Rhinomanometry. II. A system for numerical description of nasal airway resistance.

Various ways of expressing rhinomanometric results have been an obstacle for exchange of information. A method that could be generally accepted must: 1) easily give the clinician an informative figure describing the nasal airway patency in all cases: 2) provide a basis for statistical evaluation: and 3) allow a numerical description of the whole pressure-flow (P-V) curve. In our system P-V curves are traced X-Y wise and described with polar coordinates (angles and radii). The system can be applied in three modes. The 'clinical' mode describes resistance at a standardized condition defined by a circle of the pressure-flow diagram. Data can be read direct from the pressure-flow curve. The 'statistical' mode yields nearly normal distribution. The 'mathematical' mode describes the whole pressure-flow curve, in terms of changing angle with radius. This mode brings about good and stable curve-fitting. Calculation of properties of the total nose from data of each cavity can be done with a pocket calculator.