What is an EEG and How it works

Wireless Brain wave EEG project
Wireless Brain wave EEG project

what is an EEG

This is the complete step by step guide of Brain wave decoder project.what is an EEG and How to read EEG waves.We will cover each and every step with details and practical results.There are three main parts of the project The hardware,circuit designing and the software.In the hardware section we will discuss about what is an EEG, EEG project applications,The selection of electrodes for capturing EEG waves. The circuit designing part consists of designing filters for extracting EEG waves.The last part is about test results and real time EEG wave simulations. The brain wave controlling EEG project consists of many sub sections.The complete project will be covered in the following posts.

  1. Brain wave decoder EEG project step by step guide
  2. What is EEG and How it works
  3. What is the History of EEG waves and Neuro imaging techniques
  4. Brain computer interface BCI monitoring systems
  5. Functionality and Applications of the brain wave EEG project
  6. Material required for portable EEG system development
  7. How to select electrodes for brain wave EEG project
  8. circuit designing steps for EEG portable monitoring device
  9. How to design filters for EEG circuit
  10. Schematic diagrams of brain wave EEG project
  11. Simulation analysis of brain wave controlling EEG project
  12. Challenges and Problems in EEG brain wave controlling project
  13. Final results of brain wave decoder EEG project
  14. How to filter EEG waves on MATLAB
  15. Future research for EEG project
  16. Hardware and software list for EEG project


What is an EEG.How to decode brain signals with low noise and low power that could be utilized in real world applications. The main objective is to make the EEG signal readable by the microcontroller to perform any task or control any application. Once the signal filtered and amplified the circuit responds to the eyes movement. The second objective is to get the signal with accurate results that we can utilize it for further useful applications. To remove all the noise in the brain signal and make it readable. The challenge is to make the system portable and wearable with low powered and low noise.


A Low Noise, Low Powered and high sensitive analog signal from brain decoded into filtered digital output. The Brain wave decoder picks a low amplitude and a microvolt signal from brain and decodes it into a filtered and amplified output.

Background and Motivation

The core motivation behind is portable and more suitable for medical applications. The wireless and portable EEG system open the new doors in the field of brain controlled applications. The brain waves have many other benefits in the field of communication and control. For example, controlling the computer or using brain waves for smart home automation. The basic motive and the motivation to design and develop a powered portable,easily wearable system for medical application. The system can easily be used for medical monitoring and controlling applications.

Electrical Activity of the Brain

The Brain cells are called Neurons. There are countless neurons in the human brain. The electrical activity is generated when neurons communicates with each other in the brain. The neurons are active when we are sleeping and waking. An average of 100 billion of neurons in the human brain. The neurons are densely connected through synapses. That dense connection of neurons act as gateways of inhibitory or excitatory activity. The Synapses propagate information in the brain across neurons (excitatory).

What is EEG and How It Works

Electroencephalography is the term used for recording the brain electrical activity. In Electroencephalography the encephalon means brain. The term is abbreviated as EEG. The EEG is the medical and physiological way of brain monitoring. There are different methods and ways we can collect brain signals. The electrodes elastic caps mounted method is used for medical monitoring of EEG data. The electrodes are placed on different areas of the scalp to record the overall activity of the brain.

EEG measures electrical activity generated by thousands of neurons that exists in human brain. The brain electric activity is measured in voltages.

EEG is a method that provides excellent time resolution It allows us to analyze how brain areas responds in different mind states and which brain areas is active at a certain time.

The voltage fluctuations of the brain activity. These are very small in size. The brain waves occur at very low voltage and amplitude approximately 20micro volts signal. The recorded data is filtered, Amplified. We can read and control waves directly that is why we need digital conversion. The output shows the voltage or converted digital values that  changes according  to the activity.

Most Existing brain recording systems are quite expensive based on their complex designs and structures. The price differences in brain monitoring or EEG systems are because of the material and number of electrodes used.

The EEG is one of the fastest brain activity monitoring. The advance system comes in different design and structures they are designed to capture the activity with accuracy. The system uses advance and electrodes for signal picking.

As the EEG monitoring devices gives the time period of electrical activity generated by the brain. We can interpret and identify which brain areas are responding at a given time. There are different brain areas that responds with respect to their electrical activity in the brain.

How EEG Data can be interpreted

  • Occipital cortex. The occipital cortex part of the brain responds for visual information. The effects measure on the occipital region when on the focus of videos or images.

  • Parietal cortex.  The parietal part of the brain responds for focusing. When we are encountering information this part actives.
  • Temporal cortex. The Temporal cortex part of the brain responds in a speech production.
  •  Frontal cortex. This frontal part of the human brain responds in cognitive control.

Brain Waves

The Brainwaves are produced in our brain when neurons communicate with each other. By the communication of neurons, the electrical impulses generated. We can detect brain waves by placing electrode over the scalp. These waves have different functions and are divided into different frequency bands. The brain waves react or changes according to our actions what we do or what we perform or feel. Like In the domination of slower waves in brain we feel slow and tires sluggish or dreamy. Similarly, in the domination of higher waves in that time we feel hyper-alert and wired.

The waves are defined as according to the behavior and their ranges of frequencies.

INFRA- brain -(less than 0.5 Hertz)

The first is infra waves these have quite low range of frequency. These waves are slow in nature. These waves are difficult to detect.

DELTA- brain Waves -(1 to 4 HZ)

These are also slow brain waves. When we are meditating or when we are sleeping or dreaming in a sleep these occurs. These are very low in a range and aslo very difficult to detect.

THETA- brain Waves (8 to 12 HZ)

These are also occurring in sleep state of brain. These waves can also be detected in a deep meditation state. We are in a dream when the region of theta waves actives.

ALPHA Waves (8 to 12 HZ)

In the flowing thoughts the Alpha waves are prominent. These waves can also be active in meditative state. Alpha waves are known to the present waves. Mainly these are the resting state of the mind. These waves occur in calmness, alertness, and in learning.

-BETA brain Waves (11 to 30 HZ)

These waves are the desired and waves we want to capture. These waves come when we are in a waking state and alert.  These waves are in a consciousness state of the mind. The Beta1, Beta2 and Beta3, The beta1 in a frequency range of 12-15Hz. The Beta2 lies in 15-22Hz. The Beta3 lies in 22-38Hz.

-GAMMA brain Waves (< 48 HZ)

These waves are fast in nature. For passing information across the brain the Gamma waves are active.

These waves occur when we are in love state or caring as these are fast and have high range of frequency.

Everything will be cleared in step by step guide so stay connected for more tutorials and guides.If you have any query about the project feel free to comment below and Subscribe to our YouTube channel for video tutorials and project application ideas.stay happy and stay motivated.


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