The very rough video above links to a custom controller I developed at SpecialEffect for a lady who wants to play games on modern game consoles using chin movement for the left and right sticks (one at a time), three finger switches, sip/puff movement and speech.
The set-up is flexible, using a custom JoyToKey profile shifting system with the lovely Origin Instruments Breeze sip/puff device (set in joystick mode). Sip to move up a list of custom profiles, puff to move down. Press one of three Marblesoft Ultra Light switches to select a special function connected via an adapted Razer ONZA joystick on budget mounting system. This method can be adapted for various uses. I'm currently working on one-switch, eye-gaze and head-tracking methods on consoles that I hope to share soon.