Most powered wheelchairs have at least two problems: they can't climb stairs, and the user has to remain in a single seated position. An experimental new robotic wheelchair, however, addresses both shortcomings.
The chair was designed by a team of scientists at the Korea Institute of Machinery and Materials (KIMM), led by Dr. Chan-hoon Park. It consists of a central platform with a stair-climbing "crawler" module on the bottom and a standing module on top.
The rubber-tracked stair-climbing module stays retracted up inside the chair when not required, and is lowered down to the ground when the user needs to climb or descend stairs. It then adjusts its angle relative to the main wheelchair in such a way that the chair remains horizontally level.
And yes, we have seen tracked stair-climbing wheelchairs before.
That said, one claimed advantage of this particular design lies in the fact that it uses four sets of tracks – two in the front and two in the rear – to grip both the edges of the individual stairs and the treadboard platforms of those stairs. This arrangement is claimed to keep the chair from slipping, which has been a problem with some other models.
The standing module utilizes a powered parallelogram-shaped structure to move the user into standing, reclining, forward-leaning or backward-leaning postures as needed (they can also simply be raised higher in a seated position). This functionality is intended not only to make life easier for the user, but also to reduce the likelihood of bedsores or poor circulation caused by staying seated in one position for too long.
Although not integrated into the chair yet, Park and colleagues have also developed special "transforming wheels" that could assist or even replace the stair-climbing module.
Inspired by the surface tension of a water drop, the rims of these wheels remain rigid and perfectly round when moving across flat surfaces, but bend to conform to the contours of obstacles which they roll over. In other words, the wheels could simply take on the shape of the stairs in order to climb them.
"While the conventional technology for wheelchairs was focused on simply providing mobility, our newest technology for the robot wheelchair has been developed for the purpose of helping persons with lower-limb disabilities use facilities and infrastructure that have been designed and installed without considering people who have disabilities," said Park.
Source: KIMM