Controller for quadratic friend.

I suspect you mean quadriplegic - maybe you were auto-corrected in the posting.

Making things that are biocompatible is not easy - part of the issue will be making it out of material that is safe to go into the mouth, won't break apart, is resistant to saliva, is insulating so as to avoid any risk of electric shock (else it might feel like licking a 9V battery). It sounds more like a fabrication project more than anything, but then you have to cable it somehow to a device that will produce the inputs to a computer or mobile device (e.g. an Arduino emulating a keyboard for example).

I don't have any great ideas as such, but there are probably some tactile switches that can be found for PCB mounting that might have a large enough actuation area. A d-pad would be more difficult but I suppose you can build this out of a number of these switches. You would need them slim enough to fit inside the mouth comfortably, but still provide enough support (e.g. on a PCB) so they don't get badly deformed by bite force. The actuation force range will have to be experimentally determined as well - can't require too much force otherwise might tire the user out, too little and you might get false activation. Then you might consider encapsulating the whole thing in some flexible food-contact grade silicone to give it water-proof capabilities ... but sharp teeth might still make it through or take chunks out of the silicone.

Not sure how practical it might be, but if you keep a capacitive touch-screen clean and close to the user, I've seen some people actuate on-screen controls by using their nose or tongue directly.

- Gough

How about this:

Get a commercial mouth guard.

Cut as many notches on the inside edge as the number of switches you want.

Glue a small Hall effect switch into each notch using food grade silicone sealant.

Cut groves in the mouth guard to run the wires out and seal them with glue.

Get a ball magnet and coat it with the same glue.

Moving the ball to each switch is then just like moving a candy around in your mouth.

The magnet may need to be tethered on some fishing line if there is a tendency to swallow it.

I have no idea if this is dangerous - you will have to assess the risks.

There is definitely going to be a lot of trial and error, but all the above suggestions sound good. I suspect you'll discover some great sounding ideas that fail and some odd ones may work surprisingly well.

The thing that springs to mind for me is to involve your friend in the process. I'm not sure whether it's possible to bite on just one side of you mouth without dislocating you jaw. A tongue operated D-pad sounds tricky to operate. Maybe a capacitive touch sensor (not necessarily as screen) definitely sounds easier. The things is that's just me though - your friend will be in the best position to know what he can and can't do easily or comfortably.

Hey thematman92

I'm Phil from the element14 staff.
This sounds awesome and would love to see your progress.

Question, Where are you based?

Phil

I have seen a lot of joy stick-like controls, that the person can control either with a their mouth or by other parts of the face (chin, cheek).  I would think that keeping the electronics outside of the mouth would be much easier (joystick handle integrated with a mouth guard to slip onto the joy stick stem).  It seems that whatever controls you chose, it should be based on the persons degree of mobility (above the neck) and their fine motor skills.

Best of luck!

Gene

Hi Matthew,

Does it have to be located in the mouth? You could perhaps consider facial recognition software but focus just on the mouth area for control signs.

For in mouth, the user could have an electronically inert 'mouth paddle' - a short stick, like for mixing cocktails, the paddle is detected externally by the visual software or other means, the user could manipulate it around with their tongue (think of the stereotypical image of a farmer with a piece of straw hanging out of their mouth). But biting the end makes the other visible end deform/inflate so you can detect that as a button press. Could be easier to clean and less issues of electrical failure/safety?

Rod

Matthew sounds like you have quite a challenge on your hands!

I assume you have gone with the "in mouth" solution as you know your friend's abilities, and have established that is the best solution for them. On that basis, I would be thinking a matrix of buttons that are somewhere between a blister keyboard or membrane keyboard moulded in silicone. Then running the wires externally to the electronics, this way you can make the mouth part "disposable" to a degree?

I have no grounds or experience in mould making or anything alike! But I think making a mould of his mouth that you can recreate any prototypes in, and creating a 2 part mould that you can set each side of the blister buttons into, and cast them together?

The electronics side should be pretty straightforward if you can make the buttons work. Do you have a desired platform/controller you are looking to connect this up to?

Another thought, does your friend have a preference to the types of games they like? Maybe that help you to design a niche device for them rather than a generic game controller?

[I state the above as a non-game player, so could leave hardened gamers wondering what I'm talking about ]

Rod

It is certainly possible to make "smart" controllers that help when playing. I built one a few decades ago that would simulate rapidly triggering the fire button - it operated like pulling a machine gun trigger.

I'm based out of the USA, Utah state.