Abstract
A method for photoelectric in vivo recordings of the mucociliary activity of the mucosa of the upper respiratory tract is described and tested in model experiments. In vivo recordings from the maxillary sinus mucosa of rabbits were easy to analyse and the method is useful for further experimental research on animals. Examples of in vivo recordings from the human maxillary sinus during Caldwell-Luc operations are also presented. These results are compared with subsequent in vitro recordings of biopsy material.