We encountered a man who had quadriplegia due to a motor vehicle accident. He had a little motion in one hand and wanted to use a computer, but he could not use a regular mouse. If he could use the computer, he could go online, surf the internet, research whatever struck his fancy, chat with other people, email, etc. - it would open a lot of doors for him and greatly increase his standard of living. We tried a commercially available joystick mouse, and he could use it successfully. The problem was cost: the commercial model was $550 (since then, it has dropped to $400 ) which neither he nor his family could afford.
I built a joystick mouse for him out of a USB gamepad and arcade machine components. This mouse had two features lacking in the commercial model: 1) It could launch programs or commands, greatly increasing the efficiency of computer use 2) it could talk, giving auditory feedback regarding which button was pressed, as he could not move his head to look at his hands.
We have since used descendants of the first joystick mouse with several people who had cerebral palsy or other conditions that made traditional computer use difficult. The cost to build one of these is about $45.
Step 1: Materials and Tools
Wood, about 7" wide and 1/4" thick
Paint, Wood glue
(1) USB gamepad (I have had good success buying cheapies from eBay or other places - we will be destroying it in the process so don't buy the most expensive).
(1) competition joystick (happ.com is a good supplier too, but more expensive)
(6) competition pushbuttons (happ.com is more expensive here too)
(4) #10 1/2" wood screws (or metal screws)
(7) #8 or #6 1.5" Wood screws
(20) 0.187" Female Quick Disconnect Crimp Connectors
300" (25 feet) 24-28-gauge hookup wire (old CAT-5 cable works beautifully with the jacket removed)
12x12" square solid foam shelf liner
Dremel with micro drill bit (e.g. 0.0260")
1.125" hole saw (for drill)
Table Saw / regular saw for woodworking
diagonal-cutting pliers (dykes)
Soldering Iron and solder
Wire crimp tool
Hot air gun
Hot glue gun
AutoHotkey (Windows only, similar automation software exists for Mac / Linux)