Traumatic Brain Injury Eyewear “TB-Eye”

Traumatic Brain Injury Eyewear “TB-Eye” Todd Biesiadecki, Matthew Campbell, Matthew Vildzius ECE4007 L03 EM1 Advisor: Erick Maxwell October 31, 2011

Overview • Glasses to alert user of potential head injury • For non-contact sports such as skiing and cycling • Head impacts infrequent • specialized helmets not justified or practical • Unit development cost: $307.25

Device mounted on a pair of sunglasses Eyewear Nose Accelerometer and Wireless Communication Battery Head

Design Objectives • Lightweight, unobtrusive device • Battery powered • Data recording and storage • Wireless communication • Alert the user to get medical attention • Computer based graphical interface

TB-Eye System-Level Diagram

Device Operation

Accelerometer • 100G accelerometers not available or cost-prohibitive • 16G accelerometer used instead • Analog Devices ADXL345 • 145uA max. current • Measurements of 16G or more will trigger an alert • Utility of recorded data more limited vs. full range device

Microcontroller • ATMega368 microcontroller with Arduino libraries • Power consumption slightly higher than competition • Well-supported libraries • Power consumption expected to be 1-4mA while sampling • Plan to optimize code for low power by keeping the MCU in sleep mode

Battery Life in Monitoring Mode • 110mAh battery • Microcontroller: 4mA max • Accelerometer: 0.15mA • Max current: 4.15mA • Expected worst-case battery life: 26 hours • Assumes transmitter and LED indicator are off

ANT+ Transceiver • Working on code to get the transceiver working with the microcontroller • Need to get the USB transceiver working on a computer • Serial command interface

ANT vs. Bluetooth • Advantages to ANT+ transceiver • Low power • Standard protocol • Small physical size • Disadvantages • Not widely supported • Relatively short range, up to 30 meters.

Wireless Challenges • Power • Maintaining a persistent channel is costly • Information Storage • How do we store data while establishing a connection? What if we are out of range?

Graphical User Interface (GUI)

Graphical User Interface (GUI) • Still to Do • Additional Features • Text display if threshold is reached • Text input for acceleration threshold • Improve appearance and layout

PCB Layout • Schematic has been started • Need to finish schematic and layout soon to order a printed board • May be able to use a prototype board • More difficult to solder and less robust

Budget • Total budget: $405.00 • Spent so far: $131.50 • Remaining budget: $273.50 • Still to Buy • Circuit Components ($50-75) • PCB ($50-100)

Future Work • Finish GUI implementation • Achieve wireless communication • Manufactured PCB • Optimize MCU power consumption

Project Schedule • November 11th – Circuit prototype completed • November 11th – GUI completed • November 18th – PCB fully assembled • November 21th – Test procedure designed and performed on the final product

Factoid • 300,000 reported TBI cases caused by sports per year

Traumatic Brain Injury Eyewear “TB-Eye”