Eye Blink Sensors?

[ksquared]

So I built this thing for a guy who have multiple and massive physical disabilities.  http://tinypic.com/r/2q8ysgj/8

He can't use a regular computer, but he can use voice feedback and giant buttons.

It seems to work fine.  However, I know of another disabled person who could something like this: he suffers from Lou Gehrig’s disease.  Like Stephen Hawking.  http://a57.foxnews.com/global.fncstatic.com/static/managed/876/493/Hawking1.jpg?ve=1&tl=1

The only way he can interact with hardware is by... blinking.  And were gonna do this.

Therefore, I was wondering: does anyone have a viable blink sensor on the cheap?  It has to be fast enough to detect deliberate blinks, but it doesn't have to be fast enough to gather precise statistics on a rabbit or a squirrel's blinking pattern.

I *think* I can do surface mount if I have to, I can etch circuits, and I've had engineering circuits I.  I can follow insturctions and do soldering, but sadly, designing a blink sensor looks... really really hard.  So thanks for anyone who can help me!
 

[Billy]

The only way he can interact with hardware is by... blinking.  And were gonna do this.

Therefore, I was wondering: does anyone have a viable blink sensor on the cheap?  It has to be fast enough to detect deliberate blinks

In your shoes I would start with a webcam and the trial version of RoboRealm or other vision SW. Rather than trying to physically detect the eyelids moving, you should be able to see them moving. Or if you struggle with the eyelids, roborealm can probably be programmed to see the pupils (eyes open) and not see the pupils (eyes closed).

www.roborealm.com

With vision SW, you can potentially improve performance and add functionality even remotely by just updating the algo. Maybe a look to the left or right can be added to increase the number of inputs possible. 

I'm sure if you explain to the roborealm community what you are trying to accomplish, you'll have people lining up to help you.

I just checked the roborealm page. There is a module there already to get you started:
Machine Perception Toolbox
The MPT is a cross-platform collection of libraries for real-time perception primitives, including face detection, eye detection, blink detection, color tracking. Future versions will also include expression recognition, predictive color tracking, and tracking based on multisensor fusion.

Good luck!

[jlizotte]

I don't have any good links or information in front of me, but here's another way you could go....

Last year I was experimenting with a way to develop a sensor that would detect eye movement during REM sleep. I didn't get very far with it because other real-life projects got in the way, but something I found very interesting and was going to pursue was this:

Think in terms of EEG sensors....instead of sensing the actual eye-blinks (like with a camera)...sense the eye muscle activity instead. The electrical impulses from the eye muscles are MUCH stronger than the typical brainwave and are easy to detect. Google that. One great advantage to this is that by training the software to see the difference between moving your eyes left, for example, instead of up and down, you can then program various functions based on how the user is moving his eyes. In effect, you set macros for different patterns of eye movements.

Sorry I don't have more information for you...I'm just now recovering from a hard drive failure and haven't been able to recover all of my research yet, but google is your friend.

Measuring muscle activity by detecting its electric potential is referred to as electromyography (EMG). This is where I'd start with the search engines.

Sparkfun has a cheap example of the hardware needed to do this:  Muscle Sensor v3 Kit   https://www.sparkfun.com/products/11776  (Only $49.95)


John

P.S. If you decide to go this route, here's a link with more medical/scientific discussion of how your eye muscles work:  http://neuroscience.uth.tmc.edu/s3/chapter08.html