簡易な鼻腔抵抗の測定法

抄録

When the air in an inverted bell (A) falling into a water tank is discharged through a tube of least resistance, the pressure at the outlet is constant without reference to the changes of following objective resistances ®. In fact, however, the internal resistance of the apparatus is inevitable in greater flow. Then a cock (C) is placed midway on the tube and a pitot tube (B) is set closely to a nozzle attached to the naris, to read the total pressure at this point with a water manometer. While the air passes into the nose and nasopharynx and then out through the mouth, the cock is adjusted so as to fix the water column at 1 cm. in height. As the pressure drop (P1-P2) from inside the bell to the nozzle is constant, the closing angle of the cock is a function of the flow rate. The angle is also a direct index of the nasal resistance or time in seconds necessary for a liter of air to be forced out with the driving pressure of a 1 cm. water column (Fig.1).
By means of this method, it was proved that resistance of the nasal cavity was between 3 to 5 seconds for sides, in 94 per cent of 100 normal nasal passages tested.