Quantitative Office-Based Laryngoscopy: Bench Validation of a Simple Calibration Method for Submillimeter Accuracy...

Area of Science:

• Medical Imaging
• Otolaryngology
• Optical Engineering

Background:

• Quantitative laryngoscopy has been limited by the need for non-medical research prototypes.
• Commercial availability of medical devices is crucial for routine diagnostics and large-scale studies.

Purpose of the Study:

• To present and validate a simple, one-shot reference-grid calibration method for a CE-marked stereo laryngoscope.
• To enable quantitative laryngoscopic data acquisition in routine clinical settings.

Main Methods:

• Utilized a CE-marked 3D stereo laryngoscope to measure target distances at various working distances.
• Employed a reference-grid image to establish a px/mm scale for each frame.
• Assessed precision using standard deviation and accuracy via Bland-Altman analysis.

Main Results:

• Achieved a measurement precision with a standard deviation of 1.0%.
• Demonstrated high accuracy with a small bias of -0.3% and narrow limits of agreement (-2.2% to +1.6%).
• Measurement performance was consistent across different target and working distances without significant distortion.

Conclusions:

• The proposed calibration method is effective for a commercially available stereo endoscope.
• Provides precise, submillimeter distance measurements suitable for clinical and scientific applications.
• Facilitates office-based transoral laryngoscopy without requiring custom hardware.