Placement of electrodes in the signal capture system
For placement of electrodes, the 10-20 system is used, which is an internationally recognised method that describes the exact location of the scalp electrodes. If we use fewer electrodes, then the distance between adjacent electrodes is 20 per cent of the total front-back or right-left distance of the skull. If we use more electrodes, then this distance is 10 per cent of the total front-back or right-left distance of the skull.
In Fig. 3, A1 and Az represent the ears’ positions. There are no central electrodes; C3, Cz and C4 are marked just for geometrical indication.
But now all of this is outdated. Due to limited portability and increased interference, electrodes are no longer used for commercial applications. Currently, the method to study the electrical activity in the brain is ‘Emotive EPOC,’ which makes use of a wireless headset. It can track conscious as well as unconscious and emotional behaviour. EPOC marks the beginning of an important era. It is highly precise and gives fast response.
Applications of BCI
1. The BCI can be applied not only to brain-related products but also to bionic devices. These include bionic leg, bionic eye, bionic arm, bionic spinal cord, etc. All of these are based on the same concept of neuron electrical activity to give people a new lease of life.
2. The BCI has revolutionised the gaming experience too. There are a good number of BCI-based gaming options available in the market. Normally, the ‘conversation process’ through the BCI is not very efficient, but recent research has resulted in new methods that are available commercially, although at higher prices.
3. The concept of virtual reality has fired the imagination of many in the BCI field, as shown in the film ‘Surrogates’ starring Bruce Willis.
4. There is also the concept of ‘brain painting’ though its efficiency, as of now, is not very high.
5. The most important applications are expected to be in relation to cloud computing. What if, through BCI, we are constantly connected to the Internet via the cloud? This can change the world in more ways than can be imagined today.
The author is a B.Tech 4th year student at Vidya College of Engineering
