Traumatic Brain Injury Eyewear (TB-Eye)
ECE4007 Senior Design Project
Section L03 TB-Eye Team
Project Advisor, Erick Maxwell
Matt Vildzius, Team Leader
Todd Biesiadecki
Matthew C Campbell
Submitted September 26, 2011
Table of Contents
Executive Summary ......................................................................................................... iii
1. Introduction ..................................................................................................................1
1.1
1.2
1.3
Objective .............................................................................................................1
Motivation ...........................................................................................................2
Background .........................................................................................................2
2. Project Description and Goals ....................................................................................5
3. Technical Specification ................................................................................................5
4. Design Approach and Details ......................................................................................6
4.1
4.2
4.3
Design Approach ..................................................................................................6
Codes and Standards ...........................................................................................11
Constraints, Alternatives, and Tradeoffs ............................................................11
5. Schedule, Tasks, and Milestones...............................................................................12
6. Project Demonstration...............................................................................................13
7. Marketing and Cost Analysis ....................................................................................13
7.1
7.2
Marketing Analysis .............................................................................................13
Cost Analysis ......................................................................................................14
8. Summary .....................................................................................................................16
9. References ...................................................................................................................17
Appendix A .......................................................................................................................19
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Executive Summary
The team is requesting $307.25 to build a prototype of the TB-Eye Traumatic Brain Injury (TBI)
monitoring device. The device will monitor the acceleration of the wearer’s head caused by an
impact force and use colored lights to notify him if he needs medical attention. The intended
market for the TB-Eye system is athletes who are at a significant risk of TBI, including skiers,
snowboarders, and cyclists. No inexpensive, lightweight, and adaptable TBI monitoring systems
are currently on the market. Systems currently available, such as Riddell’s Revolution IQ HITS
football helmet, are expensive and are designed specifically for one sport [1]. The objective is to
create a small, light-weight, battery powered device that attaches to the frame of a pair of
sunglasses. The device will use a three axis accelerometer to monitor the acceleration of the
wearer’s head caused by an impact force and use colored lights to notify him if he needs medical
attention. Data from an impact will be stored in memory on the TB-Eye monitor and a coach or
doctor may wirelessly download the recorded data to a computer and use the Graphical User
Interface (GUI) for the device to assess the risk of injury and determine what treatment is
required. The project will be demonstrated by impacting a simulated head wearing the device. It
will be shown that the device accurately records the impact, alerts the wearer, and transmits the
data to a PC in range. The total cost of equipment is expected to be approximately $307.25. The
total production cost is an estimated $44812.25. If the device is sold at a price of $450, the
company can anticipate a profit of $46.43 per unit. The outcome of the project will be a
functioning prototype of the TB-Eye device.
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Traumatic Brain Injury Eyewear (TB-Eye)
1.
Introduction
The team is requesting $307.25 to build a prototype of the Traumatic Brain Injury Eyewear (TB-
Eye) device for athletes to wear to detect if they experience an impact to the head that may result in
traumatic brain injury (TBI). The device will attach to the frame of a pair of sunglasses that may be worn
for sports such as cycling or skiing where impacts to the head caused by falls or collisions are possible.
The device will monitor the acceleration of the wearer’s head caused by an impact force and use colored
lights to notify him if he needs medical attention. Data from an impact will be stored in memory on the
TB-Eye monitor and a coach or doctor may wirelessly download the recorded data to assess the risk of
injury and determine what treatment is required.
1.1 Objective
The objective of the TB-Eye design is to create a small and lightweight device that attaches to a
pair of glasses to detect possible traumatic brain injury in people participating in sports. The device will
be usable for several different sports, unlike helmets which are designed specifically for one sport. In
contact sports such as football, head impacts are common and expected, but in non-contact sports like
cycling or skiing head impacts are less frequent and more likely to go unnoticed or untreated especially if
a person is alone or far from medical facilities. Football helmets with integrated sensors already exist on
the market, like Riddell’s Revolution IQ HITS football helmet [1], but they are bulky, expensive, and
cannot be justified for sports with infrequent head impacts. The goal of the TB-Eye device is to record
significant impacts to the user’s head and to be unobtrusive by keeping size and weight to a minimum
while maintaining a reasonable cost and recording significant impacts to the user’s head.
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1.2 Motivation
In the United States, approximately 1.5 million people suffer from TBI each year. Of those,
50,000 die as result of their injuries and 85,000 have long term disabilities. Currently there are 5.3
million people living with these disabilities. Among the causes of TBI are deceleration injuries caused by
the head impacting a stationary object. During rapid deceleration events, the brain moves at a different
speed than the skull and different parts of the brain itself experience differential speed. These differences
in movement rate result in brain swelling, contusion, and individual neurons’ axons being broken; these
are causes of TBI [2].
Mild TBI is the “result of the forceful motion of the head or impact causing a brief change in
mental status (confusion, disorientation or loss of memory) or loss of consciousness for less than 30
minutes” and is often missed at the time of injury because symptoms are not always outwardly visible,
and the victim may be too confused or disoriented to recognize the symptoms [3]. For moderate to severe
injuries, it is particularly important to get treatment in the first hour after an injury to prevent additional
damage to the brain and worsening of the patient’s condition that may lead to death [4]. The TB-Eye
system will allow users to be alerted of injury so that they may seek medical attention immediately.
No inexpensive, lightweight, and adaptable TBI monitoring systems are currently on the market.
Systems currently available, such as Riddell’s Revolution IQ HITS football helmet, are expensive and are
designed specifically for one sport [1]. The TB-Eye system is a new product that will find application in a
wide range of athletic activities and sports without hindering the user’s athletic performance.
1.3 Background
Impacts Causing Traumatic Brain Injury
The likelihood and severity of a concussion, which is a mild traumatic brain injury, depends on
the magnitude and duration of the impact experienced. Data from studies conducted on players in the
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National Football League (NFL) show that many concussions occur between 72-125 g (1 g = 9.8m/s2)
lasting for 13-17ms. It also showed that concussions have a greater than 70% chance of occurring for
impacts ranging from 150 g or more lasting 2 ms or less to 75 g last 14 ms or longer [5]. A recent study
has called into question the prevailing notion that the threshold for concussions is 70-75 g. It was found
that concussions could occur as low as 60 g while many impacts higher than 80 g produced no concussive
symptoms [6]. In addition, milder impacts that do not result in a concussion may still cause injury that
manifests itself later. Since the threshold for TBI varies widely depending with magnitude and duration of
impact, and other factors such as a person’s health and prior conditions may play a part, it is better to err
on the side of caution and alert a user of the TB-Eye device to seek medical attention and let a medical
professional analyze the data and evaluate the person.
Accelerometers
Integrated circuit accelerometers are used in a wide variety of applications, such as vehicle
stability systems in automobiles and interactive videogames based on movement of the controller. They
can be used to detect and measure phenomena such as vibrations, impacts, and linear accelerations [7].
Measurement Specialties' Model 832 accelerometer is an example of a high-g integrated accelerometer
currently on the market [8]. The device makes use of the piezoelectric effect to convert non-constant
accelerations into electrical signals. Piezoelectric accelerometers such as the model 832 are advantageous
over other types of accelerometers due to their wide bandwidth, high linearity, and temperature
insensitivity [9]. The Model 832 accelerometer has a bandwidth of approximately 2 kHz, draws a supply
current of less than 4 µA, and can have range of up to 500g [10]. The device's high bandwidth and high
range make it ideal for applications involving high-g impact detection.
Low Power Microcontrollers
Low power microcontrollers (MCUs) are a central component of most battery powered electronic
devices. Recent advances in microcontroller technology, along with improvements to batteries and
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wireless technology have enabled new applications such as wireless health monitors with battery life
measurable in years [11]. A leading manufacturer of microcontrollers for ultra-low power applications is
Texas Instruments with their MSP430 series of MCUs. The MSP430 has several features that give it an
advantage over competing manufacturers’ products in terms of power consumption. The MSP430 is able
to wake up from deep sleep mode and stabilize a high speed clock in as little as 292ns, compared to up to
1ms for devices such as the Microchip PIC16FXXX [12]. That means the MSP430 will spend more time
in deep sleep mode and less time in active mode, and it is able to react to interrupts faster, which is
important when measuring short impacts. Another feature of the MSP420 series is a new type of random
access memory (RAM) called Ferroelectric RAM, or FRAM. Unlike Dynamic RAM (DRAM), FRAM is
non-volatile, so no power is required to preserve data. FRAM also has an advantage over traditional
EEPROM that is commonly used for non-volatile storage in that it can withstand trillions of write cycles,
not just thousands [13]. Finally the MSP430 has brown-out detection that requires no additional power
and an ultra low power watchdog timer that allow the device to run off batteries and reset itself if the
supply voltage drops too low.
Wireless Standards
Low energy wireless communication is important to many battery powered devices such as
wireless heart rate monitors and other wireless sensors. One of the leading low energy wireless standards
is known as ANT, a low-energy wireless technology using the unlicensed industrial, science and medical
(ISM) band in the 2.4 GHz spectrum to transmit and receive data [14]. ANT is a proprietary standard
marketed by Dynastream Innovations Inc. [15]. The ANT standard achieves low energy consumption by
establishing fast connections, allowing more time spent in “sleep mode,” and transmitting short messages;
ideal for applications using simple sensor data [16]. ANT uses its own protocol, ANT+, to allow
interoperability between ANT devices. The ANT+ protocol specifies data formats, channel, parameters
and network keys [17]. The main competing technology with ANT is Bluetooth Low Energy, part of the
Bluetooth 4.0 standard [18]. Bluetooth Low Energy claims to offer many of the same advantages as ANT
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over older short-range wireless standards; however, integrated circuits featuring Bluetooth Low Energy
transceivers are not yet readily available.
2.
Project Description and Goals
The TB-Eye TBI monitoring system will monitor the acceleration experienced by the user and
determine if a significant risk of brain injury exists. The system will consist of an accelerometer to
measure impact, a microcontroller to determine if risk of TBI exists, and a wireless transmitter to report
the data to a PC. The PC will display the received data graphically and clearly indicate whether the user is
at significant risk of TBI. The device will run on a 3.7 volt battery and will attach to the frame of a pair of
sunglasses.
The TB-Eye glasses will have the following features:







3.
Three axis accelerometer to measure impact
Store impact data in the microcontroller’s memory
LED light located in the peripheral field of vision to notify user of impact requiring medical
attention
o Switch located near light to turn light off.
Wireless transmitter to send data to a computer
A rechargeable lithium polymer battery usable for a minimum of one day of operation
o Battery will be located on opposite side of eyewear from device to provide even weight
distribution
A graphical interface to display and analyze data
Minimal form factor proportional to eyewear’s frame, mounted to side of frame.
Technical Specifications
The technical specifications for the TB-Eye system are shown in Table 1. The power
consumption, supply voltage, and battery capacity requirements ensure that the device will operate
normally for at least one day without recharging. The accelerometer with the range specified below will
measure any impact an athlete is likely to encounter without any significant loss in sensitivity. The weight
and size limitations, 4 x 0.6 x 0.2 inches L x W x H and 50 grams, respectively, are chosen to be
proportional to the sunglasses frame and ensure that the device will not hinder the wearer’s athletic
performance.
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Table 1. Technical Specifications for the TB-Eye System
Power Consumption
Supply Voltage
Battery Life
Battery Capacity
Weight
Size
Acceleration Range
Acceleration Recording Threshold
Acceleration Alert Threshold
Accelerometer Sampling Rate (Idle)
Accelerometer Sampling Rate (Active)
Bits of precision of microcontroller ADC
Wireless Transmission Protocol
Transmission Power
Transmission Range
Data Storage
GUI
4.
Design Approach and Details
4.1
Design Approach
61.67 mW
3.7 V
1 day of normal operation
400 mA*h
50 g
Less than 4 x 0.6 x 0.2 inches L x W x H
±100g in all three axes
10g
50g
2 kHz
6 kHz
12
ANT+
0 dBm
30m
Stores the value of acceleration and time
elapsed since the impact occurred.
Displays the acceleration data graphically
Overview
The TBI monitoring system will be comprised of a three-axis accelerometer, a microcontroller, a
wireless transmitter, a wireless receiver, a PC, an LED, and a 3.7 V battery. The block diagram, shown in
Figure 1, shows how the components are connected. Note that the analog outputs for each axis of the
accelerometer are connected to three analog input pins on the microcontroller. The accelerometer,
microcontroller, charging IC, and transmitter will be integrated onto a PCB, which will be mounted on the
frame of a pair of sunglasses. The accelerometer will monitor acceleration data for all three axes of
motion. The microcontroller will read the data from the accelerometer, determine if there is a significant
risk of brain injury, and instruct the wireless transmitter to transmit the information to the PC if necessary.
The microcontroller will also activate a warning LED on the board if the minimum acceleration threshold
is reached.
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Figure 1. High-level block diagram for the TB-Eye TBI Monitoring System.
The accelerometer, battery, and wireless transmitter will be mounted on the frame of the
sunglasses as shown in Figure 2. The accelerometer and transmitter will be integrated onto a PCB that
will also include the microcontroller and the charging IC. The warning LED will be attached to the frame
so that it is visible to the wearer without impairing his or her vision.
Figure 2. Diagram of the device mounted on a pair of sunglasses.
Impact Sensing
The device will include a model 832 XYZ accelerometer, made by Measurement Specialties. The
accelerometer has a ±100g measurement range in all three directions, has a bandwidth of 2 kHz, and
outputs a ratiometric analog voltage signal for each direction. The three analog outputs from the
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accelerometer will be connected to the ADC inputs on an MSP430 microcontroller on the board. The
microcontroller will sample the accelerometer at an idle sampling rate of 2 kHz. When an acceleration
with a magnitude of at least 10g is detected, the microcontroller will switch to an active sampling rate of 6
kHz. If the acceleration value is at least 50g, the microcontroller will turn on the LED on the board
indicating that the user must seek medical attention. The magnitude of the acceleration, along with the
time of the impact, will be stored in the microcontroller’s memory. The data will also be sent to the
wireless transmission module to be transmitted to the PC when the device is in range.
Wireless Transmission
The RF module will receive data from the accelerometer via serial interface with the
microcontroller and wirelessly transmit the data to a receiver connected via USB to a PC. The receiver
will store the data on the PC as it is received. The wireless transceiver will be based off the design of the
Sparkfun Electronics WRL-08565 module, which is based on Nordic's nRF24AP1 IC. The RF part of the
design (filter and matching network, and trace antenna) will be kept identical to the Sparkfun module
design, but the supporting components will be moved for a more compact layout, and the design will be
integrated on the same board as the rest of the device. The nRF24AP1 implements the ANT wireless
protocol, which is commonly used in personal area networks (PANs) to transmit sensor data from sports
equipment where ultra-low power is required. The receiver will be the Sparkfun WRL-08840 USB
device which plugs into a PC and is based on the same Nordic nRF24AP1 IC.
Graphical User Interface (GUI)
A GUI, shown in Figure 3, will be implemented in MATLAB to be run on a PC connected to the
wireless receiver. The GUI will read in any data seen at the receiver and display it graphically, with the
acceleration threshold clearly shown. Colored text-boxes not depicted here will inform the user of the
status of the person wearing the glasses, and will display the elapsed time since the collision, if
applicable.
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Figure 3. Sample GUI displaying force (g) detected by the accelerometer over time (s). Below
the graph is a table that will numerically display the data.
Contingency Plan
If the Nordic ANT transceiver cannot be made to work, a Roving Networks RN-42 Bluetooth
module will be used. The RN-42 is a class 2 Bluetooth module that transmits at up to +4dBm power. Data
and control of the module are handled over a serial UART connection from the microcontroller. The
module implements a Bluetooth Serial Port Profile (SPP) so it works with other SPP devices such as USB
transceivers for a computer. The power consumption of the RN-42 is higher than that of the ANT
transceiver, primarily because Bluetooth connections take more time to negotiate than ANT connections;
however power consumption of the transceiver will not be an issue since it is used infrequently. The
module has a sleep mode that draws only 26uA, and if power consumption must be lowered beyond that,
the microcontroller can be used with a switch or the enable pin on the 3.3V regulator to physically
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disconnect power. One downside to using the RN-42 is its relatively large physical size. The module is
0.53 inches wide, and requires a PCB approximately 0.6 inches wide for mounting.
4.2
Codes and Standards
1. ANT is a proprietary wireless networking protocol and embedded system designed for wireless
sensor networks. It features



Ultra-low power, flexible PANs
Reliable data communications with cross-talk immunity [19]
Flexible network topology with burst, broadcast and acknowledged data transmission
types [20]
2. Universal Serial Bus (USB) is used by the WRL-08840 for connection to a PC. It is also used to
recharge the battery. USB features



Plug-and-play capability
5V power requirement
480 Mbps data transmission rate [21]
3. Synchronous Serial Interface (SSI) is used by the MSP430 microcontroller for connection to the
wireless transceiver. It features


4.3
Supports Microwire, Synchronous Serial Protocol (SSP), and Serial Peripheral Interface
(SPI) protocols
7.2kHz-24 MHz transmission bit rates [22]
Constraints, Alternatives, and Trade-Offs
Alternatives
Linear acceleration is not the sole indicator of brain injury; rotational force experienced by the
head is one aspect that contributes to the severity of brain injuries [23]. Another sensing option available
is rotational acceleration or displacement using a solid-state gyroscope. The gyroscope could be used in
addition to an accelerometer to provide sensor data for the head’s full range of motion. Adding a
gyroscope would increase the informative power of the device, at the expense of design simplicity and
power efficiency. Because a simple, low-power design is required, only one sensor will be implemented
on the device. Linear acceleration provides the most information about the severity of the injury [23];
therefore, a linear accelerometer was chosen as the sensor to be used.
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Constraints
Since only an accelerometer will be used to detect a risk of brain injury, other indicators of TBI
such as rotational acceleration will not be accounted for in the design. Additional sensors are being
omitted from the design in the interest of simplicity, low power consumption, and small size. Another
constraint is that in order for impact data to be wirelessly transmitted from the glasses to a PC, the PC
needs to be on and attached to a receiver and the transmitter needs to be in range. While the wearer will
know immediately if there is a risk of TBI, the operator of the PC may have to wait for the wearer to be in
range before seeing the impact data. A lower-range wireless transmission protocol was chosen to
minimize the size, weight, and power consumption of the device. Finally, the durability of the device is
limited by the durability of the glasses the device is attached to. If an impact breaks the frame of the
sunglasses, the device is rendered unusable until a replacement pair is found.
Trade-Offs
The battery on the device needs to be as small as possible in order to minimize the size and
weight of the device. However, there is generally a trade-off between the size of a battery and its capacity.
Therefore, small and lightweight batteries will have a much shorter lifespan. This small capacity is being
accounted for by choosing low-power components and implementing microcontroller software meant to
reduce power consumption. Also, a high-range accelerometer is required to measure the types of impacts
athletes typically encounter. However, high-range accelerometers tend to have a lower sensitivity than
ones with a lower range because of limitations on precision of the analog output. The range of the
accelerometer needs to be as low as possible while still including the range of impact magnitudes that
athletes could potentially experience.
5.
Schedule and Tasks
The Gantt chart for the development of the TB-Eye system is shown in Appendix A. All tasks
shown will be performed by all members of the team. The first critical task in the development process is
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the schematic design. As shown in the chart, the schematic design is a predecessor for the PCB layout and
assembly of the device. In order to ensure that the device is assembled on schedule, the schematic design
design must be completed by October 3rd. The PCB layout will be complete by October 28th, and the
device will be fully integrated on to a PCB by November 4th to allow ample time for testing. The testing
of the final system, including the design and implementation of a test procedure, is tentatively scheduled
for completion by November 11th.
6.
Project Demonstration
The project demonstration will take place in the lad in Van Leer building during the week of
December 12, 2011. The project will be demonstrated by impacting a simulated head wearing the device.
It will be shown that the device accurately records the impact, alerts the wearer, and transmits the data to
a PC in range. The data on the PC will be displayed and analyzed to determine the peak magnitude and
time duration of the impact. By simulating impacts of different known magnitudes it will be shown that
the thresholds for recording and user alerts work correctly.
7.
Marketing and Cost Analysis
7.1
Marketing Analysis
The intended market for the TB-Eye system is athletes who are at a significant risk of TBI,
including skiers, snowboarders, and cyclists. The Riddell Revolution IQ HITS helmet is an example of a
TBI monitoring system currently on the market. Like the TB-Eye system, Riddell’s helmet contains
sensors that record the magnitude and duration of the impacts, and can transmit the data either wirelessly
or via USB at a later time. The helmet costs $1030.99 and is intended only for football players [1]. The
TB-Eye system differs from the Riddell helmet in that it can be used for a wide variety of athletic
activities, rather than just one sport.
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7.2
Cost Analysis
Table 2 shows an estimate of the equipment cost for the TB-Eye system. The total cost of
equipment is expected to be approximately $307.25. The accelerometer costs $165 and makes up a
significant portion of the cost of the device, but it is a critical component. The values shown are subject to
change, since free samples of many of the ICs may be available. Also, to account for the possibility of
chips breaking, multiple units of each IC may need to be purchased, which would increase the cost.
Table 2. Equipment cost for the development of the TB-Eye syetem.
Quantity
Unit Price
Accelerometer
1
$165
Microcontroller
1
$1.76
Printed Circuit Board
1
$55
Battery
1
$2.50
USB Charger
1
$0.85
Wireless Transmitter
1
$22.18
Wireless Receiver
1
$34.95
Total
$307.25
Table 3 shows the estimated labor cost for the project, assuming an hourly wage of $25.00 for
each team member. The total cost of labor is approximately $19,350. As shown in the table, the bulk of
the labor time is estimated to be spent on the prototype of the device, including writing and debugging the
microcontroller software. The hours shown are the combined hours for all three members of the team.
Table 4 summarizes the estimated total cost of production for the TB-Eye system. Fringe benefits were
assumed to be 30% of the total labor cost, and the overhead cost was assumed to be 100% of the labor
cost. The total production cost is an estimated $44812.25.
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Table 3. Labor Cost
Hours
Total Cost
Lectures/Group Meetings
384
$9,600
60
$1,500
120
$3,000
GUI Programming
60
$1,500
Integration
60
$1,500
Testing
90
$2,250
774
$19,350
Layout and Schematic Design
Prototyping/Microcontroller
Programming
Total
Table 4. Total Production Cost
Cost
Parts
$307.25
Labor
$19,350
Fringe Benefits
Overhead
Total Cost of Production
$5,805
$19,350
$44,812.25
The cost of manufacturing is estimated to be equal to $268.95 per unit. This estimate includes the
equipment cost plus the cost of the labor required to manufacture a unit. The cost of the PCB was omitted
in the calculation of the production cost, since PCBs will be negligibly inexpensive at high quantities.
Since the development board is only needed for prototyping, its cost was also left out of the production
cost. The cost of sales is assumed to be 10% of the cost of each unit sold. It is expected that
approximately 500 units will be sold over the span of a 5-year period. If the device is sold at a price of
$450, the company can anticipate a profit of $46.43 per unit.
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8.
Summary
The following has been completed thus far:



Parts list with pricing and ordering information
Prototype parts are on order
High-level design of microcontroller software
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References
[1]
Riddell. “Riddell Revolution® IQ HITS™ Helmet”. 2011. [Online]. Available:
https://shop.riddell.com/riddell/app/displayApp/%28cpgsize=20&layout=7.07_2_3_75_12_13_67_78_6_4_5_6&uiarea=6&carea=0000000001&cpgnum=1&citem=0000000
0010000000009%29/.do?rf=y. [Accessed: September 21, 2011].
[2]
Traumatic Brain Injury.com, LLC. “What are the Causes of TBI?”. 2004. [Online]. Available:
http://www.traumaticbraininjury.com/content/understandingtbi/causesoftbi.html [Accessed:
September 21, 2011].
[3]
Traumatic Brain Injury.com, LLC. “Mild TBI Symptoms”. 2004. [Online]. Available:
http://www.traumaticbraininjury.com/content/symptoms/mildtbisymptoms.html [Accessed:
September 21, 2011].
[4]
Kluger, Jeffrey. "Dealing with Brain Injuries,” Time Magazine, 6 April, 2009. [Online],
http://www.time.com/time/magazine/article/0,9171,1887856,00.html. [Accessed: 25 September,
2011].
[5]
E. Blackman. Helmet Protection against Traumatic Brain Injury: A Physics Perspective.
[Online]. http://www.pppl.gov/colloquia_pres/WC25MAR09_EBlackman.pdf [Accessed 25 Sept.
2011].
[6]
J. Gever, “Any Football Helmet Hit Can Cause Potential Concussion,” MedPage Today, 7 Dec.,
2007. [Online]. http://www.medpagetoday.com/Neurology/GeneralNeurology/7625 [Accessed 25
Sept. 2011].
[7]
Analog Devices. “The Five Motion Senses: Using MEMS Inertial Sensing To Transform
Applications”, 2009. [Online]. Available: http://www.analog.com/en/mems-sensors/high-gaccelerometers/products/whitepapers/over_Five_Motion_Senses/resources/fca.html [Accessed 5
Sept. 2011].
[8]
Measurement Specialties, “Vibration Sensor - Model 832 Accelerometer,” September 2011.
[Online]. Available: http://www.meas-spec.com/product/t_product.aspx?id=5593 [Accessed 4
Sept. 2011].
[9]
Piezocryst, “Basics: Piezoelectric Sensors,” September, 2011. [Online]. Available:
http://www.piezocryst.com/piezoelectric_sensors.php [Accessed 5 Sept. 2011].
[10]
Measurement Specialties, "Model 832 Accelerometer," Model 832 Accelerometer datasheet, July
13, 2011
[11]
Microchip Technology, “nanoWatt XLP eXtreme Low Power PIC®MCUs,” Apr. 2010 [Online].
Available: http://ww1.microchip.com/downloads/en/DeviceDoc/39941d.pdf [Accessed 5 Sept.
2011].
[12]
Texas Instruments, “Choosing An Ultralow-Power MCU,” Application Report SLAA207, Jun.
2004.
[13]
Texas Instruments, “Low-Power FRAM Microcontrollers and Their Applications,” White Paper
SLAA502, Jun. 2011.
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[14]
Nordic Semiconductor. (September 2006). Single chip 2.4 Ghz Transceiver with Embedded ANT
protocol. (Rev. 1) [Data Sheet]. Available:
http://www.nordicsemi.com/eng/nordic/download_resource/6615/1/97271469 [Accessed: 18
Sept. 2011].
[15]
ANT Wireless. “ANT Wireless – Providing Technologies That Lead the Globe”, 2011. [Online].
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[16]
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Team TB-Eye (ECE4007 L03)
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Appendix A. Gantt Chart.
Team TB-Eye (ECE4007 L03)
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