Image Acquisition and Object Motility Analysis version 1.1
for WinNT 4.0 and IPP 3.x

The purpose of the software is to visually and statistically track moving objects. Our philosophy during development was that most images are difficult to analyze without some degree of image processing. For example, moving cells cross the paths of other cells, divide during the experiment, and will often stay in contact with each other through biological and chemical processes. Additionally there may be very little contrast between cells and their background (see green image below). Instead of tracking the objects "online" (during image acquisition) we decided that the process of capturing the images, processing the images, and analyzing the images should be distinct and separate. This will allow the investigator to track only those objects that are of experimental importance. The other advantage of this "offline" approach is to lighten the load on the processor and memory intensive tasks, especially the analysis/tracking phase of the program.

The images below show the typical steps an investigator would use to track a group of cells or any object. The first image (green image) is converted to the black and white image. Any image processing, cell splitting, or cell removal can be accomplished during this step. The displacement window shows the paths that the individual cells have taken. Not pictured is a guard frame that the user may resize to ensure that cells are not visually tracked if they touch the edge of the image window, or if they lie beyond the borders of the guard frame. Their statistical movement is still tracked however, i.e., their distance traveled. Or if the investigator would like to track a specific region of the image (e.g. lower middle), the guard frame can be resized or moved where necessary. Lastly, a data table appears showing the total distance traveled, the mean distance per image - interval, and the mean velocity of each object in the experiment.

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The software also contains a "displacement limit." The displacement limit is the size (calibrated to the units used for measuring) of roughly one-cell-diameter. A typical scenario is of a single cell (cell1) close to the edge of image-frame#1. In frame#2 another cell (cell2) moves into the viewable area but cell1 moves out of the viewable area. Still there is only one analyzable object, but it is a new object. A cell that moves into the image-frame will generally not come to rest at the same spot where the cell that left resided (due to movement in the same plane). Thus when cell2 comes into view, it will usually be a distance from cell1 that is greater than the displacement limit. This scenario will generate a screen prompt and identify the two cells that have exceeded the displacement limit. It will then allow the investigator to decide if a new cell has entered the viewable area, or if the cell in question moved more quickly than expected during that time of the experiment.

The limits of the software are linked to the computer memory and the complexity of the sample. In the latest test, the program has kept track of 30 objects, in the first frame, for 50 frames. By the fiftieth frame, over 70 more objects have moved into the viewable area and have had measurements recorded for each object.