
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: