Spatial Sensitivity to Absorption Changes for Various Near-Infrared Spectroscopy Methods: A Compendium Review

Area of Science:

• Biomedical Optics
• Photonics
• Medical Imaging

Background:

• Near-infrared spectroscopy (NIRS) measures light absorption in diffuse media.
• Understanding sensitivity to localized absorption changes is crucial for NIRS accuracy.
• Spatial sensitivity maps visualize how NIRS measurements relate to specific tissue locations.

Purpose of the Study:

• To provide a historical overview of spatial sensitivity research in diffuse optical media.
• To present a comprehensive compendium of spatial sensitivity maps for NIRS.
• To offer a resource for comparing and generating sensitivity maps.

Main Methods:

• Review of experimental and theoretical studies on spatial sensitivity over 30 years.
• Generation of 1-, 2-, and 3-dimensional sensitivity maps for various NIRS methods.
• Organization of sensitivity maps by temporal domain (continuous-wave, frequency-domain, time-domain) and data-type.

Main Results:

• Detailed historical progression of spatial sensitivity investigations in diffuse optics.
• A structured compendium of sensitivity maps for diverse NIRS applications.
• Inclusion of methods and code for generating custom sensitivity maps.

Conclusions:

• This compendium serves as a unified resource for researchers in diffuse optics and NIRS.
• It enables visualization, comparison, and generation of spatial sensitivity to absorption changes.
• Facilitates a deeper understanding of NIRS measurement localization and accuracy.