A Photoplethysmography Melanin Evaluation System by Modified Boltzmann Transport Equation (BTE)

Sheng-Chieh Huang,Hui-Min Wang,Shi-Han Luo

doi:10.1155/2015/879340

Sheng-Chieh Huang, Hui-Min Wang + Show 1 more

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https://doi.org/10.1155/2015/879340

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Abstract

With the advance in cosmetic medical technology in recent years, more and more people get cosmetic medical treatments, especially skin whitening treatments. Nevertheless, people usually assess the effect of skin whitening products by vision, which is subjective and will be different from each person. To acquire the value of melanin concentration objectively, people need to go to cosmetic medical clinics. This will cause inconvenience to people. This paper develops a novel evaluation platform based on optical assessment methods, which employ different absorption and scattering properties to different wavelengths of light in human tissue to obtain melanin concentration. Moreover, this paper proposes a new method that compensates the interaction between epidermis and dermis to acquire the melanin concentration more accurately. The novel platform designed in this paper is smaller and consumes lower-power and smaller when comparing to other conventional devices in market.

Highlights

The number of medical devices used in the global market is expected to be much more in the future [1], while noninvasive treatments and skin care products are more accepted to the mass population due to their safety and efficiency and result in the fast growing of the global cosmetic market [2]
To evaluate the melanin concentration and other tissue properties, most bibliographies are usually based on Boltzmann transfer equation (BTE) [7,8,9,10,11,12], Beer-Lambert law simplified from the BTE [13,14,15,16,17,18], or empirical equations derived from diffuse reflectance model and Boltzmann transfer equation [19,20,21,22]
This study proposes a new method that compensates the nonlinearity of chromophores to calculate the melanin concentration

Summary

Introduction

The number of medical devices used in the global market is expected to be much more in the future [1], while noninvasive treatments and skin care products are more accepted to the mass population due to their safety and efficiency and result in the fast growing of the global cosmetic market [2]. The light scattered from the dermis (where hemoglobin mainly exists) will interact with the tissue in the epidermis and the main absorber is melanin. This will cause the nonlinearity and nonindependence of contribution from each concentration. The optical properties of tissue include multiple scattering, absorption, optical pathways in skin, and the penetration depth of light. Absorption in skin over the visible and near-infrared spectrum is mainly caused by many kinds of chromophores: melanin, hemoglobin, water, bilirubin, and beta-carotene [13, 21, 36,37,38,39,40].

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60 W 0–100

Conclusion