A new prototype wheelchair is set to revolutionise an age-old design, making it a lot easier for users.
It's been a labour of love, and almost a life's work, for a husband and wife engineering duo at Massey University.
"We saw a lady trying to get up a wheelchair ramp and really struggling. We were quite shocked how hard it was for her," says Dr Claire Flemmer.
So they set about designing a better one.
"One could reasonably be fairly indignant that over this century they haven't been improved," says Dr Rory Flemmer.
"We cooperate on all our research projects in whatever area it is, we spend our world together," he says.
But he credits his wife with being the driving force behind it.
"She has just said things like, do you really love me, because if you do you'll keep working."
It's taken 30 years, but they've finally come up with the answer.
Cunning engineering makes the EZYWHEELS chair much more efficient.
In the normal mode the tyres go forward and back as you turn the pushrim. But it also has a special mode called the Run mode, which uses both the forward and backward hand motion to drive the wheels forward, putting less strain on the arms.
"One hundred percent of your arm motion is actually being used to propel the chair, whereas in a standard wheelchair probably 20 percent of the actual arm motion is pushing the chair forward," says Claire.
It also has a three-gear system.
"The gearing system is similar to a bicycle. High gear is used when the path is easy, such as a flat or downward sloping, smooth surface. Low gear when the path is harder, such as up a ramp or tarred path. Run mode does not allow the user to reverse, preventing the user from rolling backwards down a slope."
"A standard chair performs poorly on even a mild upward slope and when you add age and physical ability into the mix, it can be a real challenge," says Claire.
Around one in 200 New Zealanders use a wheelchair. Juliana Carvalho says it puts real strain on her wrists and elbows.
"I struggle a bit outdoors, especially with the manual wheelchair. If you have uneven pathways, or on the grass, or even go to the beach and enjoy, you cannot because of the sand."
She's delighted at the prospect of better technology.
"I think it's amazing, because it will bring way more freedom for so many people that use wheelchairs. Sometimes they are not able to enjoy life to the fullest because of lack of accessibility. If you have a wheelchair that can overcome these barriers it will be amazing."
The wheels are designed for indoor and outdoor use and snap fit onto customised frames.
There are a few tweaks to be made, but it should hit the streets within the next year.