Rhinomanometer NR6
NR6 User
’s
Manual V 16 14/02/2020 P10 of 34
RHINOMANOMETRY OVERVIEW
The measure of Rhinomanometer or nasal airway resistance depends on measuring nasal air
flow and the pressure producing that airflow:
Nasal airflow is collected by a mask, which must form an airtight seal round the face, and is then
passed through a pneumotachograph head in which the flow is converted to a pressure
differential. This differential is transmitted to the NR6 by means of the tubes marked with red
and green bands.
Nasal pressure is the more difficult parameter to measure and this is done using one of two
standard techniques:
ANTERIOR TEST
(detailed on P13)
In the anterior test the black pressure tube is connected to one side of the nose while airflow is
measured through the other side, allowing for resistance to be calculated on that side. The
pressure tube is then moved to the second side, flow is recorded, and resistance is calculated
again. The two resistance values are then put into the formula below to calculate total
resistance:
The pressure connection to the nose is made by either:
•
a tip connector pushed through a small hole punched in microfoam tape, or a foam
insert
•
linked to the black pressure tube using anterior tubing and an anterior connector.
The reference pressure tube (blue) is connected to the mask.
It is essential that the pressure connection is airtight and this should be checked by:
1)
Connecting the anterior tubing to the side of the nose which is not being measured
2)
Holding or taping the free end of the anterior tubing against the soft part of the
subject’s cheek
3)
Asking the patient to obstruct the free side of the nose with a finger while you block the
free end of the anterior tube. If the patient then tries to gently breathe in and out
through their nose they will be able to tell you if they feel any air leakage at the tape or
foam connection to their nose.
4)
Having achieved no leakage, and without moving the anterior tube, carefully place the
mask on the face, starting just above the bridge of the nose, and ask the subject to hold
the mask in place.
1 = 1 + 1
R TOTAL R LEFT R RIGHT
R = P/F
Resistance = R, Pressure = P, Flow = F
