Real-Time Dual-Wavelength Time-Resolved Diffuse Optical Tomography System for Functional Brain Imaging Based on...

Area of Science:

• Biomedical Optics
• Neuroimaging
• Photonics

Background:

• Near-infrared diffuse optical tomography (DOT) is a non-invasive imaging technique for functional brain imaging.
• Compact time-domain DOT systems utilizing silicon photomultipliers (SiPM) have been developed.
• Previous systems required longer measurement times and offered lower temporal resolution.

Purpose of the Study:

• To present an upgraded, compact time-domain diffuse optical tomography system.
• To enhance the system's speed and imaging capabilities for functional brain studies.
• To enable real-time quantification of hemoglobin concentration changes.

Main Methods:

• The system was upgraded with eight SiPM detectors and six injection fibers for multi-point illumination.
• An automatic switch was incorporated for measurements under one second.
• A dual-wavelength (670 nm and 820 nm) light source was implemented for quantifying oxy- and deoxy-hemoglobin.
• The system was validated using a solid phantom and in-vivo tests (arm occlusion, motor cortex activation).

Main Results:

• The upgraded system demonstrated the capability to perform complete measurements in under one second.
• The dual-wavelength source allowed for quantification of hemoglobin concentration dynamics.
• In-vivo tests successfully tracked brain activation with a 1-second resolution.
• The system proved effective in monitoring dynamic physiological processes.

Conclusions:

• The novel diffuse optical tomography system offers high temporal resolution for functional brain imaging.
• The system's speed and sensitivity enable detailed monitoring of brain activity.
• This technology advances non-invasive neuroimaging capabilities.