Performing Array Analysis in BioBench

The following information also is located in the BioBench User Manual (linked below).

In addition to displaying and analyzing your data with respect to time, BioBench allows you to analyze XY data. The following two examples demonstrate array analysis features. The first example illustrates how you can profile two pressure relationships in an XY graph. The second example demonstrates how you can derive a new signal (volume) by integrating a signal (flow) to yield a flow-volume loop.

Profiling Pulmonary Pressure Relationships

In this example, BioBench profiles the relationship of pulmonary airway pressure (delivered by a ventilator) and the corresponding pressure in the lung.

1. Select View»2 Graph Analysis to display and analyze the two signals of interest.
   
   
2. Select File»Open and open the example data file called Cardiopulmonary Study. (You may need to use the Browse button to navigate to the \biobench\examples directory.) This file contains the ventilator and lung pressure signals. The following figure illustrates this step in the File Open dialog box.
   
   
3. If the Append? checkbox is active and selected, you should deselect it, so that only the file you select will open. Click on the OPEN button. The Analysis view returns and the data from the first two signals in the file automatically fill the graphs.
   
   
4. Now you need to change the signals displayed in the top and bottom graphs. Click on the label of the top graph; the Select Signal dialog box appears. Select Lung Pressure and click on OK. Refer to the Analyzing Heart Rate with BioBench example (linked below) for an explanation of this dialog box.
   
   
5. Repeat the previous step for the bottom graph and choose the Paw Pressure signal.
   
   
6. Now that you have the two signals on your Analysis view, highlight a region of data by clicking and dragging your mouse over the graphs. The following figure shows the 2 Graph Analysis view with a subset of data highlighted.
   
   
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7. Click on the Array button to the right of either graph to display the Array Analysis dialog box. Select the XY Analysis tab to display the pressure relationship loops as shown in the following figure.
   
   
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Profiling Flow-Volume Loops Using Filters and Transforms

To display flow-volume loops for pulmonary function studies on an XY graph, complete the following steps. This example also shows you how to filter and transform signals. In this example, you transform a flow signal by integrating over time to yield volume.

1. Select View»4 Graph Analysis to view the data.
   
   
2. Click on the signal label of the top graph. The Select Signal dialog box appears. Click on the Open Files button to open the data file Flow-Volume Example in the \biobench\examples directory. (You may have to use the Browse button to navigate to the \biobench\examples directory.) If the Append? checkbox is active and selected, you should deselect it, so that only the file you select will open.
   
   
3. Click on the OPEN button. You return to the Select Signal dialog box. The following figure illustrates the Select Signal dialog box for the Flow-Volume Example data file.
   
   
4. Display the Flow, Airway signal in the top graph of the analysis view by clicking on the OK button.
   
   
5. You can apply a software filter to smooth the Flow, Airway signal. To display this filtered data on the second graph, click on its label. Again, the Select Signal dialog box appears. Select the Flow, Airway signal and change the Signal Label to Filtered Flow, Airway. Choose the Median Filter option from the Filtering pull-down list, enter the value 0.050 in the # Seconds field and click on the OK button.
   
   
6. In this example, the corresponding volume signal (Volume, Airway) was available in the form of an analog voltage. To display this data in the third graph, click on its label and select Volume, Airway from Select Signal dialog box. Click on the OK button.
   
   
7. If the volume signal were not available as an analog voltage, BioBench could derive it by integrating the flow signal. To display the integrated flow (in other words, volume) signal on the bottom graph click on its label and select the Flow, Airway signal. Change the Signal Label to Integrated Flow (Volume). Choose the Median Filter option from the Filtering pull-down list, enter the value 0.050 in the # seconds field. Choose the Integral option from the Transform pull-down list and click on the OK button. The following figure shows each of these signals in the 4 Graph Analysis view.
   
   Notice that the volume signal from the ventilator (in graph three) closely matches the Integrated Flow (in graph four) which BioBench derived from the raw flow signal.
   
   
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8. To display the flow and volume signals in an XY Graph, highlight a region of data by clicking and dragging your mouse over the graphs. Be sure that you highlight at least one complete pulmonary cycle, to display a good loop. Click on the Array button to the right of any graph to display the Array Analysis dialog box.
   
   
9. Click on the XY Analysis tab and select Filtered Flow, Airway for the Y axis and Integrated Flow (Volume) for the X axis. The following figure displays the Flow-Volume loop for the highlighted breath. For more information on the XY Analysis tab, refer to the XY Analysis section of Chapter 4, Analyzing Data, of the BioBench User Manual (linked below).
   
   
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Related Links:
Analyzing Heart Rate with BioBench
BioBench User Manual

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