A dynamic phantom brain model for near-infrared spectroscopy

Area of Science:

• Biomedical Engineering
• Medical Physics
• Neonatal Research

Background:

• Near-infrared spectroscopy (NIRS) is crucial for monitoring neonatal brain oxygenation.
• Accurate NIRS instrument calibration requires reliable in vitro models.
• Existing models may not fully replicate neonatal brain physiology and optical properties.

Purpose of the Study:

• To develop and characterize an in vitro neonatal brain model for NIRS instrument testing.
• To validate the model's fluid dynamics and optical properties against a neonatal piglet brain.
• To assess the model's utility for ensuring NIRS accuracy and reliability.

Main Methods:

• Construction of a vascularized neonatal brain phantom.
• Perfusion system with regulated blood gas and hemoglobin concentrations.
• Characterization using fluid dynamics, co-oximetry, and time-resolved/continuous wave NIRS.
• Comparison of optical properties with in vivo neonatal piglet brain data.

Main Results:

• The model demonstrated stable fluid dynamics with minimal hemolysis.
• Optical properties (absorption, scattering, pathlength) closely matched neonatal piglet brain across varying oxygenation states (0-100%).
• No significant differences were observed between model and piglet brain optical parameters.

Conclusions:

• The developed in vitro neonatal brain model accurately replicates the optical properties of a neonatal piglet brain.
• This dynamic phantom provides a validated platform for testing and calibrating NIRS devices.
• The model enhances the reliability and accuracy of NIRS measurements in neonatal applications.