Setting up the walkway involves three main steps: defining the walkway, calibrating it, and adjusting detection settings. These steps ensure accurate data and reduce the amount of work needed during classification.
In addition to the initial setup, repeat the following when needed:
This step outlines the working area. Go to Setup > Define Walkway. Resize the white rectangle to match the usable section of the walkway. For larger animals like rats, avoid including the ends of the walkway to prevent tails from affecting results.
The rectangle should sit just inside the visible black bottom edges of the corridor walls, minimizing inclusion of the wall edges.
Calibration enables measurements in centimeters instead of pixels. Calibration must be redone after adjusting camera height.
Use a calibration sheet (10×20 cm rectangle). Place it face down within the camera view. Go to Setup > Calibrate Walkway. Adjust the white rectangle to align with the calibration sheet, then click OK.
Be sure to print the sheet at actual size, not scaled.
This adjusts the camera sensitivity to detect footprints reliably. Redo this step if lighting changes, camera height changes, or if you switch to animals of a different size.
Ensure the room is dark, with consistent trial lighting. The walkway ceiling should be lowered. Let the walkway lights warm up for at least 15 minutes. Use an animal of representative size for your trials.
Go to Setup > Detection Settings.
Start with Auto Detection by clicking Start Auto Detect. Let an animal run across the walkway; the software will adjust sensitivity accordingly. Multiple passes may be needed.
After Auto Detection, check if Maximum Green Intensity is between 200–205. Use Reset Prints to clear the value and measure again with a clean run.
If intensity is too high, lower the Camera Gain. If too low, increase the gain. If using CatWalk XT 10.6+, you can also increase the Green Walkway Light (default: 16.5V for mice, 16.0V for rats). Adjust by increments of 0.1 if needed.
Next, adjust the Green Intensity Threshold to filter out noise while preserving paw print clarity. A high threshold removes more noise but may cut print details; a low threshold shows more detail but may introduce noise.
Once adjusted, click OK to finish setup.