Here is the OpenInterface “code” used for the demonstration (click to zoom) :
After using OpenVibe to get the signals, we spent time on the Emotiv API.
It proposes directly different functions for three types of behavior:
- The emotions;
- The cognition;
- The expressions.
This last one, is the one wich allows to get the most results in a few time. So, we decided to use it (we don’t have time to explore all the possibility the Epoc offers).
It is also easy to use and, in a short time, we managed to implement it in OpenInterface.
Here is a list of the different expressions that we can recognize (this works for most tests) :
- The blink of eyes
- The eyebrow movement
- The left wink
- The right Wink
- The look on the right
- The look on the left
- Clench teeth
- The smile
As said before, the OpenVibe option is more flexible. So we prefer using it in a first time.
We will not explain how OpenVibe works and all its features, all this information are available on the OpenVibe’ website.
We will just explain how we can interface the Emotiv Epoc, getting back the signals and sending them into an other application using a VRPN server.
1) Interfacing the Emotiv Epoc
There are at least 2 ways to interface the Emotiv Epoc:
1) Official Emotiv SDK
Designed especially for the headset, the SDK included many tools to use it.
The Emotiv tools focus on the detection of emotions.
We have to calibrate the headset with the panel control and then, we can get back the information in a c++ application using Emotiv library (all information about using the library are available in the documentation of the SDK).
At the moment, we don’t know yet if it’s possible to get the raw signals with this SDK .
OpenVibe is an OpenSource software designed for the Brain-Computer Interface (BCI).
It can be used to acquire, filter, process, classify and visualize brain signals in real time.
It is possible to interface directly the Emotiv Epoc and getting the raw signals (but it’s necessary to have the Emotiv SDK installed).
Unlike the Emotiv SDK, It’s not directly possible to determine the emotions. However, processing options are more flexible (we can get the raw signals and do all processing we want).
For the IP, we have to use different sensors to create a human/machine interface application.
The list of the sensors that we will use is not yet fixed but it’s almost certain that we will use the Emotiv Epoc.
What is Emotiv Epoc ?
“The Emotiv EPOC is a high resolution, neuro-signal acquisition and processing wireless neuroheadset. It uses a set of sensors to tune into electric signals produced by the brain to detect player thoughts, feelings and expressions and connects wirelessly to most PCs”.