There are two ways to easy ways to display the Tidal Volume in LabChart.
The first utilizes the Spirometry Extension which is available for both the Windows and Macintosh versions of LabChart (the most recent version can be obtained from the Software Downloads page on our website). You first need to state in the Spirometry Settings dialog which channel is displaying the Spirometry Flow and which will be the Spirometry Volume. You can then access and display various calculation options in the Channel Function pop-up menu in the Channel Settings dialog, which is accessible under the Setup Menu, or by left clicking on the Channel's Title:
To display tidal volume, select the ‘Tidal Volume...' option in the channel you would like it displayed, and modify the settings to suit your requirements. This channel will then display the Tidal Volume for both recorded and incoming data.
If you do not wish to utilize the Spirometry Extension, then the channels can be set up manually as follows:
In the first channel you can record the raw data from the spirometer. This will be your Spirometry Flow. (Details of how to calibrate the flow head can be found in the Spirometer Owner's Guide.) To determine Spirometry Volume, in a second channel you will need to integrate the flow signal using the ‘Integrate...’ option in the Channel Function pop-up menu.
Depending on your preference, you may wish to add a reset, e.g. Reset Each Cycle, here. This prevents any drift in the volume signal that could be caused by uneven inspiration/expiration ratios or flow offsets; however, it will have no bearing on your Tidal Volume calculation.
Finally, in another channel you can determine the Tidal Volume by calculating the height of each Volume cycle using the Cyclic Measurements feature . Choose 'Cyclic Measurements...' from the Channel Function pop-up menu, set the source channel to the spirometry flow data, the measurement is set to ‘Height’, and if necessary change the Detection Settings Preset to 'Respiration - Air Flow'. Click OK and the Tidal Volume will be displayed in the channel.
For further technical assistance with this or any other issue, please contact ADInstruments Technical Support by clicking HERE.