Emulation of Brain Metabolic Activities Based on a Dynamically Controllable Optical Phantom.

Area of Science:

• Biomedical Optics
• Neuroimaging
• Materials Science

Background:

• Accurate simulation of brain metabolic activities is crucial for advancing neuroimaging techniques like near-infrared spectroscopy (NIRS).
• Existing optical phantoms often lack the dynamic range and control needed to mimic complex physiological changes.
• Developing advanced phantoms is essential for validating NIRS instrumentation and algorithms.

Purpose of the Study:

• To present a novel dynamic optical phantom capable of simulating brain metabolic activities.
• To establish a linear equivalent model for controlling substance concentration via voltage.
• To enhance the simulation capabilities for near-infrared spectroscopy (NIRS) signals.

Main Methods:

• Fabrication of a solid-solid dynamic optical phantom using epoxy resin, nanometer carbon powder, and titanium dioxide powder.
• Integration of liquid crystal film as a voltage-controlled light intensity regulator.
• Validation of the phantom's ability to mimic oxy-hemoglobin and deoxy-hemoglobin concentration changes.

Main Results:

• The dynamic phantom successfully mimicked near-infrared spectrum (NIRS) signals with a sampling rate up to 10 Hz.
• Maximum simulation errors for oxy-hemoglobin and deoxy-hemoglobin concentrations were 7.0% and 17.9%, respectively.
• The adjustable mimic substance concentration range was extended by an order of magnitude compared to similar phantoms.

Conclusions:

• The developed dynamic optical phantom provides a robust platform for simulating brain metabolic activities.
• The phantom's performance meets the simulation requirements for most brain NIRS applications.
• This advancement facilitates more accurate validation and development of NIRS-based neuroimaging technologies.