OSDWatch is (or rather will be) a custom wrist watch with sensors for seizure detection, and the associated software to use it as a seizure alarm system.

It is in a very early state of development!

Design constraints:

• Provide a battery life of at least 12 hours (preferably 24 hours) per charge.
• Monitor acceleration (to allow the equivalent system to the Pebble seizure detector)
• Communicate with a mobile device (phone or tablet) to provide an alarm system (so we can use the existing OpenSeizureDetector android app framework).
• Monitor additional paramaters as space and battery life allows, such as heart rate, blood oxygen saturation, skin temperature, skin conductivity.

Likely Components:

• ESP32 microcontroller module with integral bluetooth radio
• ADXL345 accelerometer
• Max30102 heart rate and blood oxygen saturation sensor
• OLED dislay
• LiPo battery charge controller.

• FreeRTOS based system (for portability if we change microcontroller)
• Tasks to carry out the following functions:
  • I2C hardware interface (so different tasks do not try to access the I2C bus at the same time)
  • Communications Interface (To handle communication with the parent android device)
  • Acceleration Handler (set up the acceleration sensor, and maintain a buffer of acceleration data, by responding to interrupts from the sensor)
  • Display Handler (update the display periodically)
  • Handlers for other sensors
  • Analysis Task - periodically analyse the sensor data to perform seizure detection.
  • Logging Task - periodically log data to the parent android device or local storage for future analysis.