1Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Hollot

Team RCADecember 5, 2012

Midway Design Review

2Department of Electrical and Computer EngineeringDepartment of Electrical and Computer Engineering Advisor: Professor Hollot

Kenneth Van Tassell, EEUser Interface & Communication

Scott Rosa, CSEServer & Data Analysis

Justin Kober, EESensor Network & Power

Timothy Coyle, EEImpact Processing & Communication

RCA (Real-Time Concussion Analyzer)

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Current concussion detection• Train coaches to recognize symptoms

Players may hide or not experience symptoms right away

RCA will monitor each player and alert the coach with the risk of concussion after each collision

Customer feedback• College trainers and high school athletic director

Concussion Detection in High School Football

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Our Previous Solution: Block Diagram

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Our Redesigned Solution: Block Diagram

Bluetooth

Android

Server

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Sensors

ADXL 193 MEMS Accelerometer• Testing• Noise analysis

PCB Design• ADXL 78 • More sensitive

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Energy Consumption• Worst Case: 25.0 kJ per game• Typical: 5.8 kJ per game

− 100 ms per hit and 100 hits per game

Coin Cell Batteries• Weight & Size• Series or Parallel

Battery Selection

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Helmet network connect but idle

Measured System Energy ConsumptionHelmet network connect and transmitting

mVmV

ms ms

Mean Voltage: 255.8 mV Mean Voltage: 305.6 mV

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Application / User Interface and UI Communication Requirements

• Easy to use• Displays Acceleration• User Adaptable

− Coach vs. Trainer• Reliable

Challenges• Unable to perform long processes on UI thread• Uncaught process errors• Working with Android Bluetooth protocol

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Android AsyncTask• Allows multi-threading in Android applications• Performs tasks asynchronously in the background

Android Debugging• Used to catch unseen errors• Found and fixed multiple runtime errors

Android Bluetooth• Using Android Bluetooth package• Measured response time of transfer to be 16.8 ms

Application / User Interface and UI Communication

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Data Processing and Storage

Requirements• Calculates rotational acceleration• Determines probability of concussion• Output within 500 ms• Store all impact data efficiently

Accomplished• Calculates rotational acceleration and probability of

concussion in average of 411.6 ms• Computational analysis• Set up server with database to store data• Tested and graphed data

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0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 120000

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Rotational Acceleration (rad/s^2)

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Test Results

C1= -12.531C2= 0.0020

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0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 120000

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Rotational Acceleration (rad/s^2)

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Test Results

C1= -12.531C2= 0.0020

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Impact Processing & Communication

ATmega32U4 8-bit AVR Microcontroller• 16MHz Clock • 10-bit ADC every 8us

Bluetooth: BlueSMiRF w/ RN-41• Redesigned for scalability• 25m Effective range

− Proof of concept vs. XBee redesign

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Experiments• Compared sensor to datasheet

− Noise in system

• Sample rate− Noise stabilized and found sample rate problem

• System output vs direct sensor output− Confirmed sampling rate problem

• Revised sample rate settings− Improved sampling rate and confirmed stable output

Statistical analysis• Mean, Variance, Histograms

− Confidence intervals of final system

Impact Processing & Communication Experiments

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Demonstration of Impact Data Collection• Accelerometer interfaced with processor• Helmet processor transmission

Demonstration of Base Station/UI Interaction• Using test data

− Receive from helmet− Run algorithm

• UI able to receive and display test results

Proposed MDR Deliverables

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Demonstration of Impact Data Collection• Accelerometer interfaced with processor• Helmet processor transmission

Demonstration of Base Station/UI Interaction• Using test data

− Receive from helmet− Run algorithm

• UI able to receive and display test results

Proposed MDR Deliverables

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Demonstration of Complete System Functionality• Show implementation of battery powered system• Impact the helmet with a known force• Transmit impact data with required sample rate from

the sensor array to Android device• Display risk of concussion with confidence interval on

Android device• Display player impact history on Android device upon

user request

Proposed CDR Deliverables

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Questions

Thank You

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Questions

Thank You

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Material Costs

This cost could be reduced by $1,200 purchasing the RN-41 and designing the BlueTooth modem ourselves

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Computational Analysis

Storage and computation can be done on a phone

Server hosts MySQL database

Max phone memory size: 64 GBMin phone memory size: 2 GBTop Ten Paid apps in Itunes 11/26/12Max App memory size: 791MBMin App memory size: 3.1MBAverage of max and min memory size: 397.05MB

Size of Entry in table is 40Bytes

0.00004MBAvaible space for just storing: 9926250hits in totalNumber of players on Umass Football team: 90Avg hits per college season per player: 1177seasons played by college player: 4hits for college team in 1 years 423720Team data for 4 years 17MBTeam data per year 4MBStore data for 99teams per yearStore data for 23college teams for 4 years

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Preliminary Weight Analysis

NFL Helmet Approximately 6lbs. or 2.722kg ATMega328P = 2g MEMS each approximately 1g Gyroscope approximately 2g Power approximately 23g Estimated total system weight (not including

packaging) = 35g-40g

5% of helmet is approximately 136g

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Requirements Analysis: Specifications

Real-Time continuous impact measurements Player specific adaptability Equipment weight increase less than 5% Effective range 150 m Responds in under two seconds Robust

• Interference• Durable

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Measured System Energy Consumption

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Worst Case Power

Worst Case Power Analysis

Device Max Voltage (V) Max Current (mA) Max Power (W)

ATmega32U4 5 200 1

BlueSMiRF Gold 3.3 100 0.33

ADXL 193 5 2   0.01

Total Power (W)

1.39

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Lower frequency response• Vibrations

Mapping to graph• More data points

Cost

Single-Axis VS. Multi-Axis

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Impact Data Collection Power circuit Sensor array Processing and transmission of sensor array

User Interface Cumulative linear acceleration User preferences Risk display Stability

Data Analysis Sub-concussive impacts integrated Statistical analysis for entire system

Proposed CDR Goals