Related Experiment Video
Updated: Aug 12, 2026
A Free-breathing fMRI Method to Study Human Olfactory Function
Published on: July 30, 2017
A novel objective olfactory assessment method based on nasal airflow changes following eugenol stimulation
Yitao Liu1, Ruiqi Xia1, Wei Feng1
1Department of Otorhinolaryngology, Wangjing Hospital, China Academy of Chinese Medical Sciences, No. 6 Huajiadi Street, Chaoyang District, Beijing 100102, China.
Background:
Current olfactory assessment relies on subjective scales or complex objective techniques. A simple, economical objective method is needed.
Objectives:
This study evaluated a nasal airflow-based olfactory assessment using eugenol stimulation.
Material And Methods:
Four hundred and twelve participants underwent VAS scoring, Sniffin' Sticks testing, and nasal airflow assessment with 2.5% eugenol. Correlation, group comparison, cluster analysis, and ROC analysis were performed. A validation cohort (n = 56) and test-retest reliability (n = 30) were also assessed.
Results:
Velocity change ratio showed weak correlations with discrimination (r=-0.10, p = 0.03), identification (r = 0.09, p = 0.04), and VAS scores (r = 0.05, p = 0.02). The OD group showed lower flow and velocity change ratios than controls (p < 0.001 and p = 0.03). Cluster analysis yielded cut-offs of <4% (flow) and <2.5% (velocity). In the validation cohort, AUC was 0.71 (95% CI: 0.56-0.86), sensitivity 72.7%, specificity 91.7%. Test-retest ICCs were 0.76 and 0.83.
Conclusions:
The nasal airflow-based assessment shows weak correlations with established tests and modest diagnostic accuracy. Its simplicity makes it potentially suitable as a screening tool, but it cannot replace comprehensive psychophysical testing.
