BIOPAC - ELTE Élettani és Neurobiológiai Tanszékphysiology.elte.hu/gyakorlat/angol/ECG II_Biopac lesson...Biopac Student Lab Le son 6: ECG II Page 5 The electrical activity of

Physiology Lessonsfor use with the

Biopac Student Lab

PC under Windows 98SE, Me, 2000 Proor Macintosh" 8.6 - 9.1

Manual RevisionPL3.6.7-ML3.0.7/061903

Richard Pflanzer, Ph.D.Associate Profes or

Indiana University chool of MedicinePurdue University School of Science

William McMullenVice President

BIOPAC ystems, lnc.

BIOPAC Systems, Inc.42 Aero Camino, Goleta, CA 93117(805) 685-0066 Fax (805) 685-0067

Email: info "biopac.comWeb Site: http://www.biopac.com

=BIOPACSystems, Inc.

Lesson 6ELECTROCARDIOGRAPHY II

Bipolar Leads (Leads 1, II, III)Einthoven's LawMean Electrical Axis on the Frontal Plane

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10000 2 0000 seconds 3 0000 4 0000 Iltn~

Page 2 Lesson 6: ECG II Biopac Student Lab

I. INTRODUCTIONWillem Einthoven developed a "stringgalvanometer" in 1901 that could record theelectrical activity of the heart. Although it wasnot the first such recorder it was a breakthroughin that it was accurate enough to duplicate theresults on the same patient. Einthoven' s workestablished a standard configuration forrecording the ECG and won him the NobelPrize in 1924. Since then, the ECG has becomea powerful tool in diagnosing disorders of theheart. [It should be noted that the clinicalinterpretation of the ECG is quite empirical inpractice, and has evolved from a long history ofreference to and correlation with known cardiacdisorders. ]

About Willem Einthoven -1860-1927Born in Semarang, JavaDutch physicianProfessor, University of Leiden, 1885-1927Nobel Prize: 1924

The electrical activity of the heart begins in the sinoatrial (SA) node, and spreads throughout theatria and to the AV node (see Lesson 5 ECG I for details). The spread of signal causes a negativecharge to occur, which induces depolarization. This depolarization of the atria is recorded as theP wave of the CG. At the AV node, the electrical signal is slowed. Then, the electrical signalconducts down the AV bundle and down the left and right bundle branches, following theinterventricular septum. The depolarization continues down the septum spreading through theventricles via the Purkinje fibers. The depolarization of the ventricles is recorded as the QRScomplex in the ECG. Following compl te depolarization of the ventricles, the ventricles tart theprocess of repolarization, which is recorded as the T wave.

Because the current spreads along sp cialized pathways and depolarize in sequence, theelectrical acti ity has a spatial orientation or electrical axi . Because the amount of electricalsignal generated is proportional to the amount of tissue being depolarized, and the ventriclesmake up the majority of the mass, the largest potential difference reflects the depolarization ofthe ventricles. Furthermore, since the left ventricle i larger than the right, more of the QRScomplex reflects the depolarization of th left ventricle.

The body contains fluids with ions that allow for electrical conduction. This makes it possible tomeasure electrical activity in and around the heart from th surface of the skin (assuming goodelectrical contact is made with th bod fluids using electrodes). This also allows the legs andarms to act as simple extensions of points in the torso. M a urements from the leg approximatethose occurring in the groin, and measurements from the arms approximate those from thecorresponding shoulder.

Ideall ,electrod are placed on the ankle and wri ts for convenience to the ubject undergoingthe ECG evaluation. In order for the ECG recorder to work properly. a ground reference point onthe body i required. This ground is obtain d from an electrode placed on the right leg above theankle.

Biopac Student Lab Le son 6: ECG II Page 3

To represent the body in three dimensions three planes are defined for electrocardiography(Fig.6.1).

Fig. 6.1

The term "lead" is defined as a spatial arrangement of two electrodes on the body. One lead islabeled "+" (positive) and the other "-" (negative). The electrode placement defines therecording direction of the lead, which is called the lead axis or angle. The axis is determined bythe direction when going from th negative to positive electrode. The ECG recorder computesthe difference (magnitude) between the positive and negative electrodes.

A good mathematical tool for representing th measurement of a lead is the vector. A vector isdefined as an arrow whose head points in the positive direction. The length of the arrow isproportional to the magnitude of the lead.

Einthoven's Triangle i defined as a configuration of three leads with the polarity shown inFig. 6.2: Lead I goes from right to left shoulder, Lead II from right shoulder to groin area, andLead III from left shoulder to groin area. To simplify calculations, the triangle will be assumedto b an equi lateral triangle. ince the legs and arms act as simple extensions of points in thetorso, we can also re-define the leads as follows:

Lead 1 Right Arm (RA) "-" electrodeLeft rm (L ) ,,+,. lectrode

Lead II Right Arm (RA) "-' electrodeLeft Leg (LL) "+" electrode

Lead III Left Arm (LA) "-" electrodeLeft Leg (LL) "+" electrode


\

'I

right leg • I

(ground) I )(~

Ihleftleg

Fig. 6.2

The direction of the lead must be paid attention to. This lead configuration is called the standardbipolar limb lead.

Einthoven's Law is stated mathematically as follows: Lead I + Lead III = Lead II. Therefore,if any two leads are known at a given time, the third lead can be determined mathematically.

Figure 6.3 shows another way to look at Einthoven's Triangle. You can move each axishorizontally or vertically and still have the same representation. This makes it a little easier tovisualize the mean electrical axis of the heart.

+.l(

6Qo

Fig. 6.3


The electrical activity of the heart at any instant in time can be represented by a vector. Themean electrical axis of the heart is the summation of all the vectors occurring in a cardiac cycle.

ince the QR interval caused by ventricular depolarization represents the majority of theelectrical activity of the heart, you can approximate the mean electrical axis by looking only inthis interval.

A further approximation can be made by looking only at the peak of the R wave which makesup the largest magnitude in the cardiac cycle. To define the mean electrical axis precisely, youneed to define it in three dimensions (X Y, and Z). This is done in practice by using astandardized et of 12 Leads. Three of these leads are the ones previously defined and allow themean electrical axis to be calculated in the frontal plane. This lesson focuses on only the frontalplane axis.

(7\J."f~ magnitude of R wave from leads

I

Fig. 6.4

As mentioned above, on way to approximate the mean electrical axis in the frontal plane is toplot the magnitude of the R-wave from Lead I and Lead III (Fig. 6.4). To do this:

l , Draw a perpendicular line from the ends of the vector (right angles to theaxis of the Lead)

2. Determine the point of intersection of the e two perpendicular lines.

3. Draw a new vector from point 0,0 to the point of inter ection.

The direction of the re ulting ector approximate the mean electrical axis of the heart. Thelength of the vector approximates the mean pot ntial of the heart.

more accurate method of approximating the mean electrical axis is to algebraically add the Q,R, and potentials for one lead, instead of using just the magnitude of the R wave. The rest ofthe procedure would b the ame a outlin d abo e.


It is important to note that, because the body is not a perfect conductor and electrodes are notperfect attachments to the skin (among many other reasons) ECG measurements from thesurface of the skin only approximate the actual activity of the heart.

II. EXPERIMENTAL OBJECTIVES1) Record ECG from Leads I and III in the following conditions: lying down, sitting up, and

breathing deeply while sitting.

2) Review the ECGs for Lead II.

3) Correlate the direction of the QRS Complex (+ or -) with the direction of the lead axis.

4) Estimate the mean electrical axis of the QRS complex using two methods.

III. MATERIALS~ BIOPAC electrode lead s t (SS2L), Qty - 2

~ BIOPAC disposable vinyl electrodes (ELS03), 6 electrodes per subject

~ Cot or lab table and pillow

~ Protractor

~ Two different colored pens/pencils

~ BIOPAC electrode gel (GEL I) and abrasive pad (ELPAD)

orSkin cleanser or alcohol prep

~ Computer system~ BIOPAC tudent Lab oftware v3.6.7 PC or v3.0.7 Mac or greater

~ BIOPAC acquisition unit (MP30)

~ BIOPACwalltransformer( CIOO )

~ BIOPAC serial cable (CBL ERA) or USB cable (USB IW) if using a USB port.


IV. EXPERIMENTAL METHODSOverview

~ As you complete the Experimental Methods (Set Up Calibration, and Recording) and the Analysis,you may need to use the following tools and/or di play options. The window display shown below isonly a reference sample - it does not represent any Ie son specific data. The sample screen shows 3channels of data and four channel mea urement boxes, but your creen display may vary betweenlessons and at different point within the ame Ie on.

channel mea urement boxe(channel # measurement type result) marker marker tools

marker label

JohnB.LD2

• • •, ~M • 1""16 ~·03l9041 ~.O.G4"3 ~.I~F~ •• 4

33133Pn ~ 141 ~ 1..-o

!<00000

~.., 0000

~ 000 i

-200

w

i

i 000 i

-i~•• zee """" - ra eso se """ ....

/ertical scales

channel boxes(Data anal sis mode only)

channel labels· ertical (amplitude)croll bar

horizontal (time) scroll barelection tool zoom tool

horizontal scale l-Bearn cursor

The ymbol explained belov are used throughout Experimental Methods and Analysis.

Key to Symbols,If you encounter a problem or need further explanation of a concept, refer to theOrientation hapter for more details.

The data collected in the as ociated step need to be recorded in the Data Report (in thesection indicated by the alpha character). You can record the data individually by hand orchoose Edit> Journal> Pa te measurements to pa te the data to your journal for futurereference.

V Mo t marker and lab I are automatic. Markers appear at the top of the window ainverted triangles. Thi ymbol i u ed to indicate that ou need to insert a marker and ke in amarker label imilar to the te t in quote. You can in ert and label the marker during or afteracqui ition. On a Mac, pre 'E C" and on a PC, pre 'F9."

>- Each ection is pre ented in a to-column format a de cribed belo .

I

FAST TRACK STEPS

This side of the les on (left hadedcolumn) is the "FAT TRACK' throughthe lesson which contains a basicexplanation of each step.

DETAILED EXPLA ATIO OF Sn:ps

Thi ide of the Ie n contain more detailedinformation to clarify the tep and/or concepts in theF T TRACK, and ma include reference diagrams,illu tration ,and creen shots.

Page 8

A. SETUPFAST TRACK Set Up

1. Turn the computer 0 .

2. Make sure the BIOPAC MP30 unitis turned OFF.

3. Plug the equipment in as follows:Electrode lead (S 2L) -CH 1

Electrode lead ( S2L) -CH 3

4. Turn the MP30 Data AcquisitionUnit ON.

5. Place six electrodes on the ubject,as shown in Fig. 6.6.

Lesson 6: ECG II Biopac Student Lab

Detailed Explanation of Set Up StepsThe desktop should appear on the monitor. If it does not

appear, a k the laboratory instructor for assistance. W

SS2L Electrode Leads

Fig. 6.5

I aboveright wri t

2 aboveleft wrist

),,! I aboveit~· left ankle

/~.w WFig. 6.6 Electrode placement

Place six electrodes as shown in Fig. 6.6:

two electrodes on the right ankle, just above theankle boneone electrode on the left leg, just abo e the anklebonetwo electrode on the left wrist (same side of arm asthe palm of hand)

2 aboveright ankle

Biopac tudent Lab

6. Attach the first electrode lead set(SS2L) from Channell to theelectrodes, following Fig. 6.7.

et Up continue ...

Lesson 6: ECG II Page 9

one electrode on the right wrist (same side of arm asthe palm of hand.

Note: For optimal electrode adhesion, the electrodesshould be placed on the skin at least 5 minutes before

the start of the Calibration procedure. WEach of the pinch connectors on the end of theelectrode cable needs to be attached to a specificelectrode. The electrode cables are each a differentcolor, and you should follow Fig. 6.7 to ensure that youconnect each cable to the proper electrode.

When the electrode cable is connected properly, theLEAD I electrode configuration will be established.

right legBLACK lead

(Ground) )

The pinch connectors work lik a mall clothespin, butwill onl latch onto the nipple of the electrode from oneside of the connector.

ote: For the two electrodes on the right ankle andthe left wri t. Lead I should go to the upper of the twoelectrodes.

Page 10

7. Attach th second electrode lead s t(SS2L) from Channel 3 to theelectrodes, following Fig. 6.8.

8. Have the Subject lie down andrelax.

9. Start the BIOPAC Student LabProgram.

10. Choose Lesson 6 (L06-ECG-2).

11. Type in your filename.

12. Click OK.

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Lesson 6: ECG II Biopac Stndent Lab

Follow Fig. 6.8 to ensure that you connect each cable tothe proper electrode.

When the electrode cable is connected properly, theLEAD III electrode configuration will be established.

Fig. 6.8 Electrode lead connections (Lead III)

Position the electrode cables such that they are notpulling on the el ctrodes. Connect the electrode cableclip (where the cable meets the three individual coloredwires) to a convenient location (can be on the subject sclothe ). This will relieve cable strain.

The Subject should not be in contact with nearby metalobjects (faucets, pipes, etc.), and should remove anywri t or ankle bracelets.

right legBLACK lead

(Ground)

('\

/~"!

}J-r.

left legRED lead

e a unique identifier. mThi ends the Set Up procedure.

Biopac Student Lab

B. CALmRATION

Les on 6: ECG II Page 11

The Calibration procedure establishes the hardware' internal parameters (such as gain offset, andscaling) and is critical for optimum performance. Pay close attention to the Calibration procedure.

FAST TRACK Calibration

1. Double check the electrodes, andmake sure the subject is relaxed.

2. Click on Calibrate.

3. Wait for the calibration procedureto stop.

4. Check the calibration data:

~ If similar, proceed to theRecording Lesson Data section.

~ If different, Redo thecalibration.

E D CALIBRATIO

Detailed Explanation of Calibration Steps

Make sure the electrodes adhere securely to the skin. Ifthey are being pulled up, you will not get a good ECGsignal.

The subject must be relaxed during the calibrationprocedure. The subject's arms and legs need to be relaxedso that the muscle (EMG) signal does not corrupt the ECGsignal.

The Calibrate button is in the upper left corner of theSetup window. This will start the calibration recording.

Th subject needs to remain relaxed throughoutcalibration.

The calibration procedure will stop automatically after 8seconds.

At the end of the 8- ec calibration recording there hould be arecognizable E G waveform with no large ba eline drifts.

Fig. 6.9

If your data re embles Fig. 6.9 (with allowance for anydifference in vertical caling), proceed to the Data Recordingection.

If the data how any large ba eline drifts you hould checkour electrode for good contact and redo the calibration bylicking on the Redo Calibration button and repeating the

entire calibration quence.


C. RECORDING LESSON DATAFAST TRACK Recording

1. Prepare for the recording.

Detailed Explanation of Steps

You will record two segments one with the Subject lyingdown, and another with the Subject sitting up.

In order to work efficiently, read this entire section so youwill know what to do before recording.

Check the last line of the journal and note the total amountof time available for the recording. Stop each recordingsegment as soon as possible so you don't use an excessive

amount of time (time is memory) W.Hints for obtaining optimal data:To minimize muscle (EMG) corruption of the ECG signaland baseline drift:

a) The subject should not talk or laugh during any ofthe recording segments.

b) When lying down or sitting up the subject should becompletely relaxed.

c) When sitting up, the subject's arms should besupported on an armrest.

d) The recording should be suspended before theubject prepares for the next recording segment.

e) The subject should breath normally during therecording to minimize EMG from the chest area.

f) Make ure electrodes do not "peel up.'

Biopac tudent Lab

Segment J--Subject Lying Down

2. Click on Record.

3. Record for 20 seconds (Segment 1).

4. Click on Suspend.

5. Review the data on the screen.

~ If correct, go to Step 7.

~ If incorrect, go to Step 6

6. If data was incorrect, Click onRedo.

I~I~~R~e~c~or~d~in~g~C~o~n~ti~nu~e~··~·~~11


You will begin to record data.

The subject should be in a relaxed state and lying down.Markers are automatic.

The recording should halt giving you time to review thedata.

If all went well, your data should look similar to Fig. 6.10.

l06-ECG-2 '[IResumeJ ~ L Done J

• t- o 31 •••• 0 40 ••••• . 40 _ .I. I~1..-

1000o

- i..•I JA .lA .LA JA .lA .lA .lA -LA .LA t J.. LA -000

1000

- I I I I 1 .I I .1 I I I I I I I .I I .I I i..•-000 n

w ,w .~~ lOw nIIQ." .e 01 el'i':

Fig. 6.10 End of egment 1 (Lying down)The data would be incorrect if:

a) the suspend button was pressed prematurelyb) An electrode peeled up, giving a large baseline driftc) The subject has too much mu de (EMG) artifact

ote: A little baseline drift when the subject breathes inand out is norma] and does not indicate incorrect data.

lick' Redo" and rep at Steps 1-5. Note that once youpre s Redo, the data ou have just recorded will be erased.

Page 14

Segment 2-Subject Sitting Up---7. Have the subject sit up in a chair,

with arms relaxed.

8. Click Resume as soon as possibleafter the Subject sits up.

9. After 10 seconds of recording theSubject should breathe in and outsuch that the breath is audible andthe Recorder should insertmarkers:a) at beginning of an inhale.

V 'breathe in".

b) at beginning of an exhale.

V "breathe out"

10. Click on Suspend.

11. Review the data on the screen.

» If correct, go to Step 13.

» If incorrect, go to Step 12.

Recording continues ...


Have the subject sit up in a chair, with arms relaxed (on anarm rest if available).

The recording will resume. In order to capture the heartrate variation it is important that you resume recording asquickly as possible after the subject has performed therequested task.

However it is also important that you do not click Recordwhile the subject is in the process of sitting up or you willcapture motion artifact.

After about 10 seconds of recording, the Director shouldinstruct the Subject to breathe in such that the inhale andexhale are audible.

Note: Subject should not breathe in too deeply as thatwill cause excessive EMG or baseline drift.

To insert Markers: Mac = Esc key, PC = F9 key mNote: Do not worry if you do not have time to type in themarker label while recording. This can always be enteredor edited after the data is recorded.

The recording should run for about 20 seconds total.

The recording should halt, allowing you to review the data.

If all went well, your data should look similar to Fig. 6.11.lO6-ECG-2

[ResumeJ ~ [ooneJ3 - . 3 ...,. . ~~. 40 nl'lOl'lf .

breathe 01.1\

= - L·I~I~I 000- 'i-' I L L IAL I. IA L I. I IA l. 1,1 IA IA I. L-000

II JI J I I I .1I 000

- 1 I I I • I 1 I I I J ~-' -000r I' r r-r " T I' r r

200 250 seconds 30 0 ~o III I 10.:;JI ,'i) • •

Fig. 6.11 Segment 2 (Sitting Up)

The data would be incorrect if:

a) the Suspend button was pressed prematurely.

b) an electrode peeled up, giving a large baseline drift.

c) the subject has too much muscle (EMG) artifact.

Note: A little baseline drift when the subject breathes inand out is normal and does not indicate incorrect data.

Biopac Student Lab Lesson 6: ECG II Page 15

12. If data was incorrect click on Redo. Click "Redo" and repeat teps 7-11. Note that once youpress Redo the data you have just recorded will be erased.

13. Click on Done. After you press Done, a pop-up window with four optionswill appear. Make your choice and continue as directed.

If choosing the "Record from another subject' option:

a) Attach electrodes per Set Up Step 6 and continuethe entire les on from Set Up Step 11.

b) ach person will need to use a unique file name.

14. Remove the electrodes. Remo e the electrode cable pinch connectors, and peel offthe electrodes. Throw out the electrodes (BIOPACelectrodes are not reusable). Wash the electrode gel residuefrom the skin using soap and water. The electrodes mayleave a slight ring on the skin for a few hours. This isnormal, and does not indicate that anything is wrong.

Page 16

v. DATAANALYSISFAST TRACK Data Analysis

1. Enter the Review Saved Datamode.

ote Channel umber (CH)designations:

Channel Displays

CHI Lead I

CH3 Lead III

CH40 Lead II

2. For each of the leads note whetherthe R wave is positive or negative.

IJlA3. Setup your display window for

optimal viewing of Lead I andLead III.

Channel Lead

CH 1 Lead I

CH 3 Lead III

4. et up the display window foroptimal viewing of the first datasegment.

II Data Anal sis continue ... I~


Detailed Explanation of Data Analysis Steps

Enter the Review Saved Data mode. Wote: Following the press of the Done button in the

previous section, the program used Einthoven's Law toautomatically calculate Lead II from Leads I and III. Sofrom the initial two channel recording you will end upwith three channels when you enter the Review SavedData mode (a shown in Fig. 6.12).

0 GoIiM-106 i~

[ouerI8P] I~3 ~. ~- ~. ~.~L '''Co'e )

ort.,.. S'ttlng up - ~~ 14 I ~ I'"-

-0 0000 l~~

= II I -0 0000 'i~= I I I I. L 1.J J. L L I IlL L J I J ILL I I I I j II I I 1.1 I I I L I I I -0 0000 ll:;;~

0000 ~~ .:~ 28 7fH 1'1 I 10..01 lot ell;>

Fig. 6.12

This is just a visual check as to whether the R wave goesup (positive) or down (negative).

To hide a channel, click on the channel box and hold down:th "option" key on a Mac, or "Ctrl" (Control) on a Pc.This will toggle between hiding and showing the data (andyour screen may take some time to update).

You also ha e the option of showing Grids on the creen.This is acti ated from the "Display Preferences' option

under the "File" menu. WThe first data segment is the area from Time 0 to the firstmarker.

The following tools help you adju t the data window: WAuto cale horizontal Horizontal (Time) croll Bar

utoscale waveforms Vertical (Amplitude) Scroll Bar

Z om Tool Zoom Previous

Biopac Student Lab

5. Set up the measurement boxes asfollows (see Fig. 6.14):

Channel Mea urement

CH 1 max

CH3 max

6. Adjust the data window to displayODecardiac cycle in the lying downsegment.

7. Use the I-Beam cursor to select theQRS interval.

Data Analysis continues ...


If all went well, your window should resemble Fig. 6.13.

Fig. 6.13

W The measurement boxes are above the marker regionin the data window. Each measurement has three sections:channel number, measurement type, and result. The firsttwo sections are pull-down menus that are activated whenyou click on them.

max: The maximum amplitude value within the areaselected by the I-Beam tool (including the endpoints).

The "Lying down' segment is the one before the firstmarker, and represents the time when the Subject was lyingdown, breathing normally in a relaxed state (Fig. 6.14).so 6a1lM-106 .

ouer'np] ~1 Im.x • -0 00377 ~. 0.02319 ~. ~.fl1Jii l II CCoIe: )

aft.,.. sltU"9 ~ 4 ~ .•.~

o 27923 ¥- 1-' -0 0000

l\;0:566<0

- ~-0 0000 1~-'

, ".., o I.U.JU seconds o r.>UU c OUYU I~II I~J ;

"101 •

Fig. 6.14

6a1lM-106

~·O.~323 ~.

-r---------~--~

Fig. 6. 1 5You'll use the recorded measurements to construct thegraphical e timate f the Mean Electrical Axis in the DataReport.

Page 18

8. Place a marker to indicate wherethe QRS measurement was taken.


To insert Markers: Mac = E c key, PC = F9 key

To place a marker after the data has been recorded click inthe marker region (region above the top channel). Placethis directly above the selected R wave. An arrow shouldappear. Type in "Measurement 1."

9. Repeat Step 6 for a cardiac cycle in Use the markers to find the proper data segment. Do notthe itting up segment. use a segment between the "breathe in' and' breathe out

markers.[lB10. Repeat Step 6 for a cardiac cycle in

the "breathe in" segment.

11. Repeat Step 6 for a cardiac cycle inthe' breathe out" segment.

12. Set up the measurement boxes asfollows:Channel Measurement

CH 1 .1CH3 .1

13. Go back to the Measurement 1marker created in Step 7.

14. Measure and record the amplitudesof the Q R, and S waves individ-ually for both Lead I and Lead III.

[Ie11ii;;;;;;[Diiiiiiataiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiil,ll

ruThe Delta Amplitude (.1) measurement computes thedifference in amplitude between the first point and the lastpoint of the selected area. It i particularly useful for takingECG measurements because the baseline does not have tobe at zero to obtain accurate, quick measurements.

ote: You must pay attention to the polarity of the.1 measurement and how you select the area to bemea ured. The polarity of the .1 measurement is based on(first point - last point). First point is where you beginyour selection· la t point is where you release the mousto end your selection.

This was the same QR region you used the first time youdid tep 6. It represents a QR cycle in the lying down,relaxed state.

You can use the marker arrow to the right of the markerregion to go to di ff rent markers.

You will be taking a total of 6 measurements.

You may wish to look at one channel at a time by hidingthe other channel(s) using the channel boxes. To measure apeak, go from the ba eline (I oelectric Line) to th peak ofthe wave.

Biopac Student Lab

15. ave or print the data file.

16. Exit the program.

liiiiEiiiiNiiiiDiiiiOiiiiFiiiiDiiiiAiiiiTiiiiAiiiiiiiiAiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii\11

Le son 6: ECG II Page 19

GeilM-L06 pr

R-Wave peak

Fig. 6.16 Sample measurement of the R wave peak

You may save the data to a floppy drive, save notes that are

in the journal, or print the data file. W

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BIOPAC - ELTE Élettani és Neurobiológiai Tanszékphysiology.elte.hu/gyakorlat/angol/ECG II_Biopac lesson...Biopac Student Lab Le son 6: ECG II Page 5 The electrical activity of