Computerized analysis of flagellar motility by digitization and fitting of film images with straight segments of equal length.

Methods are described for computerized analysis of digitized images obtained by scanning photomicrographs of swimming sperm flagella. After storing a series of image frames in computer memory, the entire series is analyzed automatically. For each sperm image, the sperm head is located to obtain a starting point for analysis of the flagellum. This location is obtained by minimizing image intensity along a model of the sperm head outline. The flagellum is modelled by a series of straight segments of equal length: 0.5 or 1 micron. The angles between these segments are adjusted to give minimum image intensity along the line of the model as well as minimizing smoothing functions. Extensions to analyze a series of images in each frame, and to measure the positions of beads attached to the flagellar microtubules, are also described.