Comprehensive Optimization of Interferometric Diffusing Wave Spectroscopy (iDWS)

Area of Science:

• Biomedical Optics
• Neuroscience
• Medical Imaging

Background:

• Noninvasive measurement of cerebral blood flow index (CBFi) is crucial for neurological monitoring.
• Conventional Diffuse Correlation Spectroscopy (DCS) has limited brain sensitivity for CBFi in adults.
• Emerging techniques aim to improve diffuse light throughput for enhanced brain sensitivity.

Purpose of the Study:

• To optimize interferometric diffusing wave spectroscopy (iDWS) for improved CBFi monitoring.
• To enhance system performance regarding channel count, camera parameters, power, noise reduction, and data processing.
• To establish stable operating conditions for a mobile iDWS system.

Main Methods:

• Systematic optimization of iDWS parameters: channel number, camera duty cycle, full well capacity, incident power.
• Implementation of noise and artifact mitigation strategies.
• Development of advanced data processing algorithms for pulsatile CBFi monitoring.

Main Results:

• Demonstration of pulsatile CBFi monitoring at 4-4.5 cm source-collector separation in adults with Fitzpatrick skin type 4.
• Successful preliminary clinical measurements in a Neuro Intensive Care Unit (Neuro ICU).
• Significant improvements in iDWS performance beyond previous reports.

Conclusions:

• Optimized iDWS offers enhanced noninvasive CBFi monitoring capabilities.
• The developed system demonstrates feasibility for clinical application in neurocritical care.
• This advancement pushes the performance limits for diffuse light spectroscopy in brain monitoring.