Detecting UP and DOWN Movements of Eyes Using EOG

In this project we will be recording electrical impulses of eyes (EOG) using BioAmp EXG Pill and Arduino Uno and then tracking the UP and DOWN movements of eyes.

The Arduino sketch for this project is provided by Mr. Aman Shrivastava who is a BCI enthusiast and was one of our beta testers in the initial stages of the startup.

What is Electrooculography (EOG)?

Electrooculography (EOG) is a technique for measuring the corneo-retinal standing potential that exists between the front and the back of the human eye. The resulting signal is called the electrooculogram.

About BioAmp EXG Pill:

BioAmp EXG Pill is one of a kind pill-size chip that can record publication-grade biopotential signals from your body be it from the heart (ECG), brain (EEG), eyes (EOG), and muscles (EMG).

The entire BioAmp series of sensors from Upside Down Labs is designed in a way to teach you the basics of the instrumentation amplifier, active bandpass filtering, soldering, programming, neuroscience, HCI, and BCI just to name a few concepts.

Supplies

HARDWARE:

1 x BioAmp EXG Pill (with JST PH 2.0 connector and a header pin)

1 x BioAmp Cable

3 x Gel Electrodes

3 x Jumper Cables

1 x Arduino Uno / Maker Uno with USB Cable (You can also use any other microcontroller board with an ADC)

1 x Nuprep Skin Preparation Gel

1 x Wet wipe / Alcohol Swab

SOFTWARE:

Arduino IDE

Note: You can get any of the kits listed below from our online stores (https://linktr.ee/Upside_Down_Labs_Stores)

• DIY Neuroscience Kit Basic
• DIY Neuroscience Kit Pro
• BioAmp EXG Pill
• BioAmp EXG Pill (EXG Explorer Pack)
• BioAmp EXG Pill (Neuroscience Ninja Pack)

Step 1: Assembly

Usually the BioAmp EXG Pill comes presoldered but in case your ordered the unassembled version of BioAmp EXG Pill then you can easily assemble the header pins and JST PH 2.0 connector as shown in the diagram above.

Step 2: Skin Preparation

Apply Nuprep Skin Preparation Gel on the skin surface where electrodes would be placed to remove dead skin cells and clean the skin from dirt. After rubbing the skin surface thoroughly, clean it with a wet wipe.

About Nuprep Gel:

Nuprep skin preparation gel is a mildly abrasive, highly conductive gel that should be applied before placing the electrodes on the skin to improve measurements. When applied gently, it strips away the top layer of skin and moistens the underlying skin layer which reduces the skin impedance with minimal skin irritation and discomfort.

Step 3: Connect Electrode Cable

Connect the BioAmp Cable to BioAmp EXG Pill. We have different variants of the BioAmp Cable so don't go with the color coding and focus on the REF, IN+ and IN- written on the BioAmp EXG Pill.

Step 4: Electrode Placements

Follow three simple steps to place the electrodes as given below:

• Connect the BioAmp Cable to gel electrodes,
• Peel the plastic backing from electrodes
• Place the IN+ and IN- cables above and below your eye & REF (reference) at the bony part, on the back side of your earlobe as shown in the diagram above.

Step 5: Connections

Connect BioAmp EXG Pill to Arduino Uno R3/Maker Uno using the jumper cables as directed below:

• VCC to 5V
• GND to GND
• OUT to A0

Note: BE VERY CAREFUL and follow the above diagram while making the connections between your BioAmp EXG Pill & Arduino Uno/Maker Uno, especially the GND and VCC else it may damage the sensor.

Step 6: Download Arduino IDE V1.8.19 (Legacy Version)

Download the Arduino IDE (legacy version) from the link given below:

https://www.arduino.cc/en/software

(We have used Arduino IDE version 1.8.19 for this project)

After downloading, connect the Arduino Uno R3/Maker Uno to your laptop using the USB Cable (Type A to Type B)

Note: Make sure your laptop is not connected to a charger and sit 5m away from any AC appliances for best signal acquisition.

Step 7: Coding Time!

Copy paste the Arduino Sketch given below in Arduino IDE (legacy version).

Vertical Eye Movement Detector: https://github.com/upsidedownlabs/Eye-BioAmp-Arduino-Firmware/blob/main/8_VerticalEyeMovementDetector/8_VerticalEyeMovementDetector.ino

After flashing the code, open the serial monitor and set the baud rate to 115200.

Note: The Arduino sketch for this project is provided by Mr. Aman Shrivastava who is a BCI enthusiast and was one of our beta testers in the initial stages of the startup.

Step 8: Its Ready

Move your eyes up and down to see the UP and DOWN written on the serial monitor of Arduino IDE.

Isn't it amazing?

Congratulations on making this project, seems like you are are all set to explore on your own and make amazing HCI projects at the comfort zone of your home. What are you gonna make after this project?

Let us know your feedback in the comments and feel free to ask any questions.

You can also mail us at support@upsidedownlabs.tech for any kind of support while you are making this project.