Detection of erythrocytes passing through capillaries by a photocell-computer technique.

Abstract

A method is described for analyzing movie film of the microscopic image of capillaries in the wing of the unanesthetized bat to simultaneously detect the passage of red cells in several adjacent capillaries. An image of the exposed film is projected onto a Plexiglas screen behind which several photocells are positioned over each capillary image. A LINC computer digitally demodulates the photocell outputs to provide a quantitative measure of the capillary image light intensity. Since the passage of a red cell changes the capillary image light intensity, the demodulated photocell outputs provide detection of passing erythrocytes. All red cells are not detected because the method utilizes too low a film-exposure rate (data-sampling rate).