Diffuse optics for monitoring brain hemodynamics

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Physics

Background:

• Cerebral hemodynamics are critical for brain function and are often altered in patient populations.
• Non-invasive optical techniques offer promising methods for monitoring brain blood flow and oxygenation.
• Previous studies have explored various modalities, but direct comparisons and feasibility in diverse patient groups require further investigation.

Purpose of the Study:

• To review recent diffuse optics experiments at PENN investigating cerebral hemodynamics.
• To demonstrate the feasibility of diffuse correlation spectroscopy (DCS) for measuring cerebral blood flow.
• To evaluate traditional near-infrared (NIR) measurements for cerebral blood volume and oxygen saturation.

Main Methods:

• Utilizing diffuse optics, specifically DCS and NIR spectroscopy, to assess cerebral hemodynamics.
• Employing optical methods to evaluate cerebral responses to functional perturbations like posture changes.
• Directly comparing optical methodologies with established techniques such as transcranial Doppler Ultrasound (TCD), Xenon-CT, and MRI.

Main Results:

• Demonstrated the feasibility of DCS for measuring cerebral blood flow.
• Showcased the utility of NIR measurements for cerebral blood volume and oxygen saturation.
• Validated optical methods against TCD, Xenon-CT, and MRI in patient and normal populations.

Conclusions:

• Diffuse optics techniques are feasible and effective for assessing cerebral hemodynamics in various patient populations.
• Optical methods provide valuable, non-invasive insights into brain blood flow, volume, and oxygenation.
• These findings support the broader clinical application of diffuse optics in neuroscience and patient monitoring.