Optical characterization of rigid endoscopes and polarization calibration methods

Area of Science:

• Biomedical Optics
• Medical Imaging
• Biophysical Sensing

Background:

• Polarization imaging offers structural insights beyond color in biological tissues.
• Polarimetry is increasingly used in pre-clinical and clinical settings for early cancer detection.
• Polarization-based endoscopy combined with near-infrared fluorescence imaging aids in diagnosing colorectal lesions.

Purpose of the Study:

• To develop a framework for characterizing spectral and polarization properties of rigid endoscopes.
• To address the issue of optical elements in custom imaging systems altering tissue polarization signatures.
• To enable accurate polarization-based endoscopic imaging for biomedical applications.

Main Methods:

• Characterization of spectral and polarization properties of rigid endoscopes.
• Development and evaluation of two calibration schemes using Mueller calculus.
• Analysis of optical limitations and polarimeter requirements for custom imaging systems.

Main Results:

• A framework was established to characterize endoscope optical properties.
• Two calibration schemes were presented and evaluated for reconstructing polarization information.
• Potential degradation of polarization signatures by standard optics was identified.

Conclusions:

• Accurate characterization and calibration of endoscopic systems are crucial for reliable polarization-based imaging.
• The developed framework and calibration schemes can help researchers overcome limitations in custom polarization imaging systems.
• This work supports the advancement of polarization imaging for improved biomedical diagnostics and early disease detection.