Development and Characterization of a Hyperspectral LCTF-based Colposcopic System

Abstract

The early detection of precancerous cervical lesions is essential to improve patient treatment and prognosis. Hyperspectral (HS) imaging (HSI) has demonstrated a high potential to become a new non-invasive and label-free imaging technique in the medical field for performing quick diagnosis of different diseases.This study presents the research and development process to integrate and characterize a KURIOS-XE2 filter (Thorlabs, Inc., NJ, USA), based in a liquid crystal tunable filter (LCTF) technology, into an existing colposcope (C5, OPTOMIC, Spain). The main goal was to capture spectral information in the near infrared range (650-1100 nm) by using a monochrome camera and acquiring 90 spectral wavelengths with a spectral resolution of 5 nm. Two different integration strategies were studied: i) filtering the emitted light by the sensor and ii) filtering the received light by the sensor, evaluating their respective benefits and limitations. Furthermore, a custom software was developed for HS image acquisition, integrating a variable acquisition time per wavelength, which allows improving the signal-to-noise ratio at wavelengths where the system presents lower quantum efficiency.The proposed system simplifies the adaptation of existing optical systems to HSI technology, improving the signal-to-noise ratio in the studied spectral range respect to other approaches. The results were compared against a previous custom implementation based on a Snapscan camera (IMEC, Belgium), covering the visual and near infrared and highlighting the advantages and limitations of both technologies for the development of a HS colposcope system targeting early detection of precancerous cervical lesions during routine clinical practice.