Equipment

Equipment

Equipment

A number of equipment is available at Dermscan Asia for biometrological evaluation of skin improvement or skin characteristics following product application.  The application of equipment depends on skin parameters of interest as follows;

 

Skin Hydration

The Corneometer® CM825 (COURAGE & KHAZAKA) determines the humidity level of the most external cutaneous layers of the stratum corneum.  The action principle of the Corneometer® is based on the modification of the electrical capacities of the detector, which is designed in the form of a condenser.  The surface of the measurement head, in contact with the skin, modifies its electrical capacity according to the humidity level of the skin.  These modifications are directly recorded on a computer.

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Skin Elasticity

The Cutometer® MPA580 (COURAGE & KHAZAKA) evaluates skin rheological characteristics caused by a three dimensional network of collagen and elastin fibers of conjunctive tissue.  It is the only method capable of measuring variations, in human, induced by active pharmaceutical or topical agents over time.  The technique consists of skin aspiration by a measurement probe.  These measurements define different parameters characterizing the biomechanical properties of the skin.  The skin is sucked into the orifice of a probe by constant vacuum pressure for a set length of time.

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Skin Texture Properties

The Visioscan® VC98 (COURAGE & KHAZAKA) takes an image of skin directly from a probe with a built in CCD-camera.  The two special halogenide lights, arranged on opposite sides of a probe, illuminate the skin uniformly.  The spectrum of the light, its intensity and the way it is arranged is chosen so that only the stratum corneum without reflections from deeper layers is monitored.  This special light excludes almost all undesired light reflections on the skin, thus bringing out a very sharp, non-glossy image of the skin &hair.  The connection of Visioscan VC98 to the PC is done via an image digitalization unit which configures the image in 256 gray levels pixel by pixel, where 0 is black and 255 is white.  In addition to the image processing function, special software permits the calculation of a variety of skin surface parameters, SELS (Surface Evaluation of the Living Skin).  Four important parameters to quantitatively and qualitatively describe the skin surface as an index are skin smoothness, skin roughness, scaliness, wrinkle.

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Skin Colour

The Minolta Chromameter® CR400 and Spectrophotometer® CM700d (KONICA MINOLTA) converts colors perceived by human to a digital code composed of three parameters:

 

L*: for clarity (from dark to light),

 

a*: for the green-to-red spectrum,

 

b*: for the blue-to-yellow spectrum.

 

a* and b* are chrominance parameters and L* is a luminance parameter.

 

Hence, it is possible to detect the slightest difference between two cutaneous zones that appear to be the same color.  Measurements are done directly on the skin using a pulsed Xenon light source and a dual beam system designed to measure the light transmitted and to correct any slight deviation.

The parameters L* (luminance) and b* (cutaneous melanin yellow color) are studied during a

depigmenting product study.  Both parameters are exploited through the calculation of the

Individual Typological Angle (ITA°), which defines the skin pigmentation degree of a subject 

according to the following formula:

 

ITA° = [Arc tan((L*-50)/b*)x 180 / ¶

 

The higher the ITA° is, the lighter the skin is.

This means the higher the parameter L* is, the lighter the skin is.  And, the lower the parameter b* is, the less yellow the skin is.

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The Mexameter® MX18 (COURAGE & KHAZAKA) is a device which enables quick, easy, and accurate determination of the skin’s color and condition.  The device is equipped with a 5 mm diameter head, which particularly measures the content of melanin and hemoglobin in the skin.  These two components are mainly responsible for skin’s color.

The measurement is based on the absorption principle.  The special probe of the Mexameter® MX18 emits light of three pre-defined wavelengths (568nm, 660nm and 880nm).

The melanin is measured by two wavelengths, chosen in order to achieve different absorption rates by the melanin pigments.  The result is expressed as Melanin Index (mx).

For the erythema measurement, two different wavelengths are used to measure the absorption capacity of the skin.  One of these wavelengths corresponds to the spectral adsorption peak of hemoglobin.  The other wavelength has been chosen to avoid other color influences (e.g. bilirubin).  The result is expressed as Erythema Index (ex).

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Skin Barrier Protection

The Tewameter® TM300 (COURAGE & KHAZAKA) measures Trans Epidermal Water Loss (TEWL) due to evaporation of water from the skin.  The cutaneous barrier acts as a regulator in skin water balance.  When this is damaged, the water exchange regulation system becomes destabilized.  This means that water migrates more easily to the outside environment, increasing TEWL.  However, if the condition of the cutaneous barrier improves, water loss decreases as the water exchange regulation mechanism recovers its balance.

A probe is made up of two captors situates at a specific distance.  A flow of water travels from one captor to another and the difference of the partial pressure is measured between the two captors.  This value corresponds to the evaporation speed of a volatile substance (in this case, water).

By employing well-defined and strictly respected experimental conditions, the Tewameter® TM300 provides reliable, simple and rapid measurements of the skin protective, restructuring or even non-drying effects of cosmetic or dermopharmaceutical products.

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Skin Exfoliating

 

The restructuring effect is evaluated by analysis of D-Squam® using Skin Image Analyser® (S.I.A) with Quantisquam® software.

The surface of stripping is lightened in a standardized way (35°) and observed with a digital

camera linked to a computer.  A 1 cm2 area is studied.  This produces a digitized image, of which the grey level analysis gives a surface occupied by the taken squamae and an exfoliation index (calculated according to the occupied surface and the thickness of the cellular layers).

The analysis of strippings by the Quantisquam® software allows the study of various parameters in the process of desquamation.  The quantification of these parameters highlights the exfoliating or restructuring effect of cosmetic or dermopharmaceutic products.

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Skin Sebum

The Sebumeter® SM815 (COURAGE & KHAZAKA) measures quantitatively sebum or surface lipid excreted to the skin surface.  A synthetic ribbon is applied to the measurement zone for precisely 30 seconds.  The ribbon will become transparent when in contact with absorbed lipids and its transparency increases proportionally with the quantity of sebum.  A reflectometry recording is used to quantify the increase in the light transmitted and to determine the total mass of lipids excreted by surface unit (in µg/cm²).

Cutaneous lipids principally come from sebaceous gland secretions and are a non-uniform substance at the skin surface.  Their rate varies according to physiological variations (age, menstrual cycle, etc.) but also according to external factors (temperature, humidity, etc.).

Under standard operating conditions, Sebumeter® measurements present the double advantage of being rapid and direct.  The instrument is used to control skin type (dry, normal or oily) and to quantify, in vivo, the effect of cosmetic or dermopharmaceutical products on the cutaneous sebum rate (sebo – regulating effect).  A kinetic action from these types of products on the sebum rate can also be studied.

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Skin pH

The Skin pH meter® PH905 (COURAGE & KHAZAKA) is fitted out with a plane electrode which applies directly on studied cutaneous surface.  The quantity of H3O+ ions present on skin surface was determined by measuring the difference in potential between two electrodes combined as a single flat electrode (a Calomel reference electrode and an electron permeable glass electrode).  The plane configuration of this electrode allows for a maximum and uniform contact with the measured cutaneous surface.

This method is used to follow pH variations under the effect of cosmetic or hygiene products in a non-invasive manner and with accurate precision.

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UV Solar Simulator

The UV Solar Simulator 601 – 300W Multiport (SOLAR® LIGHT) precisely reproduces the solar UV spectrum (290 – 400 nm) while eliminating the visible and infrared light.  This results in UV levels 15 – 20 times stronger than tropical sun without the thermal portion.  The Solar Simulator can produce UVA or UVB from its 6 individual outputs.  The intensity of light from each output can be adjusted individually providing the capability to deliver different doses of UV from each of the 6 outputs.  This allows for 6 tests to be conducted simultaneously, greatly reducing testing time.

Solar® Light Solar Simulators are used in 95% of SPF testing laboratories globally and meet the latest COLIPA, JCIA, and FDA spectral irradiance standards.

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Vsia

A new tool for face imaging & analysis at Dermscan Asia is available for quantitative assessment of skin features such as spots, pores, wrinkles, evenness, porphyrins, UV spots and photo damage.  Other key features are multi-spectral imaging by using standard white light, cross-polarized flash and UV photography to record and measure surface and subsurface skin condition, reproducible facial photography to ensure reproducibility of images between time points with built-in positioning aids, RBXTM technology providing extraordinary new visualization and analysis of sub-surface melanin and vascular conditions. 

Vsia