the cushions they choose.
But developing cushion wear tests and agreeing on how durable a cushion has to be — as well as how test results will be interpreted and used — are not easy tasks.
Cwiertnia pointed out “the big discrepancy between how
often CMS \[Centers for Medicare & Medicaid Services\] will pay to replace worn-out equipment. On the PDAC \[Pricing, Data Analysis & Coding contractor\] application to get a cushion HCPCS code for CMS, the requirement is that the cushion pass 18 months of life-cycle testing. Yet in the wheelchair seating LCD \[Local Coverage Determination\], they will only replace DME/ cushions once every five years.”
So would it make sense for manufacturers to create more durable cushions that could last five years?
“The tricky part,” Cwiertnia said, “is CMS mandates to make the cushions have to pass longer life-cycle testing \[would require\] materials to be much more durable — think thicker, stiffer, stronger — which might take away from the function of a skin protection cushion. At the same time it could interfere with inno- vation and design to make products that perform at high levels.”
Kopplin agreed that developing standards for aging is complex. “The development of a standard to simulate cushion use is a very challenging process. The overarching goal is to design lab tests that can adequately predict whether the brand-new cushion the user receives ‘out of the box’ will still behave and perform the same way in the future over months and years. This is especially critical now, as cushions are typically only replaced every five years under the Medicare reimbursement system.”
Of current work being done on this front, Kopplin said, “With this standard, we intend to measure a number of characteristics of a new cushion; then expose the cushion to appropriate chal- lenges that simulate aging; then re-measure those initial charac- teristics to see if anything changed. This was the approach taken with the development of the international standard in 2015: ‘ISO 16840-6 Simulated use and determination of the changes of physical properties of seat cushions.’ The RESNA committee is working toward a U.S.-specific standard that is similar in nature. However, some of the thoughts and discussions we struggle with are about how rigorous the test needs to be.
“The challenges we apply in the lab might at first seem overly aggressive, but they are meant to ‘accelerate’ the aging process,
so there’s a balance to find. Accelerating aging with a tempera- ture exposure that’s too high, for example, could degrade some cushion materials in ways that they wouldn’t naturally degrade in
MobilityMgmt.com
MOBILITY MANAGEMENT | MAY 2017 25