I think I have found your next wheel chair upgrade, but you may have to get your wifes permission. I saw this on the discovery channel, it is from a guy called the rocketman, and he believes, if you can strap a rocket on it, do it. This is his wheel chair when he gets older. You may have a problem registering it on the roads in Canada.

http://www.the-rocketman.com/experimental.html

Take Care
Wayne