Polydimethylsiloxane tissue-mimicking phantoms with tunable optical properties.

Area of Science:

• Biomedical Optics
• Materials Science

Background:

• Polydimethylsiloxane (PDMS) is widely used for tissue-simulating phantoms due to its favorable properties.
• However, achieving tunable optical properties, specifically absorption and scattering, has been a limitation.

Purpose of the Study:

• To develop a robust technique for fabricating PDMS-based tissue-mimicking phantoms.
• To enable independent adjustment of absorption (μa(λ)) and reduced scattering (μs'(λ)) coefficients across the visible to near-infrared spectrum (500-850 nm).

Main Methods:

• Fabrication of PDMS phantoms by incorporating carbon black powder (CBP) for absorption and titanium dioxide powder (TDP) for scattering.
• Characterization using a broadband integrating sphere system and an inverse adding doubling algorithm.
• Analysis via fitting optical properties to linear and power law functions.

Main Results:

• Demonstrated independent tunability of μa(λ) and μs'(λ) by varying CBP and TDP concentrations.
• Developed a four-parameter method for concisely quantifying broadband optical properties.
• Showcased limited mimicry of human tissue scattering properties, with potential improvements using polystyrene microbeads.

Conclusions:

• The developed manufacturing and analysis techniques offer a robust method for creating PDMS tissue-mimicking phantoms.
• These techniques facilitate independent control over optical properties, enabling better tissue simulation.
• The approach supports enhanced quality control and quality assurance for phantom applications.