This document provides instructions on setting up and using a spirometer and PowerLab software to measure lung volumes and capacities, including vital capacity, forced vital capacity, and experiments involving asphyxia, hypercarbia, and hypoxia. It details how to configure the spirometer and software, perform tests and measurements, and analyze results. Tests include vital capacity, forced vital capacity, experiments with and without soda lime, varying the gas used to fill the spirometer, and using valves. Measurements include volumes, flows, frequencies, and gas concentrations from samples.

2.  What the different volumes and capacities
mean
 How to set up the spirometer and powerlab
for:
 Vital capacity
 Forced Vital Capacity
 Asphyxia
 Hypercarbia
 Hypoxia
 How to analyse results from these

4.  SET UP SPIROMETER
 Make sure soda lime is under the
bell
 Place the bell in
 Don’t need to attach one way
valves
 Attach disposable mouthpiece
 Make tap vertical and ventilate
the spirometer (VErtical to
VEntilate) = push right down and
fill about 75% with air
 Seal the spirometer - Horizontal
( check by blowing and air
should come out of the side)

5.  Set up the computer:
 sampling rate to 20/S
 Scale amplitude to 1V
 Time base 1:1
 WEAR NOSE CLIP!
 Press start
 Sit comfortably, breath and turn tap
to vertical
 VC = max inspiration and
immediately max expiration (steady
and complete)
 Stop = few secs normal breathing ,
tap horizontal and stop the
powerlab software

6.  Draw a box around the VC
 Windows – Zoom
 Move ‘M’ to base of VC ( where just about to
breath out)
 Move cursor to peak of VC
 Read off the Volume in LITRES (directly
above the expanded trace)
 Return ‘M’ to its place
 ATPS BTPS

7.  Same as VC
BUT...
 When inspiration reaches a peak BREATH OUT
AS FAST AND HARD AS POSSIBLE AND
CONTINUE FOR ~ 3secs

8.  Same as VC
BUT...
 Place cursor on the plateau
 FEV1 = this is done from the
FVC recording, but only move
cursor as far as 1 sec from the
base. i.e t=1sec and then
read off the volume
 FEV1/FVC = percentage of air
breathed out in first second

9.  Same as VC
BUT...
 NO soda lime
 ADD one way valves
 REMEMBER TO SEAL
THE SPIROMETER at
the end

10.  Draw 2 samples from the sampling point to
discard – pinch the tubing to prevent air
leaving spirometer
 Third sample – close sampling tap, place
thumb over syringe to seal this
 Inject air into analyser – inject 2/3 and
WAIT...then as value stabilises complete the
injection (should be no more than 0.2% diff)
 Rate of change (%/min) =
final - initial/ duration of breathing

11.  SAME as asphyxia
BUT...
 FILL WITH O2 (not air)
 The tap near mouthpiece should be sealed
 Connect the o2 supply to oxygen inlet
 Fill to 75%
 TURN OFF SUPPLY FIRST
 Then close tap on spirometer
 Analyse for CO2 only

12.  Measuring mean TV and Resp. Freq
 Draw box around recording
 Select data pad
 Click on grey box above column A
 Set up box will appear
 Mean tidal volume = cycle variables
and average peak to peak (cycle
height). Press ok and answer will
appear at the top of column
 Resp freq = cycle variables; events
count. Press okay the resp freq will
appear at top of column
 ALWAYS GIVE UNITS
 Ventilation(L/min) = TV (L) x Resp freq
(breaths/min)

13.  Exact
same as VC so MAKE SURE SODA LIME IS
PRESENT
BUT...
 Don’t
refill with air
 Remember to ADD VALVES

14.  ADD ONE WAY VALVES FOR EXPERIMENTS ONLY
 NO SODA LIME FOR ASPHYXIA AND HYPERCARBIA
 FILL WITH O2 FOR HYPERCARBIA
 NO REFILLING IF WE WANT HYPOXIA

15. QUESTIONS??