Currently there's no non-invasive, objective method for measuring nasal airflow. The current
standard, the NOSE score is an inaccurate measure of physiology (it is subjective). There is
a considerable amount of data that demonstrates that the nasopharyngeal airway is the
preferred ventilatory pathway for breathing at rest and during sleep. Finding a reliable
measurement modality is important in light of this. The primary goal of this study is to
evaluate a novel approach to measuring nasal airflow in thermal imaging. Previous studies
show that higher temperatures of the nasal mucosa are related to decreased patency. The
investigators hypothesize that reduced or obstructed airflow leads to the loss of the cooling
oscillatory cycle present in normal nasal respiration. The investigators believe this
diminished or absent cycle may be detectable via thermal imaging due to predicted elevation
of mucosal temperatures (or loss of the cooling gradient). Other methods in the past aimed at
measuring temperature changes introduced error due to their invasiveness (irritation of the
mucosa lead to higher baseline oscillatory cycles). This is no longer an issue as the thermal
imager requires no physical contact with the patient to function.
There are several methods for measuring nasal patency that have been described throughout the
literature. These include objective measurements such as acoustic rhinometry and
rhinomanometry, as well as subjective measurements such as the Sino-Nasal Outcome Test and
Nasal Obstruction Symptom Evaluation (NOSE) questionnaires. More recently, snap-on thermal
imaging devices that take advantage of the processing power and high resolution of modern
phones have surfaced leading to lower costs for highly-sensitive devices that we aim to use
for measuring nasal airflow. The non-invasive nature of using thermal devices may lead to
more accurate, objective measurements of nasal airflow as a previous study demonstrated that
tactile irritation from other devices increase the mucosal temperature impeding measurement.
(Bailey et al.). Other studies documented that improved sensation of nasal airflow is
associated with cooler mucosal temperatures and that increased patency of the nasal passage
is related to lower temperatures as well (and the opposite, decreased patency to increased
temperatures). (Willatt et al.) We hypothesize that nasal airflow obstruction (NAO) leads to
the loss of the cooling oscillatory cycle present in normal nasal respiration which we can
detect via thermal imaging due to predicted elevation of mucosal temperatures.