FAQs

Frequently Asked Questions

Technical Questions

Q: What is EOG, and where does it come from?
A: Electrooculography, or EOG, is the science of measuring eye movement through change in the eye's potential. In 1849 Du Bois-Reymond had discovered theat the eye has a resting potential but it wasn't until the second half of the 1900s that this discovery was researched [1]. This technology was originally used to research sleep disorders and neudrodegenerative diseases but recently they have been used to control objects with your eyes.  The sensor works off of the fact that the front of the eye, the cornea, is positively charged while the back of the eye, the sclera, is negatively charged. The most common setup for EOG sensors is either one placed next to each eye to track horizontal movement, or two placed on the same side with one above the eye and one below to track vertical movement.

Q: What does an ideal EOG signal look like?
A: 

The signal processed from the eye moving up and down. The left picture is made by the eye looking up while the right picture is the eye moving down. [1]

The signal processed from an eye blinking three times. In the picture each  wave represents a single blink. [1]

Q: What is the voltage range of a typical  EOG signal, before amplification?
A: The typical voltage range is between -50 and -200 milliamps. The negative sign means that the inside of the eye is negative relative to the front. [1]

Q: How does EOG relate to eye movement? What types of eye movement can be obtained from an EOG signal.
A: An EOG sensor can obtain directional movement such as up, down, left, and right as well as eye gestures such as blinking and winking.

Q: Describe an EOG instrumentation system from end-to-end.
A: The EOG sensors will be attached the the face, with the number of sensors varying based on how much data that you want to collect. The electrodes are connected to an amplifier in order to increase the power of the signal. Between the amplifier and sensor there is a capacitor and resistor on each wire in order to reduce movement noise and normalize the signal. There is also another sensor attached to the users back in as a reference electrode and ground.

General Questions

Q: What exactly are you making?
A:  We are making a sleep tracking device that you will attach to both your wrist and face. The device will be able to gather data from when you sleep and present it to you in a very orderly format.

Q: How does your device work?
A: The device will work using a combination of EOG (Electroocularography) sensors and an accelerometer attached to the user's wrist. The sensors will be able to accurately track when the user is in REM sleep while the accelerometer will be able to track when the user is in a light sleep.

Q: How accurate will the device be?
A: We are not 100% sure of how accurate our device will be, seeing as we have yet to test it. Based on the research that we have gathered it should be extremely accurate, since it is combining two of the top ways for consumers to be able to track their own sleep.

Q: What are the advantages of your device over the apps I can find on my phone?
A: The apps that you can find on your phone and devices that you can wear on your wrist are similar in that they are based on accelerometers. These devices can track forms of sleep based on movement, but a lot of the data that it acquires are just rough estimates, since it can't accurately track REM sleep.

Q: Will it be a burden to wear?
A: The final design that the group has in mind should not be a burden to wear, as the sensors will be connected to a comfortable sleeping mask and the accelerometer will be in a watch. The design in mind has all of these components connecting to the user's phone, yet the group will not be able to make that final design.

Q: What are your future plans for this device?
A: The most biggest future plan for this device is to be able to connect it to a users phone so they won't need to have a computer around them when they sleep and have long wires wrapping around them.