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LABORATORY
Week 6
Blood Pressure and Pulse
Objectives:
1.
2.
3.
4.
Define the following terms: systole, diastole, sounds of Korotkoff, mean
arterial pressure, pulse pressure, cardiac output, stroke volume, resistance,
venous return, end diastolic volume, end systolic volume and heart rate.
Accurately measure a subject’s systolic arterial pressure and diastolic arterial
pressure using a sphygmomanometer and determine a subject’s pulse rate.
Using these values, determine pulse pressure and mean arterial pressure.
Determine the effect of the following variables on systolic arterial pressure,
diastolic arterial pressure and heart rate: posture, exercise; explain, in
physiological terms, any differences in the measurements taken under these
conditions compares to baseline measurements.
Determine the effect of a mild cognitive stressor (spelling forwards and
backwards) on heart rate and blood pressure using the LabScribe software
and IWX 214 unit
Introduction
When the ventricle ejects a stroke volume into the elastic arteries, the arteries stretch
and pressure (pulse) waves are created. Blood pressure is defined as the pressure that
blood exerts against any unit area of the walls of blood vessels or a chamber of the
heart. Physiologists measure the pressure of body fluids, including blood, in units called
millimeters of mercury (mmHg), and they use a measuring device called a
manometer. A sphygmomanometer is a manometer with an air cuff attached to the
reservoir; it can be used to measure the changing blood pressure associated with the
pulse.
In this exercise you will learn to measure the systolic arterial pressure (the pressure in
the arteries at the peak of ventricular contraction), the diastolic arterial pressure (the
pressure in arteries during ventricular relaxation) and the pulse rate (the number of
pulses, or heart beats, per minute). You will then explore the effects of changes in body
position, exercise, cognitive stress on arterial pressure and heart rate.
6.1
Materials
Stethoscope
Sphygmomanometer
Felt tipped pen
Watch or clock with a second hand
Step stools
Cot and/or pillows
PC Computer
IWX/214 data acquisition unit
USB cable
IWX/214 power supply
PT-104 Pulse plethysmograph
RM-204 Respiration monitor
BP-600 Non-invasive blood pressure transducer
Activity 1
Effect of Variables on MAP and HR
Resources:
Textbook:
pages 681-685, 701-711
Complete this activity in a group of four students. A different student should be a subject
in each of the four experiments. One student should measure the systolic and diastolic
pressure, one student should measure the pulse rate and the other student should
record the data. The responsibilities should be rotated among the group members until
each member has had the opportunity to be a subject, a data collector and a data
recorder.
Note:
1.
The sphygmomanometer should remain on the subject’s arm during
the entire experiment, even when not recording (the cuff is deflated) so
that rapid measurements can be made.
2.
Take every measurement twice. If the two measurements differ significantly,
take a third.
A. Effect of Changes in Posture
Measure blood pressure and pulse rate for a student as follows:
1.
2.
6.2
Sitting quietly
After reclining for 2-3 minutes
3.
4.
Immediately after standing from the reclining position (stand in
“anatomical position”)
After standing in anatomical position for 3 minutes.
Record the data in the data chart in the Lab Activities section of the worksheet.
B. Effect of Exercise
Measure blood pressure and pulse rate for a student before exercise and at intervals
after the exercise period is over. Do not allow a student with known or
suspected heart condition participate as the subject in this experiment.
1.
Measure and record the blood pressure and pulse rate for the subject
while sitting quietly.
2. The subject should stand quietly for two minutes before beginning the
experiment (this will allow for blood pressure adjustment in response to
change in position)
3. The subject will use “bench stepping” for their exercise activity.
The height of the bench should be 0.5 m (20 in) for male students and
0. 4 m (16 in) for female students
To bench step, perform the following movements sequentially:
i. Place the right foot on the step
ii. Step up with the left foot and place that foot on the platform (both
feet will be on the platform now).
iii. Step down with the right foot.
iv. Bring the left foot down.
v. Repeat the process again
The student who acts as recorder should control the rate of bench
stepping by saying aloud “Up, 2, 3, 4” to set a rate of 2 sec/cycle
a. The subject should bench step for up to 5 minutes, maintaining
erect posture for the duration of the exercise period. If the subject
is unable to complete the cycle in 2 sec. (can’t keep the pace up),
the exercise should be stopped. Record the duration of exercise
in the data section of the worksheet.
b. The subject should sit down. Record the blood pressure and pulse rate
immediately upon sitting down and at 1 minute, 2 minutes, 3 minutes, 4
minutes and 5 minutes after the exercise period.
c. Determine the subjects fitness index using this formula:
Duration of Exercise (sec) X 100
Index =
2 X {sum of the three pulse counts in recovery}
6.3
Interpret scores according to the following criteria:
90 and over: excellent
80-89:
good
72-79:
high average
63-71:
55-62:`
below 55:
average
low average
poor physical condition
d. Record all of the data in the data chart of the Lab Activities section of the
worksheet.
Activity 2
Effect of Cognitive Stress on MAP and HR
Complete this activity in a group of four students. Activities include setup, calibration,
unit conversion, baseline heart rate and blood pressure, two cognitive stress
experiments and analysis. The baseline heart rate and blood pressure and the two
cognitive stress experiments should be performed on the same subject and a different
student should be a subject each time. The responsibilities should be rotated among the
group members until each member has had the opportunity to be a subject, a data
collector and a data recorder.
Blood Pressure and Pulse Transducers Setup
All of the units are already set up on the lab table. Please make sure that you
are able to identify the BP-600 non-invasive blood pressure transducer and PT-104
pulse plethysmograph in the iWorx kit..
6.4
A. Start the Software
1
Click on the A&P folder on the desktop and click on the Labscribe shortcut to open
the program.
2
On the Main window, pull down the Settings menu and select Load Group.
3
Click on the settings group, IPLMv4.iwxgrp.
4
Pull down the Settings menu again. Select Human Psychophysiology and select
the HeartRate- BP-LS2 settings file in the submenu.
B. Calibration of the Non-Invasive BP Transducer
1
Place the blood pressure cuff on the upper arm of the subject. Align the arrow on the
cuff over the subject’s brachial artery. Have the subject rest in the supine position
while the blood pressure sensor is calibrated. The arm is placed on the table with
palm up
2. Place the PT-104 pulse plethysmograh on the volar surface (where fingerprints are
located) of the distal segment of the middle finger or thumb . Wrap the Velcro strap
around the finger to attach the unit firmly in place.( Please note that the blood
pressure cuff and the pulse sensor are to be placed on the same arm)
3. Type 20 mmHg in the Mark box to the right of the Mark button.
Inflate the pressure in the cuff to 20 mmHg and make sure the gauge stays on 20
mm Hg
4
Click on the Record button (upper right corner of the screen)
5. Click on the Autoscale button in the Pulse and Blood Pressure channels.
•
6.5
If the signal on the Pulse channel is upside down click on the downward arrow to the
left of the channel title and select the invert function
•
If the pulse signal is small or noisy, adjust the tension on the strap holding the pulse
plethysmograph to the finger.
6
Click Mark and record for ten to fifteen seconds. While recording, type 70 mmHg in
the Mark box.
7
As the recording continues, increase the pressure in the cuff to 70 mmHg. Click
Mark and continue to record at this level for ten to fifteen seconds. While recording at
a pressure of 70 mmHg, type 140 mmHg in the Mark box.
8
As the recording continues, increase the pressure in the cuff to 140 mmHg and
click Mark. Hold the pressure in the cuff at this level for ten to fifteen seconds. Then,
click the Stop button to halt the recording.
9
After the last measurement, release all the pressure from the blood pressure
cuff.
The subject should continue to relax in the supine position as he or she flexes and
extends the fingers on the cuffed arm to return of blood to the arm.
10 Select Save As in the File menu, type a name for the file. Choose a destination on
the computer in which to save the file. Click on the Save button to save the data file.
C. Units Conversion
1. Click on the double time icon to show the data collected at 70 and 140mmHg on the
Main window at the same time.
2
Place one cursor on the flat section of data collected when the pressure in the cuff
was 70 mmHg and the second cursor on the flat section of data collected when the
pressure was 140 mmHg.(any place on the flat area of the blood pressure channel)
3
To convert the voltages at the positions of the cursors to pressure values, use the
Simple Units Conversion window. To access this window, click on the arrow to
the left of the channel title, Blood Pressure. Select Units from the channel menu,
and select Simple from the Units submenu.
6.6
4
On the units conversion box,
a)
Make sure 2 point calibration is selected in the pull-down menu in the
upper left corner of the window
b)
Put a check mark in the box next to Apply units to all blocks and in the other
box.
c)
Enter the two pressures (70 mmHg and 140 mmHg used in the calibration
recording) in the corresponding boxes on the right side of the conversion
equations.
d)
Enter the name of the units, mmHg, in box below the pressures. Click on the
OK button to activate the units conversion. Now you are ready to perform the
experiment.
D. Baseline Heart Rate and Blood Pressure
1.
Instruct the subject to sit down and relax. While the subject is relaxing, make sure
the BP cuff and pulse plethysmograph are placed properly.
2. Click on the Record button, located on the upper right side of the Labscribe main
window. The signals being recorded should begin scrolling through the screen.
3. Click on the Autoscale button on the Pulse and Heart Rate channels.
4. Type Baseline HR/BP < subject’s name> in the Mark box to the right of the Mark
button.
5. Press the Enter key on the keyboard to mark the recording. Continue recording.
6. After recording for one minute, inflate the blood pressure cuff until the finger pulse
wave on the Pulse channel disappears.
7. Once the pulse wave disappears, release the cuff pressure at the rate of
~10mmHg/second. Continue to release the pressure in the cuff until the gauge reads
20mmHg.
8. Click the Stop button. Make sure the blood pressure cuff is completely deflated. The
subject should continue to relax till the next Experiment. The subject should flex and
extend their fingers to encourage blood circulation.
9. Select Save in the file menu.
6.7
Analysis- Baseline Heart Rate
1. Scroll through the recording and find the section of data recorded before the
pressure in the cuff was blocking the pulse.
2. Use the Display Time icons to adjust the display time in the main window to show a
thirty-second, artifact free section of the subject’s pulse and heart rate while
relaxing.
3. Click on the analysis window icon in the toolbar. Look at the function table listing the
various mathematical functions( Value1 , value 2,max, min, mean, T2-T1)
4. On the Heart Rate channel, click and drag one cursor to the left margin of the data
displayed in the Analysis window. Drag the other cursor to the right margin of the
same data and measure the following:
Maximum heart Rate – The value for Max on the heart rate channel is the subject’s
maximum heart rate while relaxing.
Minimum Heart rate – the value for Min on the heart rate channel is the subject’s
minimum heart rate while relaxing.
Mean Heart Rate The value for mean on the heart rate channel is the subject’s
mean heart rate while relaxing.
Analysis – Baseline Blood Pressure
1. Scroll through the recording and find the section of data recorded before, during ,
and after the pressure in the cuff was blocking the pulse.
2. Place the cursors on either side of the data to show the pulse, cuff pressure, and
heart rate from the time prior to the occlusion of the artery to the pressure in the cuff
being 20mmHg.
3. Click on the analysis window icon in the toolbar. Look at the mathematical functions
listed in the function table. It should include V2-V1, Value1, Value 2, T2-T1, and
Mean.
4. Position the cursors to make measurements at specific points on the recording,
indicated below.(systolic pressure, diastolic pressure and pulse pressure)
6.8
Description
Placement of
cursor
Parameters used
in the function
table
Systolic blood
pressure
Cursor on the first
pulse wave that
reappears after the
pressure from the
BP cuff is released
V1 on the blood
pressure channel
Diastolic blood
pressure
Place the other
cursor on the first of
the largest pulse
waves that reappear
as the pressure
from the BP cuff is
released.
Leave the cursors
on the place used to
measure the
systolic and
diastolic pressures.
V2 on the blood
pressure channel
Pulse pressure
6.9
V2-V1 on the blood
pressure channel
Record the value
E. Mild Cognitive Stressor experiments
You will be performing two exercises and at the end of each, you will be
measuring the blood pressure of the subject.
Task A – spelling 12 words (forwards) at 5 second intervals
Task B – spelling 12 words (backwards) at 5 second intervals
Experimental conditions before beginning the exercise:






Task A is performed first. The subject will spell the 12 words forwards, in the
same order as printed. ( word list can be found on page: 6.11 )
Task B is performed second. The subject will spell the 12 words backwards,
in the same order as printed.
The words in each task will be spoken by a member of the lab group at 5
seconds interval, whether the subject has finished the spelling of the
previous word or not.
Another member of the group will keep track of the number of words spelled
in error in each task. Spelling of a word that is not completed before the next
word is spoken is considered to be misspelled.
As soon as each task has ended, take the subject’s blood pressure
Each member of the group should be very clear on their specific task
and the instructions that they will be following. Suggestions to conduct
the experiment when there are three or four students in a group are
given on pages: 6.15, and 6.16
Procedure
1.
Instruct the subject to sit quietly as the rest of the lab group prepares for this
exercise. It is very important not to move during the experiment.
2.
While the subject is relaxing, place the blood pressure cuff around the upper
arm, just above the elbow. Place the pulse plethysmograph on the volar surface
(where the fingerprints are located) of the distal segment of the left middle finger or
thumb. Wrap the Velcro strap around the end of the finger to attach the unit firmly in
place. (Please note that the blood pressure cuff and the pulse sensor are to
be placed on the same arm)
3.
Type Begin Task A <Subject’s Name> in the Mark box to the right of the Mark
button.
4.
Click Record.
5. Click AutoScale on the Pulse and Heart Rate channels to increase the size of the
signals. Press the Mark button as the first word in Task A is spoken.
Continue to record as the subject attempts to spell each word forwards.
6.10
Task A
Task B
Spell forward
Spell backward
event
exert
frame
frost
flour
flack
growl
grant
house
heart
joust
juror
leach
lucky
learn
laugh
maple
mouse
niche
nickel
nectar
novel
prowl
pearl
6.
Type End Task A in the Mark box to the right of the Mark button. At the end of
Task A press Mark to mark the recording. Continue to record.
7.
Take the subject’s blood pressure. Inflate the blood pressure cuff until the finger
pulse wave on the Pulse channel disappears.
8.
Once the pulse wave disappears, release the cuff pressure at the rate of ~10
mmHg/second. Continue to release the pressure in the cuff until the
gauge reads 20 mmHg.
9.
Click Stop to halt the recording. Make sure the blood pressure cuff is completely
deflated and is not putting any unnecessary pressure on the subject's arm.
10. Instruct the subject to sit quietly as the rest of the lab group prepares for Task B.
Begin the second task as soon as possible.
11. Repeat the above instructions # 3 to # 9 for Task B (spelling backwards)
12. Open the Journal and note the number of words misspelled in each task
13. Select Save in the File menu.
6.11
E.
Analysis-Heart Rates during Task A
1
Select the section of data recorded during Task A.
2
Place the cursors on either side of the section of the data to show a 30 second,
artifact free section of the subject’s pulse and heart rate. (T2-T1 should be equal to
30 seconds)
3
Click on the Analysis window icon in the toolbar
4
On the Heart Rate channel, click and drag one cursor to the left margin of the data
displayed in the Analysis window. Drag the other cursor to the right margin of the
same data and measure the following:
• Maximum Heart Rate. The value for Max on the Heart Rate channel is the subject’s
maximum heart rate during Task A.
• Minimum Heart Rate.
The value for Min on the Heart Rate channel is the subject’s
minimum heart rate during Task A.
• Mean Heart Rate.
The value for Mean on the Heart Rate channel is the
subject’s mean heart rate during Task A.
5
Record the values for these rates in the Journal
Analysis-Blood Pressures after Task A
1
Select the section of the data of the subject’s blood pressure taken after the
completion of Task A (the section where the pulse wave disappears on inflation
and reappears on deflation)
2
Place the cursors on either side of the above section of data and click on the
analysis window icon on the toolbar.
3.
On the Pulse channel, use the mouse to click on and drag the cursors to specific
points on the recording displayed in the Analysis window to measure the
following ( specific points are indicated below in the chart)
6.12
Description
Placement of
cursor
Parameters used
in the function
table
Systolic blood
pressure
Cursor on the first
pulse wave that
reappears after the
pressure from the
BP cuff is released
V1 on the blood
pressure channel
Diastolic blood
pressure
Place the other
cursor on the first of
the largest pulse
waves that reappear
as the pressure
from the BP cuff is
released.
Leave the cursors
on the place used to
measure the
systolic and
diastolic pressures.
V2 on the blood
pressure channel
Pulse pressure
4.
6.13
V2-V1 on the blood
pressure channel
Record the values for these pressures in the Journal
Record the value
F.
Analysis-Heart Rates during Task B
1
Select the section of data recorded during Task B.
2
Use the same procedures used to measure the heart rates during Task A to
measure the heart rates during Task B.
3
Record the values for these rates in the Journal
Analysis-Blood Pressures after Task B
1
Select the recording of the subject’s blood pressure taken after the completion of
Task B.
2
Use the same procedures used to measure the blood pressures after Task A to
measure the blood pressures after Task B
Description
Placement of
cursor
Parameters used
in the function
table
Systolic blood
pressure
Cursor on the first
pulse wave that
reappears after the
pressure from the
BP cuff is released
V1 on the blood
pressure channel
Diastolic blood
pressure
Place the other
V2 on the blood
cursor on the first of pressure channel
the largest pulse
waves that reappear
as the pressure
from the BP cuff is
released.
Pulse pressure
Leave the cursors
on the place used to
measure the
systolic and
diastolic blood
pressures.
3
6.14
Record the value
V2-V1 on the blood
pressure channel
Record the values for these blood pressures in the Journal. Print the data sheet
for both Task A and Task B
Suggestions to conduct the experiment when there are three to four
members per lab group
Group of three members
Person # 1 – Subject
BP cuff and pulse plethysmograph are placed ( on the same side arm). Spells the words
pronounced by person # 3.
Person # 2 - Computer Operator.
Measures the blood pressure of the subject at the end of Task A and Task B
Person # 3
Speaks the words to be spelled at five second intervals, keeps up with the time and
marks misspelled words
Group of four members
Person # 1- Subject
Person # 2 – Computer operator
Person # 3 – spells the words and keeps up with time
Person # 4- marks misspelled words, measures blood pressure at the end of Task A and
Task B
Person # 1 – Subject
Sit quietly and not move during the experiment. Do not cross legs. Place the arm on the
table palm up. Close eyes during the experiment to not let the surroundings create a
variable. Task A is to spell the words forwards in 5 second intervals and Task B is to
spell the words backwards.
Person # 2 – Computer operator
For Task A : Type: Task A and the subject’s name on the mark box.
Click: record
Click: autoscale on all channels
Press: mark button as the first word is spoken
Type: End task A on the mark box, but do not press the mark
button till the last word is spelled.
Click: stop (after the blood pressure is taken)
For Task B: Follow the same steps as above.(If there are only three members in a
group – this person also measures the blood pressure after each task)
6.15
Person # 3 – Conducts the experiment
Task A : pronounces the words to be spelled from List A at five second intervals.( same
order as printed).
Keeps up with the time – pronounces the next word after 5 seconds even if the subject
has not finished spelling the previous word or waits for 5 seconds even if the subject
finishes earlier than the allotted 5 seconds.
Task B: Same as above
(If there are only three members in the group- this person also marks the
misspelled words)
Person # 4 – helper to person # 3
Follows the list of words on page 6.8 and marks any incorrect answers.
After the last word is spelled – measure the blood pressure.
Inflate the cuff until the pulse wave disappears on the screen. Look for a flat line on the
pulse channel.
Deflate the cuff at a reasonable rate.
Repeat the same instructions after Task B .
6.16
Checklist
A.
B.
Measuring Baseline Arterial Pressure and Pulse Rate
______
Baseline Arterial Pressure
_______
Pulse Rate
Variables (Measure Systolic Pressure, Diastolic Pressure and Pulse Rate)
Body Position:
_______
Sitting quietly
_______
After reclining for 2-3 minutes
_______
Immediately after standing
_______
After standing for 3 minutes
Exercise:
_______ Sitting quietly
_______ Immediately after exercise
_______ One minute after exercise
_______ Two minutes after exercise
_______ Three minutes after exercise
_______ Four minutes after exercise
_______ Five minutes after exercise
_______ Determination of the Fitness Index
6.17
Lab Report Pre-Lab
Name:
____________________
Week 6 Lab
Write hypotheses in which you predict the effect of each of the tested variables on arterial
pressure and pulse rate. Explain your reasoning:
A. Posture Changes:
1. Reclining for 3 minutes
It is expected that arterial pressure will _____________ because __________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
It is expected that pulse rate will ____________ because _________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
2. Standing up quickly after reclining for 3 minutes:
It is expected that arterial pressure will _____________ because __________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
It is expected that pulse rate will ____________ because _________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
6.18
3. Standing at attention for 3 minutes:
It is expected that arterial pressure will _____________ because __________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
It is expected that pulse rate will ____________ because _________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
B. Exercise
1. Immediately after exercising:
It is expected that arterial pressure will _____________ because __________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
It is expected that pulse rate will ____________ because _________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
2. One, two and three minutes post exercise
It is expected that arterial pressure will _____________ because __________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
It is expected that pulse rate will ____________ because _________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
6.19
Cognitive stressor
3.
It is expected the pulse rate and blood pressure will _______________________ while
spelling the words because ________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
6.20
B.
Lab Activities
Data Tables
Name:
_________________
1.
Proper Use of the Sphygmomanometer (include units of measurement):
Subject: __________________________________
Systolic Pressure
Diastolic Pressure
Pulse Rate
Trial 1
Trial 2
2.
Effect of Postural Changes (include units of measurement):
Subject ___________________________________
Blood Pressure
Sitting Quietly
(Baseline)
Reclining (after
2-3 minutes)
Immediately
Upon Standing
After Standing
For 3 Minutes
6.21
Pulse Rate
3.
Exercise (Include Units of Measurement)
Subject:
______________________________________
(Well- Conditioned)
Fitness Index:
______________________
Subject:
_________________________________________
(Poorly- Conditioned)
Fitness Index:
______________________
Baseline
Well
BP:
Conditioned
Subject
HR:
Immediately 1 Minute
BP:
BP:
2 Minutes
BP:
3 Minutes
BP:
HR:
HR:
HR:
HR:
Poorly
BP:
Conditioned
Subject
HR:
BP:
BP:
BP:
BP:
HR:
HR:
HR:
HR:
4.
Iworx- Cognitive Stressor (include units of measurement)
Subject __________________
condition
baseline 1
Max HR
spell forward
a
spell back
6.22
Min HR
Mean HR
Systolic BP Diastolic BP Pulse pressure