NeuroSky also has the Mind Wave Mobile 2, that may
be a step up from the original Mind Wave, but I’m not sure.
The website seems to put the emphasis on comfort, as
opposed to more functionality. It’s still around $100.
Stepping up in capability, there are some interesting
devices by EMOTIV (
http://emotiv.com). There is a five-channel one for about $300 and a squid-like 14-channel
device for a cool $800. These higher-end devices want you
to use saline pads to achieve better skin contact, so the
signals will be larger and more consistent.
Interestingly, the EMOTIV devices have gyros, an
accelerometer, and a magnetometer in them so that head
position and motion will be readable. That could be an
interesting source of data for controlling systems.
Of course, you can try to build your own. This is harder
from a mechanical perspective than
it is from an electrical perspective, in
my opinion. You’ll need some sort of
instrumentation amplifier that should
be able to detect the differential
signals that are in the microvolt
region and amplify them up to some
reasonable level. Then, they will have
to be digitized. This is where it gets
more difficult since some of them are
below 1 Hz.
A reasonable analog-to-digital
converter would be necessary that is
coupled down to those frequencies,
and then there needs to be a way to
get the data into a computer. With
enough space, that’s not too hard,
but then you also need to create a
low resistance coupling mechanism
for the sensing wires to your head.
You need to mount all of this on that
Lastly, the computer will want to
do some sort of frequency analysis to
try to classify the signals. It’s doable,
but it will be a fair amount of work to
package it reasonably.
Another idea might be to get
several of those Star Wars Force
Trainer devices and increase the
number of channels using several
NeuroSky boards and more coupling
points on the head. That could be a
way to get something that works like
the EMOTIV device implemented
It’s hard to say if all of this
is enough to get good data for
controlling a drone. I tend to
be skeptical of getting anything
interesting from an EEG that
corresponds to fine motor control.
I think that the position and motion
controls on the EMOTIV devices will
be more interesting and useful. NV
QUESTIONS and ANSWERS
10 September/October 2018