Compact tissue oximeter based on dual-wavelength multichannel time-resolved reflectance.

Area of Science:

• Biomedical Optics
• Medical Instrumentation
• Photonics

Background:

• Accurate tissue oximetry is crucial for monitoring physiological conditions.
• Existing methods may lack portability or speed for real-time applications.

Purpose of the Study:

• To develop a compact, dual-wavelength multichannel tissue oximeter.
• To utilize time-correlated single-photon counting (TCSPC) for enhanced accuracy.

Main Methods:

• Employed two pulsed diode lasers (672 nm and 818 nm) with high repetition rates.
• Utilized a multianode photomultiplier and a TCSPC board for time-resolved photon detection.
• Validated system accuracy using phantoms to determine optical properties and absorber concentrations.

Main Results:

• Demonstrated accurate determination of absorption and reduced scattering coefficients.
• Successfully reconstructed absorber concentrations in diffusive media.
• Achieved preliminary in vivo tissue-oxygenation measurements in volunteers with high temporal resolution (100 ms).

Conclusions:

• The developed compact TCSPC-based oximeter offers a promising tool for non-invasive tissue oxygenation monitoring.
• The system's speed and accuracy support potential clinical and research applications.
• Low injected power levels ensure safety for in vivo studies.