A quantitative assessment of the depth sensitivity of an optical topography system using a solid dynamic...

Area of Science:

• Biomedical Optics
• Medical Imaging Technology
• Physiological Monitoring

Background:

• Continuous wave optical topography (CW-OT) is a non-invasive imaging technique.
• Accurate depth localization is critical for interpreting CW-OT data from deep tissues.
• Developing reliable phantoms is essential for calibrating and validating optical imaging systems.

Purpose of the Study:

• To develop and validate a solid dynamic phantom for assessing the depth sensitivity of CW-OT systems.
• To simulate physiological hemodynamic changes within tissue-like optical properties.
• To evaluate the accuracy of image reconstruction algorithms for depth localization.

Main Methods:

• A solid dynamic phantom with tissue-mimicking optical properties was created.
• Seven discrete targets with thermochromic pigment were embedded at varying depths.
• Localized heating simulated hemodynamic changes, inducing absorption variations.
• Image reconstruction employed spatially variant regularization for depth analysis.

Main Results:

• The phantom successfully assessed the depth sensitivity of the CW-OT system.
• Simulated hemodynamic changes were effectively reproduced.
• Image reconstruction achieved accurate spatial localization in the depth direction.
• Depth localization accuracy was within approximately 3 mm down to 30 mm.

Conclusions:

• The developed solid dynamic phantom is a valuable tool for validating CW-OT systems.
• The phantom enables precise assessment of depth sensitivity and imaging accuracy.
• This technology holds promise for improving non-invasive monitoring of tissue hemodynamics.