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Operator & Maintenance
Manual
Manual No. Y17405
Residual Volume Analyzer
Model 17405
Last Update 20 Feb 2014
Vacu·Med
4538 Westinghouse Street
Ventura CA 93003
Tel: (805) 644-7461
FAX: (805) 654-8759
e-mail:
[email protected]
www.vacumed.com
1
Table of Contents
Chapter
Page
1
General Information
3
2
Installation
4
3
Software Installation
6
4
Calibration
6
5
Operation
Special Instruction for Underwater Use
8
15
Maintenance & Troubleshooting
17
6
Checking for Leaks
Replacement parts
Specifications
Range:
0 to 100% O2 & N2, 0 to 10% CO2
Accuracy (of reading):
±0.5% from 0 – 100% dry N2 in O2
Analog Voltage Out:
0 to 10 volt on BNC connector
Operating Temperature Range
+5° to +40°C
Gas Sampling Rate:
400 ml/min
Display Resolution:
0.1%
Power Rating:
100-240 volts ac 50/60Hz,
approximately 15VA,
Fuse:
1A 250V MDL
Weight:
5.4 pounds, 2.45 Kg
Dimensions:
11-3/4” W X 4” H X 8” D
(30cm x 10cm x 20cm)
Note: This product is not intended to diagnose, treat,
cure of prevent any disease
Warning: If this equipment is used near water, all electric power lines must
be connected to the isolation transformer which must be plugged into a
special Ground Fault Interrupter (GFI) receptacle. Ask your local
engineering department to install such GFI circuit.
2
1. General Information
1.1
Introduction
The RVA is designed to measure Residual Volume and FRC for sports physiology and
teaching. Its instrumentation is assembled on a mobile cart. There are the following
functional components of this assembly:
1.
The subject-interfacing system consisting of the 2-position 4-way stopcock (SC),
the 5-liter re-breathing balloon, the bacterial filter and the mouthpiece;
2.
The oxygen priming system consisting of the hand-operated 2-position, 5-port
lever valve (LV) essential for standardized flushing and refilling of the
re-breathing balloon with O2, the 3 liter syringe, the 5 liter O2 storage bag
and the 2-way “T” valve;
3.
The optional isolation transformer is essential in underwater RV measurements
in order to supply safe electric power.
The Model 17501 Tri-Gas Analyzer is a high precision instrument that includes an oxygen
and CO2 sensor in order to calculate the nitrogen concentration by the subtraction method
(100 - O2% - CO2% = N2%) in physiological applications.
Note: for the RV calculation we include Argon with N2, thus N2 = 79%.
This instrument operates in the sidestream mode which means that typically only a very
small portion of a breath sample is drawn through the analyzer. The performance is affected
by the gas sample pressure, therefore special care must be taken that the calibration gas
and the sample gas to be analyzed is fed to the sampling line in the same unrestricted
manner (i.e. at the same, usually barometric, pressure).
Notes on the Closed Circuit Method
The closed circuit method uses gas dilution to determine a subject’s residual volume.
A subject breathing room air is instructed to breathe all the way out to RV and then pause.
At this point, he/she is switched onto a pre-measured oxygen-filled bag to re-breathe until
the nitrogen concentration stabilizes. From the known volume of the bag, the start and the
end point nitrogen concentration, and the equipment dead space, the subject’s residual
volume can be calculated.
Gas is continuously sampled from the test bag, the sampled gas if returned to the bag after
analysis in order to keep bag volume constant.
To calibrate the analyzer using room air, compensation must be made for the presence of
water vapor in the atmosphere. This is handled automatically in software, which uses the
room temperature, barometric pressure and relative humidity to calculate the actual
percentage of nitrogen in the air.
The concentration of nitrogen in the lungs is calculated based on the barometric pressure, a
standard body temperature of 37ºC and 100% relative humidity. The measured residual
volume is expressed as BTPS.
Patience: Please allow a 1 hour warm-up time for the Tri-Gas analyzer.
In the early warm-up period, the analyzer may display a slightly negative
number, do not adjust the "Zero" and "Span" potentiometers during this
period.
3
2.
Installation
A test gas of 100% medical grade O2 is required for calibration
and operation and should be purchased locally.
The instrument location should be free from dust and excessive humidity.
Attach one end of the black 1/16” ID sample tubing to the sample inlet in the rear of the
analyzer. The other end of this tube connects to the side port located at the neck of the
re-breathing bag. The maximum recommended length of the sample tube is 5 feet.
2.1
Front Panel Description
ZERO:
Left side potentiometers adjust the Zero
(Low gas % concentration) signals.
CO2 should be set to 0.05 when calibrating with
AIR in well ventilated rooms or to 0.00 when
100%O2 is used.
SPAN:
Right side potentiometers adjust the
Span or Gain (High gas% concentration)
of the gas signals.
SAMPLE FLOW:
Adjusted internally at the factory to approx. 400 ml.
GAS SELECTOR:
Calibration gas flow from pressurized
tanks should be adjusted so the ball floats in the
green dot area.
CAL GAS 1 = 100% O2 for RV application.
CAL GAS 2 = connect a calibration gas to rear panel
CAL GAS 2 input, typically 4% CO2
RUN = Samples gas fro the rear panel GAS IN
connector
ARGON:
Air contains about 1% Argon, therefore the ARGON
switch should be ON when sampling ambient air or
breath gases. Compressed calibration gases usually
do not contain Argon, so the ARGON switch should be
OFF during calibration with gases from a calibration gas
tank. This affects only the N2 reading.
4
WATER VAPOR:
(Humidity)
Gases from a tank of compressed calibration gas
do not contain water, so the H2O dial should be
set fully clockwise (CW) for N2 reading. When
sampling ambient air or exhaled gas, the H2O dial
should be set according to the ambient relative
humidity, temperature and barometric pressure,
see page 7.
DISPLAY BARO:
This analyzer incorporates an accurate barometric
pressure sensor. Press PUSH TO DISPLAY BARO and
the N2 display will change to display the barometric
pressure.
Note: Although exhaled gas is 100% humidified,
the internal NAFION drier extracts excess water
and reduces the vapor content of the gas delivered
to the gas sensors to ambient humidity.
2.2
Rear Panel Description
CAL GAS 1:
CAL Gas from 100% O2 tank
CAL GAS 2:
CAL Gas from 4% CO2 Tank
O2:
N2:
CO2:
ON/OFF:
Analog signal out 0 - 100% O2 = 0 to 10VDC
Analog signal out 0 - 100% N2 = 0 to 10VDC
Analog signal out 0 - 10% CO2 = 0 to 10VDC
Power Switch
(Note: power from external power supply is not
turned off. To remove all power, unplug external
power supply.)
24 VDC:
Power connector from external 24VDC power supply
SAMPLE IN:
Gas Inlet port with Luer Lock connector
GAS RETURN:
Returns sample gas to the Test balloon
Note: All signal out connectors are "BNC" type female connectors,
see matching cables under REPLACEMENT PARTS in back of manual
5
3. Software Installation (or re-installation):
Install software before connecting the USB cable
between computer and USB interface.
a. Insert disk in CD drive. Open the directory for the CD drive.
You may want to change the “VIEW”.
Click into the toolbar > VIEW > DETAILS.
b. Click on SETUP.exe (In “Type” column: Windows Installer)
c. If a previous TurboFit version 5.0x is installed,
the Installation Wizard may ask: “Modify, Repair or Remove?”
d. Select REMOVE, Then NEXT and OK.
e. Click SETUP.exe again and select “TYPICAL”.
f. Continue clicking on “NEXT” until installation starts.
g. Reboot after installation.
3.1
The Software SETUP menu
Password: vacumed
Default Setting:
Deadspace:
140 ml (for mouthpiece setup on page 9
(330 ml for the Underwater setup)
30 seconds
3 Liters
Test Duration:
Bag Volume:
4. Calibration
Turn the system on and allow 60 minute warm-up with Sample Tube connected to black
Luer connector on Test Bag, Gas Selection Switch in RUN position
4.1
Hardware Calibration of 17501 Tri-Gas Analyzer
Always keep the ARGON switch in the ON position,
H2O dial fully clockwise (Fully clockwise for zero humidity).
1.
Disconnect the (black) Sample Line for Test Bag, adjust CO2 ZERO to 0.05 and
O2 SPAN to approximately 20.9
2.
Turn Gas Selection switch to CAL GAS 2, adjust gas flow from tank containing 4%
CO2 so that ball floats in green dot area, then adjust CO2 SPAN to 4.00
3.
Turn Gas Selection Switch to CAL GAS 1, adjust flow from tank containing 100%
O2 so that there is a slight overflow from the Gas Storage Bag, and adjust
O2 SPAN so that the N2 meter reads 0.00 (±0.02%) and CO2 ZERO to 0.00%.
4.
Turn Gas Selection Switch to RUN and adjust O2 ZERO so that N2 = 79.00
(±0.02%). CO2 meter will now read ambient CO2.
5.
Repeat steps 3 and 4 until N2 reads correctly in both positions of the switch.
6
4.2
Software
Calibration
From the Main Menu select
CALIBRATION. Make sure the
Low N2 is set to "0" and the
High N2 (Air) is set to "79".
Enter today's temperature,
barometric pressure and
humidity.
Note that you can obtain the
barometric pressure by
pressing the "BARO" button
next to the N2 display on the
N2 meter.
Ignore the "Peak Needle
Valve" button.
6.
Connect the black Sample Tube to the Test Bag and click AUTOCAL.
Note: The Bag will overfill if the sample tube stays
disconnected too long because the Tri-Gas Analyzer gas return
tube (the clear one) will fill the bag.
7.
Turn the Gas Selection Switch to CAL GAS 1, open the oxygen gas tank valve and
partially fill the storage bag in order to fill the gas supply line with O2.
Adjust O2 SPAN so that N2 on computer screen reads 0.00
Click START. AutoCal step 1 is complete when the CONTINUE button blinks.
Click CONTINUE.
8.
Turn the Gas Selection Switch to RUN, disconnect the black Sample Tube to
sample room air*, and adjust O2 ZERO so that on-screen N2 = 78.xx,
where 78.xx is the BTPS corrected N2 value displayed in the white field in the
lower left corner of the computer screen.
Click START when the signal has stabilized.
Note: In AutoCal step 2 the N2 calibration set point has
changed to reflect the True BTPS-corrected N2 based on
ambient conditions.
*When sampling room air make sure the black sample tube
points away from any person so as to avoid sampling any
exhalation gas.
9.
Quit to Test, reconnect the black Sample Tube
7
6.
Operation
6.1
Test Procedure
Be sure to install a new VacuMed # 3421 breathing filter in front of VacuMed
mouthpiece # 1000.
Enter the software test screen either from the Calibration Menu "Quit to Test" or from the
Main Menu click the large RESIDUAL VOLUME SOFTWARE button.
Enter the test Subject's information and SAVE.
Click on START FLUSH & FILL CYCLE
Abbreviations used:
LV =
2-position lever valve on desktop
SC =
Stopcock, manual valve with breathing port
8
See figures above.
The four-way 2-position stopcock (SC) is connected
so that the mouthpiece is connected to port 1.
Port 2 goes to the re-breathing bag, port 3 goes to O2
priming system, and the port 4 goes to room air.
Position “A” of the “SC” is the position that allows the
subject to breathe room air, shown top right.
Position “B” is the position that has the subject re-breathing
from the bag.
During test the black analyzer sample tube is connected to
the lower port of stopcock as shown in the photo on the
right.
Gas Return
Tube
Sample
Tube
There is no reason to ever disconnect the Gas Return Tube.
The hand lever of the Lever Valve
(LV) allows connecting the syringe
either to re-breathing balloon “R” or
to “T” valve (lever leaning toward
valve’s body position 2) which allows
emptying the syringe to room air
(forward stroke) and filling it with O2
(backward stroke).
See also diagrams on page 11.
Lever Valve “LV” shown in Position 1
9
Start with the subject off the mouthpiece. Proceed with the following sequence:
(Position = Pos)
Instructions also on-screen
Flush and Fill cycle, start with Stopcock “SC” in Pos A as seen on page 9, Syringe Forward
(In) and adjust O2 (Medical oxygen) gas flow to keep storage balloon “S” nearly filled. Use
the Flush - Fill sequence below. The OUT command requires complete evacuation of the
balloon “R”.
Adjust pull-push speed and oxygen flow from tank to maintain some balloon “S” inflation.
Push and pull the syringe GENTLY, without excessive force.
Step
LV
Position
Syringe
Plunger
Notes
1
1
Out
Evacuating "R" balloon into Syringe, N2% high
2
2
In
Empty Syringe through T-valve, "R" is empty, N2% high
3
2
½ Out
"R" is empty, N2% high
4
2
In
"R" is empty, N2% high
5
2
½ Out
"R" is empty, N2% high
6
1
In
"R" is partially filled, N2% lower
7
1
Out
"R" is empty, N2% stays lower
8
2
In
"R" is empty, N2% stays lower
9
2
Out
"R" is empty, N2% stays lower
10
1
In
"R" is full, N2% low
11
2
In
"R" is full, N2% low
The analyzer will show low N2 content (0-5%) when the "R" bag has been sufficiently
flushed.
Repeat step 7 to 11 (Green steps) if N2 content is not below 5%.
Last Pull (Filling) of the syringe must consist of exact, full 3-liter stroke, so make sure
sufficient gas in bag “S”. When syringe is thus filled, push LV to Pos 1. Push syringe FWD to
fill balloon “R”:
Ending in Pos 2. This position closes off the re-breathing bag
so no air can get in (diagram page 11).
The next step is critical.
10
11
Now, the bag has been filled with oxygen and the subject is instructed to go onto the
mouthpiece and to breathe normally. The subject is breathing room air at this point.
Make sure subject wears a nose clip!
Watch the subject’s breathing pattern and give the instruction to breathe all the way out.
At exactly the moment the subject has fully exhaled (Reaches RV and has paused
breathing), click on MEASURE (or just hit ENTER).
Then, just a second later, turn the stopcock
SC counter-clockwise to position B. Subject is
now rebreathing from bag “R” as shown
below. Instruct the subject to take 2 or 3
deep breaths, then continue breathing at
increased depth and rate.
If your PC has a speaker, you will hear
"pings" for 30 seconds. Then click FINISH (or
just hit ENTER). RV value will be displayed
on the printout.
For another test, repeat the Flush - Fill cycle
starting on page 10.
Stopcock
position "B"
Note: To measure FRC, subject does not exhale all the way out prior to turning valve
to position “B”. Instead, switch to position “B” during the expiratory pause, then have
subject take a deep breath and proceed breathing normally.
"R"
12
Ü Nose Clip ON, Breathe normally
Ü On command exhale FULLY,
thumb up when done,
HOLD BREATH
Ü Click MEASURE (or ENTER)
Ü Rotate Stopcock
Ü Breathe deeply for 30 seconds
Ü Click FINISH (or ENTER)
Don’t forget to shut off the oxygen and calibration gas tanks!
Click on <Finish> to view and print results.
13
After you click FINISH, all tests for that person
will show up in the AVERAGE window shown on
the right. Checkmark the tests you want to
average and click on AVERAGE RV.
You may PRINT, REPEAT TEST or QUIT.
Usually at least 3 tests are performed and
ideally results should be within 15%.
Outliers may be deleted in the REVIEW menu
or not included in the AVERAGE RV check box.
Note: Test can be reviewed and re-printed by
clicking the REVIEW button in the Main Menu.
RV test files are listed as "name.RV".
When you REVIEW results for a given subject,
you need only click on any one file with his/her
name.
All tests for that person will show up in the
AVERAGE window shown on the right.
Checkmark the tests you want to average and
click on AVERAGE RV.
14
6.5 Special Instructions for Underwater Measurement
There are two clear advantages to measuring
RV in the water:
1. Residual Volume measurements vary
from one trial to another, but the “in-Tank”
procedure measures RV as it is during the
weight measurement.
2. The test subject can submerge and
breathe while the water surface stabilizes,
thus reducing errors due to movement of the
water surface.
The most important change from the out-of
-water procedure is to change the dead
space entry. Dead space using VacuMed’s #
5336 tubing (36 inches long x 22mm ID) is
330 ml.
In order for the breathing tube to reach the
subject, is may be necessary to clamp the
stopcock holding bracket onto the rim of the
tank.
Procedure: Subject enters weighing tank and is fitted with mouthpiece and nose clip.
Subject submerges completely under water. He/she will be breathing room air at this point.
Remember, subject can hear your pre-test instructions under water. When water is calm,
instruct subject to exhale to near RV and signal you with wiggling finger when done.
Instructor:
a.
Closes red-handled valve “C” to prevent subject from breathing.
(Subject now holds breaths for about 10 seconds.)
b.
Take underwater weight.
c.
Click on MEASURE
d.
Rotate stopcock SC to position B.
e.
Open red-handled valve “C”.
f.
Signal subject to start taking a few deep breaths.
Subject’s head may surface but must keep mouthpiece and nose clip in place
Click OK to move to the next step.
The operator may choose to terminate the test at any time by clicking OK, however when
the countdown timer reaches zero, the test is automatically terminated and the next menu
is displayed.
Above reading is an example only, your actual reading will vary.
The system will emit a beeping sound at this stage. Turn the valve back to position A, room
air, and tell the subject that they can come off the mouthpiece unless you want to repeat
the measurement.
The last screen displays the results of the test and asks the operator if they want to perform
another test.
Modified in-water setup shown above.
This screen shows the progress of the RV measurement in real-time as the subject breathes
in and out of the bag. The display consists of 2 parts; the nitrogen concentration and the
countdown timer indicating the remaining test time. As the concentration of nitrogen in the
bag equilibrates with the lungs, the nitrogen reading will become stable and settle on a
final value.
15
6.4
How to replace the Oxygen sensor
These operations should be performed by the biomedical repair department.
Turn off the instrument power and disconnect the external power supply.
6.1
Unplug the external power supply.
6.2
Remove the top cover of the gas analyzer
6.3
Remove cable connector from O2 sensor by opening the tabs outward.
6.4
From the opposite end of the sensor, remove luer and pull off tube connected
to Nafion.
6.5
Loosen the plastic clamp that is holding the sensor, pull out the
sensor, replace it with a new one, reconnect all in reverse order from above.
How to replace the Internal Nafion Dryer
6.6
Follow steps 6.1 and 6.2 above.
6.7
Remove the existing “Nafion” tube by twisting the luer connectors
counter-clockwise at each end.
6.8
Install the new Nafion tube and reconnect the luer connectors tightly.
6.9
Re-install top cover.
16
7.
7.1
Maintenance
Preventive Maintenance:
Every 12 months of operation:
Replace 5 L Test Bag ("R").
CO2 and water combine into an acid that
eats the rubber, causing a leak.
Replace filter on SAMPLE IN connector
Every 24 months :
7.2
Replace the O2 sensor
(It expires even if you don't use it!)
Checking for Leaks
Note: The most common symptom of a leak is that the gas
analyzers will not calibrate. Typically this means you calibrate
Zero, then Span, then you go back to Zero and it is out of calibration.
Leaks in any of the tubing between the patient's mouth and the gas analyzer can cause
serious errors. Since air is drawn through the gas analyzer this creates a somewhat
negative pressure anywhere along the gas sample line to the gas analyzers. A leak would
therefore result in air being mixed in with the sample gas or calibration gas. You therefore
cannot see a leak when you are sampling air; however, when a calibration gas is introduced
it may be partially diluted by air. There are several ways to check for leaks, here are some
suggestion:
1. Close off the sample input line. O2 reading should drop to zero. If it does not, the leak
must be in the sample line. Replace it.
2. Open the Gas Inlet port. Since any air leak would still show up as ~78 % N2, use a
stream of gas containing 100% O2 and direct a narrow stream of this gas slowly along the
whole tubing (gas) path. Have someone watch the gas concentration as they appear on the
digital display closely. When the N2 concentration decreases you have found your leak.
7.3
Troubleshooting Guide
1. Can't reduce N2 to 5%
Leak
Check rubber bag connection
2. Meter display dead
No power.
Check for obvious. Power cable bad or not
plugged in. Make sure connections are tight
Replace with 1A Slo-Blo.
Fuse blown
Faulty internal connection to meter
3. N2 analyzer will not calibrate
Remove top panel.
Check that connectors are pushed home
Incorrect Gas Flow or feed
Leaky gas lines
Insufficient vacuum
Sample cell faulty
Leaktest per chapter 7.2
Check connections, tubing, replace pump oil
Contact factory
4. Insufficient Gain (Span)
Cannot adjust O2 to 21%
Obstructed filter
Replace O2 sensor every 24 months
Replace filter on sample line
5. No change on meter or BNC connector
when oxygen is applied
No power to sample pump
Blocked, pinched or disconnected
sample tube
Check power source
Check external and internal tubing for blockage
look for kinks in tubing.
17
Appendix A
Using the N2 Analyzer without PC software
Calibrate the TRi-Gas Analyzer as in section 4.1. The front panel H2O control can be used to
adjust the analyzer to the room air %N2 (wet). The H2O control is set fully CW for zero
humidity (as in a Calibration Gas).
The %N2 (wet) can be found by the following formula:
%N2 (wet*) = 78% X Patm – PH2O
Patm
where:
PH2O
= partial pressure of water vapor at 100% relative humidity (from table I)
Patm = barometric pressure in mmHg
78%
= the percentage of nitrogen in a dry atmosphere
Table I
Partial Pressure of Water Vapor at 100% Relative Humidity for Various Temperatures
T °C
PH2O
(mmHg)
20
17.5
21
18.7
22
19.8
23
21.1
24
22.4
25
23.8
26
25.2
27
26.7
28
28.3
29
30.0
30
31.8
31
33.7
32
35.7
33
37.7
34
39.9
35
42.2
36
44.6
37
47.0
For example, assume a room temperature of
25°C, a 60% relative humidity, and an
atmospheric pressure of 760mmHg.
We recommend the purchase of a low-cost
humidity meter, such as VacuMed's # 17043.
From the table, the 100% PH2O for 25°C is equal
to 23.8 mmHg.
Since the humidity is 60%, the actual PH2O is
23.8 X .6 = 14.3 mmHg.
Substitute values into the equation:
78% X 760-14.3 = 76.5% N2(wet).
760
Final N2 Cal Adjustment
Turn the H2O control on the front panel until a
reading of 76.5% is obtained, and lock the
control.
(*) Percentage of relative humidity determines
the wetness of air, i.e. partial pressure of water
vapor (pH2O) in atmosphere
18
References
1)
A Simple Method for Measuring Functional Residual Capacity by N2 Washout in
Small Animals and Newborn Infants. Tilo Gerhardt, et al. Pediatric Research,
vol 19, No 11, 1985.
2)
H-P Vertek Series 3500VR Nitrogen Analyzer operating guide,
part number 47302-91998
3)
CRC Handbook of Chemistry and Physics
Replacement & Spare Parts:
1018-28
1000
1193-5
1008
R1915
3421
17000-2
Y17405-1
Y17670-5
17049
3435
17625-1
21515
Mouthtube, blue
Mouthpiece, blue vinyl 1-1/8" ID
Storage Balloon, 5 liter
Noseclip, disposable
Noseclip, reusable
Low resistance bacteria filter, green
Optional BNC cable (5ft)
Twin Sample/Return Tube (black & clear)
Cal Gas supply tube (red)
Nafion Dryer (internal)
Gas Filter (Pack of 10)
Replacement Fast O2 sensor
Replacement CO2 absorber
19
Appendix B: Calculation of Residual Volume
from the Closed Circuit Test
Method
The subject is breathing room air of a known concentration of nitrogen. When he has
exhaled to residual volume, the technician switches the breathing circuit into a closed
balloon filled with a pre-measured volume of pure oxygen. From this point the subjects
re-breathes from the balloon for 30s – 60s until the nitrogen concentration has stabilized.
The final value of the nitrogen concentration is recorded and the subject instructed to come
off the mouthpiece.
The residual volume is calculated using the following formula:
RV= [BV 310 * PBAR/(PBAR - 47)(T+273)] x [(%N 2 BAL - % N2TC)/(%N2LUNG-%N2 BAL)] - VD
Where:
BV:
Volume of O2 in the balloon (in mL)
310:
Body temperature in °K
Pbar:
Barometric pressure
%N2BAL:
N2 content in test balloon after re-breathing
%N2TC:
Trace content of N2 (before re-breathing) in the balloon
%N2LUNG:
N2 content in lungs at body temperature and 100%RH
VD:
Dead space from mouth to re-breathing balloon
Revision History
Feb 2014:
Initial Issue
20