Hmmm that made me think of something.. Why can't the Copenhagen be used on a wheelchair? Would make an easy conversion.. just need to limit top speed to something sensible. Could have two of them for 2 grand.
Seems like a pretty creative idea. You would almost have to use two of the wheels. Wheelchairs pivot around when you apply power on one side, to turn. You'd need a controller that would keep the wheelchair tracking straight, or offset the power, and maybe a joystick to initiate a turn. These 'wheel' ebikes are wireless/bluetooth, and have the processing power of a smartphone. It would be something to design with software, in many ways.
You might want to extend the wheelbase a bit, find the right combination of wheels and tires, etc. If you could remove the wheels and fold the chair, the way most do, you'd get some reasonable weights and sizes to deal with.
No question that the kinds of advances people are making, especially with batteries, will change a lot of stuff. The typical powered wheelchair has had 40 pounds of lead acid batteries, which restricted the designs.
When I was on full time oxygen and really weak, driving was really stressful. Too much coming at you. The mobility scooters wouldn't do much beyond shopping. I got on my electric bike, ran it with the throttle, and started feeling a lot better, even with the oxygen tank.
Maybe if people get some decent ideas for mobility devices 'out there' something will happen. It's very frustrating, not being able to get around, do normal stuff.