Schlangen L J M, Brokken D, van Kemenade P M
Philips Research Laboratories, Prof Holstlaan 4, Eindhoven, 5656 AA, The Netherlands.
Skin Res Technol. 2003 May;9(2):122-30. doi: 10.1034/j.1600-0846.2003.00016.x.
BACKGROUND/AIMS: Skin suction experiments are widely used in order to evaluate the effects of skin treatments, both for cosmetic and for dermatological purposes. Classically, the elevation of the skin is measured at different discrete time instances after the pressure has been changed. Relations between the classical parameters - Uv, Ur, Ue and Uf - have been investigated and used in order to develop a new model for interpreting the mechanical properties of the skin.
Within a group of 68 female subjects - aged between 37 and 68 - a Cutometer has been used in order to determine classical skin suction parameters on the female facial skin. Each skin suction measurement consists of three consecutive underpressure cycles. Within the resulting parameter set, a statistical analysis has been performed to investigate interparameter relations.
Strong interparameter correlations have been found within a set of 12 classical skin suction parameters. The set contains three independent groups of interrelated parameters. Based on this observation, a one-dimensional mechanical model - consisting of springs and dampers - is constructed. When two extra independent parameters are included in the model, the elevation versus time curves as recorded during three consecutive underpressure cycles can be fully described. The model reveals that typical skin suction data can be described in terms of a quick and a slow deformation process. The two characteristic time scales are 0.1 and 7 s approximately. The 0.1 s-value matches the response time of the device used. In reality, the quick deformation process in the skin may have a shorter time scale.
In skin suction data, each underpressure cycle is usually characterized by four classical parameters - Uv, Ur, Ue and Uf. Within the 12 parameters of a three-cycle measurement, three independent groups of interrelated parameters have been found. These groups can be represented by the parameters Uv1, Ur1 and Uf1 of the first underpressure cycle. A model that is based on these three independent groups and two other independent parameters is proposed. The model provides an accurate description of the skin deformation as recorded during a measurement involving three underpressure cycles. The model is an improvement over classical interpretations of skin suction data where interrelated parameters are used. Moreover, the five-parameter model accounts for well-known mechanical characteristics of the skin such as preconditioning and visco-elastic behavior.
背景/目的：皮肤抽吸实验被广泛用于评估皮肤治疗效果，无论是出于美容还是皮肤科目的。传统上，在压力改变后的不同离散时间点测量皮肤的隆起。已经研究了经典参数——Uv、Ur、Ue和Uf之间的关系，并用于开发一个解释皮肤力学特性的新模型。
在一组68名年龄在37至68岁之间的女性受试者中，使用皮肤弹性测定仪来确定女性面部皮肤的经典皮肤抽吸参数。每次皮肤抽吸测量由三个连续的负压循环组成。在所得参数集中，进行了统计分析以研究参数间的关系。
在一组12个经典皮肤抽吸参数中发现了很强的参数间相关性。该集合包含三个相互关联的独立参数组。基于这一观察结果，构建了一个由弹簧和阻尼器组成的一维力学模型。当模型中包含另外两个独立参数时，可以完整描述在三个连续负压循环期间记录的隆起随时间变化的曲线。该模型表明，典型的皮肤抽吸数据可以用快速和缓慢变形过程来描述。两个特征时间尺度分别约为0.1秒和7秒。0.1秒的值与所用设备的响应时间相匹配。实际上，皮肤中的快速变形过程可能具有更短的时间尺度。
在皮肤抽吸数据中，每个负压循环通常由四个经典参数——Uv、Ur、Ue和Uf来表征。在一个三个循环测量的12个参数中，发现了三个相互关联的独立参数组。这些组可以由第一个负压循环的参数Uv1、Ur1和Uf1表示。提出了一个基于这三个独立组和另外两个独立参数的模型。该模型准确描述了在涉及三个负压循环的测量过程中记录的皮肤变形。该模型是对使用相关参数的皮肤抽吸数据经典解释的改进。此外，五参数模型考虑了皮肤的诸如预处理和粘弹性行为等众所周知的力学特性。
