Diffuse reflectance spectroscopy as a tool to measure the absorption coefficient in skin: system calibration

Area of Science:

• Biomedical Optics
• Dermatology
• Medical Physics

Background:

• Personalized laser skin treatments require understanding individual skin optical properties.
• Melanin content varies significantly across skin phototypes, affecting laser light absorption.
• Accurate measurement of optical properties is crucial for optimizing laser treatment efficacy and safety.

Purpose of the Study:

• To determine individual skin absorption coefficients using diffuse reflectance spectroscopy.
• To calibrate a diffuse reflectance spectroscopy probe for in vivo measurements.
• To assess the feasibility of near-real-time optical property determination for personalized laser therapy.

Main Methods:

• Utilized a seven-fibre diffuse reflectance spectroscopy probe (450-800 nm).
• Calibrated the probe using skin-simulating phantoms (intralipid and ink).
• Measured diffuse reflectance in vivo on three volunteers (skin phototypes II, IV, V) on sun-exposed and non-exposed arm areas.

Main Results:

• Successfully calibrated the diffuse reflectance spectroscopy system.
• Calculated in vivo absorption coefficients from volunteer measurements.
• Demonstrated the technique's ability to differentiate optical properties based on skin phototype and sun exposure.

Conclusions:

• Diffuse reflectance spectroscopy is a viable in vivo method for determining individual skin absorption coefficients.
• This technique supports the development of personalized laser treatments tailored to specific skin optical properties.
• Near-real-time measurement of optical properties can enhance laser treatment safety and effectiveness.