# Can a Rule-Based Expert System Diagnose Nasal Obstruction from Nasoendoscopy Videos?

## TL;DR

A rule-based expert system was tested to diagnose nasal obstruction causes and showed similar performance to ENT specialists, especially for chronic rhinosinusitis with nasal polyps.

## Contribution

A rule-based expert system was developed and validated to replicate ENT decision-making for nasal obstruction diagnosis.

## Key findings

- RB-ES showed no significant sensitivity differences from ENT specialists for nasal obstruction diagnoses.
- Sensitivity was highest for chronic rhinosinusitis with nasal polyps (CRSwNP).
- Specificity remained high overall across all conditions evaluated.

## Abstract

Nasal obstruction has multiple causes requiring specialist endoscopy for diagnosis. A rule-based expert system (RB-ES), which applies five “if–then” rules based on nasal features, may help replicate ENT decision-making in settings with limited access.

This study evaluated RB-ES in diagnosing allergic rhinitis, chronic rhinosinusitis with (CRSwNP) and without (CRSsNP) nasal polyps, and deviated nasal septum. Primary outcomes were sensitivity and specificity; the secondary outcome was agreement with ENT specialists.

Prospective cohort study.

Seventy-one participants (65 patients, 6 controls) underwent pre- and postdecongestion endoscopy. Four ENT specialists provided diagnoses. RB-ES performance was compared against confirmed clinical diagnoses.

RB-ES showed no detectable significant sensitivity differences from ENT specialists (all
p
 > 0.05). Sensitivity was highest for CRSwNP; specificity remained high overall.

RB-ES matched specialist performance in CRSwNP diagnosis. Dataset expansion and artificial intelligence integration are recommended for further validation.

II.