Near-UV to Near-IR Multispectral Illumination in a Digital Surgical Microscope

Abstract

We present a stereo-multispectral microscope equipped with an additional illumination unit allowing further narrow-band illumination in the spectral range of 400n.m up to 800nm. The combination of the normal microscope illumination with the multispectral light unit allows different illumination modalities to be realized, which enables intraoperative spectral tissue analysis with direct visualization. Two illumination methods were tested in two cholesteatoma surgeries. In addition, two cholesteatom samples were illuminated and analyzed ex vivo. Cholesteatoma showed:fluorescent characteristics in our ex vivo analysis. This behavior could be used intraoperatively using a combination of white light and strong near-UV to blue illumination to highlight cholesteatoma tissue in the microscopic image. Thus, the visual differentiability of different tissue types can be improved and the clinical decision-making process can be accelerated.