Vernier Q-S207 User manual

Type
User manual
1
QS207EKG/EMGSensor
ManufacturedandDistributedbyQubitSystemsInc.
6133841977,[email protected]
www.qubitsystems.com

October2015
1
TableofContents
OverviewofEKG/EMG 
EKG(Electrocardiogram)2
EMG(Electromyogram)5
ComponentsusedwiththeQS207EKG/EMGSensor6
QuickStartUpSteps
EKGSetup7
EMGSetup9
DataAcquisitionUsingtheLabQuestMiniInterface
LabQuestMiniInterface12
InstallingandRunningLoggerPro312
C404CustomSetupFilesInstallation:13
GraphRanges,RunTimeanddataCollectionRate14
DataCollectionandFileSaving15
DataAnalysiswithLoggerPro3 15
EKG/EMGSpecifications16
Appendix1:SuggestedEKGExperimentswiththeQS207Sensor 17
Appendix2:SuggestedEMGExperimentswiththeQS207Sensor21

QubitSystemsWarrantyInformation23
ReturnProcedure23
IMPORTANTNOTICE
TheEKG/EMGSensordescribedinthismanualisforeducationalandresearchuseonly.
Itisnottobeusedasaclinicalordiagnostictool.
2
OverviewofEKG/EMG
EKG(Electrocardiogram)
The Qubit EKG/EMG (Electrocardiogram/Electromyogram) Sensor measures voltage
waveformsproducedduring thecontraction of theheart (EKG)aswell asduringmuscle
contraction(EMG).Thevoltagechangesaregeneratedasfollows.
Heart muscle cells are polarized at rest, since the cells have unequal concentrations of
ionsacrosstheircellmembranes.Anexcessofpositivesodiumionsontheoutsideofthe
membranecausestheoutsidetobeabout90millivoltspositiverelativetotheinside.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 enterthecellthrough voltagegated sodium channels. This change
in cell potential from negative to positive (depolarization) and back (repolarization) is
calledthe"actionpotential",which
causesamusclecontraction.Otherionsandcharged
moleculessuchaspotassium, calcium,chloride,andchargedproteins arealsoinvolvedin
theactionpotential.Theactionpotentialcanberecordedbyelectrodesatthesurfaceof
theskin.Arecordingoftheheart'selectricalactivityiscalledanelectrocardiogram(EKG)
whereasrecordingofothermusclesiscalledanelectromyogram(EMG).
3
Spontaneousdepolarizationoccursinaclusterofcardiacmusclecellsintheupperwall 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
bothatriacontractsimultaneously.
Theatriaandtheventriclesareisolatedfromeachotherelectricallybyconnectivetissue.
Hencedepolarizationoftheatriadoesnotdirectlyaffecttheventricles.Anothergroupof
cellsintheright atria, called the atrioventricular(AV) node, conducts
the depolarization
oftheatriadownaspecialbundleofconductingfibres(BundleofHis)totheventricles.In
themusclewalloftheventricles,musclefibrescalledPurkinjefibresbringdepolarization
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
cellsoftheheartmuscleareinterconnected,thiswaveofdepolarization,contraction,and
repolarizationspreadsacrossalloftheconnectedmuscleoftheheart.
When a portion of the heart is polarized and the adjacent portion is depolarized,
an
electricalcurrent is createdthat movesthrough the body.This current isgreatest 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 nonpolarized
tissueislessthanone
toone.Thechangesinthesecurrentscanbemeasured,amplified,
and plotted over time. The EKG represents the summation of all the action potentials
fromtheheart,asdetectedonthesurfaceofthebody.
Theimpulseoriginating attheSAnodecausestheatriatocontract,forcingbloodintothe
ventricles. Shortly after this contraction, the ventricles contract due to the signal
conductedtothemfromtheatria.Thebloodleavestheventriclesthroughtheaortaand
pulmonaryartery.Thepolarityofthecardiacmusclecellsreturnstonormalandtheheart
cyclestartsagain.
4
Atypicalelectrocardiogram(EKG)isshownbelow.Theserepetitivewaveformsarisefrom
aflatbaselinecalledthe isoelectricline.Anydeflection from the isoelectric line denotes
electricalactivity.
TheElectrocardiogram
The5majordeflectionsonanormalEKGcyclearedesignatedbyP,Q,R,S,andT.Acycle
begins with the Pwave, followedby theQRS wave complex, and endswith the Twave.
The P wave represents depolarization (and contraction) of the
atria.The QRS wave
complexconsistsofthreewaves‐Q(smallnegativewave),R(largepositivewave)andS
(negative wave). The QRS wave complex denotes depolarization and contraction of the
ventricles.Atrialrepolarizationoccursduringdepolarization oftheventricles.Therefore
the waveform associated with atrial repolarization is undetectable in an EKG. The last
waveindicatingventricularrepolarizationisthepositiveTwave.
ThesequencefromPwavetoTwaverepresentsoneheartcycle.Thenumberofcyclesin
aminuteistheheartratewhichistypically7080beatsperminuteatrest.Sometypical
timesfortheEKGare:
PRinterval 0.12to0.20seconds
QRSinterval lessthan0.10seconds
QTinterval lessthan0.38seconds
5
EMG(Electromyogram)
Muscle contraction is controlled by motor units that have both neural and muscular
components.Theneuralcomponent,calledamotorneuron,hasacellbodyinthespinal
cordandanaxon that extends to a particular muscle.At the musclethe 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
fibresatwhich it has a neuromuscular junctionare excited in synchrony.This produces
anactionpotential,andabriefcontractileresponse.
Theexcitationofthemusclefibres
inamotorunitcanbemeasuredonthesurfaceofthe
skin using electrodes attached to an Electromyograph (EMG).Each excitation causes a
briefpotentialthatappearsasanelectricalspike,calledamotorunitspike.Thepattern
ofresponsesfromthemuscleiscalledanelectromyogram,inwhichthe
motorunitspikes
areplottedagainsttime.
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
DynamometertogetherwiththeEMGSensor.
Motor units differ with respect to the size of the motor neuron cell body and the
diameter ofthe axon.Smallermotor unitscontrol asmaller numberof fibres,whereas
6
larger motor units in the same muscle control a larger number of fibres.The EMG can
distinguishbetweenmotorunits,becausethesmallerunitsproduceanelectricalsignalof
lower amplitude than the larger units.Thus, a large frequencyof low amplitude motor
unitspikes,indicatesthatmanysmaller
motorunitsareoperating.
Theuseofvoluntarymusclesis initiated by excitation of neuronsinthemotorcortexof
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
astrongcontractionofamuscleisrequired,agreateramountofexcitationis
producedinthedescendingfibres,whichresultsinthestimulationofagreaternumberof
lowermotorunits.Thesmallermotorunitsareactivatedfirst,andthenumberof these
recruited,increaseswith the desired strength of the muscular contraction.Forstronger
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,anelectromyogramofamusclethatisputunderincreasingstrainwillshowaseries
of low amplitude motor unit spikes to begin with, and then the frequency of these will
increasebefore spikes of moderatelyhigh amplitudeare recorded.Whenthe muscle is
contracted with the greatest effort there will be a high frequency of both low and
moderatemotorspikeswithanincreasingfrequencyofthehighestamplitudespikes.
When the muscular effort is decreased gradually, the reverse situation occurs.The
highestamplitudespikesdisappearfirst,followedbythemoderatelyhighspikes,untilat
thelowestlevelofeffortjustafewofthelowestamplitudespikesremain.
ComponentsforusewiththeEKG/EMGSensor
QS207EKG/EMGsensor
PowersupplyforQS207
A263TabElectrodes(pkg.of100)
C610LabQuestMinidataacquisitioninterface(notincluded)
C901LoggerProDataAcquisitionSoftware(notincluded)
C404CustomizedSetupFiles(notincluded)
Manual
7
QuickStartupSteps
1. LoadLoggerProsoftwareontothecomputer(seepg.12)
2. LoadC404customQubitexperimentalfiles(seepg.13)
3. ConnectthepowersupplytotheQS207EKG/EMG
4. Connecttheoutputdatacableto(analog)channel1ontheLabQuestMini
5. ConnecttheUSBcablebetweentheLabQuestMiniandthecomputer
EKGSetup
1. PlacetheswitchontheQS207intheEKGposition(totheleft)
2. ConnectingtheQS207totheSubject:
Pressthestickytabelectrodesontotheskinasshowninthephotobelow.Scrubtheareas
ofskin where the patcheswillbe attached with a paper towel to removedeadskin and
oil.Rubtheskinwithasmall amountofisopropyl(rubbing)alcoholtoimprovecontact.
Placeeachelectrodesothetabpointsdown.
Pressthe1
st
electrodeontheinsideoftherightwrist.
Pressthe2
nd
electrodeontheinsideoftherightelbow.
Pressthe3
rd
electrodeontheinsideoftheleftelbow.
Connecttheblack(or"reference")alligatorcliptotherightwristelectrode.Thisisthe
referencepointfortheisoelectricline(baseline).
Connectthegreen(negative)alligatorcliptotherightelbowelectrode.
Connectthered(positive)alligatorclip
totheleftelbowelectrode.
Notethewiresmaybetapedtothearmstoavoidpullingofftheelectrodes.
Onceopened,theelectrodesshouldbestoredinarefrigerated,clean,dryand
airtightcontainer.
8
3. OpentheQS207EKGSetupfiletostarttheLoggerProsoftware.Notefor
convenience,ashortcuttothisfilecanbeplacedonthedesktop.
4. ASensorconfirmationscreenwillopeninLoggerProasshownbelow."Connect"
theQS207EKG/EMGsensoronchannel1oftheLabQuestMini.
LoggerProwillnowopenwiththefollowingscreensetupforEKG.Thepagehasa
datatable,signalmetersandgraphs.Theusercaneasilycustomizethescreen:new
tables,metersorgraphscanbeaddedusingthemenucommandInsert.Custom
equationscanbeinsertedwiththemenucommandData>NewCalculatedColumn.
Digitalfilteringcanbeaccessedasafunctioninthenewcalculatedequation.
HistogramandFFTanalysisisavailableforEKGsignalsviaInsert>AdditionalGraph.
9
5. Letthesubjectrelax.TheoutputoftheEKG/EMGsensorisnowreadyforanEKG
experiment.SeeAppendix1forsuggestedEKGexperiments.
Itisimportantthatthesubjectremainsmotionlessduringanexperiment,sincemuscle
movementwillaffectthesignal.
Note:TheQS207outputsa05Vvoltagesignalthatdoesnotrequirecalibrationby
theuser.
EMGSetup
1. PlacetheswitchontheQS207intheEMGposition(totheright)
2. ConnectingtheQS207totheSubject:
Pressthestickytabelectrodesontotheskinasshowninthephotobelow.Scrubtheareas
ofskin where the patcheswillbe attached with a paper towel to removedeadskin and
oil.Rubtheskinwithasmall amountofisopropyl(rubbing)alcoholtoimprovecontact.
Placeeachelectrodesothetabpointsdown.
Two of the electrodes (positivered; greennegative) are placed 5 to 6 cm apart on the
skinoverlyingthemuscle
tobestudied.The3
rd
electrode(groundblack)isplacedonthe
skin a short distance from the other two, outside the region where the muscle under
studyisactive(e.g.ontheankleforcalfmuscleactivity).
10
Notethewiresmaybetapedtothearmstoavoidpullingofftheelectrodes.
Onceopened,theelectrodesshouldbestoredinarefrigerated,clean,dryand
airtightcontainer.
1. OpentheQS207EMGSetupfiletostarttheLoggerProsoftware.Notefor
convenience,ashortcuttothisfilecanbeplacedonthedesktop.
2. ASensorconfirmationscreenwillopeninLoggerProasshownbelow."Connect"
theQS207EKG/EMGsensoronchannel
1oftheLabQuestMini.
11
LoggerProwillnowopenwiththefollowingscreensetupforEKG.Thepagehasa
datatable,signalmetersandagraph.Theusercaneasilycustomizethescreen:new
tables,metersorgraphscanbeaddedusingthemenucommandInsert.Custom
equationscanbeinsertedwiththemenucommandData>NewCalculatedColumn.
Digitalfilteringcanbeaccessedasafunctioninthenewcalculatedequation.
HistogramandFFTanalysisisavailableforEMGsignalsviaInsert>AdditionalGraph.
3. Letthesubjectrelax.TheoutputoftheEKG/EMGsensorisnowreadyforanEMG
experiment.SeeAppendix1forsuggestedEMGexperiments.
12
Itisimportantthatthesubjectremainsmotionlessduringanexperiment,sincemuscle
movementwillaffectthesignal.
Note:TheQS207outputsa05Vvoltagesignalthatdoesnotrequirecalibrationby
theuser.
DataAcquisitionUsingtheLabQuestMiniInterface
LabQuestMiniInterface
TheLabQuestMiniinterfacehas3analogand2digitalchannels.Theinterfaceis
connectedtothecomputer(PCorMacintosh)byaUSBcable.Theinterfaceconvertsthe
analogvoltages(12bitAtoD)todigitalsignalswhicharetransmittedtothecomputervia
USBandprocessedbytheLoggerProsoftware.ThegreenLEDindicatesthatthe
LabQuestMiniisrecognizedbythedriversandreadytocollectdata.
InstallingandRunningLoggerPro3
PCUsers:
(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.
Failuretodosomaycauseanerrorintheinstallationofthedrivers.
(2) Runtheinstallationanddonotchangethedefaultdestinationdirectory.LoggerPro3will
beinstalledinC:/ProgramFiles/VernierSoftware/LoggerPro3.
13
(3) ThesetupprocesswillautomaticallyloadtheUSBdriversforconnectingtheLabQuestMini
orotherinterfacestothecomputer.
(4) If QuickTime 6 (or greater) is not installed on the computer, install it when prompted.
QuickTimewillallowuseofthepictureandmoviefeaturesofLoggerPro3.
(5) YouwillbepromptedtoconnecttheLabQuestMiniorotherinterfaces tothecomputervia
theUSBconnection.
(6) Click‘Finish’tocompletetheinstallationprocess.
(7) Proceed to the C404 installation (below) before opening the Logger Pro withthe “QS207
EKGSetup”or“QS207EMGSetup”file.
(8) Doubleclickthe“QS207EKGSetup”or“QS207EMGSetup”file(createashortcutonthe
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
appearwitha
star(iconforLabQuestMini)inthetopleftcorner.

(9) IfLoggerProcannotdetecttheLabQuestMiniInterface,amessagewillappear“nodevice
connected”.The LED on the Mini should be green.Ared LED indicates that poweris on
(supplied by the computer through the USB) but there is no communication between the
interfaces and the computer.In
this case, exit the “QS207 EKG/EMG Setup” file and
unplugtheUSBcablefromthecomputer.ReconnecttheUSBcable.Allowthecomputerto
recognizetheMini(belltone)andthenreopenthe“QS207EKG/EMGSetup”file.
MacintoshUsers:
(1) Tostart,acompletecopyofLoggerPro3mustbeinstalledonthecomputer(You
mustbeusingatleastOS9.2).Runthe“CompleteInstallation”andensureallUSB
cables are disconnected. The following instructions are the sameas those for PC
users.
C404CustomSetupFiles:
QubitSystems’C404CustomSetupFilesCDcontainsallofQubitExperimentfiles
(designedbyQubitSystems)including“QS207EKGSetup”and“QS207EMGSetup”.The
Experimentfilescontainthesetup(i.e.graphs,table,calculationsetc)forthevarious
experiments,aswellasthecalibrationconstantsfortheQubitsensors.TheC404disk
alsocontainsmanualsforthedifferentQubitsensorsandpackages.Thesefilescanbe
14
copiedtouserspecifiedlocationonthecomputerandtheexperimentalfileofinterestfor
thissensor“QS207EKGSetup”and“QS207EMGSetup”shouldbeplacedinan
accessiblelocationorhaveashortcutcreatedonthedesktoptothefile.
GraphRanges,RunTimeandDataCollectionRate
Tomodify the range ofthe x and yaxes, click on themaximumand/orminimum values
andtypeinthenewvalues.
If you wish to alter the maximum time allotted to your experiment or the rate of data
sampling,select“Experiment”,then“DataCollection”orclickontheclockiconinthetop
menu.
Type in the run time of your experiment in the box labelled “Duration”. Note that the
maximumvalueyouselectfortheTimeaxislimitsthetimeoverwhichyoucancollect
data for a particular run.If your experiment exceeds the allotted time, select
“Experiment”,then“StoreLatestRun”.Youmaythenrestartdatacollection.Datafrom
thefirstpartofyourexperimentwillremainonthescreenasafainttraceandnewdata
willbe plotted in a bolded shadeof the samecolour.You can collect numerous runs in
thisway.Eachrunwill becollectedtoaseparatedatatable.Whenyousaveyourdata,
alloftherunswillbesavedunderthesamefilename.
15
You may also alterthe "Sampling Rate" at whichyou collect data.The default rates for
EKGandEMGare500and1000samples/s,respectively.
DataCollectionandFileSaving
To start data collection, click on the “Collect” green icon above the graphs.This will
changetoa“Stop”redicon.Clickonthe“Stop”icontostopdatacollection.
DataAnalysiswithLoggerPro3
(1) Position the cursorat thebeginning of the data set that youwish to analyze,then
clickandholdwiththemouse.
(2) Drag the cursor across the data set and unclick.
A greyed box will appear on the
screentoshowthedatarangetobeanalyzed.
(3) Select “Analyze”, and then choose from a wide variety of analysis options.For
example,use:
16
“Examine”toscrollthroughthedatapointsatspecifictimeintervals.
“Integral”tointegratetheselecteddata.
“Statistics”toautomaticallyperformavarietyofstatisticalanalyses.
Youcanalsofitcurvesandtangentstotheselecteddatabychoosingtheappropriate
menuoption.Notetheanalysisfunctionscanalsobeaccessedfromiconsinthemenu.
EKG/EMGSpecifications
powersupply: 9VDC,560mA
units:Volts
resolution: 0.0012Volts
accuracy: 1%FullScale,orbetter
offset:N/A
gain:1076
CutoffFrequencyfc: LowPass=1.6kHz,fcHighPass=0.2Hz
size(h/w/l)cm: 2.8/6.2/9.2
weight(g): 210
materials: plastic(black)
subjectisolation: 1500Vrms
warranty: 1year
17
Appendix1:SuggestedEKGE xperimentswiththeQS207Sensor
(1) RestingEKG
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
heartrateiscalculatedevery5secusingthelarge"R"peaks.
Usingthedisplayedgraphin
LoggerPro,recordthefollowinginformation:
INTERVALANALYSIS HEARTRATEANALYSIS
Interval Time(milliseconds) Item Rate(perminute)
PQMinimum
QRSMaximum
QTAverage
In a teaching lab these data may be distributed to the class for further statistical analysis.
18
(2) EKGAfterMildExercise
RecordanEKGofa personwhoisinitiallyatrest.Disconnectthesensorwiresfromthe
electrodes,butleavethepatchesonthesubject.Havethepersonexercisefor3minutes
by jogging "on the spot". Reattach the sensor wires to the electrodes when the subject
hasfinishedexercisingandrecordanewEKG.ComparetherestingEKGtotheEKGafter
mildexercise.
(3) EKGandDifferentBodyPositions
RecordtherestingEKGinasittingposition.Thenhavethepersonstandorliedownand
record a second EKG.Compare the new EKG with the resting EKG in a sitting position.
Noteanychangesinheartrate,intervaltimes,heightofRwave,etc.
(4) EKGandMildStimulants
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
showlesseffectonpeoplewhoareaccustomedtolargeamountsofcaffeine.
(5) EKGandElectrodePosition:AxisoftheHeart
Note:Thisisamoreadvanceexercise.
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
informationbasedonthelead'sorientationrelativetotheaxisoftheheart.Remember
toscrubtheareasoftheskinwheretheelectrodepatchesareplacedwithapapertowel
toremoveskinoilandmoisture.
Lead
I:
Putanelectrodeontherightupperarm.Connectthe green(negative)alligatorclipto
thiselectrode.
Putanelectrodeontheleftupperarm.Connectthered(positive)alligatorcliptothis
electrode.
Putanelectrodeontheinsidesurfacebehindtherightanklebone.
Connecttheblack
(or "reference") alligator clip to this electrode. This is the reference point for the
isoelectricline.
19
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.
LeadII:
Putanelectrodeontherightupperarm.Connectthe green(negative)alligatorclipto
thiselectrode.
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
surfaceoftheleftanklejustbehindtheleftanklebone.
Put an electrode on the inside surface of the area behind the right anklebone.
Connecttheblack(reference)alligatorcliptothiselectrode.
An imaginary line between the red andgreen electrodes yields an oblique line from
therightshouldertowardstheleftleg.LeadIIgenerallygivesthegreatestvariation
ofimpulseandistheEKGusuallyshowninmovies,textbooks,etc.
LeadIII:
TheleadIIIarrangementhasthegreen(negative)electrodeconnectedtotheleftarm
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:
Insteadoftheleftthigh,youcanusetheinnersurfaceoftheleftanklejustbehindthe
leftanklebone.
This arrangement of the red and green electrodes yields an imaginary line from the
leftshouldertotheleftleg.
Ifthethreeimaginarylineswere
connected,theywouldmakeatriangle.Thistriangle
is called theEinthoven triangle.The measuredintensity of voltage onitsthree sides
canbeusedtostudyheartfunctions andanatomy.Youcanmakeanapproximation
oftheaxisofyour heart:thatis,theorientationofthecentrelineof
themassofyour
heart.
RecordaLeadIEKG,aLeadIIEKGandaLeadIIIEKG.Comparetheresults.Determine
whichleadyieldsthemaximumRwaveamplitude.
IfthemaximumRwaveiswithLeadI,thentheaxisofyourheartisapproximatelyat
Odegreesasmeasuredfromthehorizontalandyourleft.
  • Page 1 1
  • Page 2 2
  • Page 3 3
  • Page 4 4
  • Page 5 5
  • Page 6 6
  • Page 7 7
  • Page 8 8
  • Page 9 9
  • Page 10 10
  • Page 11 11
  • Page 12 12
  • Page 13 13
  • Page 14 14
  • Page 15 15
  • Page 16 16
  • Page 17 17
  • Page 18 18
  • Page 19 19
  • Page 20 20
  • Page 21 21
  • Page 22 22
  • Page 23 23
  • Page 24 24

Vernier Q-S207 User manual

Type
User manual

Ask a question and I''ll find the answer in the document

Finding information in a document is now easier with AI