头发过度暴露在阳光下可导致人头发的化学和物理损伤。新型多光谱测量系统本工作中，我们报告了一种新型的对头发光损伤进行无损测定的多光谱成像技术。多光谱测量系统研究表明，在近红外区域的多光谱反射与头发损伤有很强相关性。较具体的说，拥有较长生长时间的头发片段以及相同头发的根部区域经过持续紫外辐射后，光损伤较严重，经电子显微镜图像观察，显示出较高的多光谱反射值。除此，通过将相同头发根部区域置于特定紫外辐射之下，可重读不同生长时间的头发片段的多光谱反射值，这表明MSI多光谱成像技术完全可用于测定头发日照时间。光损伤头发的胱氨酸含量丢失被鉴定为是头发表面纤维形态变化的主要生理因素。考虑到自然头发的环境状况，我们相信MSI无损评估头发损伤技术可在生物医疗领域评估测试目标的日照时间。

A novel method for non-destructive determination of hair photo-induced damage based on multispectral imaging technology

Yue Cao，, Hao Qu，, Can Xiong，, Changhong Liu & Lei Zheng

Scientific Reports 7, Article number: 45544 (2017)

Abstract

Extended exposure to sunlight may give rise to chemical and physical damages of human hairs. In this work, we report a novel method for non-destructive quantification of hair photodamage via multispectral imaging (MSI) technology. We show that the multispectral reflectance value in near-infrared region has a strong correlation with hair photodamage.More specifically, the hair segments with longer growing time and the same hair root segment after continuous ultraviolet (UV) irradiation displaying more severe photodamage observed via scanning electron microscopy (SEM) micrographs showed significantly higher multispectral reflectance value. Besides, the multispectral reflectance value of hair segments with different growing time was precisely reproduced by exposing the same hair root segment to specific durations of UV irradiation, suggesting that MSI can be adequately applied to determine the sunlight exposure time of the hair. The loss of cystine content of photodamaged hairs was identified to be the main factor that physiologically contributed to the morphological changes of hair surface fibers and hence the variation of their multispectral reflectance spectra. Considering the environmental information recording nature of hairs, we believe that MSI for non-destructive evaluation of hair photodamage would prove valuable for assessing sunlight exposure time of a subject in the biomedical fields.