All fiber-based illumination system for multi-exposure speckle imaging.

Area of Science:

• Biomedical Optics
• Medical Imaging
• Optical Physics

Background:

• Accurate blood flow monitoring is crucial for surgical treatment efficacy.
• Laser speckle contrast imaging (LSCI) offers real-time, label-free blood flow assessment but lacks quantitative repeatability.
• Multi-exposure speckle imaging (MESI) enhances LSCI but typically involves complex instrumentation, hindering widespread adoption.

Purpose of the Study:

• To design and fabricate a compact, fiber-coupled MESI illumination system (FCMESI).
• To reduce the complexity and size of existing MESI systems.
• To validate the quantitative accuracy and repeatability of the FCMESI system.

Main Methods:

• Development of a novel fiber-coupled illumination system for MESI.
• Utilized microfluidic flow phantoms for controlled flow experiments.
• Conducted *in vivo* experiments using a stroke model in animals.

Main Results:

• The FCMESI system demonstrated measurement accuracy and repeatability comparable to traditional free-space MESI systems.
• Successfully validated the system's performance using microfluidic phantoms.
• Showcased the FCMESI system's capability to monitor cerebral blood flow changes in an *in vivo* stroke model.

Conclusions:

• The compact FCMESI system offers a simplified and effective solution for quantitative blood flow monitoring.
• This technology has the potential to improve LSCI applications in various clinical and research settings.
• FCMESI provides a viable alternative for real-time, quantitative assessment of blood flow dynamics.