Terahertz (THz) in vivo reflection imaging can be used to assess the water content of the surface of the skin. This study presents the results of treating 20 subjects with aqueous, anhydrous and water-oil emulsion samples and observing the changes induced in the skin using THz sensing. These regions were also measured with a corneometer, the present gold standard for skin hydration assessment within the cosmetics industry. We find that THz sensing is effective at observing the presence of oil and water on the surface of the skin, these results can be verified with the measurements of capacitance taken by the corneometer. The THz measurements reveal a distinction between the responses of subjects with initially dry or well hydrated skin, this observation is particularly noticeable with the oil-based samples. Additionally, moderate correlation was found between the THz reflected amplitude and capacitance of untreated skin with a correlation coefficient of r = −0.66, suggesting THz sensing has promising potential for assessing skin hydration.

体内的太赫兹（THz）反射成像可用于评估皮肤表面的水分含量。这项研究提出了使用含水，无水和水油乳剂样品治疗20名受试者的结果，并使用THz传感观察了皮肤中诱导的变化。这些区域也用角质计测量，角质计是化妆品行业中皮肤水合评估的现行金标准。我们发现太赫兹感测在观察皮肤表面上油和水的存在方面是有效的，这些结果可以通过角膜仪测量的电容来验证。太赫兹（THz）测量揭示出最初皮肤干燥或水分充足的受试者的反应之间的区别，这种观察在油基样品中尤为明显。此外，r = −0.66，表明太赫兹感测在评估皮肤水合作用方面具有潜力。