Fast depth-sensitive fluorescence measurements in turbid media using cone shell configuration

Area of Science:

• Biomedical Optics
• Spectroscopy
• Tissue Optics

Background:

• Depth-sensitive optical measurements are crucial for analyzing layered biological tissues.
• Previous cone shell configurations for fluorescence spectroscopy had limitations in sensitivity and data acquisition speed.

Purpose of the Study:

• To demonstrate a novel depth-sensitive fluorescence spectroscopy setup for analyzing two-layered epithelial tissue phantoms.
• To improve upon existing cone shell configurations for enhanced sensitivity and reduced measurement times.

Main Methods:

• Utilized an axicon lens to create a cone shell illumination and collection geometry.
• Employed a fiber assembly with five concentric rings of collection fibers at varying radial distances.
• Performed depth-sensitive fluorescence spectroscopy on a two-layered epithelial tissue phantom.

Main Results:

• The new cone shell configuration demonstrated a broader range of sensitivities to both top and bottom tissue layers compared to previous methods.
• Simultaneous acquisition of fluorescence spectra from multiple depths significantly reduced data acquisition time.
• Eliminated the need for mechanical moving components, simplifying the setup.

Conclusions:

• The developed depth-sensitive fluorescence spectroscopy setup offers superior performance for analyzing layered tissues.
• The simultaneous multi-depth spectral acquisition and enhanced sensitivity make this method highly suitable for clinical settings.
• This technique represents a significant advancement for non-invasive optical diagnostics in medicine.