Vernier Q-S207 User manual

Q‐S207EKG/EMGSensor



ManufacturedandDistributedbyQubitSystemsInc.

613‐384‐1977,[email protected]



www.qubitsystems.com



October2015

TableofContents



OverviewofEKG/EMG 

 EKG(Electrocardiogram)2

 EMG(Electromyogram)5



ComponentsusedwiththeQ‐S207EKG/EMGSensor6

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QuickStartUpSteps

 EKGSetup7

 EMGSetup9



DataAcquisitionUsingtheLabQuestMiniInterface

 LabQuestMiniInterface12



InstallingandRunningLoggerPro312

 C404CustomSetupFilesInstallation:13

 GraphRanges,RunTimeanddataCollectionRate14

 DataCollectionandFileSaving15

 DataAnalysiswithLoggerPro3 15

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EKG/EMGSpecifications16

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Appendix1:SuggestedEKGExperimentswiththeQ‐S207Sensor  17

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Appendix2:SuggestedEMGExperimentswiththeQ‐S207Sensor21

 

QubitSystemsWarrantyInformation23

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ReturnProcedure23

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IMPORTANTNOTICE



TheEKG/EMGSensordescribedinthismanualisforeducationalandresearchuseonly.

Itisnottobeusedasaclinicalordiagnostictool.

OverviewofEKG/EMG

EKG(Electrocardiogram)

The Qubit EKG/EMG (Electrocardiogram/Electromyogram) Sensor measures voltage

waveformsproducedduring thecontraction of theheart (EKG)aswell asduringmuscle

contraction(EMG).Thevoltagechangesaregeneratedasfollows.



Heart muscle cells are polarized at rest, since the cells have unequal concentrations of

ionsacrosstheircellmembranes.Anexcessofpositivesodiumionsontheoutsideofthe

membranecausestheoutsidetobeabout90millivoltspositiverelativetotheinside.This

difference is the "resting potential". Cell membranes are impermeable to sodium,

however, stimulation of a muscle cell causes a temporary increase in permeability to

sodium. Sodium ions enterthecellthrough voltage‐gated sodium channels. This change

in cell potential from negative to positive (depolarization) and back (re‐polarization) is

calledthe"actionpotential",which

causesamusclecontraction.Otherionsandcharged

moleculessuchaspotassium, calcium,chloride,andchargedproteins arealsoinvolvedin

theactionpotential.Theactionpotentialcanberecordedbyelectrodesatthesurfaceof

theskin.Arecordingoftheheart'selectricalactivityiscalledanelectrocardiogram(EKG)

whereasrecordingofothermusclesiscalledanelectromyogram(EMG).



Spontaneousdepolarizationoccursinaclusterofcardiac‐musclecellsintheupperwall of

the right atrium. This group of cells is called the pacemaker or sinoatrial (SA) node.

Depolarization of the pacemaker generates a current that depolarizes all other cardiac

muscle cells. The wave of depolarization travels

rapidly from the right to left atrium so

bothatriacontractsimultaneously.



Theatriaandtheventriclesareisolatedfromeachotherelectricallybyconnectivetissue.

Hencedepolarizationoftheatriadoesnotdirectlyaffecttheventricles.Anothergroupof

cellsintheright atria, called the atrioventricular(AV) node, conducts

the depolarization

oftheatriadownaspecialbundleofconductingfibres(BundleofHis)totheventricles.In

themusclewalloftheventricles,musclefibrescalledPurkinjefibresbringdepolarization

to all parts of the ventricles simultaneously. This process causes a small time delay, so

there is a short pause after the atria contract before the ventricles contract. Since  the

cellsoftheheartmuscleareinterconnected,thiswaveofdepolarization,contraction,and

re‐polarizationspreadsacrossalloftheconnectedmuscleoftheheart.



When a portion of the heart is polarized and the adjacent portion is depolarized,

 an

electricalcurrent is createdthat movesthrough the body.This current isgreatest when

one half of the connected portion of the heart is polarized and the adjacent half is not

polarized. The current decreases when the ratio of polarized tissue to non‐polarized

tissueislessthanone

toone.Thechangesinthesecurrentscanbemeasured,amplified,

and plotted over time. The EKG represents the summation of all the action potentials

fromtheheart,asdetectedonthesurfaceofthebody.



Theimpulseoriginating attheSAnodecausestheatriatocontract,forcingbloodintothe

ventricles. Shortly after this contraction, the ventricles contract due to the signal

conductedtothemfromtheatria.Thebloodleavestheventriclesthroughtheaortaand

pulmonaryartery.Thepolarityofthecardiacmusclecellsreturnstonormalandtheheart

cyclestartsagain.



Atypicalelectrocardiogram(EKG)isshownbelow.Theserepetitivewaveformsarisefrom

aflatbaselinecalledthe isoelectricline.Anydeflection from the isoelectric line denotes

electricalactivity.

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TheElectrocardiogram

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The5majordeflectionsonanormalEKGcyclearedesignatedbyP,Q,R,S,andT.Acycle

begins with the Pwave, followedby theQRS wave complex, and endswith the Twave.

The P wave represents depolarization (and contraction) of the

atria.The QRS wave

complexconsistsofthreewaves‐Q(smallnegativewave),R(largepositivewave)andS

(negative wave). The QRS wave complex denotes depolarization and contraction of the

ventricles.Atrialre‐polarizationoccursduringdepolarization oftheventricles.Therefore

the waveform associated with atrial re‐polarization is undetectable in an EKG. The last

waveindicatingventricularre‐polarizationisthepositiveTwave.



ThesequencefromPwavetoTwaverepresentsoneheartcycle.Thenumberofcyclesin

aminuteistheheartratewhichistypically70‐80beatsperminuteatrest.Sometypical

timesfortheEKGare:



P‐Rinterval 0.12to0.20seconds

QRSinterval lessthan0.10seconds

Q‐Tinterval lessthan0.38seconds

EMG(Electromyogram)



Muscle contraction is controlled by motor units that have both neural and muscular

components.Theneuralcomponent,calledamotorneuron,hasacellbodyinthespinal

cordandanaxon that extends to a particular muscle.At the musclethe axon branches,

hundreds or thousands of times, to connect with numerous muscle fibres at

neuromuscular junctions. When the motor unit is activated (recruited), all the muscle

fibresatwhich it has a neuromuscular junctionare excited in synchrony.This produces

anactionpotential,andabriefcontractileresponse.



Theexcitationofthemusclefibres

inamotorunitcanbemeasuredonthesurfaceofthe

skin using electrodes attached to an Electromyograph (EMG).Each excitation causes a

briefpotentialthatappearsasanelectricalspike,calledamotorunitspike.Thepattern

ofresponsesfromthemuscleiscalledanelectromyogram,inwhichthe

motorunitspikes

areplottedagainsttime.



Note that the EMG, like the EKG measures the electrical activity, not the mechanical,

activity of the muscle.Associations between electrical and mechanical events can be

studied by observing muscle movement while using the EMG sensor. This can be done

visually by observing

 a knee jerk response after a patellar tap, or by  using Hand

DynamometertogetherwiththeEMGSensor.



Motor units  differ with respect to the size of the motor neuron  cell body and the

diameter ofthe axon.Smallermotor unitscontrol asmaller numberof fibres,whereas

larger motor units in the same muscle control a larger number of fibres.The EMG can

distinguishbetweenmotorunits,becausethesmallerunitsproduceanelectricalsignalof

lower amplitude than the larger units.Thus, a large frequencyof low amplitude motor

unitspikes,indicatesthatmanysmaller

motorunitsareoperating.



Theuseofvoluntarymusclesis initiated by excitation of neuronsinthemotorcortexof

the cerebrum.Upper motor neurons in the cerebrum have descending fibres that

terminate in the spinal cord, where they can excite the cell body of the lower motor

neuron.If

astrongcontractionofamuscleisrequired,agreateramountofexcitationis

producedinthedescendingfibres,whichresultsinthestimulationofagreaternumberof

lowermotorunits.Thesmallermotorunitsareactivatedfirst,andthenumberof these

recruited,increaseswith the desired strength of the muscular contraction.Forstronger

contractions, the larger motor units are recruited, their number increasing as effort

increases.For the greatest degree of effort, the very largest motor units are recruited.

Thus,anelectromyogramofamusclethatisputunderincreasingstrainwillshowaseries

of low amplitude motor unit spikes to begin with, and then the frequency of these will

increasebefore spikes of moderatelyhigh amplitudeare recorded.Whenthe muscle is

contracted with the greatest effort there will be a high frequency of both low and

moderatemotorspikeswithanincreasingfrequencyofthehighestamplitudespikes.



When the muscular effort is decreased gradually, the reverse situation occurs.The

highestamplitudespikesdisappearfirst,followedbythemoderatelyhighspikes,untilat

thelowestlevelofeffortjustafewofthelowestamplitudespikesremain.



ComponentsforusewiththeEKG/EMGSensor



Q‐S207EKG/EMGsensor

PowersupplyforQ‐S207

A263TabElectrodes(pkg.of100)

C610LabQuestMinidataacquisitioninterface(notincluded)

C901LoggerProDataAcquisitionSoftware(notincluded)

C404CustomizedSetupFiles(notincluded)

Manual



QuickStartupSteps



1. LoadLoggerProsoftwareontothecomputer(seepg.12)

2. LoadC404customQubitexperimentalfiles(seepg.13)

3. ConnectthepowersupplytotheQ‐S207EKG/EMG

4. Connecttheoutputdatacableto(analog)channel1ontheLabQuestMini

5. ConnecttheUSBcablebetweentheLabQuestMiniandthecomputer



EKGSetup



1. PlacetheswitchontheQ‐S207intheEKGposition(totheleft)

2. ConnectingtheQ‐S207totheSubject:

Pressthestickytabelectrodesontotheskinasshowninthephotobelow.Scrubtheareas

ofskin where the patcheswillbe attached with a paper towel to removedeadskin and

oil.Rubtheskinwithasmall amountofisopropyl(rubbing)alcoholtoimprovecontact.

Placeeachelectrodesothetabpointsdown.

 Pressthe1

electrodeontheinsideoftherightwrist.

 Pressthe2

electrodeontheinsideoftherightelbow.

 Pressthe3

electrodeontheinsideoftheleftelbow.

 Connecttheblack(or"reference")alligatorcliptotherightwristelectrode.Thisisthe

referencepointfortheisoelectricline(baseline).

 Connectthegreen(negative)alligatorcliptotherightelbowelectrode.

 Connectthered(positive)alligatorclip

totheleftelbowelectrode.

Notethewiresmaybetapedtothearmstoavoidpullingofftheelectrodes.

Onceopened,theelectrodesshouldbestoredinarefrigerated,clean,dryand

airtightcontainer.



3. OpentheQ‐S207EKGSetupfiletostarttheLoggerProsoftware.Notefor

convenience,ashortcuttothisfilecanbeplacedonthedesktop.

4. ASensorconfirmationscreenwillopeninLoggerProasshownbelow."Connect"

theQ‐S207EKG/EMGsensoronchannel1oftheLabQuestMini.



LoggerProwillnowopenwiththefollowingscreensetupforEKG.Thepagehasa

datatable,signalmetersandgraphs.Theusercaneasilycustomizethescreen:new

tables,metersorgraphscanbeaddedusingthemenucommandInsert.Custom

equationscanbeinsertedwiththemenucommandData>NewCalculatedColumn.

Digitalfilteringcanbeaccessedasafunctioninthenewcalculatedequation.

HistogramandFFTanalysisisavailableforEKGsignalsviaInsert>AdditionalGraph.



5. Letthesubjectrelax.TheoutputoftheEKG/EMGsensorisnowreadyforanEKG

experiment.SeeAppendix1forsuggestedEKGexperiments.



Itisimportantthatthesubjectremainsmotionlessduringanexperiment,sincemuscle

movementwillaffectthesignal.



Note:TheQ‐S207outputsa0‐5Vvoltagesignalthatdoesnotrequirecalibrationby

theuser.



EMGSetup



1. PlacetheswitchontheQ‐S207intheEMGposition(totheright)

2. ConnectingtheQ‐S207totheSubject:



Pressthestickytabelectrodesontotheskinasshowninthephotobelow.Scrubtheareas

ofskin where the patcheswillbe attached with a paper towel to removedeadskin and

oil.Rubtheskinwithasmall amountofisopropyl(rubbing)alcoholtoimprovecontact.

Placeeachelectrodesothetabpointsdown.

Two of the electrodes (positive‐red; green‐negative) are placed 5 to 6 cm apart on the

skinoverlyingthemuscle

tobestudied.The3

electrode(ground‐black)isplacedonthe

skin a  short distance from the other two, outside the region where the muscle under

studyisactive(e.g.ontheankleforcalfmuscleactivity).



Notethewiresmaybetapedtothearmstoavoidpullingofftheelectrodes.

Onceopened,theelectrodesshouldbestoredinarefrigerated,clean,dryand

airtightcontainer.



1. OpentheQ‐S207EMGSetupfiletostarttheLoggerProsoftware.Notefor

convenience,ashortcuttothisfilecanbeplacedonthedesktop.

2. ASensorconfirmationscreenwillopeninLoggerProasshownbelow."Connect"

theQ‐S207EKG/EMGsensoronchannel

1oftheLabQuestMini.



LoggerProwillnowopenwiththefollowingscreensetupforEKG.Thepagehasa

datatable,signalmetersandagraph.Theusercaneasilycustomizethescreen:new

tables,metersorgraphscanbeaddedusingthemenucommandInsert.Custom

equationscanbeinsertedwiththemenucommandData>NewCalculatedColumn.

Digitalfilteringcanbeaccessedasafunctioninthenewcalculatedequation.

HistogramandFFTanalysisisavailableforEMGsignalsviaInsert>AdditionalGraph.



3. Letthesubjectrelax.TheoutputoftheEKG/EMGsensorisnowreadyforanEMG

experiment.SeeAppendix1forsuggestedEMGexperiments.



Itisimportantthatthesubjectremainsmotionlessduringanexperiment,sincemuscle

movementwillaffectthesignal.



Note:TheQ‐S207outputsa0‐5Vvoltagesignalthatdoesnotrequirecalibrationby

theuser.



DataAcquisitionUsingtheLabQuestMiniInterface



LabQuestMiniInterface



TheLabQuestMiniinterfacehas3analogand2digitalchannels.Theinterfaceis

connectedtothecomputer(PCorMacintosh)byaUSBcable.Theinterfaceconvertsthe

analogvoltages(12bitAtoD)todigitalsignalswhicharetransmittedtothecomputervia

USBandprocessedbytheLoggerProsoftware.ThegreenLEDindicatesthatthe

LabQuestMiniisrecognizedbythedriversandreadytocollectdata.



InstallingandRunningLoggerPro3



PCUsers:



(1) To start, a complete copy of Logger Pro 3 must be installed on the computer.Before

starting the installation, make sure all USB cables are disconnecte d  from the computer.

Failuretodosomaycauseanerrorintheinstallationofthedrivers.

(2) Runtheinstallationanddonotchangethedefaultdestinationdirectory.LoggerPro3will

beinstalledinC:/ProgramFiles/VernierSoftware/LoggerPro3.

(3) ThesetupprocesswillautomaticallyloadtheUSBdriversforconnectingtheLabQuestMini

orotherinterfacestothecomputer.

(4) If QuickTime 6 (or greater) is not installed on the computer, install it when prompted.

QuickTimewillallowuseofthepictureandmoviefeaturesofLoggerPro3.

(5) YouwillbepromptedtoconnecttheLabQuestMiniorotherinterfaces tothecomputervia

theUSBconnection.

(6) Click‘Finish’tocompletetheinstallationprocess.

(7) Proceed to the C404 installation (below) before opening  the Logger Pro withthe “Q‐S207

EKGSetup”or“Q‐S207EMGSetup”file.

(8) Doubleclickthe“Q‐S207EKGSetup”or“Q‐S207EMGSetup”file(createashortcutonthe

desktop once moved from the C404 disk for easy access) to start Logger Pro and data

collection. If Logger Pro detects the LabQuest Mini interface, the Logger Pro screen will

appearwitha

star(iconforLabQuestMini)inthetopleftcorner.







(9) IfLoggerProcannotdetecttheLabQuestMiniInterface,amessagewillappear“nodevice

connected”.The LED on the Mini should be green.Ared LED indicates that poweris  on

(supplied by the computer through the USB) but there is no communication between the

interfaces and the computer.In

 this case, exit the “Q‐S207 EKG/EMG Setup” file and

unplugtheUSBcablefromthecomputer.ReconnecttheUSBcable.Allowthecomputerto

recognizetheMini(belltone)andthenre‐openthe“Q‐S207EKG/EMGSetup”file.



MacintoshUsers:

(1) Tostart,acompletecopyofLoggerPro3mustbeinstalledonthecomputer(You

mustbeusingatleastOS9.2).Runthe“CompleteInstallation”andensureallUSB

cables are disconnected. The following instructions are  the sameas those for PC

users.



C404CustomSetupFiles:



QubitSystems’C404CustomSetupFilesCDcontainsallofQubitExperimentfiles

(designedbyQubitSystems)including“Q‐S207EKGSetup”and“Q‐S207EMGSetup”.The

Experimentfilescontainthesetup(i.e.graphs,table,calculationsetc)forthevarious

experiments,aswellasthecalibrationconstantsfortheQubitsensors.TheC404disk

alsocontainsmanualsforthedifferentQubitsensorsandpackages.Thesefilescanbe

copiedtouserspecifiedlocationonthecomputerandtheexperimentalfileofinterestfor

thissensor–“Q‐S207EKGSetup”and“Q‐S207EMGSetup”shouldbeplacedinan

accessiblelocationorhaveashortcutcreatedonthedesktoptothefile.



GraphRanges,RunTimeandDataCollectionRate



Tomodify the range ofthe x and y‐axes, click on themaximumand/orminimum values

andtypeinthenewvalues.



If you wish to alter the maximum time allotted to your experiment or the rate of data

sampling,select“Experiment”,then“DataCollection”orclickontheclockiconinthetop

menu.



Type in the run time of your experiment in the box labelled “Duration”. Note that the

maximumvalueyouselectfortheTime‐axislimitsthetimeoverwhichyoucancollect

data for a  particular  run.If your experiment exceeds the allotted time, select

“Experiment”,then“StoreLatestRun”.Youmaythenrestartdatacollection.Datafrom

thefirstpartofyourexperimentwillremainonthescreenasafainttraceandnewdata

willbe plotted in a bolded shadeof the samecolour.You can collect numerous runs in 

thisway.Eachrunwill becollectedtoaseparatedatatable.Whenyousaveyourdata,

alloftherunswillbesavedunderthesamefilename.



You may also alterthe "Sampling Rate" at whichyou collect data.The default rates for

EKGandEMGare500and1000samples/s,respectively.



DataCollectionandFileSaving



To start data collection, click on the “Collect” green icon above the graphs.This will

changetoa“Stop”redicon.Clickonthe“Stop”icontostopdatacollection.



DataAnalysiswithLoggerPro3



(1) Position the cursorat thebeginning of the data set that youwish to analyze,then

clickandholdwiththemouse.



(2) Drag the cursor across the data set and unclick.

A greyed box will appear on the

screentoshowthedatarangetobeanalyzed.



(3) Select “Analyze”, and then choose from a wide variety of analysis options.For

example,use:



 “Examine”toscrollthroughthedatapointsatspecifictimeintervals.

 “Integral”tointegratetheselecteddata.

 “Statistics”toautomaticallyperformavarietyofstatisticalanalyses.



Youcanalsofitcurvesandtangentstotheselecteddatabychoosingtheappropriate

menuoption.Notetheanalysisfunctionscanalsobeaccessedfromiconsinthemenu.



EKG/EMGSpecifications

 powersupply:  9VDC,560mA

 units:Volts

 resolution:   0.0012Volts

 accuracy:   1%FullScale,orbetter

 offset:N/A

 gain:1076

 Cut‐offFrequencyfc: LowPass=1.6kHz,fcHighPass=0.2Hz

 size(h/w/l)cm:  2.8/6.2/9.2

 weight(g):   210

 materials:   plastic(black)

 subjectisolation: 1500Vrms

 warranty:   1year



Appendix1:SuggestedEKGE xperimentswiththeQ‐S207Sensor

(1) RestingEKG



Record the EKG of a subject at rest.The person should remain relaxed and breathe

normally. The following screen shot shows a resting EKG recorded in Logger Pro. The

heartrateiscalculatedevery5secusingthelarge"R"peaks.



Usingthedisplayedgraphin

LoggerPro,recordthefollowinginformation:



INTERVALANALYSIS HEARTRATEANALYSIS

Interval Time(milliseconds) Item Rate(perminute)

P‐QMinimum

QRSMaximum

Q‐TAverage



In a teaching lab these data may be distributed to the class for further statistical analysis.



(2) EKGAfterMildExercise



RecordanEKGofa personwhoisinitiallyatrest.Disconnectthesensorwiresfromthe

electrodes,butleavethepatchesonthesubject.Havethepersonexercisefor3minutes

by jogging "on the spot". Reattach the  sensor wires to the electrodes when the subject

hasfinishedexercisingandrecordanewEKG.ComparetherestingEKGtotheEKGafter

mildexercise.



(3) EKGandDifferentBodyPositions



RecordtherestingEKGinasittingposition.Thenhavethepersonstandorliedownand

record a second EKG.Compare the new EKG with the resting EKG in a sitting position.

Noteanychangesinheartrate,intervaltimes,heightofRwave,etc.



(4) EKGandMildStimulants



Have the subject drink a couple of cups of caffeinated coffee or cola.Record an EKG.

Compare the results with those at rest and following mild exercise.Note: This might

showlesseffectonpeoplewhoareaccustomedtolargeamountsofcaffeine.



(5) EKGandElectrodePosition:AxisoftheHeart



Note:Thisisamoreadvanceexercise.



Different arrangements of electrode patches will change  the shape and intensity of the

measured signal. Each arrangement is called a "lead." Each lead reveals unique

informationbasedonthelead'sorientationrelativetotheaxisoftheheart.Remember

toscrubtheareasoftheskinwheretheelectrodepatchesareplacedwithapapertowel

toremoveskinoilandmoisture.



Lead

I:



 Putanelectrodeontherightupperarm.Connectthe green(negative)alligatorclipto

thiselectrode.



 Putanelectrodeontheleftupperarm.Connectthered(positive)alligatorcliptothis

electrode.



 Putanelectrodeontheinsidesurfacebehindtherightanklebone.

Connecttheblack

(or "reference") alligator clip to this electrode. This is the reference point for the

isoelectricline.



 An imaginary line between the red and green electrodes shows that this lead is

measuring polarity changes across the chest, above the heart, and parallel to the

shoulders.



LeadII:



 Putanelectrodeontherightupperarm.Connectthe green(negative)alligatorclipto

thiselectrode.



 Put an electrode on the inner surface of the left thigh. Connect the red (positive)

alligator clip to this electrode. Note: Instead of the left  thigh, you can use the inner

surfaceoftheleftanklejustbehindtheleftanklebone.



 Put an electrode on the inside surface of the area behind the right anklebone.

Connecttheblack(reference)alligatorcliptothiselectrode.



 An imaginary line between the red andgreen electrodes yields an oblique line from

therightshouldertowardstheleftleg.LeadIIgenerallygivesthegreatestvariation

ofimpulseandistheEKGusuallyshowninmovies,textbooks,etc.



LeadIII:



 TheleadIIIarrangementhasthegreen(negative)electrodeconnectedtotheleftarm

and the red (positive) electrode connected to the left inner thigh with the black

(reference) electrode connected to the inside of the right ankle as before.Note:

Insteadoftheleftthigh,youcanusetheinnersurfaceoftheleftanklejustbehindthe

leftanklebone.



 This arrangement of the red and green electrodes yields an imaginary line from the

leftshouldertotheleftleg.



 Ifthethreeimaginarylineswere

connected,theywouldmakeatriangle.Thistriangle

is called theEinthoven triangle.The measuredintensity  of voltage onitsthree sides

canbeusedtostudyheartfunctions andanatomy.Youcanmakeanapproximation

oftheaxisofyour heart:thatis,theorientationofthecentrelineof

themassofyour

heart.



 RecordaLeadIEKG,aLeadIIEKGandaLeadIIIEKG.Comparetheresults.Determine

whichleadyieldsthemaximumR‐waveamplitude.



 IfthemaximumRwaveiswithLeadI,thentheaxisofyourheartisapproximatelyat

Odegreesasmeasuredfromthehorizontalandyourleft.

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