2009 Fixed EEG helmet concept for dry/wet electrodes

This is one of the most exciting projects  I have ever done.  The interesting part of this project is many fold  and requires a lot of insight  of human  skulls  and pressure  applied to the skin to make the physical connection,  and how to make a model that  can be modified  easily  for different applications and manufactured.  Then comes all the issues around the electronics  and making sure to pick up the signals correctly, but I won’t talk about that here.

One of the major interesting things in doing this project was to figure out how to apply at 10/20 system  in a solid model that was stiff helmet type that would fit a lot of different people.

One of the first things I did was I  it try to understand  where to go from on the head  so you would think the most people in one design.  One thing I realized when I designed the system, was  that if you want to fit a 10/20 system precisely, the points where you measure you will move, depending on the head size. You see this if you were blow up a balloon, and you mark a point on it, and blow it more up you see it moves. And if you look at the nature of the 10/20 system and vectors and angels, it result that the sphere and vector point crosses each other in different distance from the centre top point. (I hope it makes sense 🙂

Here are some of the pictures from the process of creating the element.

After two weeks of  hard work  it looked like this…

but my major question was how do I make  each arm fit the head  precisely.  so back to drawing board I have to work on a  more clever solution.

Second phase:

after a week off looking at this design I to build it in a different  way,  using  wires,  so  I measured up ahead according to  the 10/20 system.  and after three days look like this.  not a pretty sight but it gave me a very good idea of how the final one should look like.

now I really started to understand how the whole thing should be built in a very simple way.  and yet be very flexible and easy to reproduce in many samples.

so after a week  it looked like this.

now things start to move fast,  and I was able to make a new  design that looked cool and was easy to do.

here is how that looked,  after  bending it and man was that a good feeling when I put it on the first time.

the sensor head  suspension,  was made to fit any kind of hit no matter how  it looked at a given point.  so to be able to make it super  flexible in all directions, I decided to make it in  silicone where the  thickness of the  curved arms   would decide how  hard it would press against the head.  the first  sensor  head suspension looked like this.

It was now time to make the final  concept design of the helmet and put it together.

the sensors would look like this;

and

Here’s the final exploded electrode where you can see the little joystick  for   getting the pins through the hair,  and the  Orange suspension is made to push the sensor head into the hit no matter the angle  to the head scalp.

the final assembly looks like this  before bending,  kind of interesting I think still.



So now I just had to make it for real, and here we go….

and here is an electrode head…


and wired up… almost done 🙂

and after bending finishing it…

it looked like this:

and