1. Intelligent Mouthguard
Nick Sylvester
Lauren McGarry
Nick Jones
Howard Yeh
Faculty Advisor: Adam Bartsch PhD PE

2. Why is this important?
There is an estimated 1.6 to 3.8 million sports concussions in the US every year
These figures are epidemic caliber by the Center for Disease Control standards
A high school athletic trainer survey indicated 5% players suffer concussion each season while player surveys indicate 50% of players getting 1 concussion per season and nearly 1/3 of players suffering 2 or 3.
Math: 100 players per team -> (100)(.5) + (2.5) (33) = approx. 130 concussions per season -> Colossal difference 5<<130
Clear public safety issue

3. Solution The Intelligent Mouthguard Quantified data
Quickly identify players that need checked
Hard to fake numbers

4. Project Overview Tasks Deliverables Preliminary research Bench testing
Similar devices
Concussion threshold
Cranium rigid body dynamics derivation
Field video analysis
Bench testing
Troubleshooting guide
4 boards lab tested

5. Defining a Threshold Naval Research Center. A.K. Ommaya. 1967.
Summary: Testing on Rhesus Monkeys
Method: Colburn equation (brain mass) → Scaling factor
Threshold unit: Angular acceleration
Result: 7,500 rad/sec2
Reliability: Definition of “concussive”
Wayne State University. L. Zhang
Summary: Analysis of 24 on-field head collisions
Method: Lab reenactment of collisions
Threshold unit: Shear stress (brain stem tissue)
Result: 7.8 kPa = 50% probability
Reliability: Frequency of videos vs impact
Rhesus Monkey: inverse ⅔ power

6. Uncertainty Accuracy vs. Precision Classic example: Dartboard
What does error really mean?
for example 95%

7. Tekscan I-Scan System Similar to the Tactilus System
Heavily used in biomedical applications
Accuracies of ±5% with a repeatability of ≤ ±3.5%

8. Shockwatch
Binary
Visual Indicator
±10%-15%

9. Tactilus High Speed System
High Speed Tactile Sensor System
Can record events lasting 1 millisecond
Pressure Mapping
Used in automotive crash testing
Uncertainty of 10%

10. Sports Impact Measurement Systems
Head band with accelerometers and gyroscopes
Relays data to phone app
No mention of uncertainty
Reebok Checklight
Skull Cap with accelerometers and gyroscopes
Gives a visual indicator of a head injury
Binary tool
No mention of Uncertainty

11. X-2 Biosystems
Created after Rich Able witness his son get knocked out in a football game
Mouthpiece, head band, sticker
Multiple major sports league contracts
Mouthpiece was discontinued after being sued

12. Uncertainty of X-2 Biosystems
No uncertainties given
Closest values to uncertainty given are coefficients of determination from graphs
R2 values ranged from
Results haven’t been replicated

13. Football Helmet Design
National Operating Committee on Standards for Athletic Equipment
Helmets are designed to reduce skull fracture
Peak severity <1200 SI
11.34 ft/s drops severity <300 SI
Can’t deform during testing
Xenith helmet

14. Summary of Video Analysis
Small sample size
Each sport has unique, specific actions
ex. football hits, hockey fights
Most common characteristics
Spatial: X and Y directions

15. Video Analysis Football and Rugby
Procedure
Similar spatial and temporal components
XZ-axis
Upward from the front
Most range of motion in the neck leading to most potential to accumulate angular acceleration
Y-axis
Side of the skull is the thinnest
Look for unconsciousness events and phenomenon referred to as “alligator arms”

16. Video Analysis Example

17. Dynamics of Rigid Bodies
Understand rigid body assumptions
rA/B is constant
Rigid-body equations
Velocity: angular component
Acceleration: tangential and normal components

18. General Case But how is it derived WITHOUT rigid body assumptions?
Cannot assume relative v, a = 0
rA/B can vary
Time derivative of a vector
XYZ = global/reference axis
xyz = body
V = vector
Ω = angular velocity of body

19. Velocity Derivation

20. Acceleration Derivation

21. Acceleration Derivation

22. Testing

23. Goals of Testing
Comparison of impact data measured by mouthguard system to acceleration data recorded by a reference system or “gold standard.”
Validation—how do our measurements match up with gold standard/reference
We only did component testing

24. Materials Two systems: reference and mouthguard
2 systems—reference (gold standard) and mouth guard circuit board
Notes on paper record correlation between two systems’ data

25. Materials Foam versus Rubber
2 different materials on which the board is dropped: foam and rubber (both actually a foam)

26. Materials Rig to which both are attached
3 drops for 3 heights on 2 materials--18 tests per configuration for 3 configurations (3 axes)

27. Methods Set impact threshold and duration on computer
Mouthguard circuit board has 3 modes
Procedure:
Wake board with impact
Lift to height
Standby while reference system begins to record
When both systems are transmitting data, drop carriage
Record acceleration peaks
Record time
Set impact threshold and duration on computer—when computer will start recording data and for how long it will record. Trigger value shold be close to peak value.
Board has 3 modes, distinguished by lights on the board. Wake it up and put it in active mode for tests. After 15 seconds, it will enter radio mode, where it will communicate all its data with the computer.
So, basically how it works is:
Wake up, lift to height, standby, start recording, drop, “trigger”.
Record acceleration peaks.
Record time.

28. Results Mouthguard system Reference system
Analyzed in more detail by people other than us

29. Obstacles Senioritis Availability of boards
Software and board prototypes “misbehaving”

30. Future Work Headgear design research In-vitro testing In-vivo testing
Validating future generations should Dr. Bartsch decide to go this route

31. Questions?