In order to use the mixing chamber calculations, the flowhead must be calibrated. Detailed
instructions for flowhead calibration can be found in the Spirometer Calibration exercise found in the
Human Exercise-GA200 and Human Exercise-GA300 folders of the complete LabScribe installer.
Part of that procedure requires that the Calibrate Flowhead dialog be displayed and completed. A
calibration file is generated that can be used in future experiments, which will then require only an
abbreviated spirometer calibration process.
Online Metabolic Calculations
While recording data, many metabolic parameters can be calculated and displayed online using
Online Calculations. Choosing Online Calculations from the Metabolic submenu opens the
Metabolic Toolbar above the uppermost channel. The function titles and the corresponding data
values are displayed in the toolbar’s data boxes.
The Online Metabolic Toolbar
The online parameters are:
• Time: Time (in seconds) from the start of the recording.
• Absolute VO
): Volume of oxygen consumed in liters per minute.
• Absolute VCO
): Volume of carbon dioxide produced in liters per minute.
• Relative VO
): Volume of oxygen consumed in milliliters per minute per kilogram of body
• Relative VCO
): Volume of carbon dioxide produced in milliliters per minute per
kilogram of body weight.
• Respiratory Exchange Ratio (RER): VCO
• Resting Energy Expenditure (REE): 5.46 VO
+ 1.75 VCO
(in kcal/24 hr).
• Metabolic Equivalents (METS): Units of energy expenditure; 3.5 ml VO
/kg body weight.
• % Fat (%Fat): Estimate of energy expenditure that comes from fat as a percentage of total calories
• Calories (Calories): The total number of calories expended.
• Minimum oxygen concentration (FeO
Min %): Minimum percentage of oxygen in expired air.
• Maximum CO
Max %): Maximum percentage of carbon dioxide in expired
• Expired volume (VE): Expired air volume per minute at BTPS.
• Watts (Watts): Measure of power produced during exercise, or rate of energy use.
• Heart Rate (HR): 60/period of each cycle.
• Mark (Mark): Phase of protocol as indicated by associated mark.
Clicking on the down arrow on the left side of the Metabolic Toolbar will display a submenu with
Metabolic Online Setup menu.
• Setup: Opens the Online Metabolic Setup dialog.
• AutoSize: Adjusts the size of the Metabolic Toolbar title and data boxes.
• Set Font Size: The user can change the size of the font in the Metabolic Toolbar data boxes.
The criteria for setting up the Metabolic Online Calculations are entered into the Online
Calculation Setup dialog.
The Online Metabolic Calculations Setup dialog.
The Online Metabolic Setup dialog is configured by choosing the O
, and volume
channels to be used, and the calculations to be performed in real time.
In order to compensate for variation from breath to breath, it is possible for LabScribe to average
segments of a chosen duration. This duration should be entered in the Average text box. The ACSM
recommends an average segment duration of twenty seconds.
The subject’s weight (in kilograms) and the concentrations of oxygen (typically 20.9%) and
carbon dioxide (typically 0.04%) in inhaled air should be entered in the appropriate text boxes.
The displayed variables can be chosen from the Calculations list, by control-clicking on those
variables you would like to record in the data boxes of the Metabolic Toolbar. Selected variables can
be removed from the list by control-clicking on that variable. Definitions of all variables can be found
Clicking OK will close the dialog and the selected calculations will be displayed in the data
boxes of the Metabolic Toolbar as data are recorded.
Offline Metabolic Calculations
In addition to the online Metabolic calculations, LabScribe can perform additional offline Metabolic
calculations on previously recorded metabolic data, and display a number of XY graphs based on the
Choosing Offline Calculations from the Metabolic submenu opens the Metabolic Calculations
Dialog. The panels of this dialog can all be resized by moving the mouse cursor over the boundaries
until a double-headed arrow appears, and dragging the boundaries to resize the panels.
The Offline Metabolic Calculations dialog.
The sections of the Offline Metabolic Calculations dialog, each of which is described in more detail
• The tabbed configuration dialogs are on the upper left portion of the dialog.
• An XY graph window on the right displays a variety of metabolic graphs.
• Between the configuration dialogs and the XY graph window is the Segments Selected list, an
editable list of the cycles that can be displayed and analyzed.
• The Data Table is located on the lower part of the dialog.
The Configuration Dialogs
There are six tabbed configuration dialogs: Channels, Settings, Zones, Custom Graph, Report,
and Report Template.
The Channels Configuration Dialog
• The CO2, O2, and air volume channels are chosen from the respective menus.
• The calculated heart rate channel from your recording is chosen from the Heart Rate Channel.
• Optionally, an Energy Channel is chosen if there is one on the recording, typically a power output
from an ergometer.
The Channels configuration dialog.
The Settings Configuration Dialog
The Settings configuration dialog.
Starting at the top of the Settings configuration dialog:
• The subject’s name, age, and sex are entered in the respective text boxes.
• The amount of time to average per segment is entered in the Average (sec) text box.
• The subject’s height (in centimeters or inches) and weight (in kilograms or pounds) are entered in
the Height and Weight text boxes.
• The maximum experimental heart rate the subject may attain is entered in the Maximum Heart
Rate text box.
• The concentrations of oxygen (usually 20.9%) and carbon dioxide (usually 0.04%) in inhaled air
are entered in the Insp. O2 (%) and Insp. CO2 (%) text boxes.
• The subject’s profile can be saved for future experiments by clicking the Save Subject button at
the top of the dialog. This profile can later be retrieved and entered by clicking the Load Subject
• By clicking Calculate, the Metabolic Graph will appear in the XY graph window, and the Data
Table will be populated with the metabolic parameters. Click Calculate whenever settings are
• The subject’s anaerobic threshold (AT) is calculated automatically, and is shown in the VCO2 vs
VO2 XY graph. This value can be recalculated manually as described in the Metabolic Graph
section below. By clicking Calculate AT, the recalculated anaerobic threshold is displayed.
The Zones Configuration Dialog
Different heart rate zones are displayed in different colors on the X-axis of the default graph and the
XY graph. An individual subject’s heart rate zones can be altered by changing the
values in this dialog. The default zones are automatically calculated based on the subject’s maximum
heart rate and will typically not need to be changed.
The Zones configuration dialog.
The Custom Graph Configuration Dialog
It is possible to generate an XY graph displaying variables chosen by the user.
The Custom Graph configuration dialog.
• The desired X-axis and Y-axis variables are chosen from the menus in this dialog.
• The color for each Y variable, whether the data are displayed as dots or a line, and the Y-axis scale
are also chosen here.
• Clicking Plot will display the custom graph. Choosing Custom from the XY graph menu will display
the most recently configured custom graph.
The Report Configuration Dialog
By clicking Create Report, a dated report is generated. This report includes subject information, the
metabolic data in table form, and the current set of XY graphs. The report can be printed or saved in
HTML by clicking the respective buttons.
The Report configuration dialog.
• Included in the report are data from previously saved subject data. When Save Subject is clicked
in the Settings configuration dialog, the averaged data from the current experiment are saved as
part of the subject profile and when Load Subject is clicked in the Settings dialog of a future
experiment, these data are entered into the Results summary that is part of the report, as indicated
in the figure below.
Results summary in Report including data from this subject’s prior experiments.
The Report Template Configuration Dialog
A Report Template can be configured in HTML and saved for future use.
The Report Template configuration dialog.
• The elements to be included in the report are determined by deleting elements not desired,
changing the order of the elements, and adding elements from the Insert menu.
• Text can be directly entered into the template and its appearance customized with the HTML code
• The template can be copied and saved in a text editor from which it can be copied and pasted into
this dialog in future experiments.
The Metabolic Graph
By default, the graph displayed is of VCO2, VO2, and RER over time. All the segments are displayed.
Segments can be deselected (or selected) by clicking on the check box to the left of the segment
number in the Segments Selected list to the left of the graph. The UP and DOWN arrows on the
computer keyboard can be used to move quickly through the individual cycles. The specific
parameters shown in the graph can be customized in the Custom Graph dialog.
The Metabolic XY Graph.
The XY Graph Menu
Clicking on the arrow in the lower left corner of the XY graph pane opens a menu that offers options to
display other graphs as well as an option to copy the graph to the clipboard.
The XY Graph menu.
The menu items are:
• Clicking Copy Graph copies the current Metabolic Graph to the clipboard. It can then be pasted
into the Journal or an external application.
• View Metabolic displays the default graph.
Documents you may be interested
Documents you may be interested