tcnj athlete tracker · 2018. 10. 17. · 2.1-3 astm-d5276 standard test method for drop test of...

TCNJ Athlete Tracker: A non-invasive data acquisition system for athletes

SP I Final Presentation

Rob Cortinas, Jessica Gonzaga, Anasha Green, Aileen Saulenas

Introduction

● Approximately 420,000 collegiate students participate in sports per year [23]

● Over 12,000 injuries occur in these athletes per year [23] ● Physical well-being of athletes can be affected by

o impact forces o heat stroke

o abnormal heart activity

o dehydration

● The NCAA has established rules to help decrease the number of preventable injuries o required safety equipment o safety regulations for high impact sports (i.e. tackling in football)

● Monitoring devices exist for athletes but are deficient in different aspects o do not measure continuously o only measure one vital as opposed to several at a time o devices are obtrusive o do not alert the athlete when at risk of injury or overexertion

Problem Statement

● Society promotes physical activity for people of all ages and encourages

individuals to take part in exercise and sports

● Athletic participants assume the risk of potential injury any time they

engage in a physical activity

● Goal: To monitor the health and ensure the safety of players during their

regular practices by incorporating multiple sensors to measure heart rate,

skin conductivity, body temperature, and impact force experienced by the

body

○ Warning alarm will be used to indicate when an individual is at risk of

overexertion or injury

○ It is desired that this system will not cause an obstruction that will interfere

with the individual’s performance or ability to play the sport

Background

TCNJ Athlete Tracker

• According to the NCCSI, there have been 66 deaths due to exertional heat stroke between 1975 and 2009 [22]

• An estimated 1.6 to 3.8 million concussions occur in sports and recreational activities annually [24]

• Blunt impact to the chest can lead to sudden death from cardiac arrest during sports [25]

• Heart rate measurements can be used to optimize training intensity [20]

• Between 100 and 150 athletes die from sudden cardiac death per year [9]

• The NCCSI reported 4 deaths among college and high school football players in 2000 and 20 deaths due to heat stroke in the past 7 years in which dehydration was a contributing factor [19]

Attachment to the Body

Design Input

Requirement

Design Specifications Verification Activity Validation Activity

Method/Protocol Method/Protocol

1.Device must monitor body

temperature

1.1 Device must monitor

skin temperature of 37ºC +/-

2ºC

1.2 Device must recognize

temperatures above 39ºC as

dangerous.

1.3 Device will use skin

temperature as a surrogate

for core body temperature

readings

1.1 Objects at various

temperatures will be

measured with device and

compared to a commercial

thermometer.

1.2 Device will be exposed

to temperature above 39ºC

to verify device recognition

of dangerous temperature

1.3 No verification activity

1.1-2 The device will be

worn on an athlete

participant during a normal

team practice. Success will

be defined based on

accurately recording

temperature values and

sending an alarm should a

temperature value exceed

39ºC

1.3 Core temperature of

athlete will be measured

using a temporal scanning

thermometer and

simultaneously compared to

skin temperature measured

by device.

Justification

1.1-2 According to the Mayo Clinic, heat stroke occurs when body temperature rises to about 40ºC. In order to protect

the user, the device will warn the individual of temperatures above 39ºC. [21]

1.3 Traditional ways to measure core body temperature are invasive

Design Input

Requirement



2.Device must measure

impact forces to the body

2.1 Device must measure

impact forces to the head


impact forces to the chest

2.3 Device must warn user

when forces reach or exceed

60 G’s

2.4 Impact forces should be

recorded along the three

axes of athlete motion

2.1-3 ASTM-D5276

Standard Test Method for

Drop Test of Loaded

Containers by Free Fall.

Drop contained device onto

a flat, firm, nonyielding steel

base. Drop height is set to

30” and is dropped ten times

in ten different orientations.

2.4 Assembly will be

dropped diagonally

downward from 30” to

detect recordings in three

axes of motion


worn on an athlete



be defined based on

successfully recording

impact forces at the head

and chest in all three

directions of motion and

sending an alarm if a

recorded impact exceeds 60

G’s

Justification

2.1 An estimated 1.6 to 3.8 million concussions occur in sports and recreational activities annually. [24]

2.2 Blunt impact to the chest can lead to sudden death from cardiac arrest during sports. [25]

2.3 NHTSA standard for a sudden impact acceleration on a human that would cause severe injury or death is 75 g's for a

50th percentile male, 65 g's for a 50th percentile female, and 50 g's for a 50th percentile child [26]

2.4 When athletes receive an impact, the body will not only respond in one direction.

Design Input

Requirement




dehydration


skin resistance (ohms)

3.2 Device must recognize

skin resistance values

greater than 1,000 Ohms as

a potentially dehydrated

state [13]

3.1-2 Attach device across

nodes of a resistor and

compare resistance

measurement to banding

pattern values on the

resistor. Resistors greater

than 1,000 Ohms will also

be used to verify device

recognition.

3.1 The device will be worn

on an athlete participant

during a normal team

practice. Athletes will be

weighed before and after

practice. [7,19] Success will

be defined based on

successfully recording skin

resistances and comparing

them to percentage of mass

lost after practice. The

percentage of mass lost can

also be compared to heart

rate as heart rate rises 3-5

beats per minute every 1%

of body weight loss [4]

Justification

3.1 The National Centre for Catastrophic Sports Injuries (NCCSI) reported 4 deaths among college and high school

football players in 2000 and it has recorded 20 deaths from heat stroke over the past 7 years. Dehydration was the

contributing factor in all of these deaths [19]

3.2 Hypohydration of 2-3% of body mass can compromise athletic performance, heat dissipation, and cardiovascular

function [6,17]

Design Input

Requirement




heart rate

4.1 Able to measure from

40 beats per minute (bpm)

to 220 bpm

4.2 The device must

recognize heart rates above

190 bpm as dangerous

4.3 Heart rate measured

once per minute

4.4 The device must

measure and record beat to

beat intervals of the pulse

curve

4.1-3 Using an arterial

puncture arm mannequin,

pump a blood-mimicking

fluid composed of water,

glycerol, and sodium iodide

(viscosity 4.4±0.5 cP)

through simulated artery

using a motor with a known

revolution speed [18]. The

device will be attached to

the mannequin and the

recorded heart rate should

resemble the pulsatile

action of the motor.


worn on an athlete



be defined based on the

sensor accurately and

continuously recording

heart rate and sending an

alarm should the rate

exceed 190 bpm.

4.4 The user will be able to

view the pulse curve after a

practice or game

Justification

4.1 Minimum values of heart rate can reach values as low as 40 bpm. Maximum heart rate for collegiate athletes is

approximately 200 bpm and active athlete heart rates reach between 65% and 95% of the maximum [12] [16]

4.2 Athletes spend most of their time at heart rates near the maximum heart rate. Rates at or above 95% of the

maximum or above indicates overexertion [3]

4.3 Heart rate must be constantly measured so the player can be alerted as soon as his or her rate exceeds 95% of the

maximum

4.4 A recording of beat to beat intervals can be used for analysis of heart rate variability to determine risk for SCD

[14]

Design Input

Requirement



5.Device must record all

monitored signals

5.1 Connections to

microprocessor must be

secure. If not, user must be

informed through alarm

system.

5.2 Microprocessor must be

able to read sensor data in

order to monitor user’s

condition.

5.3 Device must record data

during the entire practice (5

hours)

5.4 Device must collect an

appropriate number of

samples

5.4.1 Temperature sampled

every 5 minutes

5.4.2 Heart rate sampled

every minute

5.5 Device must have a

sufficient amount of

memory to collect data from

all sensors for the entire

practice

5.1-2 Each sensor will be

tested individually

according to verification in

1,2, and 3 in order to assure

functionality.

5.3 Device will be turned on

for 5 hours to ensure battery

lasts.

5.4 Sampling frequency will

be set during coding of

microprocessor.

5.5 Data will be recorded on

the device until memory is

full in order to verify that

enough memory is

available.

5.1-2 All three sensors will

accurately measure vitals

and impact forces.

5.3 Athlete will complete an

entire practice with device

on and data will be checked

in order to make sure it

worked for the entire length

of the practice.

5.4 Data will be inspected

after practice to ensure

sampling rate was correct.

5.5 Athlete will wear device

through entire practice. If

memory did not run out,

validation will have been

successful.

Justification

5.1-2 Microcontroller will be used due to its size and ease of integration with sensors.

5.3 Device is useless if it cannot obtain data for the entire time it is needed.

5.4 Data must be sampled often in order to ensure no dangerous changes in vitals are missed.

5.4.1 Temperature changes do not occur as abruptly as changes in heart rate, so sampling rate does not have to be as

frequent.

5.4.2 Heart rate must be sampled often to detect if user demonstrates a heart rate at or above 95% of their maximum

5.5 If memory runs out, data will not be recorded and device would be useless

Design Input Requirement 5.Device must record all monitored signals

Design Input

Requirement



6.If any monitored metric of

1, 2, and /or 3 exceed

specified range, user must be

notified

6.1 The alarm must turn off

automatically after it sounds

for 10 seconds

6.2 Device must include an

auditory alarm (70 dBA) to

ensure that the signal is

noticed when worn

6.1 Expose device to

conditions which exceed the

specified range of 1 and 2.

Use a stopwatch to time

duration of alarm.

6.2 Expose device to

conditions which exceed the

specified range of 1 and 2.

Create background noise (60

dB). Ensure alarm can be

heard above background

noise [15]




practice. If the alarm sounds

on the field, success will be

determined if the alarm

automatically turns off

within 10 seconds

6.2 It will be observed

throughout a practice

whether the alarm is heard

when turned on. The number

of times the alarm turns on

will be compared to the

number of times the athlete’s

collected data shows

physiological values outside

of the defined range.

Justification

6.1 The duration of the alarm was determined to be long enough to notify the player while not creating a disturbance

6.2 Based on OSHA specifications for Permissible Noise Exposure [11]

Hours 8 6 4 3 2 1.5 1 0.25 < 0.25

Decibels 90 92 95 97 100 102 105 110 115

Design Input

Requirement



7.Device must operate on

battery power

7.1 Battery must

continuously supply 9V of

power

7.2 Battery must

continuously operate for 5

hours

7.3 Device must alert user

when the battery is no

longer supplying 9V

7.4 Athlete must be able to

replace dead batteries

7.1 Device will be turned

on and external supply

voltage will be probed

using a Digital Multimeter

7.2 Device will be turned

on and timed until complete

power dissipation will be

measured

7.3 Old, used battery will

be inserted into device and

the device will be turned

on. Digital Multimeter will

probe external supply

voltage. When the voltage

decreases below 9V, alarm

should be triggered.

7.4 Battery access panel

will be opened


worn on an athlete



be determined if a new

battery will last the entire

duration of the practice and

all electronic hardware

continuously operates from

the power source.




practice. Success will be

determined if an old, used

battery causes the device to

alert the athlete of the

performance malfunction.

7.4 Athlete will be asked to

change the battery and

report any difficulties

Justification

7.1 Microcontroller can operate on an external supply of 6 to 20V. If supplied with less than 7V, the 5V pin may

supply less than 5V and the board may be unstable. If using more than 12V, the voltage regulator may overheat and

damage the board. The recommended range is 7 to 12 volts. A 9V supply will adequately power the microcontroller

and additional electronic hardware. [27]

7.2 Surveyed members of the TCNJ Athletic Department claimed that the average practice would last about 3 hours.

7.3 If voltage supply decreases below 7V, the 5V pin may supply less than 5V and the board may be unstable.

Additional electronic hardware may not accurately detect monitored signals of 1, 2 and 3.

7.4 Device must include an access panel for the battery to extend the usable life of the device

Design Input Requirement 7.Device must operate on battery power

Design Input

Requirement



8.Electronics must properly

function under different

conditions that athletes

operate under

8.1 The device must be

encased to protect the

electrical components

8.1.1 The casing will exhibit

water resistance up to IPX

level 3

8.1.2 The casing will be able

to withstand impact forces

up to 60 g’s

8.1.1 Water will be sprayed

on to the device up to 60

degrees from vertical at 10

liters/min at a pressure of

80-100kN/m2 for 5 min [8]

8.1.2 The device will be

tested for impact resistance

according to the ASTM

standard D2463 [1]

8.1 An athlete will wear the

encased device during a

practice. After the practice

is over the case will not be

damaged and the electrical

components will remain

dry

Justification

8.1 Electrical components need to be protected in order to operate correctly

8.1.1 Athletes are exposed to rain and sweat during practice

8.1.2 Athletes can experience impact forces up to 60 G’s depending on the sport [10]

Design Input

Requirement



9.The device must not

inhibit regular athlete motion

9.1 The device must be

secure enough so that it does

not fall off

9.2 Shirt (or belt) must not

be constrictive.

9.1-2 Device will be

attached to interactive

mannequins in the Nursing

Department laboratories.

Success will be evaluated

based on the ease with

which the mannequins are

able to move arms/torso

while wearing the device.

9.1 Athlete will run around

while wearing the device in

order to ensure it does not

fall off.

9.2 Athlete will perform

several movements in order

to determine their range of

motion while wearing the

device.

Justification

9.1-2 The loosening or detachment of any part of the device may hinder the user’s movements in such a way that they

may be susceptible to injury

Design Input

Requirement



10.The device must be

comfortable for athletes to

wear during sports related

activities

10.1 The device should not

exceed 9 oz. in weight

10.2 Device should not

exceed a size of 6” by 4”.

10.3 Material used to attach

the device to the body must

not cause skin irritation

10.4 Device should be

attached to the back of the

body

10.5 Wiring should allow

for movement but must not

dangle near moving limbs.

10.1 Device will be

weighed on a precision

scale and the weight will be

recorded

10.2 Device will be

measured using a ruler

10.3 Atomic Force

Microscopy tool will

determine the roughness of

the material. Greater

roughness will correlate to

increased irritation .

10.4-5 Device will be

attached to the back of an

interactive mannequin in

the Nursing Department

laboratories. Success will

be evaluated based on the

ease with which the

mannequins are able to

move without interference

due to wiring


worn on an athlete


team practice. Afterwards,

athletes will be asked to

answer a questionnaire with

the following questions:

1.Were you able to

participate in practice as

you hoped to while wearing

the device

2.Was the weight of the

device a noticeable

disturbance during your

play

3.Did you find the

placement of the device to

be satisfactory?

4.Did the material irritate

your skin?

5.Did any wiring inhibit

your activity or get in your

way?

Justification

10.1 Surveyed members of the TCNJ Athletic Department claimed that an acceptable weight would be similar to the

weight of a current smartphone with a protective casing

10.2 Surveyed members of the TCNJ Athletic Department claimed that the device should be as minimal in size as can

possibly be constructed. The specified dimensions should satisfy the spatial needs of all electronic hardware.

10.3 Skin irritation will minimize the benefits attained from the device

10.4 Surveyed members of the TCNJ Athletic Department claimed that the device will interfere with normal exercise

the least if situated on a player’s back

10.5 Loose wiring could cause individuals to trip during play, potentially leading to injury.

Design Input Requirement 10.The device must be comfortable for athletes

to wear during sports related activities

Design Input

Requirement



11.The cost of constructing

the device must fit within a

budget

11.1 The device

components must be

selected and justified for

purchase according to

power, weight, dimensions,

intended function, durability

and cost

11.1 Purchase of

components and materials

of the device must first be

justified based on how well

they will fulfill their

intended function for their

price. If additional funding

is necessary above the

allotted $400, a formal

request will be submitted to

the Dean.

11.1 Final total costs are at

or below total allocated

funds for project ($400).

Justification

11.1 The starting budget is $400 to purchase necessary components for the device

Design Input

Requirement



12.Device must be safe to

use

12.1 The device will be

resistant to overheating

12.2 The device casing will

not cause injury upon

impact

12.3 The device will include

an easy-to-follow instruction

manual

12.1 The device will run

consistently for the duration

of a typical practice and be

monitored to ensure it does

not overheat

12.2 The device will be

tested for impact resistance

according to the ASTM

standard D2463 [1]

12.3 The manual will

contain simple and relevant

safety instructions


device for the duration of a

practice and it will not

overheat


device during a practice and

not experience any injury if

hit

12.3 A user will receive the

instruction manual before

using the device

Justification

12.1 Overheating of the components can cause injury to the user.

12.2 Should the athlete be hit in the location of the casing, it may crack and cause injury

12.3 Users need to be aware of the necessary safety precautions in order to to safely use the device

Design Solution

Temperature Sensor ● Choice: TMP 007 infrared thermopile sensor ● Justification

o Easily integrated with Arduino Uno o Extremely small o Does not need to come in contact with skin o Requires minimal wiring

● Alternatives o Thermocouple o Thermistor

TMP007 Schematic and Breadboard Wiring

Design Solution Accelerometer ● Choice: ADXL377 - High-G Triple-Axis Accelerometer ● Justification:

o Small, thin, operates on low power (300 uA) o Complete 3-axis accelerometer with signal conditioned voltage

outputs o Measures acceleration resulting from motion, shock, or vibration o Range of ±200g

● Alternatives: o Piezo electric disc o Triple Axis Accelerometer Breakout - ADXL345 (+/- 16g)

ADXL377 Schematic and Breadboard Wiring

Pin

Number

Description Arduino

Connection

1,3 Reserved None

2 Self Test None

4 Y Channel

Output

A1

5 X Channel

Output

A0

6,7 Ground GND1, GND2

8-13 No Internal

Connection

None

14 3.0 V Supply AREF

15 3.0 V Supply 5V

16 Z Channel

Output

A2

ADXL377 Schematic and Breadboard Wiring

-Measurement Accuracy within +/- 3g -Minimum of 2 milliseconds between sensor readings -Sensor data will be read from analog inputs A0, A1, and A2 on the Arduino as voltage measurements. The integer voltages at each pin will be scaled to correspond to units of g force.

Design Solution

Skin Conductivity ● Choice: Ag/AgCl electrodes ● Justification: o inexpensive o non-invasive

● Alternatives: o Ion Selective Electrode (ISE) o Intra-oral hydration

microsensor o Epidermal Skin Hydration

Sensor: ultrathin, stretchable sensor system capable of conformal lamination onto the skin

o Urinalysis o Drawing blood [17]

Design Solution Heart Rate Sensor ● Choice: Reflective photoplethysmography (PPG) sensor ● Justification

o Simple design consisting of infrared light and photodetector o Does not need to penetrate all tissues: beneficial for use on the back

● Alternatives o Electrocardiogram (ECG) o Transmission PPG o Pulse Oximetry

Reflective PPG Sensor Schematics

Design Solution

Device Casing ● Choice: 3D printing of case using

ABSplus thermoplastic material attached via a belt

● Justification: o Strong material

Strength easily altered by changing dimensions

o Inexpensive to manufacture o Lightweight

● Alternatives: o Use of Vero Blue material o Integration into compression shirt o Attachment to body via clip

Design Elements of Casing

● Rectangular shape, rounded corners

● Separate access doors for battery and for electrical components o Snap closure

● Ports for sensors to interface with skin and allow for wiring

● Speaker ports for alarm system

Design Solution

Alarm System • Choice: Piezo Buzzer - PS1240

• Justification: o Creates the loudest tones at

4KHz, but operates on a scale between 2 KHz and 10 KHz

o Creates tones at 70 dBA. This decibel level is under OSHA regulation (85dB) for safe noise exposure

• Alternatives: o Piezo Tone, Electronic Tone–Screw

Terminals (Same decibel capabilities, more expensive)

o Piezo Tone–Two Wire Leads, Three Wire Leads

o 5V Buzzer (Cannot adjust frequency)

Gantt Chart: September 2014-January 2015

Data Collection from members of the TCNJ Athletic Department Ordered materials for the Accelerometer, Temperature Sensor, and Piezo Buzzer Constructed circuit schematics for hardware and SolidWorks model of device casing IRB Proposal Hardware Assembly

Tasks:

Gantt Chart: February 2015- May 2015

Hardware Assembly Signal Processing 3D Printing Bench Testing Testing on Human Subjects

Tasks:

Budget

References

1) "ASTM D2463 - 10b Standard Test Method for Drop Impact Resistance of Blow Molded Thermoplastic Containers." ASTM D2463 - 10b Standard Test Method for Drop Impact Resistance of Blow Molded Thermoplastic Containers.

2) Baggish, A. L., and M. J. Wood. "Athlete's Heart and Cardiovascular Care of the Athlete: Scientific and Clinical Update." Circulation 123.23 (2011): 2723-735.

3) Barbero-Alvarez, J. C., V. M. Soto, V. Barbero-Alvarez, and J. Granda-Vera. "Match Analysis and Heart Rate of Futsal Players during Competition."Journal of Sports Sciences 26.1 (2008): 63-73.

4) Casa, D. J., Armstrong, L. E., Hillman, S. K., Montain, S. J., Reiff, R. V., Rich, B. S., ... & Stone, J. A. (2000). National Athletic Trainers' Association position statement: fluid replacement for athletes. Journal of athletic training, 35(2), 212.

5) "Exertional Heat Stroke." College of Agriculture, Health and Natural Resources Korey Stringer Institute. University of Connecticut, n.d. Web. 02 Dec. 2014.

6) Goulet, E. D. (2012). Dehydration and endurance performance in competitive athletes. Nutrition reviews, 70(s2), S132-S136.

7) Harvey, G., Meir, R., Brooks, L., & Holloway, K. (2008). The use of body mass changes as a practical measure of dehydration in team sports. Journal of Science and Medicine in Sport, 11(6), 600-603

8) "IP Code." Waterproof Specifications. N.p., n.d. 9) Link, M. S., and N. A. M. Estes. "Sudden Cardiac Death in the Athlete: Bridging the Gaps Between Evidence, Policy,

and Practice." Circulation125.20 (2012): 2511-516. 10) Naunheim, Rosanne S., John Standeven, Chris Richter, and Lawrence M. Lewis. "Comparison of Impact Data in

Hockey, Football, and Soccer."The Journal of Trauma: Injury, Infection, and Critical Care 48.5 (2000): 938-41. 11) Occupational Noise Exposure. (n.d.). Retrieved December 2, 2014, from

https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9735

12) Palatini, P. "Need for a Revision of the Normal Limits of Resting Heart Rate."Hypertension 33.2 (1999): 622-25. 13) Q & A: The Human Body’s Resistance. (n.d.). Retrieved December 2, 2014, from

https://van.physics.illinois.edu/qa/listing.php?id=6793 14) Selvaraj, N., A. Jaryal, J. Santhosh, K. K. Deepak, and S. Anand. "Assessment of Heart Rate Variability Derived from

Finger-tip Photoplethysmography as Compared to Electrocardiography." Journal of Medical Engineering & Technology 32.6 (2008): 479-84.

https://van.physics.illinois.edu/qa/listing.php?id=6793

References

15) Steinbach, P. (2012, November 1). Designing Sound Systems to Meet Stadium Audio Challenges - Athletic Business. Retrieved December 2, 2014, from http://www.athleticbusiness.com/designing-sound-systems-to-meet-stadium-audio-challenges.html

16) "Target Heart Rates." Target Heart Rates. N.p., n.d. 17) Volpe, S. L., Poule, K. A., & Bland, E. G. (2009). Estimation of prepractice hydration status of National Collegiate

Athletic Association Division I athletes.Journal of athletic training, 44(6), 624. 18) Yousif, Majid Y., David W. Holdsworth, and Tamie L. Poepping. "A Blood-mimicking Fluid for Particle Image

Velocimetry with Silicone Vascular Models." Experiments in Fluids 50.3 (2011): 769-74. 19) Zetou, E., Giatsis, G., Mountaki, F., & Komninakidou, A. (2008). Body weight changes and voluntary fluid intakes

of beach volleyball players during an official tournament. Journal of Science and Medicine in Sport, 11(2), 139-145.

20) Semin, Katherine, Alvah C. Stahlnecker, IV, Kate Heelan, Gregory A. Brown, Brandon S. Shaw, and Ina Shaw. "Discrepancy between Training, Competition and Laboratory Measures of Maximum Heart Rate in NCAA Division 2 Distance Runners." Journal of Sports Science and Medicine 7.4 (n.d.): 455-60.

21) Mayo Clinic Staff. "Diseases and Conditions - Heatstroke." Mayo Clinic. Mayo Clinic, 12 July 2014. Web. 19 Nov. 2014.

22) "Exertional Heat Stroke." College of Agriculture, Health and Natural Resources Korey Stringer Institute. University of Connecticut, n.d. Web. 02 Dec. 2014.

23) Dick RW, Hootman JM, Ingersoll CD. “Collegiate Athletic Injuries Trends and Prevention – A report on the NCAA Injury Surveillance System (ISS).” National Athletic Trainers’ Association (NATA) and National Collegiate Athletic Association (NCAA), 2007. Web. 2 Dec. 2014

24) Daneshvar, Daniel H. et al. “The Epidemiology of Sport-Related Concussion.” Clinics in sports medicine 30.1 (2011): 1–17. PMC.

25) BJ Maron, LC Poliac, JA Kaplan, FO Mueller. “Blunt Impact to the Chest Leading to Sudden Death from Cardiac Arrest During Sports Activities.” The New England Journal of Medicine. Volume 333, Number 6, pp 337-342, 1995.

26) Eppinger, Rolf et al. “Supplement: Development of Improved Injury Criteria for the Assessment of Advanced Automotive Restraint Systems -II.” NHTSA. Report. SES1 – SA11, March 2000.

27) ATMEL, “8-bit Microcontroller with 4/8/16/32K Bytes In-System Programmable Flash,” ATmega328P datasheet, Oct. 2009.

tcnj athlete tracker · 2018. 10. 17. · 2.1-3 astm-d5276 standard test method for drop test of...

Documents