Progress in the measurement of ciliary beat frequency by automated image analysis: application to mammalian tracheal epithelium.

The investigations on the activity of respiratory ciliae in vivo are of considerable interest for the study of physiopathological disorders resulting from chronic infection or inhaled pollutants. We present an image analysis method for the measurement of ciliary beat frequency on mammal or human in vivo samples. Videofilm sequences of samples placed under the microscope were analyzed frame by frame by image analysis. The operator defines on the screen several areas of interest on the cell apex. The variation of grey levels in each areas allows the calculation of ciliary beat parameters. This method permits one to investigate the effects of pharmacological agents or noxious pollutants on ciliae beating and the physiological causes underlying them. Our results on rabbits were in agreement with the data published in literature, showing no significant difference between intratracheal frequencies obtained at medium and lower levels. The upper level near the cracoid cartilage has shown a greater variability than the other two levels with higher beating frequencies, a difference of likely physiological importance.