Wheelchairs are not well engineered. They are even less well engineered for someone who has had a stroke. Unlike a spine injury, a stroke does not take your legs and leave your arms; rather you lose arm and leg on one side. The weak leg means these folks are in a wheelchair where their strong leg gets weaker. Also, a conventional wheelchair can be tricky to roll with just one hand as you tend to turn - so stroke survivors need a motorized wheelchair where the strong arm gets weaker too.
The pedal wheelchair leverages the strong leg of the stroke survivor. The build is akin to a bicycle in that the pedal does not move with the wheels, but can move the wheels. On straightaways, one can push with the strong leg for additional motive force. Additionally, because of the one -arm problem described above, the wheels can be locked and unlocked to either roll together or separately.
The pedal could also be used to exercise the weak leg.-- bungston, May 05 2010 Rowchair http://web.mit.edu/...chair/rowchair.htmlThis might be an alternative approach to some of the same problems. Would still benefit from more leg exercise, though. [jurist, May 05 2010] Arm-Powered Quadcycle http://dvice.com/ar...arm-powered-qua.phpOr perhaps something akin to this Quadcycle (which is quite similar to the Irish Mail cars you may remember from your youth). [jurist, May 05 2010] Pedal wheelchair http://www.wikipate...d-wheelchair/Page-1Looks like it would work one-legged, but I'm not sure. [mouseposture, May 05 2010] Elegant and helpful. [+]-- gisho, May 05 2010 What [gisho] said. [+].-- 8th of 7, May 05 2010 It occurred to me that some adaptive reconceptualization of the rowing chair might be an effective way to approach the problem. Which led me to the attached <link>, as refined by an MIT team.-- jurist, May 05 2010 This is a *really* good idea [+]. It may have been thought of before, <link> but it's by no means widely known to exist. It deserves to exist and to be widely known, though.-- mouseposture, May 05 2010 random, halfbakery