Knowledge Base

Select the Data for Analysis

Data Segmentation Profiles

Using a Data Segmentation Profile, you can select one part from each run which complies with three parameters (minimum number of consecutive steps, range of desired speed, maximum allowed speed variation). This is useful, for example, if you have a run in which the animal briefly stopped at the beginning of a run but then continued to walk normally. With a Data Segmentation Profile, select only the 'good' part of the run for analysis and export.

1. Choose Profiles > Data Segmentation Profile > New.
2. Under Parameters, you can set the following:
   • Minimum number of consecutive steps per run – Only the part of the run with the minimum number of consecutive steps which complies with the next two parameters is selected. We advise you to use at least 12 consecutive steps.
   • Average speed should range from (in distance unit/second) – Only the part of the run which complies with the set speed range is selected.
   • Maximum allowed speed variation (in percent) – Only the part of the run which complies with the maximum allowed speed variation is selected.

Note: All profiles in CatWalk XT are used for all experiments stored on your computer. If you make a change in a profile, this change is applied to all experiments that you open afterwards.

Selected Data Overview Tab

The results of your data segmentation are shown under Results:

The Selected Data Overview sheet shows, per Treatment Group and Time Point, the number of Selected Animals / Runs / Steps, the Total number of Animals / Runs / Steps in the experiment, and the Percentage of selected Animals / Runs / Steps. You can choose whether you want to see the selected Animals, Runs, or Steps by selecting the corresponding option at the bottom.

The chart on the right is a graphical representation of the selected data. You can choose whether you want Time Points or Treatment Groups displayed on the x-axis by selecting the corresponding option at the bottom. The number of Selected Steps and Total Steps per Treatment Group for each Time Point are also displayed in the bar chart on the right.

Complete Data Overview Tab

In the matrix, the average speed intervals (1 to 10 cm/sec, 1 to 20 cm/sec, 1 to 30 cm/sec, etc.) are displayed on rows. The speed variation is displayed in 10% intervals on columns. Each cell in the matrix shows the resulting number of steps for a specific combination of average speed and speed variation. The 3D chart shows a graphical representation of the data in the matrix.

Select the Analysis Parameters

Parameter Profiles

In a Parameter Profile, you specify which parameters you want to calculate. You can create multiple Parameter Profiles to produce results tables with specific parameters.

To create a Parameter Profile:

1. Do one of the following:
   • Choose Profiles > Parameter Profile > New.
   • In the Profiles Explorer, right-click Parameter Profiles and select Add New Profile. Enter a name for the new Parameter Profile.
2. Select Paws, Paw combinations for Phase Dispersions and Couplings, and the Parameters you want to display and export.
3. Click OK. The newly created Parameter Profile is added in the Profiles Explorer and set to active.

Notes:

• The selection in a Parameter Profile affects the Paw Statistics, Phase Dispersions, and Couplings result tables.
• Only parameters selected in the active Parameter Profile are analyzed and exported.
• All profiles in CatWalk XT are used for all experiments stored on your computer. If you make a change in a profile, this change is applied to all experiments that you open afterwards.

Tip: If you have multiple Parameter Profiles, you can make a specific one active by right-clicking a Parameter Profile and selecting Set as Active. The currently active Parameter Profile is displayed in bold and blue in the Experiment Explorer.

Analyze the Data

Visualization

1. Choose Analyze > View Run Visualizations.
2. Under Trial & Run Selection, select a trial and run from the list.
3. Under Video, select a playback speed from the list and play back the run by pressing the play button or by moving the slider.
4. Under Visualizations, click the tab:
   • 3D Footprint Intensities – To display the print intensities for each individual frame of a stance for all paws. The 3D charts can be rotated in all directions.
   • 2D Footprint Intensities – To view the print intensities of the paws. The red line represents the maximum intensity found in the frame. The colored area under the red line represents the mean intensity in the frame.
   • Footfall Patterns – To view the order in which the paws were placed on the glass plate.

Paw prints which are not selected in the currently active Data Segmentation Profile are displayed in gray in the video window and are not displayed in the Visualizations.

Run Statistics

1. Choose Analyze > View Run Statistics.
2. Under Trial & Run Selection, select a trial and run.
3. Under Statistics, click on one of the tabs to see the analysis results sheet of the corresponding parameter(s).

Which parameters you see in the Paw Statistics sheet and Phase Dispersions/Couplings sheet depends on the data selection you made in the currently active Parameter Profile.

For some results sheets, click in the cells to view more details under Views.

Paw prints that are not selected in the currently active Data Segmentation Profile are displayed in gray. For these non-selected prints, no run statistics are calculated.

Group Statistics and Charts

You can calculate the statistics of all parameters, grouped per treatment group and time point, and view the corresponding charts.

1. Make sure you have selected the right Data Segmentation Profile and Parameter Profile.
2. Choose Analyze > View Group Statistics and Charts.
3. Under Numerical Results, click a category to display the results.
4. Under Graphical Results, click a category to view the corresponding parameter charts.

To customize your charts, under Graphical Results, click the customize icon.

Source: CatWalk XT 11.0 Quick Start Guide, Noldus Information Technology