Enhancing skin tone representation in optical vascular phantoms

Area of Science:

• Biomedical Engineering
• Optical Technology
• Materials Science

Background:

• Racial disparities and bias in optical medical devices disproportionately affect individuals with darker skin tones, impacting diagnostic accuracy and healthcare equity.
• There is a critical need for more representative tools in the testing and development of optical medical devices to ensure equitable performance across diverse populations.
• Current testing methods often lack adequate representation of various skin tones, leading to potential misdiagnosis and biased outcomes.

Purpose of the Study:

• To develop optical skin-mimicking phantoms that accurately represent a wide range of human skin tones.
• To create a practical and durable tool for the development and evaluation of optical medical and consumer wearable devices.
• To address the issue of misdiagnosis in people of color by providing equitable testing solutions.

Main Methods:

• Multi-layered, water-free silicone-based optical phantoms were designed and fabricated to mimic the optical and mechanical properties of skin.
• A vascular structure was integrated into the phantoms, coupled with a micropump system to simulate blood flow.
• The phantoms were rigorously evaluated using spectroscopy and hyperspectral imaging techniques.

Main Results:

• Phantoms with varying skin tones, characterized by individual typology angle values from 51.4 to -7.5 degrees, demonstrated optical and mechanical properties comparable to real skin.
• Spectroscopic analysis revealed closer spectral agreement with skin using coffee-based pigmentation compared to commercial pigment mixtures.
• The darker superficial phantom layer effectively masked the spectral signature of the blood-mimicking liquid, simulating heavily pigmented epidermis.

Conclusions:

• The successful demonstration of optical skin-mimicking phantoms with integrated vascular structures and diverse skin tones offers a significant advancement.
• These phantoms serve as valuable and durable tools for enhancing the development of optical medical devices and consumer wearables.
• The developed phantoms have the potential to improve the accuracy and equity of optical technologies for diverse global populations.