Virén T, Iivarinen J T, Sarin J K, Harvima I, Mayrovitz H N
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Cancer Center, Kuopio University Hospital, Kuopio, Finland.
Int J Cosmet Sci. 2018 Apr;40(2):134-140. doi: 10.1111/ics.12444. Epub 2018 Feb 20.
The aim of this study was to evaluate the performance of a hand-held indentation device for fast and reliable determination of skin stiffness.
Device accuracy to indentation depths of 0.6 and 1.3 mm was first evaluated on plastic foam materials with mechanical properties verified by a laboratory material testing device. Subsequently, the device's sensitivity to detect age-related changes in skin stiffness was evaluated among 46 healthy women (18-79 years). Finally, the reproducibility of the method was tested with six healthy subjects.
High correlation was detected between indentation stiffness of reference material and Young's modulus determined with mechanical testing device (0.6 mm indenter: r = 0.97, P = 0.05; 1.3 mm indenter: r = 0.98, P = 0.04). Age-related decrease of 38% in skin stiffness was observed in healthy volunteers (P < 0.05). The coefficient of variation for 0.6 and 1.3 mm indenters was 7.4% and 8.5%, respectively. No trend related to hysteresis effect was observed from repeated measurements.
The presented indentation technique was accurate against the laboratory material testing device. Furthermore, skin changes related to ageing could be detected with the indentation technique. The new device was found to be feasible for monitoring skin stiffness in cosmetics and clinical conditions.
本研究旨在评估一种手持式压痕装置在快速、可靠地测定皮肤硬度方面的性能。
首先在通过实验室材料测试装置验证了机械性能的塑料泡沫材料上，评估该装置对0.6毫米和1.3毫米压痕深度的准确性。随后，在46名健康女性（18 - 79岁）中评估该装置检测与年龄相关的皮肤硬度变化的敏感性。最后，对6名健康受试者测试该方法的可重复性。
参考材料的压痕硬度与通过机械测试装置测定的杨氏模量之间存在高度相关性（0.6毫米压头：r = 0.97，P = 0.05；1.3毫米压头：r = 0.98，P = 0.04）。在健康志愿者中观察到皮肤硬度随年龄增长下降了38%（P < 0.05）。0.6毫米和1.3毫米压头的变异系数分别为7.4%和8.5%。重复测量未观察到与滞后效应相关的趋势。
所提出的压痕技术相对于实验室材料测试装置是准确的。此外，通过压痕技术可以检测到与衰老相关的皮肤变化。发现这种新装置在化妆品和临床情况下监测皮肤硬度是可行的。
