Time domain diffuse correlation spectroscopy with a high coherence pulsed source: in vivo and phantom results

Area of Science:

• Biomedical Optics
• Medical Imaging
• Physiological Monitoring

Background:

• Diffuse correlation spectroscopy (DCS) and time-resolved reflectance spectroscopy (TRS) aim for non-invasive tissue analysis.
• Standard DCS lacks path length resolution, limiting its quantitative accuracy compared to TRS.
• Previous time-domain DCS studies were restricted to phantoms and animal models.

Purpose of the Study:

• To demonstrate time-domain diffuse correlation spectroscopy (TD-DCS) for in vivo measurements.
• To achieve path length resolved DCS for improved quantification in human subjects.
• To assess the feasibility of TD-DCS for practical clinical applications.

Main Methods:

• Utilized an actively mode-locked Ti:Sapphire laser for high-coherence short pulses.
• Implemented TD-DCS for measurements on the adult forehead and arm.
• Achieved high signal-to-noise ratio with a temporal resolution of approximately 1 second.

Main Results:

• Successfully performed path length resolved DCS in vivo.
• Demonstrated the capability of TD-DCS for accurate tissue blood flow assessment.
• Validated the approach for human studies, overcoming previous limitations.

Conclusions:

• Time-domain DCS enables path length resolved measurements in vivo.
• This technique offers improved quantification for non-invasive tissue analysis.
• TD-DCS shows significant potential for translation to clinical practice.