Time-domain NIRS system based on supercontinuum light source and multi-wavelength detection: validation for tissue...

Area of Science:

• Biomedical Optics
• Medical Instrumentation
• Spectroscopy

Background:

• Near-infrared spectroscopy (NIRS) is crucial for non-invasive tissue oxygenation monitoring.
• Existing NIRS systems often require wavelength switching, limiting acquisition speed and efficiency.
• A need exists for advanced NIRS systems capable of comprehensive spectral analysis in clinical environments.

Purpose of the Study:

• To present and validate a novel multi-wavelength time-domain near-infrared spectroscopy (TD-NIRS) system.
• To assess the system's performance for muscle and brain oxygenation monitoring.
• To demonstrate the system's capability using established protocols and phantom studies.

Main Methods:

• Utilized a pulsed supercontinuum laser emitting broadband light across 32 spectral channels.
• Acquired time-resolved photon distributions (DTOFs) at up to 3 Hz.
• Validated performance using BIP, MEDPHOT, and nEUROPt protocols with homogeneous and inhomogeneous phantoms, blood-lipid phantoms, and in-vivo human forearm measurements.

Main Results:

• The TD-NIRS system demonstrated accurate measurements of hemoglobin concentrations and oxygen saturation, closely matching reference values.
• System performance was quantitatively assessed for linearity, coupling, accuracy, and depth sensitivity.
• In-vivo measurements during cuff occlusions successfully monitored hemodynamic changes, aligning with physiological expectations.

Conclusions:

• The presented multi-wavelength TD-NIRS system offers a robust and efficient solution for clinical tissue oxygenation monitoring.
• The system's design, leveraging a supercontinuum source, provides comprehensive spectral data acquisition.
• Validated performance indicates its suitability for advanced research and clinical applications in neuromonitoring and muscle oximetry.