Analysis of the eyelid movement enables doctors to diagnose several types of neurological and ophthalmic diseases.
The project's goal is to assemble a system that accurately collects information on the eyelid's movement for few minutes and in the end,
move the measured data through Wi-Fi to a user's computer.
Using small and light magnets, attached to the eyelids of the client, and magnetic sensors attached to glasses, we can gather information about the eyelids movement.
Eyelid’s movement results in movement of the small attached magnets and therefore a change in the magnetic fields that is being measured by the magnetic sensors.
The magnetic sensors measure the magnetic field in the three axes and in a rate higher than 1kHz (for all the sensors together).
The duration of the whole measurement should be around fifteen minutes. During this time, the data is transferred from the sensors to the SD card.
Passing the information through Wi-Fi is possible thank to the micro-controller in use, which is the ESP8226, using its capability to open an access point.
The user connects to it with a personal computer. In the end of the measurement the data is transmitted from the SD card, through the ESP8266 to the computer.
A brief time after the batteries are inserted into the battery holder and supply the system with voltage, the ESP opens the access point.
The access point is stopped if the user removes the batteries or if the user, after connecting with the computer to the ESP, orders to start a measurement.
There is an option to transmit the measured data to the computer while measuring (simultaneously), called online state. In this case, during the measurement the Wi-Fi is not turned off.
The use of the online option is primarily for intactness checking.
The system includes a micro controller (ESP8266), four magnetic sensors (TLV493D), SD card, battery holder (for rechargeable AAA batteries) and a DC to DC converter.
There are additional resistors, capacitors, LEDs and a shift register in order to create the working points and help to operate the system.