If your patient has any control of his head movements, he might also be able to use what we call a "headmouse". A headmouse is also a camera-based system and it tracks a reflective dot placed on a body part that the patient can still move. For example, the tracking dot for my headmouse is placed on the bridge of my eyeglasses, between the two lenses and I move the mouse pointer around by moving my head an inch or two in the direction that I want the mouse to move. I use foot pedals to click the mouse buttons, but you can get free software that can do that if your patient can no longer press any type of button.
The headmouse system I use -- the SmartNav by NaturalPoint -- costs about $400, as opposed to the several thousand dollars that most eyegaze systems cost. You simply mount it on a computer like you would any other webcam. I use mine to do everything from surfing the Web to drawing pictures and editing video.
If you can give us a better idea of what physical abilities your patient still has, we can give you much more specific recommendations on the types of equipment and software that might work for him. You might also check and see if your state has a government agency that provides assistive technology to the disabled and see if you can get some local assistance through those kinds of means.
