Activity 16
PS-2820
Volume of Breath – Pulmonary Function Test
Physiology: Breathing, pulmonary function
Qty
1
1
DataStudio GLX setup file: breath.glx
Equipment and Materials
PASPORT Xplorer GLX
PASPORT Spirometer
Part Number
PS-2002
PS-2152
Purpose
The purpose of the activity is to explore the pulmonary function test (PFT) and the volume of
breath.
Background
Breathing in and out (inhaling and exhaling) is as natural as anything
we do. Our respiratory system manages the complex task of
exchanging gases – oxygen for carbon dioxide - with the circulatory
system. The lungs are spongy organs filled with countless small
sacks called alveoli that are surrounded by networks of the smallest
blood vessels called capillaries. The alveoli and capillaries ‘trade’
gas particles as the blood in the capillaries moves along near the
alveoli.
A pulmonary function test (PFT) is a common clinical test that uses
a spirometer to measure how well a patient's lungs are working. A
spirometer is an instrument that measures the amount of air that is
moved during breathing. During this test, a patient breathes through
the spirometer for several quiet breathing cycles and one forced
breathing cycle (one large inhalation followed by one large
exhalation).
The PFT can provide important measurements in a graph of volume
exchanged over time. One of the more significant measurements is
Forced Expiratory Volume in one second (FEV1), which provides an
indication of how well a patient can exhale during maximum effort.
FEV1 is typically reduced in patients with obstructive lung diseases
(e.g. asthma, chronic bronchitis, emphysema) and increased in patients with restrictive lung
diseases (e.g. pulmonary fibrosis). The Forced Expiratory Volume Percentage (FEV1 %) is
typically 75% to 85% in a healthy subject.
Pre-lab Questions
Measure the volume of air inhaled and exhaled during normal and force breathing. Use the data
to determine the Forced Expiratory Volume in one second (FEV1), and then calculate the Forced
Expiratory Volume Percentage (FEV1 %).
1.
How will the volume of air inhaled and exhaled by females compare to the volume of air
inhaled and exhaled by males?
2.
How will the Forced Expiratory Volume Percentage (FEV1 %) for females compare to the
FEV1 % for males?
Biology with Xplorer GLX
© 2005 PASCO
p. 103
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
A PFT usually includes the measurements of four specific lung volumes.
1.
Tidal volume (TV) is the volume of one breath, or the amount of air moved into and out of
the lungs during quiet breathing (breathing without effort).
2.
Expiratory reserve volume (ERV) is the amount of air moved out of the lungs during a
forced expiration (exhalation), below the level of tidal expiration (exhalation).
3.
Inspiratory reserve volume (IRV) is the amount of air moved into the lungs during a forced
inspiration (inhalation), above the level of tidal inspiration (inhalation).
4.
Residual volume (RV) is the amount of air remaining in the lungs at the end of a forced
expiration. This volume is not directly measurable using a spirometer, but it can be
measured using other techniques.
•
Forced Expiratory Volume in one second (FEV1) is the volume of air moved out of the
lungs in the first second of a forceful expiration following a maximal inspiration. This is a
valuable test for pulmonary function, especially in cases of asthma or emphysema.
Biology with Xplorer GLX
© 2005 PASCO
p. 104
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
A Pulmonary Function Test also includes the measurement of four specific lung capacities.
1.
Inspiratory Capacity (IC) is the maximum amount of air that can be inspired after a normal
expiration (IC = TV+IRV).
2.
Vital Capacity (VC) is the maximum movable amount of air contained by the lungs (VC =
TV+IRV+ERV).
3.
Functional Residual Capacity (FRC) is the amount of air left in the lungs after a normal
expiration (FRC = RV+ERV). Because RV cannot be directly measured using a
spirometer, FRC cannot be directly measured.
4.
Total Lung Capacity (TLC) is the total volume that the lungs can hold during a maximum
inspiration (TLC = RV+ERV+TV+IRV). Because it involves the residual volume, TLC
cannot be measured in spirometry.
Biology with Xplorer GLX
© 2005 PASCO
p. 105
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
Safety Precautions
•
Follow all directions for using the equipment.
Procedure
GLX Setup
1.
Connect a PASPORT Spirometer to the top of the
GLX. The Graph Screen will automatically open with
Lung Volume (Liters) versus Time (s).
2.
Open the GLX setup file labeled breath.glx (see the
appendix at the end of this activity). The setup file is
set so the Spirometer records data at 50 measurements
per second. The setup file includes the calculation of
lung volume based on Functional Residual Capacity
(assumed to be 2.5 liters) and Total Flow (liters).
Figure 1: Connect sensor to GLX
Equipment Setup
1.
Connect a mouthpiece to the handle; note the small pin on the
mouthpiece and the aligning notch on the handle.
2.
Lay the mouthpiece and handle on a tabletop away from any air
currents.
Prepare to Record Data
•
Data recording is easier if one person handles the GLX, a second
person keeps track of the number of breaths, and a third person does
the breathing.
Figure 2: Connect
mouthpiece to handle
•
The breathing pattern is as follows: Four normal breaths followed by
a very deep breath in (inspiration) and a very, very deep breath out (expiration) followed
by two more normal breaths.
•
The person who keeps track of breaths should ‘talk’ the person through the breathing by
counting and describing the breaths as follows: One – Two – Three – Four – Deep Breath
In – Deep Breath Out – Five – Six.
•
The person who is being measured (the ‘breather’) should sit or stand comfortably. The
person will need to breath only through the mouth during the measurement, so the person
will need to hold his or her nose closed during the measurement. The person who is being
measured should NOT look at the data as it is recorded.
Biology with Xplorer GLX
© 2005 PASCO
p. 106
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
Record Data
1.
Press the Start key
on the GLX. Note the flashing red
WAIT indicator on the sensor. Wait until the green READY
indicator is lit before you move the mouthpiece and handle.
2.
After the green READY indicator is lit, place the tapered end of
the mouthpiece between the breather’s front teeth with the lips
creating a seal around the mouthpiece to make sure that all
breath flows through the mouthpiece.
3.
Have the breather hold his or her nose and then perform the
following breathing sequence:
•
Four normal, quiet breaths.
•
Deep inspiration (inhalation) followed immediately by a
maximum-effort, deep expiration (exhalation).
•
Two normal, quiet breaths.
4.
Stop data recording.
Indicators
Analysis
1.
Use the built-in analysis tools in the Graph Screen to determine
the Tidal Volume (TV), the Forced Expiratory Volume (FEV1),
and the Vital Capacity (VC).
•
In the Graph Screen, press F3
to open the Tools menu and select ‘Delta Tool’. Use the
Delta Tool to find the values you need.
2.
Record the Tidal Volume, Forced Expiratory
Volume (FEV1), and Vital Capacity in the Data
Table.
3.
Use the Forced Expiratory Volume (FEV1) and
the Vital Capacity to calculate the Forced
Expiratory Volume Percentage (FEV1%) and
record this value.
4.
Determine whether there are differences between
females and males in the Tidal Volume and the
Forced Expiratory Volume Percentage (FEV1%).
Record your results in the Lab Report
section.
Biology with Xplorer GLX
© 2005 PASCO
p. 107
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
Appendix:
To open a specific GLX file, go to the home screen (press
). In the home
screen, select ‘Data Files’ and press ‘Activate’ (
). Use the cursor keys to
navigate to the file you want. Press F1 ( ) to open the file.
Biology with Xplorer GLX
© 2005 PASCO
p. 108
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
Lab Report - Activity 16: Volume of Breath
Name ________________________________ Date ___________
Pre-lab Questions
Measure the volume of air inhaled and exhaled during normal and force breathing.
1.
How will the volume of air inhaled and exhaled by females compare to the volume of air
inhaled and exhaled by males?
2.
How will the Forced Expiratory Volume Percentage (FEV1 %) for females compare to the
FEV1 % for males?
Data
Make a sketch of one run of Lung Volume versus Time, including labels for the y- and x-axes.
Data Table
Measurement
Value
Tidal Volume (TV): volume of one breath
Forced Expiratory Volume in 1 second (FEV1)
Vital Capacity (VC): maximum air in the lungs
Forced Expiratory Volume Percentage (FEV1%)
Biology with Xplorer GLX
© 2005 PASCO
p. 109
Activity 16
Volume of Breath – Pulmonary Function Test
PS-2820
Questions
1.
How does the Tidal Volume (TV) for females compare to the Tidal Volume (TV) for
males?
2.
How does the Forced Expiratory Volume Percentage for females compare to the Forced
Expiratory Volume Percentage for males?
3.
How did the results compare to your answers to the Pre-Lab Questions?
Biology with Xplorer GLX
© 2005 PASCO
p. 110