In Vivo Measurement of Optical Properties of Human Skin for 450–800 nm and 950–1600 nm Wavelengths

Abstract

Laser or light-emitting diode therapy has been developed for medical care and skin rejuvenation. Some of these therapies are not only ineffective, but also unsafe. To address these issues, the optical properties of human skin that characterize radiation transfer to the skin have to be clearly understood. In this study, we use in-house instruments to measure the in vivo absorption and scattering coefficients for 198 Japanese participants in visible (450-800 nm) and near-infrared (950-1600 nm) region. The average values and standard deviations of the optical properties are recorded. The effects of age, gender, and body parts on these parameters are analyzed. For the scattering coefficient, the highest value is observed for the inner forearm and the lowest for the region between the thumb and forefinger; females exhibit higher values than males in the visible and some of near-infrared wavelengths; and the value decreases with the age for males in the visible region. In terms of the absorption coefficient, males exhibit higher values than females in the visible region and some of near-infrared wavelength; and the values increase with age in the visible region; the magnitude relations between the body parts differ with the wavelength.

Characterizing reduced scattering coefficient of normal human skin across different anatomic locations and Fitzpatrick skin types using spatial frequency domain imaging

“…3 and 4 ). The difference in scattering properties among anatomical locations has been previously attributed to anatomical structural variations, 16 – 18 , 20 including skin thickness, collagen structures, and mitochondrial density. 31 For all 15 subjects, we observed highest values for cheek and forehead (averaged 1.52 and , respectively, in Fig.…”

“…Kono et al used reflection spatial profile measurement to measure optical properties at 450 to 800 nm and 950 to 1600 nm for 198 subjects on the inner forearm, cheek, and dorsal hand between thumb and forefinger. 20 However, these studies had two limitations: (1) they only covered a small range of anatomical locations for measurements of scattering properties and (2) the measurement systems were restricted to point-based or single-line measurements that required multiple measurements to characterize the heterogeneity of large regions on the body. In summary, clinical translation of DOS requires a broader characterization of in vivo human skin that spans multiple anatomical locations and pigmentation levels, while also accounting for the heterogeneous nature of each sampled region.…”

Reliability assessment for blood oxygen saturation levels measured with optoacoustic imaging

“…For both tissue segments, the μ eff spectra are in line with the broad range of effective attenuation coefficients of human tissue reported in the literature (approximately between 0.1 and 1 mm −1 ). [39][40][41][42][43] Note that, for both the artery and the vein, spectral correction was only performed for the respective subset of irradiation positions corresponding to the tissue segment that is optically characterized by the μ eff given in Fig. 5.…”

Optical characteristics of human skin with hyperpigmentation caused by fluorinated pyrimidine anticancer agent

“…In our previous study, we measured the optical properties of the skin of 198 Japanese people with normal skin [19]. The normal Japanese skin typically classified as III to IV according to the Fitzpatrick Skin Type [20].…”