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Project synopsis on

ELECTROENCEPHALOGRAPHY

Under taken by:

Name 1 Roll no. 1 Name 2 Roll no. 2

Name 3 Roll no. 3 Name 4 Roll no. 4

ABSTRACT

Electroencephalography(EEG) is anelectrophysiologicalmonitoring method to record electrical activity of thebrain. It is typically noninvasive, with theelectrodesplaced along thescalp, although invasive electrodes are sometimes used in specific applications. EEG measures voltage fluctuations resulting fromionic currentwithin theneuronsof thebrain.In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a period of time,as recorded from multiple electrodesplaced on the scalp. Diagnostic applications generally focus on thespectral contentof EEG, that is, the type ofneural oscillations(popularly called "brain waves") that can be observed in EEG signals.

WORKING PRINCIPLE

The working of this project is divided into various stages which are as follows:

-Stage 1 -50 Hz Notch Filter

-Stage 2 - Instrumentation Amplifier

-Stage 3 - 7Hz High Pass Filter

-Stage 4 - 31Hz Low Pass Filter

-Stage 5 another 50Hz Notch Filter

The above mentioned are all filter stages. Apart from this, a module consist of some other filters and voltage protection circuit is also used. The data received from the sensor and all these stages is then fed into the computer using the Bluetooth (due to 50 Hz noise in wires, Bluetooth module is used).

BLOCK DIAGRAM

BREADBOARD SCHEMATIC (Only Filters)

ABOUT BRAIN WAVES

Wave / Frequency / Associated Mental State
Gamma / 27 Hz and up / Gamma is associated with the formation of ideas, language and memory processing, and various types of learning.
Beta / 12hz - 27hz / Wide awake. This is generally the mental state most people are in during the day and most of their waking lives.
Alpha / 8hz - 12hz / Awake but relaxed and not processing much information.
Theta / 3hz - 8hz / Light sleep or extreme relaxation.
Delta / 0.2hz - 3hz / Deep, dreamless sleep. Delta is the slowest band of brainwaves.

COMPONENTS REQUIRED

 HARDWARE

  1. The filters module
  2. Capacitors
  3. Diodes
  4. Connecting Wires
  5. Resistors
  6. Instrumentation Amplifier
  7. Operational amplifier
  8. Dry electrodes

 SOFTWARE

  1. Processing
  2. Brainwave Visualizer

APPLICATIONS

  • Hardware costs are significantly lower than those of most other techniques
  • EEG prevents limited availability of technologists to provide immediate care in high traffic hospitals.
  • EEG sensors can be used in more places than fMRI, SPECT, PET, MRS, or MEG, as these techniques require bulky and immobile equipment.
  • EEG is relatively tolerant of subject movement, unlike most other neuroimaging techniques. There even exist methods for minimizing, and even eliminating movement artifacts in EEG data[
  • EEG is silent, which allows for better study of the responses to auditory stimuli.
  • EEG does not aggravateclaustrophobia, unlike fMRI, PET, MRS, SPECT, and sometimes MEG
  • EEG does not involve exposure to high-intensity (>1 Tesla) magnetic fields, as in some of the other techniques, especially MRI and MRS. These can cause a variety of undesirable issues with the data, and also prohibit use of these techniques with participants that have metal implants in their body, such as metal-containing pacemakers

REFERENCES