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MOXUS Metabolic System
Instruction Manual
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CONTENTS
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WARRANTY
CAUTIONS
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5
SYSTEM SETUP
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SOFTWARE SETUP
7
DAILY SYSTEM STARTUP & SHUTDOWN
10
SYSTEM CALIBRATION
Gas Calibration
Gas Verification
Volume Calibration
Volume Verification
Calibrating Other Channels
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CONDUCTING A TEST
Subject Information
Test Preparation
Start Test
End Test
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RUN TIME FEATURES
Data Graphs
Tabular Display
Export to Excel
Edit Data
Hide/Unhide Column
Column Move From/Move To
Sort Column Ascending/Descending
Select Column
Properties
Mark Invalid/Valid Data
Column Width
Averaging Interval
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OTHER FEATURES
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REPORTS
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CONTENTS CONT’D.
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APPENDIX A – THEORY OF OPERATION & FORMULAS
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APPENDIX B – COMPUTER REQUIREMENTS
42
APPENDIX C – CONSUMABLES / SPARE PARTS
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APPENDIX D - TROUBLESHOOTING
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APPENDIX E – CARDIAC OUTPUT MODULE [optional]
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APPENDIX F – CANOPY SYSTEM [optional]
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APPENDIX G – CLINICAL SYSTEM OPERATION
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Warranty and Claims
We warrant that any equipment of our own manufacture or manufactured for us pursuant to our
specifications which shall not be, at the time of shipment thereof by or for us, free from defects in material or workmanship under normal use and service will be repaired or replaced (at our option) by us free
of charge, provided that written notice of such defect is received by us within eighteen (18) months from
date of shipment. All equipment requiring repair or replacement under this warranty shall be returned to
us at our factory, or at such other location as we may designate, transportation prepaid. We shall examine
such returned equipment and if it is found to be defective as a result of defective materials or
workmanship, it shall be repaired or replaced as aforesaid. Our obligation does not include the cost of
furnishing any labor in connection with the installation of such repaired or replaced equipment or parts
thereof, nor does it include the responsibility or cost of transportation. In addition, instead of repairing or
replacing the equipment returned to us as aforesaid, we may, at our option, take back the defective
equipment and refund in full settlement the purchase price thereof paid to Buyer. If you are returning
equipment from outside the United States, a statement should appear on the documentation accompanying
the equipment being returned declaring that the goods being returned for repair are American goods, the
name of the firm who purchased the goods, and the shipment date.
This warranty shall not apply to any equipment (or part thereof) which has been tampered with or altered
after leaving our control, or which has been repaired by anyone except us, or which has been subject to
misuse, neglect, abuse, or improper use. Misuse or abuse of the equipment, or any part thereof, shall be
construed to include, but shall not be limited to, damage by negligence, accident, fire, or force of the
elements. Improper use or misapplication shall be construed to include improper or inadequate protection
against shock, vibration, high or low temperature, overpressure, excess voltage and the like, or operating
the equipment with or in a corrosive, explosive or combustible medium unless the equipment is
specifically designed for such service, or exposure to any other service or environment of greater severity
than that for which the equipment was designed.
This warranty does not apply to used or second-hand equipment, nor extend to anyone other than
the origina1 purchaser from us.
THIS WARRANTY IS GIVEN AND ACCEPTED IN LIEU OF ALL OTHER WARRANTIES,
WHETHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES
OF FITNESS OR OF MERCHANTABILITY OTHER THAN AS EXPRESSLY SET FORTH HEREIN,
AND OF ALL OTHER OBLIGATIONS OR LIABILIES ON OUR PART. IN NO EVENT SHALL WE
BE LIABLE UNDER THIS WARRANTY OR ANY OTHER PROVISION OF THIS AGREEMENT
FOR ANY ANTICIPATED OR LOST PROFITS, INCIDENTAL DAMAGES, CONSEQUENTIAL
DAMAGES, TIME CHARGES, OR ANY OTHER LOSSES INCURRED BY THE ORIGINAL
PURCHASER OR ANY THIRD PARTY IN CONNECTION WITH THE PURCHASE,
INSTALLATION, REPAIR, OR OPERATION OF EQUIPMENT, OR ANY PART THEREOF, COVERED BY THIS WARRANTY OR OTHERWISE, WE MAKE NO WARRANTY, EXPRESS, OR
IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OF FITNESS OR OF
MERCHANTABILITY, AS TO ANY OTHER MANUFACTURER’S EQUIPMENT, WHETHER
SOLD SEPARATELY OR IN CONJUNCTION WITH THE EQUIPMENT OF OUR
MANUFACTURE. WE DO NOT AUTHORIZE ANY REPRESENTATIVE OR OTHER PERSON TO
ASSUME FOR US ANY OTHER LIABILITY IN CONNECTION WITH EQUIPMENT, OR ANY
PART THEREOF, COVERED BY THIS WARRANTY.
4
***CAUTION***
DO NOT USE THIS INSTRUMENT IN THE PRESENCE OF FLAMMABLE
ANESTHETICS OR FLUORINATED GASES.
NOT FOR USE WITH ANESTHETIC GAS MIXTURES.
THESE INSTRUMENTS MUST BE ELECTRICALLY GROUNDED.
DO NOT USE AN UNGROUNDED CONNECTOR OF ANY KIND.
DO NOT OPEN CABINETS WITHOUT PRIOR FACTORY AUTHORIZATION.
FOR HIGHEST ACCURACY, TOP COVER MUST REMAIN ON INSTRUMENTS.
5
SYSTEM SETUP
FOR INSTALLATION, SETUP AND CHECKOUT OF SYSTEM COMPONENTS REFER
TO THE INSTALLATION GUIDE INCLUDED WITH THE SYSTEM. ALSO REFER TO
GAS ANALYZER MANUALS AND CLEANING INSTRUCTIONS. PLEASE REVIEW
APPENDIX A: AEI METABOLIC SYSTEM THEORY OF OPERATION & FORMULAS,
FOR A SYSTEM OVERVIEW AND DETAILS NECESSARY FOR CORRECT
OPERATION OF THE SYSTEM AND INTERPRETATION OF THE DATA.
ALL AEI METABOLIC SYSTEM MANUALS, INCLUDING THE INSTALLATION GUIDE
AND THIS MANUAL, ARE LOCATED ON THE SOFTWARE CD AND ARE ALSO
INSTALLED IN THE C:\PROGRAM FILES\AEI TECHNOLOGIES DIRECTORY ON
THE COMPUTER.
IT IS RECCOMMENDED THAT BOTH THE S-3A O2 ANALYZER AND CD-3A CO2
ANALYZER ALWAYS REMAIN POWERED ON. THIS WILL GREATLY REDUCE
SYSTEM WARM-UP TIME AND PROLONG THE LIFE OF THE ANALYZERS. THE R-1
PUMP, INTERFACE BOX, COMPUTER AND PRINTER MAY BE TURNED OFF WHEN
NOT IN USE.
NOTE: THE MOXUS SYSTEM IS NOW ON THE 3RD GENERATION. THE FIRST
GENERATION MOXUS HAD THE DATA ACQUISITION ELECTRONICS INSTALLED
ON THE COMPUTER AND RAN UNDER THE DOS OPERATING SYSTEM. THE 2ND
GENERATION MOXUS DATA ACQUISITION ELECTRONICS WERE PLACED IN A
LONG ALUMINUM ENCLOSURE [INTERFACE BOX]. THE 3RD GENERATION MOXUS
DATA ACQUISITION ELECTRONICS ARE PLACED IN A SQUARE PLASTIC BOX
[INTERFACE BOX]. THIS MANUAL IS FOR THE 3RD GENERATION MOXUS ONLY.
FOR PREVIOUS GENERATIONS PLEASE REFER TO THE ORIGINAL MANUAL
PROVIDED WITH THE SYSTEM.
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SOFTWARE SETUP
Run the AEI Metabolic System Software program by double-clicking the icon on your
desktop. A box of text in the lower right corner of the screen asks you to Please Wait.
Wait until this box disappears. When the software has been loaded properly the box will
disappear and the software is ready for use. NOTE: Do not attempt to operate the
software until the Please Wait message disappears.
Operating Modes and Options
IMPORTANT! Required for proper operation
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In the Menu Select: Tools > Hardware Dx.
Select System Mode as ‘MOXUS’.
Select Volume Source as ‘Pneumotach’ [or ‘Turbine [VMM-400]’ or ‘Turbine [KTC3]’
on some models, if used].
De-Select ‘Calibration gas = High/Low” if checked [unless otherwise advised].
For Cardiac Output Option see Appendix E.
For Canopy System Option see Appendix F.
For Clinical System see Appendix G.
For automatic inspiratory fiO2 and fiCO2 sampling [Canopy System Option only]
click ‘Sample Inspiratory Air’ The Canopy System Option can allow for automatically
sampling the inspiratory O2 and CO2 concentrations every 10 minutes. Ten minutes
after the Test has started collecting data the system will automatically switch to start
sampling from the Sample Air input instead of the mixing chamber; with the data
being marked Invalid. After 30 seconds the system will automatically switch back to
start sampling from the mixing chamber again. After another 30 seconds the data
will have stabilized and is now considered Valid data. These steps are repeated until
the Test is stopped. NOTE: The initial inspiratory O2 and CO2 concentrations should
be entered in the Subject Data window. These values will be used for the initial 10
minutes of the Test. These initial values will also be applied for the entire test if the
Sample Inspiratory Air checkbox is un-selected. NOTE: This feature is
recommended only for studies of 30 minutes or more AND in an environment in
which the ambient air is likely to change during the course of the test [for example: a
small room with several people working near the subject].
The Expiratory Flow Measurement checkbox should NOT be checked. To allow for
measurement of Flow on the expiratory side contact AEI Technologies for
assistance.
Cal Bypass checkbox should NOT be checked. To allow bypassing the Interface Box
for gas calibration contact AEI Technologies for assistance.
The Quick Cal checkbox should NOT be checked. To allow for a shortened gas
calibration time contact AEI Technologies for assistance.
Click ‘OK’. The software will automatically re-initialize.
Completely close the program. Re-start the program.
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Setup Defaults
IMPORTANT! Required for proper operation
• In the Menu Select: File > Properties > Setup tab:
• Change ‘Standard Calibration Gases’ values to your Laboratory Calibration
Gas values. Enter the value in the appropriate box.
• Enter the approximation of ambient inspired gas values (to be measured and
adjusted later, after calibration of the analyzers). FiO2 = 20.93% typical for
fresh [outdoor] air; FiCO2 = 0.04% typical for fresh [outdoor] air.
• Confirm that the Mixed Volume Delay is set at 6.9 Liters. This is for the
supplied breathing valve and tubing (2.7 liters) and the mixing chamber (4.2
liters). If different components are used refer to Appendix A.
• The default Analyzer Time Delays are 3 Seconds for the CO2 Analyzer and
3.3 seconds for the O2 Analyzer. NOTE: Systems variations may alter these
delay times. For most accurate phasing refer to Appendix A.
• Confirm that the Calibration Syringe volume is set to the supplied syringe
volume as recorded on the provided syringe calibration certificate, or enter
your own Calibration Syringe volume.
• Confirm that the Volume correction [Ve and Vt only] is calculated in BTPS
(preferred) or STPD. NOTE: All metabolic data [VO2, VCO2, etc.] is always
presented and saved in STPD without regard to this selection box.
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Averaging Interval
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In the Menu Select: File > Properties > Avg Interval
Choose the Averaging Interval for the test by sliding the bar to the desired setting.
NOTE: By setting the Averaging Interval to 0 seconds you will get breath-by-breath
data. However, the exhaled breaths are still sampled from the mixing chamber.
Institution Name & Address
In the Menu Select: View > Preferences. Fill in the Institution Name and Address. This
information will appear at the top of the printed reports.
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DAILY SYSTEM STARTUP & SHUTDOWN
Each day, before System Calibration or starting a test, perform the following:
STARTUP
• Turn the Range Knob on the right of the S-3A/I O2 Analyzer to the T.C. Setting. The
value displayed on the panel meter should in be 6.790 (+/- 0.003). If the displayed
value falls outside of this range, wait and allow time for the value to stabilize.
• Turn ON the R-1 Pump. Adjust the black, needle valve knob below the flow meter
until the bottom of the lower SILVER float ball is set at the 2 on the graduated meter.
This represents a gas sample flow rate of approximately 175 ml/min. Refer to
Analyzer manuals for flow rate graphs. NOTE: DO NOT CHANGE THIS SETTING
DURING AND AFTER SYSTEM CALIBRATION IS PERFORMED. Changing the
sample flow rate will adversely alter calibration.
• Turn ON the Interface Box, Computer and Printer. It is also recommended that the
S-3A O2 Analyzer and CD-3A CO2 Analyzer always be left powered ON. This will
prolong the life of the analyzers and greatly decrease the system warm-up time.
• Start the AEI Metabolic System Software program by double clicking the icon on
your desktop. A box of text in the lower right corner of the screen asks you to
‘Please Wait’. Wait until this box disappears. When the software has been loaded
properly this box will disappear and the software is ready for use. NOTE: Do not
attempt to operate the software until the ‘Please Wait’ message disappears.
SYSTEM LEAK CHECK
• Turn the R-1 Pump Power ON.
• Temporarily disconnect the small-diameter sample tube from the Mixing Chamber
with a quarter-turn of the Leur connector.
• Using your finger [or a bend the tubing] to close off the tube opening.
• Verify that both balls on the flow meter drop completely to the bottom of the tube and
stay there with no bouncing (Zero flow).
• Remove your finger and verify that the SILVER float returns to a setting of 2 on the
Flow meter and that the Analyzer readings return to 20.93 % and 0.04%.
• Re-connect the sampling tube to the Mixing Chamber with a snug fit.
• Wait at least 10 minutes before System Calibration.
CALIBRATION GAS TANKS
• Fully open the Calibration Gas tank valves [>1 full turn counter-clockwise] and adjust
both Calibration Gas regulators to 15 psi.
DRYER DESICCANT
• Observe the small desiccant beads through the window of the Dryer Box. The beads
should be a deep blue color. When any of the beads start to change color from blue
to either purple or pink then it is time to change the desiccant. To change the
desiccant slide the cover [with an arrow and ridges] off by pressing down on the
inner edge of the cover and at the same time sliding it out. Discard all the desiccant
and add new desiccant such that the beads completely fill all empty space in the
box. Replace the cover.
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At the end of the day:
CALIBRATION GAS TANKS
• Turn off the Calibration Gas for both cylinders. Use the cylinder wrench to shut off
the gas supply by securely tightening the main cylinder valve in a clockwise
direction. NOTE: Do not over tighten.
S-3A OXYGEN ANALYZER CELL RESTORE
• Once every week press the Cell Restore on the front panel of the S-3A/I O2
Analyzer. This should typically be done at the end of the day’s testing because the
analyzer takes about 1 hour to recover from this procedure.
o Turn the R-1 Pump Power.
o Wait about 15 minutes until the Cell Restore light on the front panel
extinguishes.
o Turn Power OFF on the R-1 Pump
POWER OFF
• It is recommended to turn Power OFF on the R-1 Pump, Interface Box, computer,
and Printer at the end of each day’s testing. It is also recommended that the S-3A
O2 Analyzer and CD-3A CO2 Analyzer always be left powered ON. This will prolong
the life of the analyzers and greatly decrease the system warm-up time.
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SYSTEM CALIBRATION
Gas Calibration and Verification and Volume Calibration and Verification should be
performed before every test. When used for teaching, demonstration, and testing where
data will not be published, Gas Verification and Volume Verification may be sufficient;
and then re-calibrate only when necessary.
IMPORTANT NOTE: Always perform Daily System Startup before System Calibration
and Validation.
System Calibration window
Gas Calibration: O2 and CO2
NOTE: For best results both S-3A O2 analyzer and CD-3A CO2 analyzer must be
Powered On for 16 hours minimum before calibration.
• Click on the ‘Calibration’ button on the upper left of the screen.
• In the Valve Control section on the right side of the System Calibration window select
‘Calibrate Exp’. This will select the tank with typical expiratory gas values; for example
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16%O2 and 4%CO2.
• Wait 1 minute for the gas analyzers to stabilize.
• Calibrate the S-3A O2 analyzer:
o Turn the Range Switch to the %O2 position.
o Turn the CALIBRATE/SAMPLE SWITCH to the SAMPLE position.
o Slide the black lever on the ZERO POT to unlock the dial.
o Set the ZERO POT to mid-range (“5” on the vernier counter).
o Turn the CALIBRATE/SAMPLE SWITCH to the CALIBRATE position.
o Adjust the ZERO POT to obtain the exact O2 calibration gas value on the S-3A
analyzer panel meter. NOTE: If you run out of range on the ZERO POT: set the
CALIBRATE/SAMPLE SWITCH in the SAMPLE position; turn the ZERO POT all
the way back in the opposite direction; set the CALIBRATE/SAMPLE SWITCH in
the CALIBRATE position; adjust the ZERO POT. Repeat until the panel meter reads
correctly.
o Turn the CALIBRATE/SAMPLE SWITCH back to the SAMPLE position.
o Slide the black lever on the ZERO POT to lock the dial.
• Calibrate the CD-3A CO2 analyzer:
o Turn the CALIBRATE/SAMPLE SWITCH to the SAMPLE position.
o Slide the black lever on the SPAN POT to unlock the dial.
o Set the SPAN POT to mid-range (“5” on the vernier counter).
o Turn the CALIBRATE/SAMPLE SWITCH to the CALIBRATE position.
o Adjust the SPAN POT to obtain the exact CO2 calibration gas value on the CD-3A
analyzer panel meter. NOTE: If you run out of range on the SPAN POT: set the
CALIBRATE/SAMPLE SWITCH in the SAMPLE position; turn the SPAN POT all
the way back in the opposite direction; set the CALIBRATE/SAMPLE SWITCH in
the CALIBRATE position; adjust the SPAN POT. Repeat until the panel meter reads
correctly.
o Turn the CALIBRATE/SAMPLE SWITCH back to the SAMPLE position.
o Slide the black lever on the SPAN POT to lock the dial.
• In the Valve Control section on the right side of the System Calibration window select
‘Calibrate Air’. This will select the tank with typical ambient air gas values; for example
20.94%O2 and .03%CO2.
• Wait 1 minute for the gas analyzers to stabilize.
• Calibrate the S-3A O2 analyzer:
o Turn the Range Switch to the %O2 position.
o Turn the CALIBRATE/SAMPLE SWITCH to the SAMPLE position.
o Verify that the S-3A analyzer panel meter value is within +/- 0.02% O2 of the O2
calibration gas value.
o If it does not verify, repeat the O2 calibration using the ‘Calibrate Exp’ calibration
gas. If still not correct please contact AEI Technologies service.
o Turn the CALIBRATE/SAMPLE SWITCH back to the SAMPLE position.
• Calibrate the CD-3A CO2 analyzer:
o Turn the CALIBRATE/SAMPLE SWITCH to the SAMPLE position.
o Slide the black lever on the ZERO POT to unlock the dial.
o Set the ZERO POT to mid-range (“5” on the vernier counter).
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o Turn the CALIBRATE/SAMPLE SWITCH to the CALIBRATE position.
o Adjust the ZERO POT to obtain the exact calibration gas value on the CD-3A
analyzer panel meter. NOTE: If you run out of range on the ZERO POT: set the
CALIBRATE/SAMPLE SWITCH in the SAMPLE position; turn the ZERO POT all
the way back in the opposite direction; set the CALIBRATE/SAMPLE SWITCH in
the CALIBRATE position; adjust the ZERO POT. Repeat until the panel meter reads
correctly.
o Turn the CALIBRATE/SAMPLE SWITCH back to the SAMPLE position.
o Slide the black lever on the ZERO POT to lock the dial.
In the Valve Control section select ‘Standby’ to stop the flow of gas.
Verify Low Cal Value and High Cal Value on the System Calibration window exactly
equal the Calibration Gas values of the tanks. If needed, enter new values as
follows:
o Place cursor and click in the Low Cal Value Box for the Oxygen Channel
and enter the exact value of the lower O2 Calibration Gas that you will be
using (usually 15 – 16% O2).
o Place cursor in the High Cal Value Box for the Oxygen Channel enter the
exact higher O2 Calibration Gas value to be used (preferably 20 – 21%
O2).
o Perform the same steps for the CO2 Channel. Enter the exact higher
CO2 Calibration Gas that you will be using (preferably 4 - 6% CO2) and
the exact lower CO2 Calibration Gas that you will be using (usually 0 –
0.03% CO2).
o Click “Save”
Click the channel select box for the O2 Channel (Top Left side of the window)
Click on the LO CAL button on the System Calibration window. Wait about 90
seconds until the cycle is complete and the O2 Channel is “deselected’.
Select the O2 Channel again.
Click on the HI CAL button on the System Calibration window. Wait about 90
seconds until the cycle is complete and the Status box at the right of the O2 Channel
will then read “Calibrated”.
If the channel indicates “Error” press the Save button, if available, and repeat the
software calibration steps. Several repetitions may be necessary.
Click the select box for the CO2 Channel.
Click on the LO CAL button on the System Calibration window. Wait about 90
seconds until the cycle is complete and the CO2 Channel is “deselected’.
Select the CO2 Channel again.
Click on the HI CAL button on the System Calibration window. Wait about 90
seconds until the cycle is complete and the CO2 Channel Status will read
“Calibrated”.
If the channel indicates “Error” press the Save button, if available, and repeat the
software calibration steps. Several repetitions may be necessary.
Click “Save”
Gas Verification
NOTE: For best results both S-3A O2 analyzer and CD-3A CO2 analyzer must be
Powered On for 16 hours minimum before calibration.
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Click on the ‘Calibration’ button on the upper left of the screen.
In the Valve Control section of the System Calibration window select ‘Calibrate Air’
Wait 1 minute for the analyzers to stabilize.
Verify that the MixO2 Average Data is within +/- 0.01% of the High Cal Value. Also
verify that the MixO2 Average Data is within +/- 0.02% of the values displayed on the
S-3A analyzer panel meter. NOTE: the MixO2 Average Data value is used in the
metabolic calculations – not the analyzer panel meter value.
Verify that the MixCO2 Average Data is within 0.01% of the Low Cal Value. Also
verify that the MixCO2 Average Data is within +/- 0.02% of the values displayed on
the CD-3A analyzer panel meter. NOTE: the MixCO2 Average Data value is used in
the metabolic calculations – not the analyzer panel meter value.
If the values are not within acceptable tolerances then perform the Gas Calibration
and Verification again.
In the Valve Control section of the System Calibration window select ‘Calibrate Exp’
Wait about 1 minute for the analyzers to stabilize.
Verify that the MixO2 Average Data is within +/- 0.01% of the Low Cal Value. Also
verify that the MixO2 Average Data is within +/- 0.02% of the values displayed on the
S-3A analyzer panel meter. NOTE: the MixO2 Average Data value is used in the
metabolic calculations – not the analyzer panel meter value.
Verify that the MixCO2 Average Data is within 0.01% of the High Cal Value. Also
verify that the MixCO2 Average Data is within +/- 0.02% of the values displayed on
the CD-3A analyzer panel meter. NOTE: the MixCO2 Average Data value is used in
the metabolic calculations – not the analyzer panel meter value.
If the values are not within acceptable tolerances then perform the Gas Calibration
and Verification again.
In the Valve Control section of the System Calibration window select ‘Sample Air’
Verify the MixO2 Average Data indicates a stable reading in the range 20.50 – 20.96
%O2. NOTE: Factors such as smog and altitude may effect the O2 concentration.
Verify the MixCO2 Average Data indicates a stable reading in the range 0.01 – 0.15
%CO2. NOTE: Factors such as smog and altitude may effect the CO2
concentration.
Volume Calibration
NOTE: For Canopy System Volume Calibration see Appendix F.
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Prepare for Volume Calibration by removing the mouthpiece or mask from the nonrebreathing valve. Make certain that the saliva trap and black cap are screwed on
tightly to the breathing valve.
Make certain that the inspiratory and expiratory ports of the non-rebreathing valve
are also screwed in tightly. The corrugated breathing hose should be snug on the
expiratory port.
The Pneumotach, if used, should be inserted snugly into the inspiratory port of the
non-rebreathing valve; or, alternatively, a breathing hose should be snug on the
inspiratory port and Pneumotach [refer to Installation Instructions]. [The black end of
the turbine cartridge, if used, should be inserted snugly into the inspiratory port of
the breathing valve.]
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Attach the 3-Liter Calibration Syringe directly to the mouthport connector on the nonrebreathing valve where the mouthpiece is normally attached. Be certain the syringe
plunger is pushed against the stop. NOTE: The syringe that is supplied is calibrated
to National Standards [NIST], and must not be adjusted without being recalibrated to
a known standard volume.)
Do not operate the syringe until after opening the Volume Calibration or Volume
Verification window.
On the right hand side of the System Calibration window you will find a small box
labeled “Pneumotach” [or "Turbine"]. In this box, select ‘Calibration’.
A Volume Calibration window will be opened.
Stroke the Calibration Syringe. While stroking the syringe, the user must apply a full
stroke each time, stopping against the mechanical limits of the syringe without
banging against the stop. For exercise testing, a stroke rate of 4 seconds [45 L/min]
for each outward stroke is recommended for best results; for resting energy
[canopy], a stroke rate of 7-8 seconds [24 L/min] for each outward stroke is
recommended. Use of a clock second-hand or metronome produces better
consistency.
After the first two strokes, the relative volume of each stroke measured by the
MOXUS System is displayed.
After 5 or 6 complete strokes, look at the displayed Relative Vol. NOTE: The values
may not represent an accurate volume [in fact, it may be totally erroneous] at this
time, but the displayed volumes should be consistent.
If the volumes are not consistent click ‘Recalibrate’ to repeat Volume Calibration.
The inconsistency may be due to: the strokes may not have been full strokes, or
there may be a leak in a tube or a leak (or backflow) in a component of the nonrebreathing valve.
Select ‘OK’, and the Volume Verification window will appear.
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Volume Verification
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Stroke the Calibration Syringe. While stroking the syringe, the user must apply a full
stroke each time, stopping against the mechanical limits of the syringe without
banging against the stop. For exercise testing, 5 strokes at a stroke rate of 1 to 5
seconds [36-180 L/min] for each outward stroke is recommended; for resting energy
[canopy], 5 strokes at a stroke rate of 6-8 seconds [22-30 L/min] for each outward
stroke is recommended.
Each stroke of the pump will be recorded in milliliters on the Volume Verification
Window and the actual error and percent error for each stroke will also appear.
After the first two strokes, the Volume of each stroke measured by the MOXUS
System is displayed.
After 5 or 6 complete strokes verify that the Avg Error is within +/- 2%. Typically, +/1% or better can be achieved. If so, simply Click OK and the window will close.
Alternatively, the ‘Clear Grid’ button may be pressed and a different stroke speed
may be verified. The ‘Clear Grid’ button will clear the grid and establish the zero flow
condition for the Pneumotach.
If the error is greater than the tolerance of +/- 2%, you may click on the Recalibrate
button to re-calibrate the flow. The Volume Calibration window will open and you will
be prompted to pump the calibration syringe at least another 5 times.
Once the re-calibration is complete, you conduct another verification to confirm that
system is now measuring the volume within +/- 2%. Repeat this process until you
complete an effective calibration and verify that the system is operating within the
acceptable tolerance range.
Click ‘Save’
Calibrating Other Channels
This must be done by providing an analog input, which is equal to a known “low”
calibration value, and another input, that is equal to a known “high” calibration value.
You must enter the high and low Cal values, and name the channel.
Calibration of the MOXUS System is now complete and you are ready start a test.
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CONDUCTING A TEST
Gas Calibration and Verification and Volume Calibration and Verification should be
performed before every test. When used for teaching, demonstration, and testing where
data will not be published, Gas Verification and Volume Verification may be sufficient;
and then re-calibrate only when necessary.
IMPORTANT NOTE: Always perform Daily System Startup before System Calibration
and Validation.
Subject Information
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Turn off Canopy Pump, if used.
Click on the ‘Subject Data’ hot button on the Toolbar.
If a previous test is currently open [i.e. the data is displayed on the screen] then a
message will appear asking if you would like to clear the existing subject data:
o Click ‘No’ if you would like to retain the existing Subject Data for the next
test; or if you are not ready to start the next test.
o Click ‘Yes’ if you would like to start a new test and re-enter the Subject
Data for the next subject.
Enter the Subject Name. NOTE: Do not use special characters such as “/”, “.”, “, etc.
The program will add the date and time to the Subject Name to create the File Name
and automatically save the file for this test under this File Name in the MOXUS
Metabolic
System
subdirectory
[typically:
c:\Program
Files\AEI
Technologies\MOXUS].
Enter the height, weight, age, and sex for the test subject. NOTE: Units conversion
is automatic.
Enter the room [ambient] barometric pressure, temperature and relative humidity.
NOTE: Units conversion is automatic.
Measure and enter ambient [inspiratory] fiO2 and fiCO2 concentrations:
o Select Menu: Tools > Calibration to open the System Calibration window.
o Click on the Sample Air button on the System Calibration window. [NOTE: For
Interface Box delivered before January 2014 temporarily disconnect the
small-diameter sample tube from the Mixing Chamber with a quarter-turn of
the Leur connector].
o Wait at least 60 seconds to allow the MixO2 and MixCO2 Average Data
readings on the System Calibration window to stabilize.
o Check that the values are reasonable. Nominal indoor ambient O2 is 20.50 to
20.96 and CO2 is 0.01 to 0.15; however, your typical values may be slightly
outside these ranges. Re-calibrate if the values are not typical.
o Record the Average Value MixO2 and MixCO2 readings on the Subject Data
window for fiO2 and fiCO2 respectively.
o Click on the Standby button on the System Calibration window. [NOTE: For
Interface Box delivered before January 2014 re-connect the sampling tube to
the Mixing Chamber with a snug fit].
o Exit the System Calibration window.
You also have the option of entering up to 3 lines of Comments for this particular test
run. These comments become a permanent part of the data file and they will appear
on the Summary Page of the Exercise Report that you can print out following the
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test.
Optionally, Resting HR, Resting BP, and MVV may be entered.
The Test Date and Test Time are automatically entered.
Click ‘OK’.
Test Preparation
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Reattach the mouthpiece or mask to the breathing valve
Prepare the Test Subject:
o Get the Test Subject in position (on the treadmill, ergometer, bed, etc.) to
begin testing.
o If you plan to utilize the headgear to support the breathing valve, fit it onto the
subject at this time. Alternatively, if you are planning to utilize the Support
Arm on the cart, you should position the arm so that the attached breathing
valve and mouthpiece are placed directly in front of the subject.
o If you are using the Polar Telemetry System to monitor heart rate, you should
moisten the underside of the chest belt and strap it into position on the
subject at this time. Please place the Polar Receiver as close as possible to
the subject by taping it to the treadmill handrail or ergometer handlebar.
o If a mouthpiece or mask is used: Instruct the subject to insert the mouthpiece
completely into the mouth and position a nose-clip in place; or attach the
mask to the subject ensuring that there are no leaks.
o The subject should begin to breathe normally to flush the mixing chamber and
fill it with exhaled gases before starting the test.
Click on the ‘Start Test’ button on the Toolbar. This opens the Real-Time Data
window for a final check of the system operation prior to the actual start of the test
and saving of data.
Before performing a test using the Canopy Hood wait about 5 seconds, and then
turn on the Canopy Pump. Refer to Appendix F.
Wait about 30 seconds for the numeric values on the Real-Time Data window to
start to change and then stabilize.
Check the numeric values on the Real-Time Data window to be certain that the tidal
volume and ventilation is being measured and that the FeO2 and FeCO2 values
have changed from ambient to reflect the concentrations in the expired breaths.
Verify also that these values are tracking the readings on the individual analyzer
panel meters.
If heart rate is being measured verify that the “heart symbol” is flashing and that the
heart rate is being displayed appears correct.
If a Treadmill or Ergometer is connected verify that the Work/Grade and Speed are
correctly displayed.
Start the Test
•
•
Click on the flashing Start Test button at the bottom right of this window.
The Real-Time Data window will minimize and 3 new windows will appear:
o At the top, 2 Data Graphs will appear to track parameters during the test run.
o On the bottom, the Tabular Data window will appear.
o The test data shown is based on the Averaging Interval that you selected on
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the Avg Interval window.
o The Real-Time Data window can be displayed by clicking on ‘Window’ in the
menu and selecting the Real-Time Data window.
Two minutes following the beginning of a test, ventilation, gas analysis and heart
rate signals are tested for validity. Should any or all of the signals be found to be
obviously unacceptable, a warning prompt is displayed and the operator is given a
choice to continue or terminate the test. Data is collected during this message.
During a Test you may perform the following as explained in the next section of this
Manual:
o Data Graph configurations
o Add another Graph
o Tabular configurations
o Averaging Interval changes
o Manual entry of off-line data, such as treadmill speed or workload.
o Cardiac Output tests (with optional equipment. See Appendix E for
instructions on performing cardiac output studies)
All data is automatically be saved in the AEI Metabolic System Software subfolder
[typically, C;\Program Files\AEI Technologies\Moxus].
End the Test
•
•
Once the test is complete click on the ‘End Test’ button on the Toolbar.
o A small window will open asking if you are sure that you want to end the test.
o Click YES to stop data collection and end the Test.
NOTE: to start another test enter new subject information, even if using the same
subject.
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RUN TIME FEATURES
Data Graphs
Data Graphs may be changed and rescaled within the Properties window by clicking on
the desired Data Graph to select it then right-clicking over the desired graph. Once in
the Properties menu, select the “Graphs” tab. NOTE: The Data Graphs should only be
changed or added during the first 10 minutes of a Test; otherwise Data Graphs may be
changed after the test is complete.
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The axis parameters are then selected for X axis, Primary Y Axis and Secondary Y
Axis. If the Secondary Y Axis is not to be used select ‘<none>’.
Manual scaling is the default setting. Enter the desired limits in the Lo and Hi boxes
by inserting a numeric value. Automatic scaling is not recommended for general use.
The graph is scaled automatically, and “zooming” is enabled, if the ‘Auto Scale’ box
is selected.
Grid markings may be placed on the graph by checking the Grid checkbox. Unclick it
to remove grid marks.
When comparing two Y parameters, it is often useful to have the scaling equal to
each other. The operator can do so by checking the ‘Use Primary Axis’ checkbox. If
it is left unchecked, the graph scaling will be set as indicated in the Lo and Hi
settings.
Additional Data Graphs may be added by selecting in the Menu:Tools>Add Graph.
21
Tabular Display
Parameters may be altered in the tabular display by means of right click on the tabular
data. When right clicking in the tabular data section, the following menu is displayed.
NOTE: The Tabular Display is limited to 9457 rows. Longer Averaging Intervals allow
data to be viewed for longer tests.
Export to Excel
NOTE: It is generally not advisable to export data to Excel during a test; Export to Excel
should be performed after the test is complete.
• Click on the box marked ‘Export to Excel’. The Export Window will open.
• The Excel file is saved in the AEI Metabolic System Software subfolder [typically,
C;\Program Files\AEI Technologies\Moxus]. However, you can change this setting
by clicking on the folder icon and setting the destination to the folder of your choice
or to a CD.
• Fill in the File Name that you choose for the Excel file.
• Click OPEN. The program will export your data file as a new .xls file to the
destination that you have selected.
• The newly created Excel file is now ready to be opened.
• There will be two tabs within the Excel file: Subject Data and Tabular Data.
• The only initial adjustment that will have to be made within Excel is to expand the
column widths so that all the subject data, parameter headings and numeric values
fit into the columns properly.
• The file can now be manipulated normally as a standard Excel spreadsheet.
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Edit Data
NOTE: It is generally not advisable to Edit Data during a test; Edit Data should be
performed after the test is complete.
The Edit Data function allows the user to disable (or re-enable) individual breaths that,
due to aberrations such as sighs, swallowing, coughing, talking or tubing artifacts, might
skew the true average. Generally speaking, longer averaging intervals will lessen the
need to disable aberrant breaths.
To disable a breath, choose ‘Edit Data’ from the menu that is presented by right clicking
on the tabular data. The Tabular Data is then changed from an averaged breath display
to a breath-by-breath display. The data for each breath can then be reviewed. Breaths
that need to be disabled are chosen by double-clicking on the breath number at the far
left of the tabular display. A “disabled breath” is displayed as a row of faded text.
Double-click on the “12” in the left hand column to disable the breath at 00:31
Conversely, a disabled breath may be re-enabled by double-clicking on the breath
number. The text will be displayed normally.
Once editing is complete, right click on the tabular data and select ‘End Data Edit’ to
return to an averaged data display.
Hide/Unhide Columns
The Hide and Unhide functions in the Right Click Tabular Menu allows the user to
remove and add back columns from the Tabular Display and Tabular Report. Simply
Select the column you wish to remove and then right-click to bring up the menu.
Selecting ‘Hide’ removes the column from the table. The hidden columns are
permanently saved as hidden columns from the Tabular Display (but not hidden in the
Tabular Reports) until unhidden by the ‘Unhide’ function. The Hidden column is
indicated by a slightly thicker dividing line in the column heading.
To Unhide, Select the column immediately to the right of the column you wish to unhide.
Selecting ‘UnHide’ displays the parameter in the table again.
Selecting ‘UnHide All’ will display all the columns of data.
Column Move From/Move To
These functions are complimentary and allow reordering of the data columns. For
example, to move RER to the column next to Freq, Select the RER column. Then
select ‘Move from’.
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Next, select the Ve column (the column where you want to place RER) and select ‘Move
to’. Ve will be pushed to the right and RER will be placed in its column.
The moved columns are permanently saved in the Tabular Display (but not changed in
the Tabular Reports). If needed, to restore the columns to their Default order: close and
then open the program; open any saved data file; in the Tabular Display right-click and
select ‘UnhideAll’; then select ‘UnHide’; then select ‘MoveFrom’; last select ‘MoveTo’;
close the program. The columns are now restored to default locations.
Sort Column Ascending / Descending
Allows reordering of data depending upon the column that is selected when choosing
these functions. This is most useful when you wish to display the end of the test at the
beginning of the column. To do so, Select the Time column. Then right click and select
‘Sort Descending’. The Time column can be returned to the original state by selecting it
and then selecting ‘Sort Ascending’.
Select Column
Selects a column for use with other menu functions such as Sort Ascending, Move etc.
A column can also be selected by clicking the mouse on the desired column header.
Properties
Displays the properties menu for selecting choices for graphs, averaging intervals,
setup parameters, etc.
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Mark Invalid/Valid Data
Allows elimination of selected data rows that are printed on the report. This function is
most useful to eliminate the warm up and cool down periods of a test thereby reporting
only on the exercise protocol of the test.
Select the data row(s) that you wish to be removed from the report. Next, select “Mark
Invalid Data” from the Tabular Right-Click menu.
To mark the data rows as Valid again: select the data row(s) that you wish to be added
back to the report. Next, select “Mark Valid Data” from the Tabular Right-Click menu.
NOTE: the data cannot be marked a valid while performing a test.
Column Width
The width of each column may be adjusted by placing the mouse over the column line
in the heading such that a ‘double arrow’ appears. Hold down the left mouse button and
adjust the column width as desired; then release the mouse button. The column width is
permanently saved in the Tabular Display (but not changed in the Tabular Reports)
Averaging Interval
Change the Averaging Interval by placing the pointer on the graphs and right-clicking
the mouse. The Properties window will appear. Move the sliding bar to adjust the
interval. NOTE: Data from every breath is always collected and saved by the software
independent of the Averaging Interval selected. The Averaging Interval selection is for
display purposes only. Setting the Averaging Interval to ‘0’ will display Breath-By-Breath
data. Changing the Averaging Interval to ‘0’ should only occur during the first 10
minutes of a Test; otherwise it should be changed after the test is complete.
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Data Entry
The Data Entry button allows the user to manually enter certain numeric data at any
desired time during a test. This is useful, for example, for manual entry of Heart Rate,
Speed, etc; or using USER to mark data.
Cardiac Output tests (with optional equipment)
See Appendix E for instructions on performing cardiac output tests.
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OTHER FEATURES
Full Screen Graphs/Chart
View the Full Screen display of Data Graphs or Tabular Data by clicking on the
“maximize” window square in the upper right corner of the desired window.
Click on the “Restore” window square to replace the window to its original position.
ZOOM
NOTE: The ZOOM feature is enabled only when “Auto Scale” is enabled.
• The Graph function also includes a ZOOM feature.
• As an example, if the total test includes 10 minutes of data, each graph that you callup will display the parameters you choose over 0-10:00 of the test.
• If you would like to see a graph displaying only those data points collected during the
3:00 to 5:00 time frame, you can set the graph to zoom into that specific period.
• This can be done within a particular graph by placing the pointer inside the graph on
the starting time that you want to zoom into (the 3:00 mark of the test) and leftclicking the mouse.
• Hold the left-click and move the pointer to the end time within the graph that you
want to zoom into (for example the 5:00 mark of the test).
• The Graph will now re-set and zoom-in to display only the data collected between
the 3:00 and 5:00 marks of the test.
• Restore the full-scale graph by selecting File > Properties or simply by right-clicking
on the graph to bring up the Properties window. Click on the ‘Graphs’ Tab. Click the
‘OK’ button to restore the full-scale graph.
File Open
• In the Menu Select: > File > Open and a window will open which will list all of the
data files (.dat) in the MOXUS Metabolic System folder.
• Open a file by double-clicking on the name of the specific data file that you want to
view.
• When the file is opened, the full screen display will include two graphs in the top half
of the screen and the tabular data record of the test in the bottom half of the screen.
Real-Time Graph
The Real-Time Graph feature is enabled by selecting the ‘Real-Time Graph Enable’
checkbox on the Real-Time Data window.
Each Real-Time Graph in the Real-Time Data window is enabled or disabled in the
Graph Selection window by clicking on the box to the left of each parameter. To change
the scaling, click on the desired parameter in the Graph Legend window, enter the
desired minimum and maximum scale values in the boxes to the right and click ‘Apply’.
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REPORTS
Print Reports
Exercise Summary Report
NOTE: Not available for Canopy System, see Appendix F.
• Click on REPORTS > EXERCISE to Print the Report.
• The Report includes the full tabular data chart for the test as well as a Summary
Page with Resting / Max Achieved values and comparisons to predicted Max values
for the subject.
Energy Expenditure Report
• Click on REPORTS > ENERGY to Print the Report.
Calibration Report
• Click on REPORTS > CALIBRATION to Print the Report.
Print Preview
To preview the reports before printing select FLIE>PREVIEW>[Report]
Setup Graphical Reports
Go to “FILE” and select ‘OPEN’. Select a file with data in it. Press ‘OPEN’, and go to
“REPORTS” and select ‘SET-UP’. Select the display of the page that you want to
change first.
IN THE EXAMPLE ABOVE, PAGE 1 IS SELECTED
Scroll through the page to display the image of the graph to be changed, and left click
on that graph. Select the tab “DEFINITION”. Select the desired “x”, “y1”, “y2” data to be
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displayed on that graph. If you wish the axis for the two “y” axis to be the same, select
‘USE PRIMARY AXIS’. Select each of the graphs that you wish to change, sequentially,
and select each page in turn.
SETTING CONFIGURATION OF GRAPH TO LEFT BY LEFT CLICKING GRAPH
NOTE: THE “X” AXIS IS ALWAYS THE HORIZONTAL AXIS, AND THE “PRIMARY Y
AXIS” AND “SECONDARY Y AXIS” ARE ALWAYS THE LEFT AND RIGHT AXIS,
RESPECTIVELY.
ADDING ADDITIONAL PAGES OR GRAPHS
Select ‘SET-UP’, and select a page. Select the ‘PAGE CONFIGURATION’ tab, then
select ‘INSERT BEFORE PAGE’ or ‘INSERT AFTER PAGE’, and select the desired
layout. Left click, with the curser, on the desired graph, or click on ‘GRAPH
DEFINITION’ tab. Select the desired data to be graphed.
Select ‘SAVE’. A “SAVE REPORT” dialog box will open. When you select ‘SAVE’, a
prompt will appears warning that “GRAPH.RPT” already exists. Click ‘YES’ to save the
changes. Otherwise, click ‘NO’ to discard changes.
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APPENDIX A
THEORY OF OPERATION & FORMULAS
System Modes
The method the AEI Metabolic System Software collects, displays, saves and reports
data is dependent upon the testing methodology and system configuration selected on
the Hardware Diagnostics window:
1. When utilizing a mouthpiece or mask with a human subject [MOXUS or MAX-II
System mode], and sampling gas from a mixing chamber, data is acquired on a breathby-breath [i.e. 1 data point per breath] basis.
2. When sampling from an animal chamber [MOXAR System mode] data is acquired on
a 1 data point per second basis.
3. When utilizing the system for general Data Acquisition [DATA ACQ System mode]
data is acquired on a 1 data point per second basis.
4. When utilizing the Canopy hood on a human subject [Canopy System Option] data is
acquired on a 1 data point per second basis.
5. When a test will be collecting data for over 6 hours Long Term Monitoring is required
[Long Term Monitoring option]. Averaging Intervals of 5 seconds or more should be
used. Data is acquired on a 1 data point per second basis multiplied by the Averaging
Interval. NOTE: Changes to display, table, or operational parameters during a test in
Long Term Monitoring mode may result in lost data. If parameters must be changed do
so in the first minute.
Design Philosophy
The AEI Metabolic Systems Software, or MAX-II Software, is the result of a demand for
the accurate measurement of oxygen uptake and other parameters during exercise
testing or at rest, while allowing maximum flexibility in the system configuration, graphic
display and reporting of data. The Software allows the user to change the manner in
which he or she views the data while the test is proceeding. In addition, the Software
provides the ability to set up multiple configurations to minimize setup time when
switching equipment for different testing methodologies.
The AEI Metabolic Systems Software is utilized in a variety of AEI Technologies
systems and product options. These include: The MOXUS, MAX-II, and MOXAR
Metabolic Systems; Canopy System and Cardiac Output options; and Long Term
Monitoring and DAQ modes. NOTE: all of these selections may not apply to the system
you purchased.
In order to achieve maximum accuracy, the Software uses a breath as the basic unit
upon which all data is calculated [MOXUS and MAX-II System modes only]. As the
program corrects all phase delays between the gas analyzers and the other “real time”
data, the data displayed for each breath is precisely corrected. Facilities are included to
change the delay factors to allow for changes in sampling rate, tubing length, and other
alterations to the apparatus. We utilize an active mixing chamber for the exhaled gas,
thereby smoothing out rapid breath-by-breath variations and producing more accurate
data for most applications.
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During exercise testing, spurious data may be sent to the computer. This may be
caused by a loose heart rate sensor, the mouthpiece or tubing falling off, the subject
swallowing and possible other small occurrences. This Software does not allow the
user to erase or edit any data, however, the erroneous data, which is collected during
one of these episodes, may be “Marked Invalid” (ignored). The data will be retained in
the user’s data file, but will be excluded from averaging in the final report and on the
graphs that are printed by the software. Such Marked Invalid data may, if desired, be
reselected as Valid again. Users may also select the time interval that is of interest to
them during any test and plot or print only that data, ignoring portions of the data [by
marking Invalid] falling outside of the selected time period. For instance, the exercise
recovery period may be ignored.
This Software allows the operator to enter certain data, manually, during a test, and
may be labeled by user via Manual Data Entry. This data may be printed against other
data. This feature allows data to be stored and compared to other data.
Analog to Digital Conversion
Analog to Digital conversion of all analog input signals occurs at 250 Hz with 16 bits of
resolution [3rd generation only]. Each channel has an averaging value that is preset for
the frequency content of the data on that channel. The resulting averaged value is
transmitted to the AEI Metabolic System Software computer, via the USB cable, as a
single data point: either on a breath-by-breath basis or a 1 data point per second basis.
Saved Data
All data points sent to the AEI Metabolic System Software are continuously saved every
30 seconds in a file with a .dat extension and a prefix containing the Subject Name,
Test Date and Test Time. For example: If you entered - John Smith – as the name on
the Subject Data window, and the subject data was entered on the 15th of November
2002 at 11:30 [24 hour clock basis], the file will be named John Smith1115021130.dat
and it will automatically be saved in the AEI Metabolic System Software subfolder
[typically, C;\Program Files\AEI Technologies\Moxus].
This Saved Data file contains “raw data” and it is saved before any calculations are
performed on it. However, the MixedO2 and MixedCO2 channels, breath-by-breath
sampling only, are delayed in time before saving. The Saved Data file is viewable by the
user only when opened using the AEI Metabolic System Software.
Breath-by-Breath Measurements
The MOXUS is breath-by-breath metabolic system sampling from the mixing chamber.
The user can adjust the phasing delays as appropriate.
The Time displayed on the tabular display is the time for a particular breath and it may
not exactly correspond with ‘real time’ as displayed in the Time box at the top. This is
because there are sometimes delays in communication between the computer and the
Interface Box.
Breath-by-Breath Phasing Delays
Breath-by-breath exhaled gas concentrations are measured and saved after
incorporating an appropriate phasing delay. This delay is necessary because of two
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factors: 1) the time necessary for the expired air to transverse the volume of the nonrebreathing valve, tubing and mixing chamber [Mixed Volume Delay]; and 2) the gas
analyzer tubing and response delays [O2 Analyzer Delay and CO2 Analyzer Delay].
Following the end of each breath the system waits until the subject has exhaled a
volume at least equal to the value set for the Mixed Volume Delay. It then waits a
specified number of seconds for each of the analyzer time delays. It then phases the
MixedO2 and MixedCO2 data with the breath that produced that data.
It is therefore important to understand how the data is displayed in the graphs, table,
and reports during a test.
For typical exercise applications where averaged data, and not breath-by-breath data, is
desired these delays need not be exact. The software default values for these delays
are typical system approximations and are acceptable for most applications. For breathby-breath applications, low tidal volume tests [e.g. resting or child applications],nonstandard system configurations, or critical metabolic measurements it is best to
determine the correct time delays.
The volume of the non-rebreathing valve, tubing and mixing chamber that is entered for
the Mixed Volume Delay can be computed in 1 of 3 ways:
1. measure the actual volume of the components with water and a graduated
cylinder.
2. calculate the total volume used from known inside dimensions.
3. a combination of 1 and 2 above.
The delay times for the O2 Analyzer Delay and CO2 Analyzer Delay can be computed
in 1 of 2 ways. NOTE: these time delays will change proportionally to the sample flow
rate:
1. by measuring the actual analyzer response times for a gas to travel from the
mixing chamber outlet to each analyzer. Disconnect the sample tubing from the
mixing chamber and allow to stabilize. Then quickly apply the calibration gas
[remembering to relieve the pressure] and measure each analyzer’s response
time to reach 90% of reading. The time can be measured with a stopwatch or
using the Real Time Graphs.
2. For each analyzer: calculate the total volume of the sample tubing from the mixing
chamber outlet to each analyzer using from tubing inside diameter and tubing
length. Then multiply by the sample flow rate to determine the time. Next, add the
analyzer’s response time.
Ambient Temperature, Pressure and Humidity
Ambient [inspiratory air] Temperature, Pressure and Humidity must be entered on the
Subject Data window before each test so that an accurate calculation of ventilation can
be made. These parameters are used to convert the ATP flow data to BTPS and/or
STPD units. Accuracy for these measurements should be: Temperature +/- 1 deg. C;
Pressure +/- 2 mmHg; Humidity +/- 5% rh.
BTPS and STPD
All metabolic data [VO2, VCO2, etc.] is always presented and saved in STPD without
regard to the selection box in the Properties/Setup window. The display of Ve and Vt
may be displayed in either the default BTPS or, if selected, STPD.
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The Testing Environment
It is strongly recommended that all metabolic data be performed in a room where there
is good circulation of outside [fresh] air. Most indoor HVAC [heating, ventilation, airconditioning] systems are adequate for this purpose. In cases where there is no HVAC
system of the HVAC system is poor it is best to move the testing to a room with better
circulation. If this is not practical then a combination of fans and open windows may be
necessary.
The ambient temperature and humidity should be reasonable so as not to cause the
subject any unnecessary discomfort. The number of persons in the room should be
minimized to prevent buildup of CO2 during the test and to minimize disturbing the
subject.
Flow Measurement
The flow signal from a Pneumotach, if used, is sampled and converted to a linearized
flow signal using a calibration look up table. This adjustment corrects non-linearity in the
Pneumotach, transducer, and electronics. The respiratory phase is determined through
the use of a comparator circuit, triggered by flow, which generates a true signal during
inspiration and a false signal during exhalation or pause. The integrator is zeroed during
the expiratory phase and then accumulates all linearized flow rates during the
inspiratory phase. This accumulation ends with the onset of exhalation. A gain factor is
then used to convert the accumulated value to an actual volume in liters (inspiratory,
ATPS).
Warm Up
For best results it is strongly recommended that both S-3A and CD-3A gas analyzers be
powered on for at least 16 hours before calibration and testing. Also, it is strongly
recommended that the R-1 Pump be powered on for at least 10 minutes before
calibration and testing. An Uninterruptible Power Supply may be utilized for maintaining
a power-on condition if the Moxus must be unplugged to move it to a different location.
If necessary, reasonable results [that may not meet specifications] for calibration and
testing may be achieved with warm up times shortened to 4 hours for both gas
analyzers and 1 minute for the R-1 Pump. Both S-3A and CD-3A gas analyzers should
always remain powered on to avoid the warm up period; this will not adversely affect the
useful life of the analyzers.
Sample Flow
The new Interface Box [square plastic box] electronics has internal valves and pressure
restrictors to allow for easier calibration. However, this requires that the R-1 Pump flow
be set with the bottom ball at 2 [about 175 cc/min] and a regulator pressure of 15 psi
and a 1/16”ID sample tubing length of 20” – 24” on the Mixed Inspired port. [NOTE: For
Interface Box delivered before January 2014 also connect a 20” – 24” tube to the Air In
port]. If a different sample flow rate or tubing length is desired; or if the calibration gas
can no longer be connected directly to the Interface Box - please contact AEI
Technologies for assistance.
The gas analyzers, particularly the S-3A, are sensitive to the sample flow rate. For this
reason the sample flow rate must not be changed after hardware calibration of the
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analyzers. The R-1 Pump will maintain a stable sample flow rate during calibration and
testing.
Channel Calibration
The AEI Metabolic System Software performs a linear calibration for each channel and
saves 2 resulting calibration values: Offset and Factor. During a Test each channel data
is multiplied by the Factor and then added to the Offset. Offset and Factor values for
each channel may be observed on the Calibration Report.
Calibration Gas
There are a variety of grades of bottled calibration gases available on the market today.
We strongly recommend that only Primary Laboratory Standard gases, certified
gravimetrically, be used to calibrate the AEI Metabolic Systems. This grade of gas is
normally delivered either with a very specific label or an attached certificate stating its
contents out to two decimal places. Specified accuracy should be +/- 0.02% absolute or
better for concentrations over 2%, +/- 10% of component for lower concentrations.
Naturally, utilization of the most precise calibration gases assures you of the most
accurate calibration possible for your AEI Metabolic Systems gas analyzers.
It is strongly recommended that 2 calibration gas cylinders be used for gas analyzer
calibration: typically 21.00%O2 and 0.03% CO2 for one cylinder; and typically
16.00%O2 and 4.00% CO2 for the other. This assures accurate measurement of
expiratory gas and for accurately measuring inspiratory [ambient] gas concentration
values. If standard outside
The AEI Technologies Calibration Gas Module is designed to meet these stringent
requirements.
Room air is a suitable and convenient choice of calibration gas for some non-critical
applications. It must be dried, free of contaminants, and well ventilated with fresh
outside air.
Heart Rate Detection
The heart rate detector is a part of the MOXUS and MAX-II Metabolic Systems. It can
accept signals in 2 different forms: the output pulses of a Polar transmitter and receiver;
or an amplified analog ECG signal (1 volt per millivolt). The range of the Polar
transmitter/ receiver is approximately 2 feet or less, and the best reliability is achieved
when the labels on the transmitter and the receiver are positioned in parallel planes.
When receiving the analog ECG, the software detects the "R" wave, measures the "R R interval", and computes an average heart rate.
RER [Respiratory Exchange Ratio] Variations
There are many reasons for observing variations in the measured RER values as
compared to the ‘norms’. Some of these reasons include:
-RER [the ratio at the mouth] is similar to but different from RQ [the ratio at the
muscles]. RER should typically be compared at ‘steady state’ levels of exercise as
opposed to changing levels of exercise.
-The subject quite often may hyperventilate at the beginning of the test because of
unfamiliarity or hurrying; thus raising the RER to 1.0 or higher.
35
-The RER can vary greatly at rest depending upon the substrate utilized, fat or carbs
[Wasserman p. 49].
-The RER can vary greatly during the first minute of an exercise test due to retained
CO2 [Wasserman p. 43].
Real-Time - These values are measured on a breath-by-breath OR on a 1 sample per
second basis during the acquisition of data depending upon the System Mode. They
are measured either at the end of the breath or at a later time as determined by a delay
factor (see below) during. These measurements form the basic data from which all
reported results are generated and are never seen by the user. They are always
measured under ambient conditions. This Real Time data is always stored.
Breath-by-breath - These values are directly calculated from the real-time results of
each breath. As such they may be reported for breath-by-breath results or averaged
directly. These represent the conversion of the real time results into user interpretable
values. They are appropriately transformed for gas conditions based on the current
settings of temperature and pressure and humidity. These values are never stored;
rather they are recalculated each time they are needed.
Calculated Values - These values are dependent on the breath-by-breath data. They
can be calculated either from the breath data or from averaged breath data. These
values are not averaged themselves. They are appropriately transformed for gas
conditions.
Formulas
Breath-by-breath
Calibration method
Real value = (A to D * Factor) + Offset
Time of breath
Time = time at end of inspiration
Ttot
Total time of breath
Ti
Inspiratory time
MixO
2
Averaged A to D value of O2 channel with calibration
MixCO
Averaged A to D value of CO2 channel with calibration
2
Vt - Summation of instantaneous flows with calibration.
36
Haldane Transform and STPD/BTPS correction is applied as required.
End Tidal CO
Previous Peak value at the time of the breath converted with
calibration (Phased for analyzer and sampling delay).
2
Other analog inputs
Averaged A to D value converted with calibration
Heart rate
Averaged Value based on pulse input or precise R-R timing
Calculated information from breath by breath or averaged values that may not
be directly averaged. Note - in the below formulas “avg” may be either a single breath
or the arithmetic average of breaths in a given time period.
Frequency
F = 60 / Ttot
avg
avg
Minute ventilation
Ve = Vt * F
avg
avg
avg
Ti/Ttot ratio
Ti/Ttot = Ti = Ttot
avg
avg
avg
Vt/Ti ratio
Vt/Ti = Vt / Ti
avg
avg
Ve/BSA ratio
Ve/BSA = Ve / BSA
avg
Oxygen consumption, Exercise
VO = (Vi * FiO ) - (Ve * MixO );
Vi = Ve * (1-FeO -FeCO )/(1-FiO -FiCO )
2
avg
avg
2
avg
avg
2
2 avg
2
2
2
CO production, Exercise
VCO = (Ve * MixCO ) - (Vi * FiCO );
Vi = Ve * (1-FeO -FeCO )/(1-FiO -FiCO )
2
2
avg
avg
2 avg
avg
2
avg
2
Respiratory exchange ratio
RER = VCO / VO
2 avg
VO2/Ve ratio
VO /Ve = VO
2
2 avg
2 avg
/ Ve
VCO2/Ve ratio
VCO /Ve = VCO
2
2 avg
avg
/ Ve
2
2
avg
37
2
VO /Kg ratio
VO /Kg = VO
2
2
2 avg
O pulse
O Pulse = VO
/ Wt(kg)
2
2
2 avg
/Heart Rate
avg
Body Surface Area
Body Surface Area (BSA) = .202 x (Wt./2.2)
VO /BSA
VO /BSA = VO
.425
x (Ht./39.37)
.725
2
2
2 avg
/ BSA
VCO /BSA
VCO /BSA = VCO
2
2
2 avg
/ BSA
THE FOLLOWING VALUES REQUIRE AN END TIDAL CO2 DATA Dead Space
VD = (EtCO
- CO Mix * P ) / EtCO *Vt -DS
Where DS is the valve and mouthpiece dead space
2 avg
2
avg
barom
2 avg
avg
system
system
VD/VT ratio
VD/VT = VD / VT
avg
avg
Alveolar volume
VA = Ve - [f *(VD +DS )]
Where DS is the valve and mouthpiece dead space
avg
avg
avg
system
system
The following calculations are used for the raw data only and are not used for
calculations in the Energy Expenditure Report.
Daily urea nitrogen (UN) = Urea Nitrogen / 24
(Note: Corrects patient entry to grams per hour)
Protein = (6.25 x 4.2 x UN)
Resting Energy Expend. (REE) = (3.94 x VO ) + (1.11 x VCO ) >From Weir Equation
2
2
Adjusted Metabolic Expenditure (AME) = (REE - 2.17) x UN
Non protein respiratory quotient (NPRQ) =
(VCO - (4.8 x UN))/(VO - (5.9 x UN))
2
2
Carbohydrate+Fat metabolism (CHOFAT)=AME - Protein
% Carbohydrates =
(CHOFAT/AME) x ((97.4 x NPRQ) - 68.9)/ ((59.4 x NPRQ) - 30.8) x 100
38
% Fats =
(CHOFAT/AME) x ((38.0 x (1.0 - NPRQ))/(59.4 x NPRQ) - 30.8) x 100
The following calculations are used to derive steady state data in the Energy
Expenditure Report:
Volume of CO produced by protein catabolism (VCO ) =
Urea Nitrogen x 4.9
2
2un
Volume of O produced by protein catabolism (VO ) =
Urea Nitrogen x 5.9
2
2un
Nonprotein respiratory quotient (RQ) =
(VCO - VCO ) / (VO - VO )
2
2un
2
2un
Kilocalories of energy produced by protein (KCALPRO) =
UN x (5.9 x 4.463)
Where: 5.9 = grams protein / gram nitrogen
4.463 = Kcal / gram protein
Kilocalories of energy produced by fats and carbohydrates
(KCALFAT+CHO) = ( 4.686 + RQ - .707 x .361) x ((VO - VO )
.293
2
2un
Total Kilocalorie expenditure (KCAL) =
KCALPRO + KCALFAT+CHO
Total Kilocalorie expenditure normalized to body weight
(KCAL / Kg) = KCAL / Body Weight
Percentage of total kilocalories from protein (% PRO) =
KCALPRO / KCAL x 100
Ratio of Kilocalories of FAT+CHO to Total Kilocalories
(KCAL ratio) = KCALFAT+CHO / KCAL
Percentage of total Kilocalories from carbohydrates (% CHO) =
504.7 x (RQ - .707)
x KCAL ratio
5.047 x (RQ - .707) + 4.686 x (1 - RQ)
Percentage of total Kilocalories from fat (% FAT) =
468.6 x (1 - RQ)
5.047 x (RQ - .707) + 4.686 x (1 - RQ)
x KCAL ratio
Percentage participation of protein in total O consumption
(% PROO2) = VO / VO
2
2un
2
39
Ratio of O participation in FAT+CHO to total VO (O ratio) =
(VO - VO ) / VO
2
2
2
2un
2
2
Percentage of participation of CHO in total O consumption
(% CHOO2) = (100 x RQ - .707 ) x O2 ratio
.293
2
Percentage of participation of FAT in total O consumption
(% FATO2) = (100 x 1 - RQ ) x O2 ratio
.293
2
Protein metabolism (in grams) (PRO) =
VO x % PROO / .94
where .94 = liters of O per gram of PRO
2
2
2
Carbohydrate metabolism (in grams) (CHO) =
VO x % CHOO / .81
where .81 = liters of O per gram of CHO
2
2
2
Fat metabolism (in grams) (FAT) =
VO2 x % FATO / 1.96
where 1.96 = liters of O per gram of FAT
2
2
Predicted energy expenditure (Harris-Benedict)
For men:
HBEE = 66.487 + (13.7516 x Weight) + (5.0033 x Height) - (6.7550 x Age)
For women:
HBEE = 655.0955 + (9.5634 x Weight) + (1.8496 x Height - (4.6756 x Age)
The following predicted variables are derived based on information provided in
the Subject Data window:
Upper limit of normal weight for males (Treadmill and Cycle)
= (.79 x height (in.) * 2.54)-60.7
Upper limit of normal weight for females (Cycle)
= (.65 x height (in.) * 2.54)-42.8
Upper limit of normal weight for females (Treadmill)
= (.79 x height (in.) * 2.54)-68.2)
For the following predicted equations for VO , substitute the predicted weight
value if the actual weight exceeds the predicted weight unless a specific equation
for overweight subjects is listed.
2
Predicted VO (males - normal weight - Cycle)
2
40
= Weight (kg) x (50.72 - 0.372 x Age)
Predicted VO (males - normal weight - Treadmill)
= Weight (kg) x (56.36 - 0.413 x Age)
2
Predicted VO (females - normal weight - Cycle)
= (Weight (kg) x 42.8) x (22.78 - 0.17 x Age)
2
Predicted VO (females - overweight - Cycle)
= Height (cm) x (14.81 - 0.11 x Age)
2
Predicted VO (females - normal weight - Treadmill)
= Weight (kg) x (44.37 - 0.413 x Age)
2
Predicted Heart Rate = 210 - 0.65 * Age
Predicted Ve = MVV
Predicted Vt = IC x 1000
41
APPENDIX B
COMPUTER REQUIREMENTS
•
The AEI Metabolic System Software must be used with a Microsoft Windows
XP Professional [preferred] or Microsoft Windows 7 32-Bit ONLY Professional
operating system computer. A “USB” interface port is required to connect to
the Interface Box or control unit. A CD/RW drive or USB Flash Drive is
recommended for data storage and transfer.
•
The VGA graphics and monitor must be capable of displaying and should be
set in “1024 x 768” format.
•
The program supports all printers that are “Microsoft Windows” compatible. A
default printer driver must be installed to Print or Preview reports.
•
The AEI Metabolic System Software is designed to operate on a ‘clean’ standalone computer. The computer should not be connected to a network or to the
Internet. Also, there should be no other programs operating on the computer
at the same time as the AEI Metabolic System Software.
•
A laptop or small chassis desktop that fits under the monitor is recommended.
•
Microsoft Windows should be operating in ‘English (United States)’ as
standard formatting.
•
User must have full administrator rights in Microsoft Windows.
42
APPENDIX C
CONSUMABLES / SPARE PARTS
Part Number
Description
15-2002
15-2003
Breathing Valves
Breathing Valve, Large, with Trap, Arm Mtg
Breathing Valve, Large, with Trap, Arm Mtg, Insp Port Adaptor
15-1150
15-1160
Moxus Calibration Gas
Calibration Gas, E Size, Disposable, 0.03% CO2, 21.00% O2, Bal. N2, Moxus
Calibration Gas, E Size, Disposable, 4.00% CO2, 16.00% O2, Bal. N2, Moxus
15-1131
15-1132
Calibration Gas, E Size, Disposable, 6.00% CO2, 40.00% O2, Bal. N2,
Calibration Gas, E Size, Disposable,15.00% CO2, 40.00% O2, Bal. N2,
15-2300
Calibration Syringe, 3-Liter (1.375 ID O-Ring)
15-1045
Mask Kit
(2) Small and (1) Medium Masks (series 7450), Mask Calipers, Head Cap,
Adaptor for breathing valve. Used in place of Mouth Piece.
669197
669196
669195
201492
201493
201494
691143
200525
612738
Masks Parts
669197 Small Mask 114 (7450)
669196 Medium Mask 113 (7450)
669195 Large Mask 116 (7450)
201492 Headgear Small HG-SM
201493 Headgear Medium HG-SM
201494 Headgear Large HG-LRG
691143 Caliper
200525 Head cap
612738 Adapter (Madp 7450)
37082JE
37083JE
37084JE
42276JE
42176JE
42173JE
Mouth Piece Parts
Mouth piece, Medium Bite, Silicone Rubber
Mouth piece, Large Bite, Silicone Rubber
Mouth piece, Small Bite, Silicone Rubber
Nose clips, Reusable
Headgear, Holder for Rudolph Valve
Headgear Cover
15-1020
15-1023
12-1031
Dryer Kit
Efficient Nafion-based desiccant box
with 1 Liter bottle molecular sieve & silica gel indicator
Nafion Drying Tube
Desiccant, Indicator, 1 Liter
15-1780
Breathing Tubing, Corrugated, 35 mm, 9 ft.
43
15-1781
15-4020
HR- WATCH
HR- REC
15-1700
Sample Tubing and Fitting Kit
10 ft of 1/16 inch, and 20 ft of 1/8 inch,
10 male 1/16 in Leur Fittings
10 female 1/16 inch Leur Fittings
10 1/8 inch male Leur Fittings
Polar Heart Rate Monitor
Heart Monitor System (Monitor Reciever & Cable)
Heart Monitor (HR - WATCH)
Heart Monitor Reciever (HR - REC)
Heart Monitor Cable (15 - 1700)
44
APPENDIX D
TROUBLESHOOTING
DO I KNOW THAT IT IS WORKING?
The first step is to pull down the "Tools" menu, and select "Hardware DX",
which displays the Hardware Diagnostics window.
MAKE CERTAIN THE CORRECT SYSTEM, FLOW DEVICE, AND
OPTIONS ARE SELECTED. This window also allows measuring the
voltages of all of the signals coming into the computer, in volts, in digital
counts, or in actual calibration values. A good place to start is comparing
the data presented on this window in volts with the expected analog
voltage output of a device.
If this is not the case, the calibration gas being used may not contain the exact value of
gas listed on the label. As an example, if a gas is labeled simply as 16% Oxygen but the
S-3A/I CONSISTENTLY reads 16.15% (after being set to read ambient air correctly),
this may be the accurate measurement of the gas.
We would recommend toggling between ambient and the questionable calibration gas to
determine the true value of the cylinder. Once again, if the analyzer reads the same
value for the gas consistently (16.15%), we would advise you to contact your gas
supplier.
45
APPENDIX E
CARDIAC OUTPUT MODULE [Optional]
CARBON DIOXIDE REBREATHING METHOD
SETTING UP OF THE SYSTEM
Select Menu: Tools > Hardware Dx
Check the Cardiac Output checkbox.
Choose Properties/Setup/Cardiac Output.
Set the Low CO2-Low O2 and High CO2-High O2 values of the gas cylinders. The
Low O2 (regardless of its label) should be the O2 level in the Low CO2 cylinder.
The High O2 should be the O2 level in the High CO2 cylinder.
Set the target ETCO2 level as the torr level above the end-tidal CO2 during rebreathing. For instance, if the end-tidal CO2 is 40 and a rebreathing CO2 of 46 is
desired, set the target rebreathing CO2 level at 6 torr above the end-tidal CO2.
Set the Volume Fill for the rebreathing bag as a multiple of the tidal volume. For
instance, if the tidal volume is 1.0 liters and you wish to have the bag filled to 1.5
liters, enter a setting of 1.5. This setting will yield a bag volume of 3 liters if the
patient’s tidal volume is 2 liters. A setting of 1.5 is initially recommended. Initial
studies have shown it to be the minimal volume achievable without complete
collapsing of the bag as rebreathing of CO2 progressively triggers an increase in
tidal volume throughout the cardiac output test.
Max Bag Fill Volume is set by default to 5000 ml. This setting is used primarily for
safety to prevent overfilling the rebreathing bag. For a standard 5 liter rebreathing
bag, we recommend leaving it set at the default value.
# Breaths ignored after CO is set to 10 by default. The purpose of this entry is to
allow the subject’s ventilation to reestablish to normal levels following carbon dioxide
rebreathing with resulting tachypnea. This, in conjunction with normal analyzer
delays and dead space volume settings, accounts for the delay seen in the
resumption of data plots following cardiac output studies.
Press Save and OK to exit the window.
Electrical connections
Connect the 9 pin DB ribbon cable between the Cardiac Output module and Cardiac
Output connection on the Interface Box [or MAX-II].
Connect the Cardiac Output module to power.
Connect BNC ‘T’ connector common to the etCO2 connector on the Interface Box.
Disconnect the BNC cable from the CO2 input on the Interface box [cable from the CD3A analyzer] and connect to one end of the BNC ‘T’ connector. Connect the supplied
BNC cable from the other end of the BNC ‘T’ connector to the CO2 input on the
Interface box.
46
Tubing connections and valve assembly
Connect the 15%CO2/40%O2 and 6%CO2/40%O2 cylinders the cardiac output module
Hi and Low Fill Tank fittings with 1/8 inch ID tubing, respectively. The outlet pressure on
both regulators should be set to approximately 20 psig and resulting in the flow to the
bag of about 100 ml./sec.
Connect the compressed air cylinder to the system with the white plastic quick connect
hose to the Pressure Tank connector. The outlet pressure on this regulator should be
set to 55 psig.
Remove the mouth port from the standard Hans Rudolph 2700 valve and attach the
Hans Rudolph cardiac output valve in it’s place as shown below:
Breathing Valve
Breathing Valve is shown in blue. Cardiac output valve is shown in orange.
The cardiac output valve and bag assembly is supplied with tubing connected at one
end. Connect the other end to the rear of the Cardiac Output module as follows:
Connect small 1/16 inch ID tubing to the Mouth Port fitting .
Connect large 1/4 inch ID tubing to the Empty Bag fitting.
Connect 1/8 inch ID tubing with Black tape to the Top Balloon fitting.
Connect 1/8 inch ID tubing with Blue tape to the Bottom Balloon fitting .
Connect 1 of the 2 remaining 1/8 inch ID tubing to the Fill Bag fitting.
Connect the remaining 1/8 inch ID tubing to the Sensing fitting.
Disconnect the Nafion tube from the Interface Box and connect to the Dryer port on the
Cardiac Output Module using 1/16 inch ID tubing. Keep the tube as short as possible.
47
Connect from the Dryer top barb on the Interface Box to the Cal Valve port on the
Cardiac Output Module using 1/16 inch ID tubing. Keep the tube as short as possible.
Testing Equipment Operation
We recommend checking all equipment operation prior to the beginning of the test. The
Properties window under Tools displays a Cardiac Output tab that allows alteration
of settings before and during the test. It also displays a Control tab that allows one to
manually operate the equipment, before a test, as shown below:
When “Normal” is selected, the lower balloon (the balloon nearest the rebreathing bag)
inflates and the upper balloon deflates. The lower balloon should be examined to make
sure that it remains fully inflated and does not slowly deflate.
When “Rebreathe” is selected, the lower balloon deflates and the upper balloon inflates.
The upper balloon should be examined to make sure that it remains fully inflated and
does not slowly deflate. If either balloon appears to be “sucked-in”, simply remove and
replace the tubing to that balloon, and switch to the other mode (either “normal” or
“rebreathe”), to allow air to be sucked into the balloon pump with the disconnected
tubing..
When “Fill Bag” is selected, the lower balloon inflates and the rebreathing bag fills, using
a 50/50 mixture, to the minimum volume, as indicated by both Hi Fill and Lo Fill lights on
the Cardiac Output module illuminating. If the bag does not fill, check all tubing
connections, the lower balloon inflation and the pressure setting on the regulators and
the cylinder contents.
48
When “Empty Bag” is selected, the Cardiac Output bag evacuation pump activates, and
remains “on” until the bag is deflated completely. The pump turns off once the bag is
fully deflated. If the pump does not turn off, check the tubing between the vacuum /
pressure switch, check the bag for leaks and check the inflation of the lower balloon.
All other routine configuration settings are made in the Properties window:
Setup tab
The O2 and CO2 delays will need to be increased to account for the increased tubing
length for the etCO2. Typically, the delays will increase by 2 seconds.
Cardiac Output tab
The filling of the rebreathing bag with respect to volume and CO2 concentration is
automated and changes to meet the patient’s condition. Twenty tidal volumes prior to a
CO2 rebreathing trial are observed and averaged. This tidal volume average determines
the volume to which the bag will be filled and is influenced by the settings in the “C/O
Bag fill volume”. As shown above, the bag will be filled to 3 liters (2 x the average tidal
volume) if the subject’s tidal volume is 1.5 liters. Regardless, the bag volume will never
be less than 1500 ml nor larger than 5000 ml regardless of the tidal volume as a safety
measure. As the filling of the bag is based on time, the software needs to know the
filling flow rate of the gas mixture. Typically, this will be about 100 ml/sec if the gas
regulators on the cylinders are set to 20 PSIG.
The target bag CO2 concentration is achieved by proportionally mixing gases from both
cylinders. The software requires the entry of gas concentrations from both cylinders in
49
order to determine how much of each gas is needed to achieve the proper CO2 target
value.
It is important that cylinder content values be precisely entered. Therefore, whenever a
cylinder is changed, the technologist must examine the cylinder label to ascertain it’s
true gas mixture. The target bag CO2 value is determined similarly to the target tidal
volume. The software averages 10 CO2 measurements prior to the cardiac output trial.
This average is then compared to the value entered under “etCO2 Fill (over average
Torr). Therefore, if an average end-tidal CO2 is measured at 40 torr, the software will fill
the bag to a concentration of 70 torr (40 torr end-tidal CO2 + setting of 30 torr).
Normal oxygen uptake and carbon dioxide production measurements are interrupted
while a CO2 rebreathing trial is underway. Upon completion of a cardiac output trial, the
extra CO2 that has accumulated in the blood during the rebreathing trial must be
washed out of the lungs prior to resumption of VCO2 measurements. Otherwise,
spuriously high VCO2 and RER data will result. It is for this reason that there is a setting
in the C/O setup window for “# breaths to ignore after CO”.
Once all configuration settings are made, click on OK.
All settings can be changed during an exercise test to allow modifications for bag filling
volumes and target CO2.
EtCO2 CALIBRATION
Enter the Cal High and Cal Low values for the etCO2 channel on the System
Calibration window. These values should be identical to the values for the CO2
channel. Then select both the CO2 and etCO2 channels for calibration. Perform
both Hi and Lo software calibration. Save the result.
Equilibration point
PetCO2
Time
EQUATIONS
The following equations are used in the program to calculate cardiac output
CaCO2 ml = antilog [(loge PaCO2 x 0.396) + 2.38]
Note: If entered into the program, arterial CO2 substitutes for PetCO2.
CvCO2 ml = antilog [(loge PvCO2 x 0.396) + 2.38]
50
Note: Ven PCO2 is measured by moving the line to the equilibration point on the
graph.
Cardiac Output (Q) ml/min = VCO2 / ((CvCO2 - CaCO2) x 1000)
NOTE: To filter the effect of aberrant breaths on the data, the program averages 20
PetCO2 values and 10 VCO2 values prior to each measurement.
51
Cardiac output has traditionally been measured by the Fick technique which relates the
oxygen uptake to the arterial to mixed venous O2 content in the following equation
Qt = VO2 / CaO2 – CvO2
Where: Qt = Cardiac Output VO2 = Oxygen Uptake CaO2 = Arterial blood oxygen
content CvO2 = Mixed venous blood oxygen content
As the collection of arterial and mixed venous blood samples requires the invasive
placement of catheters, this technique has not enjoyed widespread use in exercise
physiology measurements.
An indirect Fick method has been developed which substitutes the use of CO2
measurements in the equation as follows:
Qt = VCO2 / CaCO2 – CvCO2
Where: VCO2 = Carbon dioxide production CaCO2 = Arterial blood carbon dioxide
content CvCO2 = Mixed venous blood carbon dioxide content
Arterial blood CO2 content is non-invasively estimated by measuring the expired CO2 at
the mouth with a rapid CO2 analyzer and examining the observed waveform for it’s
peak. This measurement is commonly referred to as “end-tidal CO2 or PetCO2” and is
measured in mmHg [torr]. This measurement closely approximates PaCO2 (the partial
pressure of CO2 in arterial blood) in subjects with normal lungs. CaCO2 is then
calculated with the following formula:
CaCO2 (ml) = antilog [(loge PaCO2 x 0.296) + 2.38]
For subjects with underlying pulmonary disease, the software allows entry of arterial
blood PCO2 in place of end-tidal PCO2 measurements in order to more accurately
estimate cardiac output.
Measurement of VCO2, of course, is non-invasive and is routinely measured during
exercise testing. The measurement of mixed-venous CO2 content can also be
approximated non-invasively. It is known that, if a normal subject rebreathes from a bag
filled with CO2 roughly approximating that of the mixed CO2 in the blood, a rapid
equilibration occurs between the lungs, the alveolar capillary blood and the rebreathing
bag.
To be accurate, the equilibration needs to be completed with 10 seconds; otherwise,
recirculation of the blood from the lungs through the system and back to the lungs is
likely to occur. Thereafter, the result will then be a constant increase of CO2 in the
rebreathing bag, nullifying the measurement. This is easily corrected in subsequent
measurements by either adjusting the rebreathing bag target CO2 either up or down.
The example windows below show acceptable and suboptimal CO2 rebreathing curves.
52
Acceptable CO2 curve showing equilibration at the placement of the blue line
CO2 concentration does not equilibrate and continues to rise. CO2 concentration in the
bag is too low and needs to be increased on the next measurement.
53
CO2 concentration does not equilibrate and continues to oscillate after 10 seconds.
CO2 concentration in the bag is too high and needs to be decreased on the next
measurement.
SOURCES OF ERROR AND LIMITATIONS WITH THE FICK REBREATHING
TECHNIQUE
The Fick method of measures cardiac output by an indirect method. As with any indirect
measurement, the accuracy of the measurement is subject to certain conditions.
The "Fick" method of measuring cardiac output is based on the assumption that the
cardiac output of an individual is the result of dividing the CO2 production of that
individual by the difference between the arterial CO2 (coming out of the lungs) and the
mixed venous CO2 (going into the lungs). To do this measurement accurately, we must,
first, measure the mixed expired CO2 and the end-tidal CO2, immediately before
rebreathing. This is a valid assumption if the subject is at a constant level of activity
during these measurements.
Another assumption is that, if a subject rebreathes his or her exhaled gas, under certain
circumstances, that an equilibration point will be reached which is equal to the CO2
concentration of mixed venous blood. This may be valid when the test subject has
healthy lungs, and when the tidal volume of the subject is large enough to flush out his
or her dead space (bronchi, pharynx, etc.). In subjects with impaired breathing, and
significant intrapulmonary mixing, or in subjects with very low tidal volumes (less than 2x
dead-space), the "Fick" method determines the mixed venous value inaccurately.
Another basic assumption, is that the end-tidal CO2 partial pressure, represents a
similar value to the alveolar CO2 partial pressure. This also is only true for subjects with
healthy, homogeneous, lungs, and it is not true for those with lung disease, or those
who breathe with very low tidal volumes (insufficient to wash out their dead space).
54
Another assumption, that must be made, is that the additional CO2 that is generated in
the rebreathing process will not return to the lungs before equilibration is reached. It is
generally assumed that if equilibration occurs within 10 seconds of the onset of
rebreathing, that this will not be a factor. In order to ensure rapid equilibration the CO2
content and the volume added to the rebreathing bag is critical to hasten equilibration.
The analysis of the gas in the rebreathing bag is, also, not without its problems.
Background levels of oxygen, within the bag, affect the measurement of CO2 by nondispersive infrared analyzers. To be assured that the test subject does not become
hypoxic, while rebreathing, the bag must be filled with a higher concentration of oxygen
than room air (typically 40%), which is reduced as the subject consumes oxygen during
rebreathing. The changing level of oxygen during rebreathing has an effect on the
measurement of the CO2 concentration; however, it has minimal error [<2%].
Higher levels of CO2 are a stimulant to respiration. Because of this, the "Fick"
rebreathing procedure is very uncomfortable at higher levels of exercise. This test is
much more tolerable at lower levels of exercise, or at rest.
RUNNING A CARDIAC OUTPUT TEST
Prior to running a test flow volume and all analyzers must be calibrated. See the
Calibration section for further instructions.
Once the test has begun and after a 10 breath waiting period the Cardiac Output button
appears. Pressing this button will enable the Cardiac Output process.
A Cardiac Output status box will appear. The rebreathing bag will initially empty at the
start of the program to begin preparing it for the next cardiac output trial.
The next status box shows Measuring CO2. During this time, the system is measuring
the averaged VCO2 used in cardiac output calculations. The system is performing the
standard metabolic measurements until the Fill Bag button is pressed. The window
shows the CO2 overfill – The amount of CO2 in torr to add to the measured end-tidal
CO2 to determine the target value (see above). This can be changed before each CO
measurement.
NOTE: as workloads are changed the subject should be allowed to stabilize at the
workload prior to starting a cardiac output measurement. It is advised to note the CO2
and Volume reading just before the initiation of cardiac output. Following the CO
measurement, the subject should be allowed to reestablish these measurements prior
to calling additional measurements in order to assure that all rebreathed CO2 has been
cleared from the subject and normal VCO2 is achieved.
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Cardiac output testing is begun by clicking on “Fill Bag” button. The rebreathing bag is
filled (Fills bag to the target CO2 concentration and volume. Note that the minimum and
maximum volume are always as set in the CO Setup window under Properties.
Therefore, if the minimum volume was set at 1500 ml, then the bag will be filled to 1500,
even if the Vt multiplier results in a volume less than this minimum volume. The same
rule applies to maximum volume.)
The system will now wait for 20 processed breaths to occur to determine the averaged
tidal volume and VCO2.
NOTE: It is important to remember that the subject is rebreathing CO2 and will
experience dizziness, shortness of breath and tachycardia if the test is prolonged
more than necessary. The test should be terminated as soon as equilibration is
achieved (shown by the arrow), ideally within a 10 second window and, more
importantly, before recirculation begins.
NOTE: For safety reasons, the test will automatically end and the subject will be
switched back to normal metabolic measurement if the test is prolonged up to 30
seconds.
This is immediately followed by the re-breathing process. The picture shows the cardiac
output rebreathing display. Allow the patient to rebreathe from the bag until an
equilibration is achieved. Click DONE when the subject has reached equilibration or you
have determined that equilibration will not be achieved at this time. The Cardiac Output
test will terminate and the normal testing sequence will continue. However, this window
will remain open to allow setting the equilibration point manually via the mouse.
Click OK to close this window and display the Cardiac Output value.
Following a cardiac output test, the status box will sequence through Emptying Bag and
Ignoring Breaths (To allow washout of the extra CO2 loaded to the patient during the
rebreathing trial.)
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NORE: The tabular metabolic data should be observed for restabilization of the target
volume and CO2 before another cardiac output trial is measured. This assures that all
rebreathed CO2 is cleared from the subject and that the RER is stabilized. If
equilibration is not acceptable adjust the etCO2 Overfill amount in the window before
starting another CO test. Typically this adjustment is no more than +/- 3 Torr.
Additional trials can be measured simply by clicking on the “Fill Bag” button.
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After the last trial, it is recommended that the tabular metabolic data be allowed to
restabilize before stopping the test and removing the subject from the mouthpiece. This
will allow the phase delays from normal metabolic measurements prior to the cardiac
output trial to be processed and the CO data to be properly tagged in time.
Following completion of the metabolic test, the cardiac output trials must be reviewed
and processed for the data to appear on the report.
PROCESSING CARDIAC OUTPUT DATA
First press the Preview CO button. Processing of data consists of examining the
equilibration curve from each of the trials, deciding whether or not the equilibration is
valid, rejecting those that are deemed invalid, identifying the equilibration point,
adjusting the equilibration marker as needed, and manually entering PaCO2 when it is
directly measured from arterial blood.
A typical processing window for CO2 equilibration is displayed on the next page:
Detailed instructions are provided in the window located in the lower left hand corner.
The red downward sloping straight line displayed on the graph represents an estimate
of the FiO2 in the rebreathing bag based on the oxygen consumption just prior to the
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beginning of the trial and the starting FiO2 in the bag.
Time, Breath number and Cardiac Output Sequence (trial number) are displayed to
assist the operator in determining the timing of the measurement relative to the entire
exercise test.
Upon viewing a graph, the technologist should first determine whether or not the curve
is valid for measurement. There should be a discernable equilibration point where there
is minimal to no oscillation of the CO2 tracing and it must occur within ten seconds from
the onset of rebreathing (the time at which the CO2 tracing rises from the baseline to
start the equilibration process). If no discernable equilibration is present, the trial should
be deemed invalid, and the checkmark should be removed from the “Data Valid”
checkbox.
Next, the technologist should determine whether or not he/she agrees with the
computer’s determination of the equilibration point. If not, the equilibration line is easily
moved using the left button mouse drag function. Both the Venous pCO2 and Cardiac
Output readings will instantly change as the line is dragged to the desired placement
point.
Normally, the “Arterial pCO2” value, which is displayed, represents the averaged endtidal CO2 measured just before the trial. If desired, a measured arterial blood PCO2
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result may be manually entered in substitution. The Cardiac Output reading will be
updated once the mouse is clicked outside of this box.
Additional trials may be evaluated by either clicking the Next button or clicking on the Up
arrow next to the Cardiac Output Sequence window. At any point, you may view earlier
trials by clicking on the Down arrow next to the Cardiac Output Sequence window or
clicking on the Previous button.
The Cancel button exits from the measurement and disregards all changes.
Once all graphs have been processed, click on the OK button to store the data.
VIEWING GRAPHS AND PRINTING REPORTS
Once the data is processed and selected, cardiac output (CO) and Venous PCO2 data
is automatically display in the window and printed tabular data listing. Cardiac output
and mixed venous PCO2 data is also available for graphing against time or any other
test parameter.
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APPENDIX F
CANOPY SYSTEM
***CAUTION***
Constant attention to the subject by a qualified individual is required at all times
when the subject is under the canopy. If air flow through the canopy stops or a
loss of power occurs immediately remove the canopy from the subject.
NOTE: The following steps, procedures, and features apply only to the
Canopy System Option.
Canopy System Setup
•
•
•
•
•
•
•
•
Place the Canopy Pump assembly on the bottom shelf of the cart and plug power
cord into the power strip on the cart.
Remove thin plastic protective cover, if any, from the Canopy hood.
Attach the plastic Drape to the Velcro on the outer lip of the Canopy Hood.
Attach a Canopy Connector each end of the Canopy Hood. The connector will
unscrew into 2 parts; then fit through the hood and screw parts together.
Connect the supplied 7/8” corrugated hose to the Pneumotach using the supplied
connector [white plastic piece about fist sized].
Connect the other end of the 7/8” corrugated hose to the Canopy Connector at
the NARROW end of the hood. This end of the hood is closest to the mouth. A
short 30cm piece of the 7/8” corrugated hose can be attached to the other
connector in situations where people may introduce exhaled breath to the hood’s
inlet port.
Connect a large corrugated hose from the other end of the Pneumotach to the
Mixing Chamber input.
Change the 3-way Valve on the side of the Canopy Pump to the Vertical position.
Software Setup
RUN AEI METABOLIC SYSTEMS SOFTWARE PROGRAM
In addition to the Setup of the Software perform the following:
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Select Menu: Tools > Hardware Dx
• Select: CANOPY
• Click OK
• The program will re-initialize. Completely close the program. Re-start the
program.
Volume [Flow] Calibration for Canopy Option
•
•
•
•
Disconnect the hose from the expiratory side of the Pneumotach [where it
connects to the Mixing Chamber].
Connect another hose to the inspiratory side of the breathing valve and the
expiratory side of the Pneumotach.
Perform Flow Calibration as described on Page 12 using a stroke rate of 7-8
seconds for each inspiration.
When Flow calibration and validation is completed re-connect the hose from the
Mixing Chamber to the expiratory side of the Pneumotach.
Running a Test
•
•
After entering Subject information and starting the Canopy Pump place the
Canopy Hood over the Subject’s head. Adjust the Hood location such that the
subject’s mouth is about 10cm away from the outlet of the Hood and then tuck
the drape under the subject. A small pillow under the subject’s head may be
desirable for comfort.
The Canopy System continuously monitors and displays the flow rate of air
passing through the canopy in Liters/Minute. Adjust the Flow Rate on the Real
Time window such that the feCO2 is in the desired range [typically 0.7 – 0.8
%CO2]. The Flow Rate is adjusted by SLOWLY turning the black knob on the top
of the large Canopy Pump [gray metal box on the bottom shelf]. Clockwise
rotation of the knob decreases flow; counter-clockwise rotation of the knob
increases flow. NOTE: Do not turn the knob to completely shut off air flow
through the canopy.
Converting Canopy System to Exercise System
• Select Menu: Tools > Hardware Dx
• De-Select: CANOPY
• Click OK
• The program will re-initialize. Completely close the program. Re-start the
program.
• Disconnect the tubes and adaptors from the Pneumotach.
• Connect the Pneumotach to the inspiratory port of the breathing valve with a
large corrugated hose.
• Connect the large corrugated hose from the Mixing Chamber input to the
expiratory port of the breathing valve.
• Turn the 3-way Valve mounted on the Canopy Pump to the Horizontal position.
• To revert back to a Canopy System, reverse the above steps.
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APPENDIX G
CLINICAL SYSTEM OPERATION
NOTE: Operating in the Clinical System mode does not imply that the MOXUS
Metabolic System is approved for operation as a medical device. Please contact AEI
Technologies for details.
The MOXUS Metabolic System has an optional mode that allows use of Clinical System
features such as Data Encryption, Password Protection, and Subject Name ID.
To enable the Clinical System operation:
Select Menu: Tools > Hardware Dx
• Select: CLINICAL SYSTEM
• Click OK
• The program will re-initialize. Completely close the program. Re-start the
program.
To disable the Clinical System operation:
NOTE: you need to use the ‘admin’ password [found in the Installation Instructions] to
disable this feature.
Select Menu: Tools > Hardware Dx
• De-select: CLINICAL SYSTEM
• Click OK
• The program will re-initialize. Completely close the program. Re-start the
program.
Data Encryption
In Clinical System operation all data will be encrypted utilizing the TrueCrypt encryption
freeware. The TrueCrypt program and associated documentation is available for free
download from their website: www.truecrypt.org. To install and setup TrueCrypt please
refer to the documentation available on their website or contact your network
administrator. The Volume File created is then Mounted as a virtual Drive m:. All data is
then encrypted and stored in Drive m:; including all *.dat data files, all *.xls files
exported to Excel, and the REErpt.txt report text file.
Password Protection
In Clinical System operation a Password is required to operate the Metabolic System
software. There will be 2 levels of password protection: User and Admin. The User
password is simply a null [just click OK; do not type any characters]. This will allow
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Calibration, running a Test, most Features, printing and viewing Reports. Access to alter
Setup information [Hardware Diagnostics, Properties, and Preferences windows] is not
allowed. The Admin password is found in the Installation Instructions and allows
complete access to all commands and features of the software.
Subject Name ID
In Clinical System operation the subject’s name should not be entered on the Subject
Data window. Please enter a Subject ID instead. The data file will then contain the
Subject ID, Date and Time rather than the Subject Name, Date and Time.
AEI Technologies, Inc.
201 Hunters Crossing Blvd
Suite 10-171
Bastrop, TX 78602
800-793-7751
630-548-3545
Fax: 630-548-3546
[email protected]
www.aeitechnologies.com
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