A UK company producing wheelchair wheels with integrated suspension is setting its sights on European expansion.
Nottinghamshire-based company, Loopwheels replaces standard spokes with carbon composite springs which act as shock absorbers to reduce pain and discomfort for wheelchair users.
In some European countries, including Germany, Loopwheels can be prescribed by clinicians. The company has now expanded to Finland and Norway where its wheels will be supplied to customers through the countries’ respective state insurance systems.
Carbon composite is a strong material that flexes and returns to its original position when put under stress. The material is commonly associated with archery bows and prosthetics limbs, however, in 2015, Loopwheels inventor, Sam Pearce envisaged the technology being used as a more effective suspension for wheelchairs.
Loopwheels co-founder, Gemma Pearce said: “With our wheels, we aim to make life a lot more comfortable. The spring technology reduces pain and discomfort and it reduces tiredness, which makes wheelchair users feel more able to get out and about and go further for longer.
“The springs within the wheels create a smoother ride and also provide some momentum to the wheelchair, which makes it easier to get over small obstacles. So, it is easier to get over bumps, get up and down a curb and ride over surfaces that aren’t completely even.
Thought to be one of the first of its kind, Loopwheels have a rigid rim with an internal suspension system consisting of three composite carbon ‘leaf’ springs which continually adjust as the user travels. Loopwheels claims this creates a more efficient form of suspension.
Pearce said: “People have been trying to put suspension inside wheels for about 120 years, so it’s not that people didn’t have the idea, they just couldn’t make it work. It was the idea of using carbon composite that enabled us to create the Loopwheel.”
“One of the main benefits of our wheels is the low unsprung mass,” Pearce said, “You want to reduce the amount of mass that you’re moving beyond the point of suspension, so if you have your suspension in the centre of the wheel, the only mass that you’re moving that isn’t suspended is the rim of the wheel and the tyres.
“Essentially, you haven’t got the whole of the chair being carried as mass, making it a more efficient form of suspension.”
A common issue faced by wheelchair users is exposure to vibration which is a common cause of pain, discomfort and tiredness.
Pearce said: “There has been a lot of published research over the years which measures the amount of vibration that is experienced by wheelchair users, and it shows that people are exposed to levels of vibration that is not good for them.
“It can affect quality of life because exposure to vibration can negatively impact your health and cause tiredness. It is particularly acute for people with conditions such as Multiple Sclerosis and spinal injuries associated with pain, particularly lower back pain.
“Too much vibration is also associated with increased spasticity and difficulties with bladder control.”
Loopwheels and its competitor, Softwheel are the only two companies in the world currently building suspension into wheelchair wheels.
Pearce said: “Softwheel had exactly the same idea of putting suspension inside the wheel, but they do it in a different way. Instead of carbon composite springs within the wheel, they use gas struts to act as shock absorbers within the wheels.”
After launching the Loopwheels for wheelchairs in 2015, the company received £147,000 grant funding from the UK Government’s Innovate UK fund to carry out an R&D development project which concluded in the summer of 2019.
Pearce said: “We worked with a company that specialises in stress analysis and do a lot of work with the Formula One, using composite material in various applications. They worked with us to produce virtual predictions of how materials will deform.”
Loopwheels has recently redesigned the technology to lower the weight and improve its spring mechanism by introducing a choice of spring rates based on weight and personal preferences.
Pearce said: “With the new design, we only have three springs in the wheel rather than six. This has allowed us to reduce the weight to less than three pounds, which is the magic formula, as anything under this weight is considered a lightweight wheel.
“Our wheels will never be as light as a spoked wheel, but it’s a trade-off of comfort versus weight.”
In January 2021, the University of Pittsburgh in the United States will use Loopwheels as part of an independent clinical evaluation, comparing the suspension wheels to other wheelchair wheels on the market.
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