Instrumented Football Helmet

1
Instrumented Football Helmet

• Louis Criso (ECE)
• Francis Kitrick (ECE)
• Ryan Lewis (ME)
• Robert Sorbello (ECE)

2
Problem Statement

• Design a working football helmet that can analyze
  the force of impact and determine if the impact
  is dangerous to the player.
• A microprocessor in the helmet will store data
  regarding the impact for analysis that can be
  later uploaded to a computer.

3
Motivation

• According to the National Football League, there
  are 160 concussions sustained every year.
• Roughly 17 of all high school football players
  in the U.S. will suffer a concussion each year.
• If left untreated, a concussion can be
  detrimental to a players long-term health.

4
Approach

• Equip a standard football helmet with pressure
  sensors and accelerometers to measure and store
  the impact force sustained.
• Build a testing apparatus to properly test and
  calibrate our design to prepare it for game
  situations.

5
The Schematic

• Processor
• MMC
• Accelerometers
• Flex Sensors
• Battery
• Voltage Regulators

6
The Printed Circuit Board (PCB)
7
ARMexpress LITE Features

• 32K Flash memory
• 6 A/D channels, 10bit resolution, 100kHz sample
  rate
• SPI support with 600 Kb transfer rate

8
Memory Map
                                                  
            
9
A/D Channels

• 6 A/D Channels
• 15 KHz sampling rate
• 615 KHz 90K of data for one second
• So we would need 9K of space to record hits for
  100 ms (1/10th of a second)
• The A/D channels will be consistently buffered
  through the flash memory until a certain
  threshold is reached.
• Once this threshold is reached by any one of the
  sensors, then the next 100 ms will recorded to
  the flash memory and written to the memory card.

10
Programming Logic

• Overall software design of helmet includes
• Clock divider
• Obtaining inputs from sensors
• Determine intensity of recorded data
• Output accordingly

11
First step setting the sampling rate

• ARM processor runs at 60mhz. We want to scale
  this down to 15khz.
• First step in software is to create a delay
  function/clock divider.
• Using intervals obtained through clock divider,
  store input from sensors into variables/memory.

12
Next using the data

• Data from all sensors are stored in assigned
  spots according to the type of sensor it was
  obtained from. (accelerometer or pressure)
• Values from sensors are compared against
  calculated threshold values corresponding to
  intensity of hit to the helmet.

13
The Output

• If the recorded hit is safe ie. below the
  threshold value, value is discarded from memory.
• If the hit is determined un-safe ie. Stronger
  than allowable for the players safety then that
  incident is recorded by saving the values of the
  hit onto the card memory.
• Finally alarm (led, buzzer) is triggered.

14
Apparatus Design

• Simple pendulum
• Use design specifications from existing patent
  for football helmet testing (US 6,871,525 B2).
• 2 m long arm with a 19 kg impactor, generating
  280 J of energy.
• With this information from patent generated
  MathCAD file to solve for initial angle (75
  degrees)

15
Post Impact Analysis

• After the information from the sensors and
  accelerometers is gathered, the data needs to be
  analyzed to determine threshold.
• The Gadd Severity Index (GSI)
• Pass/fail basis over 1,000 is a fail.

16
End Deliverables

• Plan on delivery a working football helmet that
  can measure the force of impact, determine if the
  impact was of danger to the player, and store
  this data to be analyzed later.
• A working testing apparatus to test future
  football helmet designs.

17
Budget

Item Budget
Accelerometer 31.25
Wireless Adaptor 70.00
PIC Microprocessor 10.00
Li-Ion Battery and Manager 10.00
Building Material 30.00
Testing Material 50.00  
201.25  
18
Questions?Comments?