I am thinking of a project proposal for my robotics course and we are required to make one that has a potential application on physical therapy or medical fields. One thing that came across my mind is a motorized wheelchair that moves when a stress ball control is squeezed by the user. As a robotics novice, I wonder if I could integrate a sensor circuit with a rubber ball so that when it is pressed, perhaps by a stroke patient, it triggers some driver circuit. is this possible? if so, how? My experience with robotics is limited to arduino, servo motors and basic sensors.
You could try to insert a piezo-element into the stress ball, or coat a piezo element with rubber, which can be squeezed by the user.
This element will give a voltage peak on the on- and off ramps of the squeezing. You can find the proper schematics for the electronics online. Now you just need to detect this pulse with a computer system (possibly an arduino) and off you go.
Is this what you mean?
Edit: I am no expert on which element to use, but try to find one with the right output voltage for your detection element. Since they are passive elements, most of them are fairly cheap and robust.
Barometers are cheap, easy to use, and very sensitive. They can be placed inside a sealed rubber ball and detect changes in pressure. See for example these sensors: www.takktile.com. (The makers of these sensors encase them in rubber, which you may or may not want to do).