The present invention relates to a system and method for measuring the direction and speed of movement of mucus flowing along a ciliary tissue surface, wherein said system comprises: a) a probing unit comprising: dispensing means for controlled seeding of labeled particles into said flowing mucus probe illumination means for illuminating the mucus flowing over said ciliary tissue surface optical sensing means for detecting the movement of said labeled particles optical coupling means for optically coupling said illuminated mucus to said optical sensing means and b) a control unit comprising at least one illumination source, and means for processing optical or electrical signals received from said optical sensing means and determining the direction and speed of said mucus according to said received signals c) means for transferring optical or electrical or control signals between said probing unit and said control unit.
