ThickSkull

ECE445Fall2016DesignReview

JosiahSpears jnspear2 Xingyang(Xandy)Liu xliu141

TA:JohnA.Capozzo

October4,2016

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ContentINTRODUCTION....................................................................................................................................3

MOTIVATION/STATEMENTOFPURPOSE...........................................................................................................3EXISTINGSOLUTIONS....................................................................................................................................3PROBLEMSWITHEXISTINGSOLUTIONS;OURSOLUTION......................................................................................4OBJECTIVES.................................................................................................................................................5

DESIGN.................................................................................................................................................6BLOCKDIAGRAM..........................................................................................................................................6SENSORMODULE.........................................................................................................................................7DATATRANSMISSIONMODULE.....................................................................................................................12DATAPROCESSINGMODULE........................................................................................................................13POWERMODULE.......................................................................................................................................14

REQUIREMENTSANDVERIFICATIONS.................................................................................................14

REQUIREMENTSANDVERIFICATIONSPOINTTABLE............................................................................17

TOLERANCEANALYSIS........................................................................................................................18

COSTANDSCHEDULE.........................................................................................................................20COSTANALYSIS..........................................................................................................................................20SCHEDULE.................................................................................................................................................21

ETHICSANDSAFETY............................................................................................................................23ETHICS......................................................................................................................................................23SAFETY.....................................................................................................................................................24

CITATIONS..........................................................................................................................................24

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IntroductionMotivation/StatementofPurposeOne of the biggest issues facing the game of American football is that of concussions.ConcussionscanbefoundonalllevelsofAmericanfootball,inchildrenstartingfromtheageof10, through high school, college and especially the pros. In the article, “Concussions AmongUnitedStatesHighSchoolandCollegiateAthletes,”theOhioStateresearchgroupconcludedthatover300,000headtraumainjuriesfromsportsoccurintheUSannually[1].Thearticlealsostatesthatparticipationinsportsisthesecondleadingforheadtraumaforpeoplefromtheages,15-24 [1]. Asmoreandmore researchhasbeen conducted,playingwith concussionshasbeenshowntobedetrimentaltoaplayer'shealth,andcouldpotentiallyhavealastingadverseimpactonhisorherhealthgoingforward.Havingasystemtohelpcollect,time-log,storeandtransmitpertinentrealtimedatarelatingtoadiversesetofconcussionsymptoms(inthiscasefour)willhelpdoctorsandresearchscientistsintheirquesttobetterunderstandconcussionsandmakequickerin-gameconcussionanalysisanddiagnosis.ExistingSolutionsSeveralexistingattemptstoatleasthelpmitigatethisproblemarecurrentlyonthemarket.FourmajorproductsthattriedtosolvethisproblemaretheRiddleSRS,RiddleInsite,ShockboxandChecklightbyReebok.TheRiddleSRSemploysHITS,asoftwaredevelopedatVirginiaTechandDartmouthCollege,tomeasuretheimpactofrealtimegamehitsandtopredict likelihoodofconcussion based on themagnitude of the hit. They use iMemsMotion Signal Processing tocalculatelinearacceleration,andcompiledataaboutthelocation,directionanddurationofthehit.Theyusewirelesscommunicationstosenddatatothesideline[2].TheRiddleInsite,isamoresensitive,moreexpensiveversionoftheRiddleSRS.Itcontainsthemostsensitivemeasurementsystemofcollisions[2].Theyemployalightweightfive-zonesensoranduseared-yellow-greenLEDsystemtovisiblyshowhowhardeachhitwas[3].TheShockboxsolutionusesBluetooth to communicate to a systemon the sidelines. It is aportable sensorsystemthatcanbeplacedinanyhelmet.ItusesSCAT,SportsConcussionAssessmentTool,tokeeptrackof thenumberofhitsandhowhardeachhitwas.However, thisdatacanonlybeaccessedafterthegame,whichdoesnotpreventplayersfromplayingwithaconcussionduringthegame.LikeSRS,theymeasure linearandrotationalacceleration.Theymakesurethatthepeak acceleration does not reach over the 70-100 g threshold, which is where majority ofconcussionsfall[4].Thelastcompetitor,ChecklightbyReebok,measuredtheaccelerationoftheheaddirectly.Italsorecordedthenumberofhitstakenbytheplayer.TheyusedHIC,HeadImpactCriteriatomeasureimpact,onlymeasuringlinearacceleration.However,sincethestartoftheproject,webelievethatChecklighthasbeenremovedfromthemarket[5].

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ProblemswithExistingSolutions;OurSolutionAlthoughthemarketforheadtraumadatacollectionseemsquitecrowded,everysinglesolutionmentionedabovehasseveredifficultiesproducingon their claims.CNNdida studyofRiddleInsite.TheresultsshowedthattheInsitestruggledtosignalahardhit,havinganinaccuracy30%[6]. It is important tokeep inmindthat this is themostsensitivesensingsystem. Ifasystemcannotbetrustedbyplayersanddoctorsalike,howcanitbringanyvalue?Anotherissuewithseveralofthedesigns,especiallyShockbox,isthatthesensorswerejustplacedinsidethehelmet[4].Thismayallowittobeusedwithanyhelmet,butitchangesthefeelofthehelmetsfortheplayers.Sportsisallaboutcomfortabilityandrepetition.Ifthedesigninfringesonthis,thenmanyplayers,especiallypros,willnotwanttouseit.The biggest issue that the ThickSkull team has with all of the existing solutions is how onedimensionaltheyare:theyonlymeasurethemagnitudeofthehitorthenumberofhits.Everyplayer’sbodyisdifferentthantheotherandwillrespondtohitsdifferently.Somanyfactorsgointoconcussionsandthebodyreactsbygivingoffmanysignsthatcanbemeasuredandcollected.Ourteamagreesthatthemagnitudeofhitsshouldbeconsideredaswellasthenumberofhits,sincemany pro players become concussed during routine tackles, because of the buildup inimpact.Butweneedmuchmoredata, so thatwecanhaveabetterunderstandingofhowaconcussionaffectsaperson,andtoincreasethelikelihoodofidentifyingsituationswhereplayersmaybeatriskofbeingconcussed.Ourmissionistoincreasetheamountofdatacollectedandthetypeofdatacollectedinreal-time.Weplantoprocessthisdataandpresentitinaclearandmeaningful way so that it can be used by doctors when they diagnose concussions and byresearchesastheytrytounderstandmoreaboutconcussionsandtheirlastingeffectsonhumans.

Webelieveweshouldmeasureforwell-definedconcussionsymptoms,sinceaplayer'sbodywillgiveoffspecificsignsthatitispotentiallyconcussed.Firstweplantotaketwoheartbeatmeasurements.Thefirstoneisrestingheartrate.Weplantomeasureforaplayer’srestingheartrate,rightbeforethestartofthegame,duringhalftimeandafteragame.Aplayer'srestingheartratedecreasingfromthepreviousmeasureisaconcussionsymptom.Additionally,anincreaseinexercisingheart rate isalsoakeysymptomofconcussions.Weplan tocontinuouslymonitorheartrateduringagame(whiletheyareonthefield)andtakeatime-averageofthis.Ifthereisasharpincreaseordecreasecomparedtothetime-averagevalue,thenwewillflagthatpersonas needing further checked. Dr. Kevin Jackson, who does research on concussion effects onfootballplayersattheUniversityofIllinoisconfirmedthatthesemeasurementsaresymptomsofconcussionsand that compilingandprocessing thisdatawouldbring value tohis andothersresearchinthisarea[7].Weplantomeasurethesefoursymptoms-numberofhits,magnitudeoflinearandrotationalaccelerationofhits,restingheartrateandexerciseheartrate-andincorporatethemintoasinglePCB design so that we can incorporate them into a comfortable aesthetically alternative toexisting.We decided to embed this system into the helmet tomaintain the same feeling asnormalhelmetsthatplayerscurrentlyuse.Theacceleration,andhitnumberdatathatisgatheredbythehelmetwillbeimmediatelytransferredtowhatwecallourdataprocessinghub,whichison the sideline. Since the heart rate is measured almost continuously, we will store a

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conglomerateofdataonthehelmetPCBbeforewesendittothehub.Thedatatransferwillbedone using Bluetooth technology. We will incorporate existing antennas along with customFPGAsonboththehelmetanddataprocessinghubtoallowforcommunicationbetweenthehelmet and the sideline hub. At the sideline hub, the data is stored and processed and theresultingprocesseddataisstored.Wewilluseanalgorithmtotakethisdataandmakeapredictionastowhethertheplayerisinjeopardyofbeingconcussed.Theplayercanthenbebroughttothesidelineandbeadministeredaquickpsychologicevaluationbasedonastandardquestionnaire,developedbypsychologistandneuroscientists.Wethenwillclearlypresentthetestresultswithandaconglomerationofthefourtypesofdatasothatadoctorcanusethisextrainformationtohelphimmakeadecisionastowhethertheplayershouldgobackintothegame.Aresearcherorneurologistcouldusetheresultsofknownconcussedplayerstoplayersperceivedtonotbeconcussedtolearnmoreaboutthehumanbodyreactsandfunctionswhenitisconcussed[7].ObjectivesGoals/objectives

• Createahardwarecircuitthatwilladdvaluetoheadtraumadetection(thisisfocusedtowardfootballplayers)

• Createthiscircuitsmallenoughsothatitcanfitwithoutanoticeabledifferenceinthefeelandeaseofuseforplayerscomparedtoexistingmainstreamhelmets

• Measurefourdatapointsofconcussionsymptoms,twomorethanexistingsolutions• Transferthisdatafromhelmetstoasidelinemodule• Present this data in a processed and organized manner so that it can be used by

researchesanddoctorsinconcussionstudiesandprognosis.Features

• Measurelinearaccelerationofhits• Measurerotationalaccelerationofhits• Measurenumberofhits• Measurethedifferenceinrestingheartrateoftheplayer,atthestartofthegame,at

halftime,andattheendofthegame• Measurethedifferenceinexercisingheartrate,toseeifwecandetectspikesinheart

ratecomparedtothetimeaverage• AnalogtoDigitalconversioninsidethehelmet• Temporarydatastorageinsidehelmet• Thisdatacanbecommunicatedbetweenhelmetanddataprocessinghubinreal-time• Thisdatacanbestoredandprocessedintheprocessinghubonthesideline• Timelogsthisdata• PresentsthisdatainanclearformatusingaGUIsothatdoctorsandresearcherscaneasily

accessthedataandanalyzeit

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Note:Manyofthegoalsinthisprojectarealsofeatures.Becauseourprojectistryingtoaidresearchesthedifferencebetweengoalsandfeaturesismuddledatbest.

DesignBlockDiagram

Figure1HardwareblockdiagramoftheSystem

Thesystemconsistsoftwosubsystems:thehelmetandthehubatthesideline.Thehelmetisembeddedwithasensormodule,transmissionsideofthedatatransmissionmodule,andapowermoduleforthehelmet[Figure1].Thehubconsistsofadataprocessingmodule,receptionsideofthedatatransmissionmodule,andapowersupplymoduleforthehub.

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Figure2Softwarelevelgeneralflowchart

Thesoftwaresideofthesystemisimplementedintwosubmodules:processor(helmet)submoduleandprocessor(hub)submodule.Theprocessor(helmet)submoduleobtainsdigitizedpulsewaveand3-axisaccelerationfromthepulsesensorsubmoduleandaccelerometersubmodule.Thenfromthesedigitaldata,BPMiscalculatedandaccelerationsarefilteredandonlyaccelerationsofthehitsarekept.Thepre-processeddataisthentransmittedthroughdatatransmissionmoduletotheprocessor(hub)submodule.Theprocessor(hub)submodulethenstoresthedatapointsandprocessesthemwithalgorithm.TheresultsarepresentedontheGUI.SensorModuleTheobjectiveofthesensormoduleistomeasuretherawdataaswellastopre-processtherawdataintomeaningfulldatapointsreadytobesenttodatatransmissionmoduleinthehelmet.Itincludesthreesubmodules:accelerometersubmodule,pulsesensorsubmodule,andaprocessorsubmodule(helmet).Theaccelerometersubmoduleandpulsesensorsubmodulecollectpulsewavesandaccelerationinrealtimerespectively.Therawdataisthensenttotheprocessorsubmodule(helmet)inSPIandI2Cprotocolsrespectively.Theprocessorsubmodule(helmet)thenpre-processestheserialdataandcalculatestheheartbeatrate(BPM)andforceofthehit.Thepre-processeddataisthensenttothedatatransmissionmodule.

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AccelerometerSubmodule

I/O Name DescriptionInput ACCELERO_SCL AccelerometerI2CserialclocksignalOutput ACCELERO_SDA AccelerometerI2Cserialdatasignal

Table1I/Otableofaccelerometersubmodule

Figure3Accelerometersubmoduleschematic[8]

The3-axisaccelerometersensesthelinearaccelerationinthreedirections:x,y,z.TheanalogdataisthenconvertedtodigitaldatathroughaninternalADC.Thenthedigitaldataissenttotheprocessor(helmet)throughI2Cprotocol[8].WechooseH3LIS331DLSTMicroelectronicsbecauseitsfeaturesmeetourrequirements.Someresearchesindicatethat86%ofimpactsinfootballarebelow50gandthatconcussionspredominantlyfallinarangebetween70–100g.Andaseverehitcouldbeashighas150g[4].TheH3LIS331DLaccelerometerisabletomeasurewiderangeofaccelerationupto±100g/±200g/±400g,whichissuitableforourcause.Its3-axissensorsenseslinearaccelerationinx,y,zdirections.Throughouralgorithm,wecanalsocalculaterotationalacceleration,anotherdatapointweareinterestedin.Theoutputdataratecanbeashighas1kHz,whichmeanstheaccelerationreadingisupdatedevery1millisecond.Thisisfastenoughtotracktheaccelerationsofhits.

Features ValuesSensortype 3-axissensingSupplyvoltagerange 3.3Vto5VDCCurrentrating Typical300μA

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Accelerationscale ±100g/±200g/±400gOutputdatarate 0.5Hzto1kHzOutputdatawidth 16bitCommunicationprotocol I2CserialdigitaloutputinterfacePackage 3×3×1mmTFLGAOperatingtemperature -40°Cto+85°CShocksurvivability 10000gTypicalApplications Shockdetection

ImpactrecognitionandloggingConcussiondetection

Table2FeaturesofH3LIS331DLaccelerometer

PulseSensorSubmodule

I/O Name DescriptionInput PULSE__CLK SPIserialclockInput PULSE_SPI SPIserialdatainInput PULSE_CS SPIchipselectOutput PULSE_IN SPISerialdataoutput

Table3I/Otableofpulsesensorsubmodule

Figure4Pulsesensorsubmoduleschematic[9]

ThepulsesensorsubmoduleincludesagreenLED(AM2520ZGC09),aminiaturesurface-mountambientlightphotosensor(APDS-9008),anoperationalamplifier,andanAnalogDigitalConverter.

Features ValuesSupplyvoltagerange 1.6Vto5.5VOperatingtemperature -40°Cto85°CResponsivity ExcellentSensitivityvariation Lowacrossvariouslightsources

Table4FeaturesofAPDS-9008lightphotosensor

Features Values

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Supplyvoltagerange 2.7Vto5.5VCurrentrating 5nAtypicalstandby;550μAactivemaxOutputdatawidth 10bitSamplingrate 200kspsmaxCommunicationprotocol SPIOperatingtemperature -40°Cto+85°C

Table5FeaturesofMCP300210-bitADC

TheoperatingtemperaturerangeforthegreenLEDandtheambientlightphotosensoriswellbeyondthetemperatureoftheworkingenvironment,thusmakingthesepartssuitableforourproject.ThesamplingrateistheADCisalsohighenoughtocapturetheanalogsignals.Theanalogsignalcapturedbythelightsensorisfilteredbyhigh-passfilterandtheACsignalisamplifiedandnormalizedbytheoperationalamplifier.ThentheoutputoftheamplifierisfedintotheAnalogDigitalConverter,afterwhichthedigitalsignalissenttotheprocessor(helmet)submoduleviaSPIprotocol.

Figure5AmplifiedandNormalizedpulsewave

TocalculateIBI(InterBeatInterval),weneedtoknowtheexacttimewhenabeathappens.Variousheartresearchershavedifferentdefinitionsaboutwhichreferencepointshouldbeusedtoindicateapulse[9].Inourproject,wechoosethe50%ofthewaveformamplitudeontherise.Thisreferencelevelstartsatmid-level(V/2),andgetsconstantlyupdatedfromtheprevious50%level. Atimerisusedtokeeptrackoftheintervaltimebetweenpulses,andtheintervaltimeisstoredintoanarray.Tomitigatetherelativeerrorinmeasurement,wetaketheaverageof10consecutiveIBItorepresenttheinstantaneousheartrate.

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Tomitigatenoisesignalbetweenpeaksandfalsereadingondicroticnotch,weonlystartlookingforpulse200msafterthelastpulse.Weassumeheartbeatratewouldnotbeover300bpm,whichtranslatesto200msIBI.Thisgraphshowstheoutputofthepulsesensorafterithasbeenfiltered,amplifiedandnormalizedaroundacenterlevel(around2.5V).Thisdecisionallowsfordistinctdifferencestobepickedupeasieronthegraph,becausethedifferencebetweenthepeakandthetroughofthepulsewaveismaximizedandcuttingoffofthevaryingsignalisavoided.Processor(Helmet)Submodule

I/O Name DescriptionOutput ACCELERO_SCL AccelerometerI2CserialclocksignalInput ACCELERO_SDA AccelerometerI2CserialdatasignalOutput PULSE__CLK SPIserialclockOutput PULSE_SPI SPIserialdatainOutput PULSE_CS SPIchipselectInput PULSE_IN SPISerialdataoutput

Table6I/Otableoftheprocessor(helmet)submodule

Figure6Processor(helmet)submoduleschematic[10]

Features ValueLogicElements(LEs) 4608M4KRamblocks 26TotalRAMbit 119808

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Embedded18x18Multipliers 13PLLs 2MaxuserI/Opins 142

Table7FeaturesofEP2C5T144

Aprocessorisembeddedinthehelmet.ThesensorssenddigitaldatatotheprocessorthroughI2CorSPIprotocols.TheprocessorthencalculatestheBPMfromthepulsesensordatainputandobtaintheaccelerationofthehitsfromtheaccelerometerdatainput.Theresultingdataisthensenttodatatransmissionmoduletobetransmittedtothesidelinehub.DataTransmissionModuleThedataistransmittedthroughadatatransmissionmoduletothedataprocessingmoduleandarestoredthereforanalysis.Thedatatransmissionmoduleconsistsofalong-rangeBluetoothtransmitterandreceiver,suchthatdatacanbetransmittedtothesidelinehubfromanywhereofthefootballfield,whichis160ftx360ftinsize.

Figure7Placementofthehubandthefurthestdistancefromtheplayertothehub[11]

Theoptimumlocationofthehubwouldbethecenterofthelongside,fortheareawithcertainradiuscoversmostofthefield.Thefurthestdistanceisbetweenthehubandthefurthercornerofthefield.Itsdistanceis:

160$ + (360/2)$ = 240𝑓𝑒𝑒𝑡 ≈ 73𝑚TheWirelesslong-rangeBluetoothtransmitterandreceiver(SparkFunBluetoothMateGold)hasrangeupto100m,whichisbeyondourrange.

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Features ValuesOperatingvoltage 3.3Vto6VOperatingcurrent 25mAaverageCommunicationspeed 2400-115200bpsOperatingTemperature -40°Cto70°C

Table8FeaturesofSparkFunBluetoothMateGold

DataProcessingModuleThedataprocessingmoduleconsistsofthreesubmodules:datastoringsubmodule,processor(hub)submodule,GUIsubmodule.Theprocessorreceivesthedatafromthetransmissionmoduleandstoresinthedatastoringsubmodule.Theprocessoralsoanalyzesthedatathroughanalgorithmanalyzingtheimpactsandheartbeatresponsesandstorestheresultsinthedatastoringunit.Finally,adetailedreportontheimpactsispresentedthroughaGUIsubmodule.Processor(Hub)SubmoduleTheprocessoratthehubreceivesdatafromthedatatransmissionmodule.Itstoresthedataintothedatastoringmoduleandalsoanalyzesthestaticdataaswellasthedynamicdataviaanalgorithm.TheresultoftheanalysisisstoredinthedatastoringmoduleandsenttoGUIforpresentation.ThecoreoftheprocessorisanFPGA,whichprocessesthedataatahighprocessingrateandhastheabilitytocommunicatewithitsperipherals.DataStoringSubmoduleThissubmoduleisalargememorywherethedatacollectedandtheanalysisresultsarestored.Dataisstoredandretrievedbytheprocessorforfurtheruse.Thememoryisdynamicallyallocatedtoaccommodatemultiplehelmet.GUISubmoduleTheprocessorpresentstheBPM,accelerationofeachhits,andanalysisresultsintheGUIsubmoduleforaclearandinteractivepresentationoftheresults.A9.7-inchLCDscreenisusedforgraphicalpresentationoftheprocesseddata.

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PowerModule

Figure8Powermoduleschematic[10]

Thehelmetandthehubarepoweredbytwopowermodulesindividually.Thepowermoduleinthehelmetincludesalight-weight,small-sizerechargeable5Vbattery.Itprovidespowerfortheothermodulesinthehelmet.Thepowermoduleinthehubincludesarechargeablebattery,aswellasanAC-DCconverter,whichallowsthehubtocontinuefunctioningwhenbatteryisbeingcharged.Thehelmetispoweredbya5VrechargeableLi-ionbattery.The5Vpowersupplyisregulatedinto3.3Vand1.2Vwithvoltageregulatedtopowerothermodules.Thebatteryinthehelmetisprotectedbyfoamtocushiontheimpact.

RequirementsandVerifications

EquipmentandRequirements Verifications

Accelerometer 1) Measurelinear

accelerationwithaccuracyofatleast80%

2) Measureaccelerometerreadingwithina10mstimeperiodwithlessthan5%error

LinearAcceleration1.) Takethehelmetwiththeaccelerometerinitand

dropitfrom3feethigh.(Useatapemeasureoryardsticktocalculatethisdistance.)

2.) Therearetwodifferentwaystochecktheaccelerationvalue.Ifourcompletedesignworks,thenwecancheckthevalueoutputontheGUIandcompareittothetheoreticalvalueof1g.Ifourcompletedesigndoesnotwork,thenwecanconnecttheFPGAoutputpins73,74,75,76,79,80,81,86,87,88,89,90,91,92,93,94tosixteenLEDsonabreadboard.EachLEDwillcorrespondtoabit,with

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alitLEDrepresentingaoneandanon-litoneazero.Simpleconversionfrombinarytodecimalvaluewillgiveusthedesiredresult.CompareValuesoftheoretical(1g)toactualandcalculatetheerror.Timingrequirement1) Wespecificallychoseachipthatwouldmeasure

anaccelerationpeakassmallas1ms,muchsmallerthanthe10msrequirement.However,tobesurewewilltake100differentrunsoftheexperimentlistedinpart1ofthelinearaccelerationverification.Ifanimpactisnotreportedin95ormoreofthedrops,thenourtimingisnotaccurateenough,andtherearecertainaccelerationjumpsthatouraccelerometersarenotabletodetect.

Pulsesensor 1) Measureheartbeat

withanaverageaccuracyof90%forbothrestingandexercisemeasurements

1) WewilluseanoximeterfromMcKinleytomeasureaperson’sheartrate.Theoximeterisattachedtoaperson’sindexfinger.Liketheaccelerationmoduletherearetwowaysoftesting.ToprovemodularfunctionalityiffullsystemisnotworkingwewilldisplaythecalculationsfromtheFPGAinsidethehelmet(pins96,97,99,100,101,102,103,104,112)toabreadboardwithtenLEDs.

Processor(Helmet) 1.) Processorrunsat90%

of50MH2.) ItHas2GBofmemory3.) PulseSensorDatais

stored,ProcessedandsenttoBluetoothmoduleinbetween.9-1.1s

1) UsebuiltinAlteraTimeQuesttoverifythattheclockdrivingtheFPGAchiphasa90%valueof50MH

2) Makesurethattheexternalmemoryisa2GBsize.Wedonothavetomeasureexactly,becauseourdesigndoesnotuseclosetoall2GB.

3) Analyzetheclockdrivingalloftheprocessesinvolvedinpulsesensordatastorage,processingandtransmissiontotheBluetoothmoduleusingAlteraTimeQuest.Addallofthecalculatedtimestogetherandchecktoseeifvaluesarewithinrange.

Powermodule(Helmet) 1) Powerthe

accelerometerbetweena2V-3Vpowersupplyand30-40μAcurrent

1) Useoscilloscopetoviewthethreevoltageoutputsofthepowermoduleunderzeroloadcondition

2) Connect10kOhmresistoracrossthe2.5Vvoltageoutput,30kOhmresistoracross5Vvoltageoutput,1MOhmacross3Vtomodelfullloadcondition

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2) Powerthepulsesensorwith4.5-5.5Vpowersupplyand2-6macurrenteach

3) PowerAlteraCycloneIIFPGAwith4.5-5.5Vpowersupply

4) PowertheBluetoothmoduleatpowersupplyof2.5V-3.5Vat1.3-3.9μA

3) Forbothzeroloadandfullloadconditions,thevoltagewaveformsshouldhavevoltagerippleof±1.5%voltageripple(ADP2116)

Wirelessdatatransmissionmodule

1) Antennaerelay’sdataata90%accuracyrate

2) Errordetectis95%accurate

1) ConnecttheoutputdatafromtheFPGAonthehelmet,pins(114,115,118,119,120,121,122,125,128,129,132,133,134and135)toLEDsonthebreadboard.ConnecttheinputsoftheFPGAhub(pins114,115,118,119,120,121,122,125,128,129,132,133,134and135)toLEDsonthebreadboard.ComparethisvaluesoftheLEDS.Theyshouldbothmatch.Thistestwillbedone50times.TheLEDSneedtomatch45timesormoretofulfillthisrequirement

2) Checkwhenthereisanerror,bycomparinginputtooutput,andthencomparethattoourerrordetectionoutput

Processor(Hub) 1) Processorrunsat90%

of50MH2) PulseSensorDatais

stored,ProcessedandsenttoGUImoduleinbetween.9-1.1s

3) Simultaneouslyaccelerometerdataisstored,processedandsenttoGUImoduleinbetween.9-1.1s

1) SamprocessasmentionintheProcessorhelmetmodule

2) SamemethodasverificationthreefromProcessor(helmet)section

3) Sameastwo

Datastoragemodule(onHub) 1) Datastoredtimeis

between.5-.7s2) Datastorageis4GB

1) SamemethodasverificationthreefromProcessor(helmet)section

2) Makesurethattheexternalmemoryisa4GBsize.Likeonthehelmet,wedonothavetomeasure

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exactly,becauseourdesigndoesnotuseclosetoall4GB.

GUImodule 1) Makessurethatthe

GUImoduledisplaysthecorrectdatainthecorrectformat100%ofthetimeontheRaspberryPiLCD’’touchscreen

2) PresentaquestionnaireontheGUI

1) RuntheGUIalgorithmandcomparethedesireddataandpresentationwiththedesign.Ifthereareanydiscrepanciestheseneedtobetakencareofbeforethefinalproductisreleased.

2) ConfirmsthatthequestionnairecanbeseenandansweredonanLEDscreenorphone

Powermodule(Hub) 1) PowerRaspberryPi

LCD’’touchscreenwith4.5-5.5Vpowersupply

2) PowerAlteraCycloneIIFPGAwithexternalstoragewith4.5-5.5Vpowersupply

3) PowertheBluetoothmoduleatpowersupplyof2.5-3.5Vat2.2-2.6μA

1) Useoscilloscopetoviewthethreevoltageoutputsofthepowermoduleunderzeroloadcondition

2) Connect30kOhmresistoracross5Vvoltageoutput,1MOhmacross3.3Vtomodelfullloadcondition

3) Forbothzeroloadandfullloadconditions,thevoltagewaveformsshouldhavevoltagerippleof±1.5%voltageripple(ADP2116)

RequirementsandVerificationsPointTableModule PointsAccelerometer 5PulseSensor 5Processor(Hub) 7.5Powermodule(Helmet) 5WirelessdataTransmissionModule 5Processor(Hub) 7.5DataStoragemodule(Hub) 5GUIModule 5PowerModule(hub) 5

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ToleranceAnalysisThisprojectisaboutcollectingmoredatatohelpresearchersanddoctorsinconcussionstudyanddiagnosis.Althoughseveralaspectscancontributetoconcussion-likesymptoms,theprimaryfactorincausingconcussionsarethehits.Thushitdetection,calculatedusingouraccelerometer,isthemostimportantpartofourproject.Ifweareunabletodothisaccuratelytoacertainpoint,thenourprojectdoesnotaddmuchvalue.Ourcompetitorsarelessthan70%accurateindetectinghardhits[6].Withtime,moneyandtechnologyrestrictionsimprovingonthisaccuracyisquitedifficult.Addingourheartbeatsensormeasurementsdoeshelpmitigatesomeofthisinaccuracy.However,wedoplantoimproveonthisexistingaccuracy.Baseduponcalculationsandtheaccelerometerdatasheetwebelievethatwecanmeasureaccelerationata20%tolerance.Beforeweexplainhowwereachourhardhitaccuracycalculation,weneedtofirstexplainwhatresearchesdefineasahitandahardhit.Onewayofclassifyingahitandahardhitisbygroupinghitsintotheiraccelerationvalues.Ingeneral,ahitisdefinedasacollisionresultingina20gaccelerationorhigher.Ahardhithasanaccelerationof50gorhigher[12].Figure1showstheclassificationofhitsbasedontheiraccelerationvalues.

Figure1:GraphshowingtheClassificationofHitsBasedonAcceleration[12]

Withanaccelerationtoleranceof20%inmind,wemustcalculatetheminimumvalueinthe50gandaboverangethatwillstillbeconsideredahardhit,assumingmaxerroranddecreasingerror(errorsubtractedfromactualvalue).Wedonotcareaboutvaluesthatareincreaseerrors(errorisaddedtoactualvalue)inthisrangebecausetheywillstillbecomputedasahardhit.Ourcalculationswillnotexceed100g,sincetheprobabilityabovetheseaccelerationvaluesisverylow,thusinaccuratelyskewingouraccuracyresults.Belowisthecalculationofthemaxvaluewhereerrorisfound.

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𝑥 −𝑥5 = 50𝑔

45 𝑥 = 50

𝑥 =2504 = 62.5𝑔

Therangeofvaluesthatwillnotregisterashardhitsiftheerrordecreasesfromtheactualvalueisbetween50g-62.5g.Calculatingtheerrorpercentageofhitsinthe50-100rangeisfoundbelow.

x =62.5 − 50

50 = 25%

𝑥 = $;%$= 12.5%

(assumingerrorisaslikelytobepositiveasnegativeandthatpositiveerrordoesnotcauseanerror)

Nowwemustcalculatetheerrorcausedfromwhenahitisbelow50gaccelerationbutiscalculatedasahardhitbecauseofpositiveerror.Althoughthiserrorislessofanissueastheaboveerroritisstillerror.Theprocedureusedtocalculatetheabove50gvalueswillbeusedbelowaswell.

Calculationformaxvaluewhereerrorisfoundforbelow50g.

𝑥 +𝑥5 = 50𝑔

65 𝑥 = 50

𝑥 =2506 = 41.6667~41.5

Therangeofvaluesthatwillregisterashardhitsiftheerrorincreasesfromtheactualvalueis41.5-50g.Calculatingtheerrorpercentageofhitsinthe50andbelowrangeisfoundbelow.

x =50 − 41.5

50 = 17%

𝑥 = =>%$= 8.5%

(forsamereasonasintheabove50grange)Calculatingtotalerrorisdonebyaddingtheerrorcalculationofboththeaboveandbelow50granges.

12.5% + 8.5% = 21.5%hardhiterror

Itisimportanttokeepinmindthatmostconcussionhitsarewithinthe70-100grange[12].Ourdevicehasa100%accuracywithinthisrange,asverifiedbythecalculationsintheabove50gcategory.

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Takingintoaccountthatouroverallerroris21.5%,whichis8.5%betterthanourexistingcompetition,andthatourerrorduringtherangewheremostconcussionsoccuris0%,the20%toleranceforouraccelerometerisjustifiedandwellwithintheobjectivesofthisproject.

CostandScheduleCostAnalysisLabor

Name Hourlyrate($/hr)

Totalnumberofhoursinvested(hr)

Totallabor($)

JosiahSpears 32.2 240 19,320

Xingyang(Xandy)Liu 32.2 240 19,320

Totallabor($) 38,640

Parts

Parts Count Price($)

Total($)

Pulsesensor 1 10.00 10.00

SeeedstudioGrove-3-AxisDigitalAccelerometer(±400g) 1 34.99 34.99

EP2C5T144AlteraCycloneIIFPGAMiniDevelopmentBoard 2 21.90 43.80

RaspberryPiLCD’’touchscreen 1 64.95 64.95

AnalogDeviceADP2116DC-DCmulti-outputregulator 2 2.50 5.00

SparkFunBluetoothMateGold 2 34.95 69.90

USB2.0maleto5.5mm/2.1mm-5VDCPowerCableBarrelConnectorJackPlug

1 4.78 4.78

GeeetechAlteraUSBBlaster 1 8.99 8.99

Total 242.41

GrandTotalLaborcost+partscost=$38,640+$208.41=$38,848.41

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Schedule

Week Task Responsibility

9/12 Finalizeprojectproposal Contactprofessorswithexpertiseinantenna/communications PrepareforMockDesignReview Eagleassignment

JosiahSpears

Finalizeprojectproposal Contactbioinstrumentprofessor PrepareforMockDesignReview Eagleassignment

XandyLiu

9/19 OrderFPGAsandantennas Schematicdesignforthesensormodule PCBlayoutforbothpowermodules

JosiahSpears

Orderaccelerometerandpulsesensor PCBlayoutdesignforthesensormodule Schematicdesignforbothpowermodules

XandyLiu

9/26 Schematicdesignforthedataprocessingmodule PCBlayoutforthedatatransmissionmodule

JosiahSpears

PCBlayoutdesignforthedataprocessingmodule Schematicdesignforthedatatransmissionmodule

XandyLiu

10/3 FPGAdesignrelatedtodatastorageinsidethehelmet JosiahSpears

FPGAdesignrelatedtointeractionwithsensorsandantennae XandyLiu

10/10 Solderingassignment Test/Debugofsensormoduleonthebreadboard ProgramtheFinitestatemachineofFPGAandtesttomakesureitworksConfigureFPGAinteractionwithDAC

JosiahSpears

Solderingassignment Test/Debugofpowermoduleonthebreadboard Testingtheinteractionsbetweenthepowerandsensormodules

XandyLiu

10/17 BuildtheFPGAcodeformemorystorageandretrieval Startonindividualprogressreports

JosiahSpears

22

Startonindividualprogressreports ImplementthememorywiththeFPGAandsensors

XandyLiu

10/24 CodeGUIforinterfacebetweenuseranddevices Finishindividualprogressreports

JosiahSpears

Finishindividualprogressreports Buildpowermoduleandconnecttohelmetmodule R&VSecondTable

XandyLiu

10/31 Test/DebugtheentiredataprocessingmoduleConfigureBluetoothonhelmetmodule

JosiahSpears

Test/Debugtheentiredataprocessingmodule Learnaboutwirelessdatatransmissionprotocols

XandyLiu

11/7 IncorporatedatatransmissioninFPGAdesignofsensormodule R&VTableFinal

JosiahSpears

IncorporatedatatransmissioninFPGAdesignofdataprocessingmodule Testing/Debuggingthedatatransmissionmodule

XandyLiu

11/14 Test/Debuginterconnectionandcommunicationbetweenindividualmodules

JosiahSpears

Test/Debugtheentiresystemsothatitproducesthedesiredproduct

XandyLiu

11/21 Write Introduction and Research of project into Paper Put this part into the Presentation

JosiahSpears

WorkonPresentation StartonFinalPaper

XandyLiu

11/28 FinishPresentation ContinueworkonFinalPaper

JosiahSpears

FinishPresentation ContinueworkonFinalPaper

XandyLiu

12/5 FinishPaper• Introduction• Verification• Conclusion

JosiahSpears

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FinishPaper• Design• Cost• Reference

XandyLiu

EthicsandSafetyEthicsTheThickSkullProjectisaffectedbythefollowingethicalstandardsfoundintheIEECodeofethics[13].Ourteamtakesthefollowingethicalstatementsextremelyseriouslyandhavecarriedthemouttothebestofourknowledge.Wetakeprideinthefactthatwehaveandwillcontinuetoupholdthemandunderstandthatnotfollowingthemreflectspoorlyonusaselectricalengineers,soon-tobeUIUCgraduates,andmembersofourglobalsociety.

[1]Toacceptresponsibilityinmakingdecisionsconsistentwiththesafety,health,andwelfareofthepublic,andtodisclosepromptlyfactorsthatmightendangerthepublicortheenvironment

[3]Tobehonestandrealisticinstatingclaimsorestimatesbasedonavailabledata.[4]Torejectbriberyinallitsforms[5]Toimprovetheunderstandingoftechnology,itsappropriateapplication,and

potentialconsequences.[6]Tomaintainandimproveourtechnicalcompetenceandtoundertaketechnological

tasksforothersonlyifqualifiedbytrainingorexperience,orafterfulldisclosureofpertinentlimitations.

[7]Toseek,accept,andofferhonestcriticismoftechnicalwork,toacknowledgeandcorrecterrors,andtocreditproperlythecontributionsofothers.

[9]Toavoidinjuringothers,theirproperty,reputation,oremploymentbyfalseormaliciousaction.

[10]Toassistcolleaguesandco-workersintheirprofessionaldevelopmentandtosupporttheminfollowingthiscodeofethics.

Ethics[1]appliestoourprojectinmanyways.Bycreatinghelmetadd-ons,ourdesign

couldpotentiallydecreasethesafetyofhelmetsandcouldpresentmoresafetyhazards,withtheinclusionofbatteries.Wemustdisclosethepotentialsafetyhazardswithourdesignandletthepublicknowthestepswehavetakentoalleviatethem.Ethics[3]isrelevanttoourprojectbecauseitdiscussesthefactofmakingfalseclaims.Forourprojectwecannotclaimthatourproductisgoingtosolveconcussionsorpredictthem.Becauseoutprojectdealsinaverypoliticalarena,concussions,therecouldcomeatimewherewewouldbebribedsothatwestopourproductionorinsteadbeforcedtofalselyreportoutresultsorcapabilities,ethics[4].Ethics[5]appliestousbecausewebelievepartofourmissionistoshownon-engineeringsportsleadersthepossibilitiesoftechnologyandsciencetocreatesaferenvironmentsin

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sports,whilekeepingthemrealisticoncurrentabilitiesandlimitations.Ethics[6]appliestousbecauseifdonehaphazardlyorignorantly,ourdevicecouldimmediatelyorfuturisticallydamagelives.Anyengineeringproject,mustincludeethics[7],wherewemustalwaysgivecredittooutsideresourcesandusetheiradvicetoimproveourproject.Ethics[9]goeshandinhandwithethics[1].Sinceourdesignmodifiessafetyhelmets,thiscouldincreaseinjuriesifwedonotmakeconsumersawareofthedifferencesandneededprecautions.Ourultimategoalistoaddvaluetotheconcussionfieldinneuroscience,whichwillallowustoenactethicscode[10].

SafetyEachmemberofourteamhasreceivedtheGeneralLaboratorySafetyandElectricalSafetycertificatesinordertousethelabsintheECEB.Ourprojectdoesnotdealwithlargeamountsofpowerdistributionorgeneration,sincethehighestamountofvoltagecapacityneededis5-5.5V.1)Battery

• Makesurethattheoperatingtemperatureforpowersupplyisbetween0degreeto45degreesCelsius.

• DonotputtheLithium-ionbatteryunderwaterorfire.Donotcompress,dismantle,orprickthebattery.

• Thebatteryiswell-cushionedinsidethehelmetsoastoreducetheimpactonthebattery.

• Makesurethetwoterminalsarenotshortatanytime.• Goodinsulationwithinthehelmetfromthehumanbodyorotherelectronicdevices.

2)Theproduct• Theproductisforbiddentobetestedonhumansubjectsotherthantheteammembers.

Citations[1]

S.K.F.C.L.C.R.W.D.R.D.C.LukeM.Gessel,"ConcussionsAmongUnitedStatesHighSchoolandCollegiateAthletes,"JournalofAthletcTraining,vol.42,no.4,p.495–503,2007.

[2]

Riddell,"riddellIQ,"Riddel,[Online].Available:http://www.riddell.com/riddell-iq.[Accessed10September2016].

[3]

Riddel,"RiddleInsite,"[Online].Available:http://www.riddell.com/InSite#whatitis.[Accessed14September2016].

[4]

Shockbox,"FootballHelmetSensors,"[Online].Available:http://www.theshockbox.com/football-sensors/.[Accessed14September2016].

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[5]

Reebok,[Online].Available:http://www.reebok.com/us/checklight/Z85846.html.[Accessed14September2016].

[6]

S.Smith,"Headimpactsensors:On-the-fieldplaceboordanger?,"21November2013.[Online].Available:http://www.cnn.com/2013/11/15/health/youth-head-sensors/.[Accessed14September2016].

[7]

D.K.Jackson,Interviewee,[Interview].26September2016.

[8]

STMicroelectronics,"H3LIS331DLMEMSmotionsensor:low-powerhigh-g3-axisdigitalaccelerometer,"September2013.[Online].Available:http://www.st.com/content/ccc/resource/technical/document/datasheet/3e/48/02/c7/a4/e6/41/bb/DM00053090.pdf/files/DM00053090.pdf/jcr:content/translations/en.DM00053090.pdf.[Accessed2October2016].

[9]

J.MurphyandY.Gitman,"OpenHardware,"[Online].Available:http://pulsesensor.com/pages/open-hardware.[Accessed2October2016].

[10]

OpenImpulse,"EP2C5T144AlteraCycloneIIFPGADevelopmentBoard,"4May2011.[Online].Available:https://www.openimpulse.com/blog/wp-content/uploads/wpsc/downloadables/EP2C5T144-Altera-Cyclone-II-FPGA-Development-Board-Diagram.pdf.[Accessed2October2016].

[11]

A.Haley,"FootballFieldDimensionsandGoalPostSizes:AQuickGuide,"15June2015.[Online].Available:http://www.stack.com/a/the-dimensions-of-a-football-field.[Accessed13October2016].

[12]

Shockbox,"Research,"[Online].Available:http://www.theshockbox.com/helmet-sensors-technology-for-concussion-management/shockbox-helmet-sensors-research/.[Accessed14September2016].

[13]

IEEE,"IEEECodeofEthics,"[Online].Available:http://www.ieee.org/about/corporate/governance/p7-8.html.[Accessed16September2016].

[14]

MicrochipTechnologyInc.,"2.7VDualChannel10-BitA/DConverterwithSPISerialInterface,"2007.[Online].Available:http://ww1.microchip.com/downloads/en/DeviceDoc/21294C.pdf.[Accessed2October2016].

[15]

AvagoTechnologiesLimited,"APDS-9008MiniatureSurface-MountAmbientLightPhotoSensorDataSheet,"7November2008.[Online].Available:http://docs.avagotech.com/docs/AV02-1169EN.[Accessed2October2016].

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