Assistance needed with Paraplegic Wheelchair Design

[ajbloomy]

I wanted to design a wheelchair that can move without the use of the arms. Instead I wanted to design a chair that can be controlled using a person's body weight, like a segway. Apart from using micro-sensors and computers like a segway does can anybody think of another way of designing a wheelchair that can be controlled with only a person's body weight.
Thanks

 

[Enthalpy]

You can put force sensors at varied chair locations in contact with the body: buttock, back, shoulder blades...

The biggest difficulty I see, independently of where and how, is that the user wants to do more in the chair than move. You need some way to tell the chair not to interpret every move as a control. When doing something else with the arms (your aim I suppose) the rest of the body move as well.

A very accessible big switch would be a disappointing solution, I feel.

 

[ajbloomy]

Thanks for the thoughts

 

[skeptic2]

What muscles can the person use? Head and facial muscles? What muscles can he use below the neck? Have you considered the use of blow tubes at the person's mouth? Blowing into different tubes could be detected and used to control the motion.

A friend of mine needed a wheelchair for a while and remarked there is one thing that could be improved. He said when going up or down a wheelchair ramp, it is difficult to hold the wheelchair with one hand while moving the other hand back to get another grip on the wheel. If the ramp is somewhat steep or the person's arm strength is weak, the wheelchair tends to rotate. What is needed is a ratchet on the wheels that will hold the wheelchair in place while the user moves his hands back to get another grip. It would be nice to also have a wheel lock so the person doesn't have to use his strength to hold the wheelchair in place while stopped on a slope.

 

[Mordred]

Considering some of the concerns already posted, an alternative thoughtrickier to implement could possibly be along this line

http://www.hongkiat.com/blog/brain-controlled-gadgets/

this wouldn't require use of the body allowing greater flexibility in who can use, among the various wheel chair users

 

[ajbloomy]

The design brief states that the user must be able to control the wheelchair with something other than their arms or legs. The idea of a self locking wheel is a great idea and could be included in this design.
One idea I had originally was to use a person's body weight to move the wheelchair. This idea could be achieved if the wheelchair's base was essentially a large ball that was free to roll in any direction. The problem is then how to make the wheelchair stable.
My dilemma is that I'd like to design a wheel chair for this brief but I don't have the skillset required to use minicomputers or micro-sensors.

 

[Mordred]

I have some concerns on a pressure based control system myself.

1) What if the person is bumped?
2) What if the person passes out and leans over?
3) gusts of strong wind?
4) different elevations ie downhill as opposed to up hill.

 

[Bobbywhy]

One more concern: What if the person sneezes? Would that propel him and his chair out into the intersection with traffic?