SU-E-J-67: A Potential New Technique to Measure Respiratory Tidal Volume Using Optical Surface Imaging: A Geometric...

Area of Science:

• Medical Imaging
• Biophysics
• Respiratory Physiology

Background:

• Accurate measurement of dynamic respiratory tidal volume is essential for clinical applications.
• Existing methods for measuring torso volume changes during respiration have limitations.
• Optical Surface Imaging (OSI) offers a potential non-invasive solution.

Purpose of the Study:

• To evaluate the feasibility of using Optical Surface Imaging (OSI) for accurate measurement of torso volume changes.
• To develop a novel method for assessing dynamic respiratory tidal volume.
• To validate OSI against established volume measurement techniques.

Main Methods:

• Utilized a clinical OSI system to capture surface images of geometric and deformable torso phantoms.
• Calculated phantom volumes from surface images using a treatment planning system.
• Compared OSI volume measurements with theoretical calculations, water displacement experiments, and CT scans for deformable phantoms.

Main Results:

• OSI demonstrated high accuracy for geometric phantoms (0.0%±1.6% vs. geometric calculation; 0.6%±3.8% vs. water containment).
• For deformable torso phantoms, OSI measured volume changes with 1.5%±2.5% accuracy compared to CT imaging.
• A strong one-to-one correlation (r²=0.999) was observed between OSI and CT volume measurements.

Conclusions:

• The OSI system accurately measures both static phantom volumes and dynamic torso volume changes.
• OSI provides a precise, non-invasive method for assessing respiratory volume changes, with an overall accuracy of approximately 3%.
• Further investigation involving human subjects is warranted to confirm clinical utility.