Pressure‐flow relationships in a laryngeal airway model having a diverging glottal duct

A laryngeal airway model was constructed using polyester resin in order to empirically test current pressure‐flow equations of the larynx. The model was five times larger than life size and had 13 pressure holes to allow measurement of wall pressure profiles. The glottis had a diffuser shape with a 40° divergence angle. This glottal shape is prominent during glottal closure within a vibratory cycle. Three glottal diameters were used: 0.0054, 0.0200, and 0.0918 cm (prototype values). There were essentially two regions of laryngeal pressure for steady flow conditions. The subglottal pressure acted on the laryngeal surfaces upstream of the entrance to the glottis, and the supraglottal pressure acted on the laryngeal surfaces within the diverging region of the glottis. Flow separation near the glottal entrance is suspected. Large negative pressures were not found in the glottis, and the two‐duct, glottal pressure‐flow equations of Ishizaka and Matsudaira were not well supported. The translaryngeal pressure dr...