An electric wheelchair that can climb most stairs, including spiral staircases, has been developed by Zurich-based students. The Scalevo Wheelchair can mount one stair per second and was designed by 10 students at the Swiss Federal Institute of Technology (ETH Zurich) and the Zurich University of the Arts.
When being used on normal flat ground, it balances on two wheels like a Segway and allows users to turn on the spot in order to quickly change direction. Two rubber tracks mounted to the bottom of the chair can be summoned at the press of a button to allow the user to climb stairs.
According to Carlos Gomes, of ETH Zurich, "We have two main wheels, two large wheels to drive around on the flat ground in a balancing mode like a Segway. And then we have two rubber tracks which we can extend to the angle of the stairs and let the wheelchair be always upright on every angle on the stairs."
Colleague Miro Voellmy said the rubber tracks make the system entirely safe, even if stairs are uneven or cracked. "Tracks are excellent for this use case because they have a very large footprint, which makes it near impossible to tilt, and they are also very smooth so it doesn't feel like you're driving up stairs, so it just feels like you're driving up a ramp because they're so flat and they adapt to the stair profile. So it doesn't matter if the stair is wooden or metal or glass, the tracks they grip and there's no danger of slipping," said Voellmy.
Their prototype was built in ten months and has been subjected to a series of tests. According to Gomes, "We tested the wheelchair on several staircases, even on a spiral staircase, because we can move the tracks independently and all kinds of staircases we are able to drive [on] 34 to 17, I think, degrees. And this is almost every stair. You can drive everywhere."
Previous stair-climbing wheelchairs have failed to make the grade. Six years ago the iBot, devised by Johnson & Johnson, was discontinued. It was regarded as expensive and required users to have use of at least one arm and some upper body control, according to the Huffington Post.