EP2884882A1

EP2884882A1 - Improved skin and scalp diagnosis device and method

Info

Publication number: EP2884882A1
Application number: EP13707376.3A
Authority: EP
Inventors: Walter Arkesteijn
Original assignee: Symae Technologies Holding BV
Current assignee: Symae Technologies Holding BV
Priority date: 2012-08-20
Filing date: 2013-03-01
Publication date: 2015-06-24
Also published as: WO2014029509A1

Abstract

A device for determining elastic and/or visco-elastic properties of skin or scalp, comprising a measuring probe having a probe pin and a measurement system for registering a displacement of the probe pin, wherein the probe pin is provided in a probe chamber having an opening for contact of the probe pin with skin or scalp, the probe pin being biased to be flush with the opening or to protrude from the opening., a surrounding of the opening and/or a part of the opening being provided with one or more recesses, the device further comprising a pump connected to each of the recesses for applying an under-pressure in each of the one or more recesses.

Description

Improved skin and scalp diagnosis device and method

Technical field

The present disclosure relates to skin and scalp diagnosis tools, more in particular to a device for determining elastic and/visco-elastic properties of skin or scalp. However, the disclosure also relates to a test strip reader for receiving a test strip in light path between at least one visible or invisible light source and at least one light sensor, the test strip being for collecting sample material from skin or scalp. Furthermore, the disclosure relates to a number of test strips for collecting sample material from skin or scalp.

Background Art

The objective assessment of the condition and type of someone's skin, either being facial, body or scalp skin is important in the fields of dermatology, pharmacy and cosmetics. Instruments which can measure or objectively rate parameters that are considered relevant in the definition of skin type and skin condition are a necessity in the objective determination of cosmetic safety and efficacy, the determination of a suitable care regiment, or the selection of cosmetical products for a particular condition or type.

Various ways for assessing skin type and skin condition or the effect of a treatment are available. A common method makes use of a questionnaire about life style, skin care and skin perception, with or without the rating of observations which in combination with a scoring system leads to a determination of a skin type and skin condition. An example can be found in HO 2006/055902 (BADMANN LESLIE) 26-5-2006. Skin type and skin condition assessment methods which are solely based on questionnaires and observations are criticized because of their sensitivity to errors of interpretation, perception and influences like lacking expertise, commercial interest or empathy.

Therefore, instruments for measuring and analysing to help objectively determine characteristics of the skin are available. Examples of such instruments can be found in US 2009253162 (REVEAL SCIENCES LLC) 8-10-2009. That particular invention consists of a computer connected imaging system in combination with skin test strips and is therefore relatively large. Compact solutions that apply an imaging system to read out skin test strips are known from patent application KR 20010110850 (WON IL) 15-12-2001 and commercial products like the Aramo Smart from Aram Huvis (South Korea) . However, the methods offered by such systems are known to be impractical and inaccurate as they are sensitive to differences in illumination, focussing and movement of the test strip during the acquisition.

BP 2339964 (OREAL) 6-7-2011 describes a handheld system able to measure skin characteristics like sebum, skin tone and the hydration state of the stratum coraeum. Unfortunately, the applied test strips miss sensitivity in the low and medium sebum ranges and the device lacks means for measuring bio-mechanical skin characteristics. Also the actual momentary hydration level of the skin is measured instead of assessing the actual condition of the stratum comeum differentiation and desquamation processes.

The understanding of the causes and mechanisms that lead to a dry skin condition are known to be very complex, a point well brought forward in the article by MATTS, P.J., et al. The 'Dry Skin Cycle* - A New Model of Dry Skin And Mechanisms for Intervention. Royal Society of Medicine Press Ltd, 2007. Therefore, one of the objectives of the presently disclosed inventions is to provide improved and more accurate means for determining 'skin dryness' .

The subjective assessment of skin dryness by sight or touch is complicated by the influence of the ambient meteorological conditions on the skin's hydration state. Skin lipids filling the open structures of scaly skin reduce the scattering and reflection of light of the scales. As a consequence of those conditions the visual appearance of signs related to a dry skin condition are greatly diminished.

Also, many years of training an experience are required to make an accurate skin dryness determination on such visual observation alone. In an effort to solve this, skin hydration measuring devices like the Courage hazaka Corneometer® or the Moritex Moist Sense are used as help in the assessment of skin dryness. However, it is commonly known that a high ambient temperature and humidity may provide misleading information regarding the true condition of the progression of the stratum corneum desquamation and differentiation process as the measured water content of the stratum corneum is of influence to these processes but does not deterministically define them. As climate conditions vary significantly, especially in an uncontrolled environment like the point-of-sale, a casual hydration measurement can easily lead to a misinterpretation of the condition of the stratum corneum.

In a similar way skin surface lipid levels are considered an important parameter which is commonly linked to the performance of desquamation and differentiation processes but again these do not deterministically control or regulate them.

It is also known that the mechanism which regulates these mechanisms does not work identically in the skins of different individuals or at different areas of the body of the same individual. There are also abnormal skin conditions like seborrheic dermatitis or psoriasis in which the mechanisms that regulate the processes are disrupted while individual skin parameters may appear normal.

An alternative approach to assess the skin dryness state is not by measuring important process contributors but by actually sampling and studying information resulting from the desquamation and shedding processes itself.

In the dermatological research industry, tape stripping of the skin' s surface is a commonly used method to sample and study the condition of the stratum comeum desquamation and shedding process. Traditionally stripping materials are constructed as a clear transparent film which has an adhesive surface. When this material is applied to the skin's surface and peeled off, the corneocytes from the surface of the skin are collected on the adhesive surface. Commonly used tape stripping materials are the D-Squame^® discs from the CUDERM Corporation from Dallas, Texas, USA and the Corneofix · tape from Courage hazaka, Cologne, Germany.

It is commonly accepted that the structure and thickness of the collected clusters of corneocytes on the tape strip are linked to the health state of the stratum comeum. For instance a dry skin condition can lead to an abnormal cohesion of the corneocytes and an abnormal course of the desquamation and shedding process. A tape stripping of a skin in such condition will reveal large and thick clumps of stuck-together corneocytes instead of single cells.

The tape strippings can be visually evaluated when held against a dark background, creating a contrast against the white corneocytes clumps on the tape' s surface or they can be quantified using various methods. Simple visual light or infrared absorbance methods are described in SBRUP, J. , et al. A simple method for the study of scale pattern and effects of a moisturizer-qualitative and quantitative evaluation by D-Squame^® tape compared with parameters of epidermal hydration. Clinical Experimetal Dermatology. 1989, vol.14, p.277-282; and in VOEGLE, R. , et al. Efficient and simple quantification of stratum corneum proteins on tape strippings by infrared densitometry; Skin Research and Technology. 2007, vol.13, p.242-251.

An alternative method to quantify the amount of collected corneocytes is via the colour measurement of stained samples as described in the article by PIERARD, G.E., et al. Squamometry: The assessment of xerosis by colorimetry of D-Squame adhesive discs. Journal of the Society of Cosmetic Chemists. 1992, vol.43 , no.6, p.297-305. A more advanced method is by means of image analysis SCHATZ, H., et al. Quantification of dry (xerotic) skin by image analysis of scales removed by adhesive discs (D-Squames) . Journal of the Society of Cosmetic Chemists. 1992, vol.47, p.297-305.

In cosmetic practice, skin type are usually distinguished in in three to four classes; normal, combined, lipid dry and oily skin. These skin type definitions are commonly used by consumers to describe their skin when seeking proper skin care and cosmetic products. It is commonly known that the usage of cosmetics types which are intended for other skin types may create adverse effects.

Typically questionnaire systems as previously described are used as aid in this assessment. Alternative methods rely on measurement instruments or assessment aids which visualize parameters which are believed relevant to the skin type definition. Typically, the casual lipid level of the skin's surface is commonly used as an important parameter in the determination of cosmetic skin type.

These skin surface lipids are a complex composition resulting from the mixture epidermal components and the secretions coming from the sebaceous and other glands. In cosmetics, pharmacy and the dermatology field various methods are known to quantify skin surface lipids. Good overviews of such methods are described in the article CLARYS, P., «t al. Quantitative evaluation of skin surface lipids. Clinics in Dermatology. 1994, vol.13, no. , p.307-321; and in the preambles of DB 3213944 (HENKEL KGAA) 27-10-1983 and US 4738537 (OREAL) 19-4-1988

The visualization and measurement concepts of these methods of can roughly be divided in four types: The first is a method where the skin surface lipids are transferred to a flat, lens or prism shape optical element having a texture- less surface. The lipids adhering to this surface will distort the optical behaviour of the element. The amount of this distortion is considered to be an indication of the amount of skin surface lipids. Examples of inventions using such a technique are described in US 4494869 (NEUMANN HANS D) 22-1-1985. and JP 2004077332 (MORITEX CORP) 11-3-2004. The construction from this Japanese patent is known from products like the Moritex Triple Sense. An important disadvantage of this measurement method is the early saturation of the measurement system. This is caused by the fact that the imporous measurement surface cannot absorb skin lipids. As a consequence, it is practically impossible to accurately measure medium and high lipid levels. Also, as the measurement is solid and not pliable, the measured result is influenced by the contact surface area. This is especially notable when measuring textured or wrinkled skins.

The second method relies on the change of transparency of a matted optical element. When skin lipids are transferred to a ground glass plate or a transparent foil with a matt surface, the skin lipids will fill the porous surface cavities of the optical element allowing more light to pass the optical element instead of scattering of the surface.

The amount of deposited skin lipids are then linked to the change of light transmission, a concept, which is for example well described in the patent application US 4738537 (OREAL) 19-4-1988. Examples of products which work on such principle are the Courage hazaka Sebumeter^® and the instrument called Lipometre® from l'Oreal. Though a matted surface has a slightly higher absorbance volume then the texture-less measuring surface of the first method, it is known to lack sensitivity in the higher measuring ranges. Another disadvantage of this method is its inability to differentiate the epidermal lipids from the lipids secreted from the sebaceous glands.

The third method relies on the principle that the optical transparency of a microporous, lipid absorbing material changes when skin surface lipids are absorbed into the microscopic pores of the material. The transfer of lipids into these porous surface cavities causes a local change in transparency. The extent and pattern of this transparency changes provides information about the amount of lipids present on the skin, information which is considered relevant for the determination of skin type. A disclosure according to this principle is described in US 5935521 (COURAGE BREWING LTD) 10-8-1999 . An example of a commercially available product according to his concept is the Courage Khazaka Sebufix* skin lipid absorption foil. The main disadvantages of this method are the low sensitivity to low casual skin lipid levels, the long application time of the testers on the skin and its insensitivity to lipids having an epidermal origin.

The fourth method is similar to the previous method with the difference that the porous material is adhered or placed on a visually contrasting background. The optical characteristics of such a porous material changes when lipids are absorbed into the cavities. Typically, the absorbed lipids form an optical pathway from the surface of the porous material to the contrasting coloured background. In this way a pattern defining the areas which have absorbed skin amounts of lipids can easily be distinguished by eye, photometric measurement or analysed using an imaging system. Products based on this principle are commercially available as Sebutape* by CUDERM, USA and Skin type test by USP from Austria. Patent applications US 4532937 (CUDERM CORP) 6-8- 1985 and BP 0577799 (BREHM ROBERT) 12-1-1994 provide good background information regarding the applied method. It is known that both the CUDERM and USP products lack sensitivity in the low lipid ranges and are virtually insensitive to epidermal lipids. The USP product has an additional disadvantage; it is hygroscopic making it highly sensitive to moisture and sweat present on the skin.

In science and cosmetics practice_/ the instrumental assessment of the biomechanical behaviour of skin is an important tool in determining the mechanical condition of the skin. It is commonly believed that the bio-mechanical characteristics of skin are linked to the formation process of fine lines and wrinkles. For this reason the determination of for instance the elastic or visco-elastic properties of the upper layers of the skin is considered important in the process of selecting and prescribing cosmetics that are suitable to combat these signs of skin aging.

DS 3832690 (COURAGE + KHAZA A ELECTRONIC GMBH) 12-4- 1990 describes the most popular method for assessing biomechanical properties like the elastic and visco-elastic indices of human skin. A probe with an opening is placed on the skin. When a vacuum is applied on the probe, the skin deforms under the forces of the vacuum. The probe is equipped with an optical system constructed of glass mirror elements, a light transmitter and a light receiver. With this optical system, the extent of skin deformation is determined by measuring the amount of light beams that are blocked when the skin enters the opening of the probe under the force of the applied under-pressure .

This construction has many disadvantages. First of all, as the probe construction is open, any biological materials or contaminations present on the skin's surface will enter the probe's opening. Not only creates this situation a hygiene concern but it also influences the measuring accuracy of the system as contaminants sticking to the inner surface of the probe will block the optical pathway of the measuring system. As a consequence the device requires frequent cleaning and checking of the calibration.

Additionally the glass or glass-like construction of the optical system is very fragile and breaks easily when the probe falls on or bumps into hard surfaces. Other known disadvantages of this construction are the influence of the force with which the probe is applied on the skin on the measured result and the fact that that any hairs or the squames or scaly skin sticking out of the skin's surface will disturb the optical measurement. Also as a direct optical method is used; the optical characteristics, in particular the light absorption characteristics of the skin and the scattered light that comes from light that has refracted in to the skin will influence the measurement result making the instrument potentially sensitive to the skin tone and surface condition.

The slightest force of the probe on the skin will cause the soft skin to bulge and enter the probe's opening even before vacuum is applied. As a consequence of this skin bulging a false measurement reading is easily obtained. Another disadvantage is the sensitivity to air leaks, when valve opens and under-pressure is applied on the probe, part of the under-pressure stored in the vacuum pressure is immediately lost. Also when the skin does not completely close of the probe head, for instance because of the presence of hairs, it will be difficult to maintain required constant under-pressure . These influences are combatted by a large vacuum reservoir and a large pump and even the use of a double sided donut shaped sticker to adhere the probe to the skin.

Consequently, the proper working of the system relies on the presence of a large vacuum reservoir and controlled valve system and high capacity pump. Such components are relatively large, making the construction of a compact or completely handheld system virtually impossible.

Disclosure of Invention

While several methods for analysing skin are currently available, none of them simultaneously combine an economical means to determine skin dryness via a desquamation analysis, skin type via skin lipid measurement and the skin's elasticity and/or resilience and/or visco-elasticity and/or fatiguing via a suction-based biomechanical analysis into one compact handheld embodiment.

One or combinations of these analyses are considered especially valuable in the determination of the skin type and skin, or scalp condition for the purpose of determining suitable cosmetics and care.

Therefore the object of this disclosure is to obtain a skin or scalp analysis system which integrates a desquamation or a skin lipid level or a biomechanical characteristics analysis system, or a combination of any of those analyses into one compact, light and portable and handheld housing. Preferably, simultaneously, the measuring accuracy, measurement reproducibility, simplicity of use, hygienic use and purchase and usage costs are improved.

Exemplary embodiments of the disclosure may provide a portable skin diagnosis device comprising: • A first measuring system, comprising:

1. a probe pin which can make contact with the skin's surface

2. a measurement system that registers the displacement of the probe pin

3. a system to create and control an under-pressure

4. an opening in a surface, making contact with the skin, which can be subjected to the under-pressure

5. A central processing and control system which processes sensor data, drives measurement I/O and calculates the relevant visco-elastic measurement parameters.

6. A means to provide the measurement data to the user or communication interface.

• A second measuring system comprising:

1. A system that is constructed to optically record the reactive response of an external test strips.

2. One or multiple types of external test strips suitable for testing a skin or hair characteristics of one of more kinds.

In one aspect, the present disclosure concerns a device for determining elastic and/or visco-elastic properties of skin or scalp, comprising a measuring probe 5 having a probe pin 8 and a measurement system for registering a displacement of the probe pin 8. The probe pin 8 is provided in a probe chamber 13 having an opening of which preferred embodiments are detailed below. The opening allows for contact of the probe pin 8 with skin or scalp. The probe pin 8 is biased to be flush with the opening, or biased to protrude from the opening. As will be discussed below, in the examples, the form of being flush with opening is having the end of probe pin 8 flush with a surface of the measuring probe 5. A surrounding of the opening and/or a part of the opening is provided with one or more recesses, of which examples are further detailed below. The device further comprises a pump 24 connected to each of the one or more recesses for applying an under-pressure in each of the one or more recesses.

It is preferable that the measurement system comprises a visible or invisible light source and a light sensor for measuring the displacement of the probe pin passing through the light path. However, also other measurement systems are possible, for instance based on principles of magnetism or electromagnetism.

Examples of a probe chamber will further below also be referred to as vacuum chamber or under-pressure chamber.

Exemplary embodiments of this disclosure may provide a means that is robust, reliable, compact and light and capable to analyse the properties of skin in a non- or low invasive manner.

According to the embodiment shown in Figure 1,2 and 3, the device 1 is autonomous, handheld and portable, may be equipped with an attachment 7 for a clip or carrying strap and can be hold in one hand while being operated by the other .

According to the embodiment shown in Figure 4, the device 1 is configured to function as an accessory of an external device 11 like a tablet, PDA, phone, computer or other digital device.

According to the example embodiment shown in Figure 1, 2 and 3, the device is equipped with a biomechanical measuring probe 5 having a measuring pin 8.

As shown in the Figure 1,2 and 3, the device 1 may be equipped with a test strip reader 6, having an opening 9 for inserting the test strips . A visual indication 10 may guide the use on how to properly insert the test strips into the device . As all measuring can be integrated in the same embodiments, the device 1 is easy to handle, to hold in the hand or hang on clothing or around the neck or arm.

According to other embodiments the device 1 has a power or user control button 4 and can carry a display screen 2 showing the measuring progress or results.

According to some embodiments the device 1 is powered by disposable or rechargeable batteries 3 which are located in the housing of the device.

According to the embodiments shown in figure 4 the device is directly connected to a digital device 11 like a phone, tablet or PDA.

Other embodiment of this disclosure may provide a wireless means to communicate with an external device such as a computer, PDA, tablet or phone or other digital device. Examples of means of wireless communication are for example via Bluetooth®, WiFi, Zigbee® or infrared.

According to other embodiments the device can be equipped with a connector or wire connection allowing the communication to other devices such as a computer, PDA, tablet or phone or other digital device. Examples of means of wired communication are for example via USB, coaxial, serial, UART, Ethernet, ETA or the 19 pin or 30 pin connections of the mobile devices made by Apple Inc.

Aside the description of the structural constructions, the foregoing and following descriptions are exemplary and explanatory only and are not restrictive of the disclosure as disclaimed.

In figure 5 a, an exemplary diagrammatic view of the biomechanical measurement probe 5 is shown. The surface of the probe 5 is shaped flat and round and is designed to allow easily rest on the skin which needs to be measured. In the centre of the probe's 5 surface a probing pin 8 is located. The probe pin is biased to protrude from the opening. In this example, a spring element is provided for biasing the probe pin 8. The biasing may also be to the extent that the probe pin is flush with the opening. In that case, the end of the probe pin is flush with the surface of an external part of the measuring probe, a part that will in use be placed against skin.

As illustrated in Figure 5a, this probe pin is kept in the rest position by means of a light spring 12 which pushes on the foot 19 of the probe pin and pushes it to the bottom position 20 of the vacuum chamber 13. The purpose of this pin is to measure the displacement of the skin under the forces induced by the under-pressure created in the vacuum chamber 13 when air is sucked out via port 14 by an air pump 24. A connection between the vacuum chamber and the skin may be given by a recess surrounding the opening through which probe pin 8 extends for contact with the skin. As detailed below, the recess may be a ring-shaped cavity formed around the probe pin 8. The cavity may be seen as a radial extension of the opening. However, the cavity may also be at a radial distance from the opening. Furthermore, the cavity not necessarily needs to be ring-shaped. In fact, it is even possible that instead of one recess, a number of recesses are available for applying by means of the pump an under-pressure to the skin. In such an embodiment the recesses may be positioned around the opening through which the probe pin can extend.

The displacement of the probe pin 8 is monitored by an optical flag sensor construction; consisting out of a visible or invisible light source 18, a flag 16 which is part probe pin 8 and an optical sensor 18 which is sensitive to the light emitted from the light source 18.

Figure 5 b shows a blown-up cut-through diagrammatic drawing of a variation of the probe surface 5 construction. In this embodiment of the biomechanical measuring probe 5, a ring shaped cavity 33 is formed around the probe pin. This cavity has a port opening 34 connecting the ring shape cavity to the under-pressure chamber 13 shown in of figure 5 a. As a consequence under-pressure in the chamber 13 will also induce a suction force on the skin in contact with the ring shape cavity 33 and in this way avoid that the skin slips into the opening of the probe pin instead of deforming under the forces. Thus, the skin surrounding the opening for the probe pin 8 is "grabbed", so as to ensure that the skin cannot be sucked into opening when a vacuum is applied in the underpressure chamber 13. This construction variation is especially valuable when measuring thin skin, like the skin around the eyes.

An alternative advantage of this embodiment variation is that the probe 5 is able to adhere itself to the skin during the measurement cycle as the contact area of the ring cavity and thereby the adhesion forces on the skin are higher than the forces induced on the surface area of the probe pin and by the spring 12. As a consequence the probe can be held gently held against the skin without the need that the user has to apply tension on the probe during the measurement. This has the positive effect that the measurement accuracy is less influenced by the user holding the device on the skin 21.

The device is preferably provided with a control system for controlling the pump in a predetermined way.

A schematic representation of an example of the device according to the invention is pictured in Fig. 6. The device may also be referred to as a bio-mechanical measurement system.

Figure 6 shows a diagrammatic overview of the most important elements being part of the biomechanical measurement system. By means of a manifold, the underpressure port 14 is parallel connected to a pressure sensor

23 , a leak valve 25 and under-pressure pump 2 . The leak valve is an example of a leak to atmospheric pressure between the above-described one or more recesses 33, 34 and the pump

24. The leak valve may be permanently opened, and not closeable .

The control system may be arranged to control the pump so as to establish, despite the leak, a relatively strong constant pressure in each of the one or more recesses. This applies, as will be explained, in general in a situation when the probe pin no longer protrudes from the opening.

The air pump 24 has a suction capacity which is a multiple of the capacity that the leak valve can bleed to the atmospheric pressure 26. When the probe's surface 5 is hold against the skin, the pneumatic system is closed with the exception of the opening the leak valve 25. When, in this situation, the air pump suction air flow is increased, for example by increasing the power applied to the motor of the air pump, the under-pressure within the system increases rapidly accordingly. When the power to the air pump 24 is completely stopped, atmospheric air 26 enters the bleed valve 25 and since the total volume within the system 13 is low, the under-pressure drops rapidly till the system pressure 13 is equal to the atmospheric pressure 26. The control system may comprise a microcontroller 28.

In combination with a control loop algorithm inside the microcontroller 28 and an electronic circuit 27 that can control the air pump flow capacity, this system allows the on-demand creation of accurately controlled under-pressures in the system 13 without the need of large components like purge valves, solenoid controlled regulator valves, high displacement air pumps or reservoirs; components which are crucial in concepts known from prior art. As the volumetric capacity within the system 13 is relatively small, a small air pump 24, with a capacity much smaller than the pumps known from prior art can be used without affecting the responsiveness of under-pressure control loop.

According to an embodiment of the invention, the same microcontroller 28 can calculate bio-mechanical parameters like for example but not limited to the skin's elasticity, visco-elasticity or resilience parameters and display the calculated results on a display screen 30 or communicate this data to an external device via the external interface 31.

The air pump 24 of the device can not only be a compact type but also a low power type, allowing the device to be run autonomously via a power management 29 system on a low voltage and a relatively low capacity battery system.

The advantages of the probe construction as presented in figure 5 and diagram of the biomechanical measuring system shown in figure 6 over prior art is therefore clear. A device 1 built according to the present disclosure can be constructed more compactly. Also the device 1 is more easy to use since it can sense skin contact via monitoring the displacement of the pin 8, is insensitive to hairs present on the skin' s surface and is insensitive to the colour and texture of the skin. Thereby it does not require the frequent calibration checking as skin contaminations entering the probe will not reach the measuring optics. Also the here presented invention is not as fragile as the technology used in prior art as no glass components are needed.

The control system is arranged to start the pump 24 or a measurement cycle, for instance governed by a control loop algorithm inside the microcontroller 28, on the basis of a registered displacement which corresponds to a placement of the probe pin against skin or scalp. Figure 7 a,b,c and d are exemplary diagrammatic views of the biomechanical measuring probe 5 during the different states of the measurement. Figure 8 shows an exemplary view of the regulated system pressure 13 and a typical displacement curve of the probe pin 8 when human skin is exposed to pressure transitions when passing the different states of the measurement sequence.

Figure 7 a shows the probe 5 in its rest position; a light spring 12 pushes the probe pin foot 19 to the bottom 20 of the probe housing 5. The corresponding position of the probe pin 7 is shown in figure 8 as a corresponding negative value 36 since the probe pin sticks out the surface of the probe 5.

Figure 7 b illustrates the situation when the probe 5 is placed on the skin 21. The probe pin 8 is slightly pushed in by the contacting skin and the forces induced by the spring 12 causes a small bulging 22 of the soft skin 21.

As will be explained in more detail below by means of an example, the control system is arranged to determine a level of under-pressure in each of the one or more recesses for neutralizing a force exerted on skin or scalp by the biased pin 8, so that for measuring the elastic and visco-elastic properties, the effect of the biasing of the probe pin 8 on the skin is suppressed.

Preferably, the above-mentioned measurement system comprises a visible or invisible light source and a light sensor for measuring the displacement of the probe pin 8 passing through the light path between the light source and the light sensor. The following explains in more detail how this might be implemented in an example.

The displacement of probe pin 8 is monitored by the optical flag sensor construction; the flag 16 moves into the light path 17, blocking off a small part of the light coming from the light source 15. This reduction in passing light 17 is detected by the optical sensor 18, which in turn is interpreted by the microcontroller 28 as a displacement of the probe pin 37 as shown in the corresponding graphs of Figure 8 and a close-up 47 of part this graph in Figure 9.

This change 37 in pin position is used as a start signal for the measurement sequence. The pump 24 is started by the control loop in the microcontroller 28. An underpressure is quickly build up in the system 13, initially the air 22 captured between the probe and bulged skin 21 is evacuated. Consequently the probe pin is further lifted 38 by the pushing of skin 21 which is exposed to the under-pressure present in the chamber 13. The under-pressure rises 35 quickly till the control loop throttles back the air pump power to maintain a steady 41 air pressure level.

During this ramping up 35 of the under-pressure one important point is passed. Figure 7 c shows the point where the under-pressure 13 applied on the skin at the probe area 8 equals the force induced by the spring 12 and the skin is flush 21 with the probe's front surface 5. At this specific pressure point 40 the pin probe position is exactly at the zero 39 line. This point is an important element of the invention, as the purpose of detecting this equilibrium is to determine the counter pressure 40 forces required to neutralise 39 the force of the spring 12 which caused the skin to bulge 22. Figure 9 shows a blow up 47 of the transition point shown in figure 8.

Without such spring force neutralisation, the spring load induced by the probe pin 8 on the skin 21 will bias the measurement results since the slightest force induced by this spring load will simple push the skin back when the underpressure within the system 13 is removed.

As explained in more detail above, the device is provided with a leak to atmospheric pressure. The leak is for instance formed by a leak valve 14, and is preferably situated between the one or more recesses and the pump 24. Further, as also illustrated by example, the control system is preferably arranged to control the pump 24 so as to establish, despite the leak, a relatively strong underpressure in each of the one or more recesses. This response of the control system preferably occurs when on the basis of the measurement system it has been detected that after first protruding, the probe pin at a later stage no longer protrudes from the opening.

Effectively the skin is exposed to a constant underpressure for a few seconds till the end-point 41 is reached. During this time, the skin has deformed to the state as shown in figure 7 d. This skin deformation process is characterised by the elastic and visco-elastic 43 biomechanical properties of the skin 21 under test.

The control system is arranged to control the pump 24 such that the under-pressure instantly changes from the relatively strong constant under-pressure to the level of under-pressure for suppressing the effect of the biasing of the probe pin 8. This is further detailed, by means of example, as follows.

After point 41 has been passed, the microcontroller 28 instantly stops the air pump 24 and as atmospheric air 26 quickly enters the system 13 via the leak valve 25 the underpressure quickly drops. However, the control loop in the microcontroller quickly kicks in before the dropping pressure passes the earlier determined spring-load neutralising pressure point 40. Effectively, the control loop in the microcontroller 28 drives the pump in such a way that the forces induced by the spring 12 on the skin 21 are virtually neutralised and the elastic 44 and visco-elastic recovery 45 of the skin can be monitored by the probe pin 8 without the biasing influence of the spring 12 forces.

Another aspect of this disclosure concerns a test strip reader for receiving a test strip in a light path between at least on visible or invisible light source and at least one light sensor. This device may also be referred to as an optical readout system for external test strips. The test strip reader may be a part of the above-described device for determining elastic and/or visco-elastic properties of skin or scalp. However, the test strip reader may also be provided as a stand-alone, i.e. not incorporated in the device for determining elastic and/or visco-elastic properties of skin or scalp. Preferably, the test strip reader is arranged for assessing that a test strip has been fully inserted when at least one predetermined light sensor no longer receives light from at least one predetermined light source, receives less than a predetermined amount of light, or registers more than a predetermined reduction in light .

Figure 10 is an exemplary diagrammatic view of the invented optical readout system of external test strips 48. A test strip 48 is inserted via a small opening 9 into the housing 6 in such a way that the reactive area 49 of the test patch 49 is correctly aligned with the optical readout system constructed out of optical sensing element 50 and a visible or invisible light source 51.

The angle 52 of incidence relative to the position of the optical sensing element is chosen in such a way that the specular reflection of the light 51 bouncing of the surface 49 of the active area does not reflect into the optical sensor 50. Such condition can be obtained by a specific incidence angle 52 or by tilting the test strip 48 at a tilting angle 53 relative to the optical sensor 50 and light source 51.

The objective is to create an illumination and observation geometry in which the before and after response of an applied tester can be observed with the highest possible visual contrast. This is important as a higher observation contrast will improve the readout accuracy of the test strips 48. Next to avoiding specular reflections from bouncing into the optical sensor 50, a special construction of the test strips 48 has been invented which improves the measurement accuracy even further. This part of the invention is further described in the section which is explaining figure 15 b.

Important improvement over prior art with this invention is that the optical sensing element 50 can be a simple photo sensitive sensor instead of a camera. Such simple sensor could be, for instance but not limited to, a photodiode. In prior art, advanced image analysis techniques, for instance the method described in the earlier cited SCHATZ,H. article, are applied to calculate the measurement results from the reaction observed on the test area 49. In the present invention the analysis of the test area 49 can be done by a simple photometric measurement. This has the advantage that a device constructed according to the invention can be made more compact then the devices based upon prior art.

In another aspect the present disclosure concerns a number of test strips. One of these test strips is provided with at least one optical absorbance or optical reflection area for identifying the test strip.

Figure 11 a,b and c are exemplary diagrammatic views of three types of test strips 48. For the purpose of explaining the working principles of the invention, the embodiment in figure 11 a the active 49 is reactive to a one specific test parameter and the active area 49 in figure 11 b is sensitive to a second test parameter and the active area 49 in figure 11 c is sensitive to a third test parameter. As the function of the test strips 68,69 and 112 is different, the device 1 has to be able to detect this. In prior art technology, barcodes or identification shapes are printed on the test strips 48 and a barcode reader or imaging system are used to identify these markings. However such systems are relatively large, complex and expensive.

Therefore a new means to identify the test strips has been invented. The test strips are equipped with one or multiple light absorbance areas. For illustrative purposes in this explanation, two areas are assumed; light absorbing areas 56 and 57. Such light absorbance can be obtained by for instance but not limited to applying graphical printing colours or shades on the areas 56 and 57 which are unique for the type of tester.

Figure 12 is an exemplary diagrammatic view of a test strip 48 identification system. When light 54 is on and light 55 is switched off the light coming from light source 54 will partially be absorbed by area 56 and partially reflect 59 into the photo sensor 50. The amount of reflected 59 light depends on the spectral absorbance characteristics of the pigments in the absorption area 56. Different colours or different tones of the areas 56 will render measurable different photometric responses 50. By adding more areas and more sequentially switchable lights, for example by adding area 57 and light 55, the amount of identification dimensions and thereby the number of detectable individual types of test strips 48 can be increased.

This invention also allows detecting if test strips 48 are inserted in the right direction into the device. If the backside and opposite sides facing the areas 56 and 57 have distinctive light absorbance characteristics, it will be observed as such and the conclusion can be drawn that a test strip 48 is incorrectly inserted and the microcontroller 28 can alert the user by displaying a message to the display 30 or by reporting it over the external interface 30.

In general, it applies that the test strip reader may comprise at least one light source for facilitating identifying the test strip. As indicated above, the test strip reader may be arranged for assessing that a test strip has been fully inserted when the light sensor no longer receives light from the light source, receives less than a predetermined amount of light, or registers more than a predetermined reduction in light.

As mentioned earlier on, a device such as a test strip reader, may be a stand-alone, or incorporated in another device. In any case, it is preferably arranged for assessing that a test strip reader has been fully inserted and it applies that a light sensor no longer receives light from the light source, when it receives less than a predetermined amount of light, or when it registers more than a predetermined reduction in light. This may be referred to as a test strip position detection system.

Figure 13 a and b are exemplary diagrammatic views of the test strip 48 position detection system. Figure 13a illustrates the situation where a test strip 4 is not fully inserted into the test strip reader 6. A light 60 emits visible or invisible light. To make the device more compact, this light is first reflected against a reflective surface 62. As the test strip 48 is not fully inserted, a small amount of light can pass between the edge 63 of the test strip and the end-stop 66 in the device housing. This passing light is detected by an optical sensor 50 which is for example, but not limited to, a photodiode or imaging system.

When the test strip 48 is further moved 67 into the test strip reader 6 housing the situation occurs as illustrated in Figure 13 b. The source light 61 is completely blocked as the gap between the edge 63 of test strip and the wall 66 is closed. As the sensor 50 then no longer receives the source light 61, a complete insertion of the test strip 63 can be concluded.

A test strip preferably comprises a recessed area for containing samples. The test strip may comprise sampling carrier material covered by an open-windowed top layer. It is possible that the test strip further comprises a bottom layer. Such a test strip improves hygienic conditions of use.

Figure 14 a,b,c and e are exemplary diagrammatic views of an exemplary construction of a test strip 48 which improves the hygienic conditions of use over prior art. Figure 14 b illustrates a blown-up cut-through diagrammatic area 70 near the testing area 49 of the test strip 48 as schematically indicated 70 in Figure 14 a. The sampling material 49 of the test strip is sandwiched between a bottom carrier 73 and a windowed top carrier 72. In this way the sampling area 49 surface is located beneath the top surface of the top carrier 72.

It will be understood that it is also possible to have one layer, provided with a recessed area. This would correspond to sampling carrier material covered by any open- windowed top layer of the same material as the sampling carrier material. Such a one layer test strip could also be seen to have a bottom layer. However, each of the sampling carrier layers, open-windowed top layer and bottom layer, may also form a separate layer, preferably of a different material .

Figure 14 c illustrates the situation when a skin test strip 48 has been applied to the skin's surface. Substances 74 previously present on the skin, like for instance skin cells, sguames, lipids and flora are transferred to the surface of the tester area 49. Figure 14 d and e illustrate how the windowed top carrier 72 creates a protective recess 75 that prevents that sampled substances 74 can contaminate the opening 9 and the internal parts of the skin test strip reader 6.

A test strip may comprise a sampling carrier material having an adhesive surface so that skin squames will adhere to the surface. The carrier is provided with a colour for contrasting between the skin squames and the carrier. The carrier may be provided with a transparent foil between the adhesive surface and the carrier, so that on illumination with parallel light at an angle, light is reflected from the sampled material, and/or so than on illumination with parallel light at an angle, other light components are refracted and absorbed. Light at an angle is understood to be light which does not perpendicularly incident on a surface .

Figure 15a schematically shows for such a test strip, by way of example, the area 76 in which the testing area 49 is of the skin stripping kind. Figure 15 b illustrate a construction of a skin stripping tester which consists of a carrier 73, a dark coloured contrasting background 79, a transparent foil 84 and an adhesive surface 77. The transparent foil is for instance a polyester film. The purpose of this part of the invention is to improve the observation contrast between the samples skin squames and the background. This is obtained by reducing the amount of disturbing surface reflections caused by the shininess of the adhesive 77 surface. This effect is obtained in two ways; first by illuminating the test area 49 with parallel light 80 at such an angle 81 that part of the light is specular reflected 82 outside the view of the photo sensor 50 and second by refracting 83 and absorbing 84 other light components by means of the transparent refraction layer 78. This has the effect that the observation contrast of sampled sguames is significantly improved when compared to prior art as the backseattered light coming from the squames becomes more apparent while other reflections are suppressed.

Figure 15 c shows a typical prior art construction, in which the transparent refraction layer 78 is not present and samples squames 85 are adhered on the adhesive surface 87 of a dark 90 coloured carrying substrate 89. In this prior art construction the observed contrast is significantly lower.

Figure 15 d shows another typical prior art construction in which the tester consists of two parts; a transparent tape 91 with an adhesive surface 92 on which the loose squames 85 adhere after making skin contact and a dark 95 coloured carrier 94. To observe the sampled squames, the tape 91 is stuck 93 onto the carrier 9 . The squames can then be visually observed from above.

For an accurate electronic analysis of tape stripping testers made according to such prior art construction, advanced image analyse equipment is required instead of a simple photometric measurement technology. In the case of prior art constructions according to Figure 15 d, for the reason that air pockets captured between the tape 91 and the carrier 94 effectively render a contrast change which is similar to that of sampled squames 85 thus complicating the visual analysis of the sample taken. In case of a prior art construction according to Figure 15 c that the specular light reflected of the shiny adhesive layer 87 reflects light by a specular reflection which in amount is similar to the amount of light scattering from the squames 85.

When a skin stripping tester constructed according to the elements displayed in figure 15 b is combined with the illumination and observation geometry as displayed in figure 10, the observation contrast is of such a quality, that a simple and compact photometric optical system can be used to accurately quantify the amount of sampled squames.

The amount of skin lipids present on a human skin varies on skins with varying skin conditions. This makes it difficult to accurately measure the skin lipid level over the whole range. Some devices, like the Courage Khazaka Sebumeter* is known to lack sensitivity in the medium to very oily measurement ranges. In particular in skin conditions like seborrheic dermatitis the greasiness levels on the skin will saturate the sampling tape of the Sebumeter*; making it impossible to measure high skin oil levels.

Other techniques lack sensitivity in the lower to medium skin lipid levels. For instance, skin lipid testers which are based on the visual change of transparency when lipids are absorbed in the cavities of a porous membrane or a thin layer of binded porous crystals are known to lack sensitivity in the lower skin lipid ranges as the volume of these surface oils is insufficient to fully fill the pore cavities and create the optical pathway which results in this change in transparency.

The lipids present on the human skin are a mixture of sebum secreted by the sebaceous glands and lipids of epidermal origin. The prior art methods presented above are not able to visualise or identify these lipids types separately. The invented constructions of the skin lipids testers presented in this publication not only have an greatly improved measurement range but are also able to visually differentiate and quantify the amount of lipids coming from the two sources.

A test strip for absorbing skin lipids may have a sampling carrier material which comprises a layer of microporous material for absorbing the skin lipids. The voids of the microporous material may partly, be filled with a filler material so as to reduce the total volume of the voids. The voids may also be partly filled with a filler material so as to ensure that the absorbance of even small volumes of the skin lipids result in visible change in the surface of the material, even when the lipids are not absorbed throughout to the other side of the material. An example of this is now discussed.

Figure 16 a is cut-through microscopic enlargement of a skin lipid tester in which the reactive tester area 49 is a microporous membrane polymer 101 which is mounted on a carrier 99 having a contrasting surface 100. When the tester has been applied on the skin, skin surface oils are transferred to the surface of the membrane 100 and absorbed. If the sebum volume which is present in the duct of the sebaceous gland and the immediate surroundings is sufficient to fill the capacity of the pores in such a way that it reaches the other side 102 of the membrane; it becomes visual 102 as the membrane locally changes in transparency.

However in the case of prior art constructions; if locally only low levels of skin lipids are present on the skin's surface, the volume of the transferred lipids is insufficient to reach the other side 103 of the membrane and the transparency of the membrane does not change at all. As a consequence prior art skin lipid testers based on this absorption principle are insensitive to low sebum levels and the lipids coming from the epidermis itself.

Figure 16 b shows a further microscopic enlargement 98 of the membrane and cavities. In this figure the membrane structure 140 and pore cavities 105 are symbolically shown. The purpose of this part of the here presented invention is to improve the reaction sensitivity of the tester material to low sebum levels and low volumes of epidermal skin lipids.

As it became apparent that prior art testers lacked sensitivity because low amount of skin lipids could not sufficiently fill the pore cavities changing the transparency a way was invented to change the volume in the pores. Many different membrane constructions and membranes build from different geometries were tested but none of them showed to have the desired effect.

Finally a way was invented to chemically change the pore volume and capillary absorption behaviour of the membrane. By treating the membrane with a filling 105 material, the total volume in the pores can be reduced. This has the effect that low volumes of skin lipids can now migrate to the other side 102 and change the transparency of the membrane. Also it was discovered that the filling material has the beneficiary effect that epidermal lipids that are absorbed by the filler 106 become optically visible as light surface 103 discolorations . This is causes by the fact that a coloured porous filler material reflects diffuse white light. When the filler has absorbed skin lipids, it's colour becomes visible as the transparent lipids form an optical interface with the filler particles.

A layer of microporous material may be of polyethylene or polypropylene, preferably in the shape of a membrane film. The filler material, also referred to as filling material, may be a mineral oil, petroleum jelly, low molecular weight polyethylene, polyethylene glycols (PEGs) , talc, calcium carbonate, titanium dioxide, barium sulphate or a mixture thereof .

Figure 17 a and b are exemplary diagrammatic views of an alternative construction of an improved skin lipid tester 107. In this embodiment the improved sensitivity is obtained by mounting a microporous membrane or a thin layer of absorbing crystals 109 and a transparent film 110 with a matt top surface on the same carrier 111. The matt film 110 is sensitive to the low and medium skin lipid levels and the membrane is sensitive to the medium to high sebum levels. By combining both materials on the same tester; a tester with a wide sensitivity range is created.

Some or all of the aspects of test strips as referred to above might be combined in a single test strip.

Although in the above the inventions have been described in a detailed way, it should be understood that many modifications are possible. For instance, the reference to a strip should be understood also to embrace embodiments which are not strip-shaped. A recess may also be a simple hole or cavity. These all fall within the framework of the inventions as defined by the appended claims.

Brief Description of Drawings

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present disclosure and together with the written description serve to explain the principles, characteristics, and features of the disclosure. In the drawings:

• Figure 1 is a diagrammatic frontal view of an exemplary embodiment of the device according to some embodiments .

• Figure 2 is another, perspective side view of the exemplary Figure 1 device.

• Figure 3 is another, perspective side view of the exemplary Figure 1 device.

• Figure 4 is a diagrammatic perspective view from of the device according to some embodiments.

• Figure 5 a,b are diagrammatic view of a bio- mechanical measuring probe according to some embodiments . • Figure 6 is a diagrammatic view of an example configuration of a bio-mechanical measuring system according to some embodiments.

• Figure 7 a,b,c,d are diagrammatic views showing exemplary steps during the bio-mechanical measuring of skin according to some embodiments.

• Figure 8 show the probe pin displacement and underpressure transitions when going to the different steps of the bio-mechanical measurement.

• Figure 9 shows a blow-up of a part of the graph of Figure 8.

• Figure 10 is a diagrammatic exemplary view of illumination and photometric or imaging geometries according to some embodiments.

• Figure 11 a,b,c show diagrammatic views of different example embodiments of external tester of different types having areas which can partially reflect or absorb visible or non-visible light according to some embodiments.

• Figure 12 is an diagrammatic view of an exemplary external testing device showing how the areas of Figure 11 a,b,c are used to identify the type and correct insertion of the external testing device.

• Figure 13 a,b are diagrammatic views of the exemplary configuration of the external testing device position detection system.

• Figure 14 a,b,c_fd are diagrammatic views of the exemplary external testing device showing the recess area.

• Figure 15 a,b are diagrammatic view of the exemplary external testing device showing the improved construction of a skin stripping tester relative to prior art; Figure 15 b,d. • Figure 16 a,b,c are diagrammatic views of the exemplary external testing device showing the construction of an improved skin lipid tester relative to prior art; Figure 16 d.

• Figure 17 a,b shows diagrammatic views of the exemplary external testing device showing the construction of an improved skin lipid tester according to an alternative construction.

The following paragraphs provide further disclosure of the present subject matter.

1. Device for determining skin, scalp or hair properties, comprising a measuring probe for determining the biomechanical skin properties and an optical measurement unit with an opening for reading associated strip-shaped media which are provided with a test zone 49 of one or more different diagnostic arts.

2. A device according to paragraph 1, wherein the biomechanical measurement probe 5 is provided with a contact pin 8 and a compression spring 12.

3. A device according to paragraph 2 , wherein in the surface of the measuring probe a ring-shaped recess is made which is connected with the under-pressure chamber 13.

4. A device according to paragraph 2, wherein a controller 28 determines the under-pressure at which the force 12 which is via contact pin 8 exerted on skin 21, can be neutralized.

5. A device 1 according to paragraph 1, wherein the art of strip-shaped media 48 can be identified photometrically by the availability of one 56 or more identification zones 57.

6. A device 1 according to paragraph 1, wherein measurement unit is provided on one 54 or more 55 light sources which can shine light on the identification zones 56 and 57 and wherein the reflected light 59 can be measured by a light-sensitive element 50.

7. A device 1 according to paragraph 1, wherein the complete insertion of the strip-shaped media 48 in the opening 9 of the optical measurement unit 6 can be detected by light-sensitive element 50, on the basis of visible or invisible light 65 which originates from light source 60 is blocked as soon as rim 63 of the strip-shaped media 48 makes contact with internal wall 66.

8. A device according to paragraph 1, wherein the strip- shaped media 48 are provided with a heightened window around the test zone 49.

9. A device according to paragraph 2, wherein the strip- shaped media 48 are constructed of a carrier 73 which is provided with a contrasting colour or tint 79 on which subsequently a transparent film layer 78 is which is provided with an adhesive layer 77.

10. A device according to paragraph 1, wherein the strip- shaped media are constructed of a carrier 99 which is optionally provided with a contrasting colour or tint 100 on which a microporous material is provided 101, wherein in the pores 105 of the microporous material 101 a filling material is provided which changes in its visual appearance after skin fats have been absorbed 103 even before the fats have formed an optical path 103 to the other side of the porous layer 101.

11. A device according to paragraph 1, wherein the strip- shaped media 48 are constructed of a carrier 107 on which both a microporous skin fat absorbing layer 109 is provided and a non-porous material 101 with a matt surface.

12. A device according to paragraph 1 with the addition of a measurement system for skin hydration. 13. A device according to paragraph 1 or 12, wherein the measurement probe for biomechanical properties has been left out.

14. A device according to paragraph 1 or 12, wherein the optical measurement unit for reading the strip-shaped media 48 has been left out.

15. A device according to paragraph 1 or 12 or 13 or 14 , wherein the device via a wired or wireless connection (USB) , by means of a wired or wireless connection the measurement data and control of the device system a communication connection with an external digital apparatus.

Claims

Claims A device for determining elastic and/or visco-elastic properties of skin or scalp, comprising a measuring probe having a probe pin and a measurement system for registering a displacement of the probe pin, wherein the probe pin is provided in a probe chamber having an opening for contact of the probe pin with skin or scalp, the probe pin being biased to be flush with the opening or to protrude from the opening, a surrounding of the opening and/or a part of the opening being provided with one or more recesses, the device further comprising a pump connected to each of the recesses for applying an under-pressure in each of the one or more recesses . A device according to claim 1, wherein a spring-element is provided for the biasing of the probe pin. A device according to claims 1 or 2, wherein the device is provided with a control system for controlling the pump in a predetermined way. A device according to claim 3 , wherein the control system is arranged to start the pump or a measurement cycle on the basis of a registered displacement which corresponds to a placement of the probe pin against skin or scalp. A device according to claim 3 or 4, wherein the control system is arranged to determine a level of underpressure in each of the one or more recesses for

neutralizing a force exerted on skin or scalp by the biased pin, so that for measuring the elastic and visco- elastic properties the effect of the biasing of the probe pin on the skin is suppressed. A device according to any one of claims 3-5, wherein the device is provided with a leak to atmospheric pressure between the one or more recesses and the pump, and wherein the control system is arranged to control the pump so as to establish, despite the leak, a relatively strong constant under-pressure in each of the one or more recesses, once the probe pin is no longer

protruding from the opening. A device according to claims 5 and 6, wherein the control system is arranged to control the pump such that the under pressure instantly changes from the relatively strong constant under pressure to the level of under pressure for suppressing the effect of the biasing of the probe skin. A device according to any one of the previous claims, wherein the measurement system comprises a visible or invisible light source and a light sensor for measuring the displacement of the probe pin passing through the light path. A device according to anyone of the previous claims, wherein the device is further provided with a test strip reader for receiving a test strip in a light path between at least one visible or invisible light source and at least one light sensor.

. A device according to claim 9, wherein the device is arranged for assessing that a test strip has been fully inserted when the light sensor no longer receives light from the light source, receives less than a

predetermined amount of light, or registers more than a predetermined reduction in light. . A device according to claim 9 or 10, wherein the test strip is provided with at least one optical absorbance or optical reflection area for identifying the test strip . . A device according to claim 11, wherein the device comprises at least one light sources for facilitating identifying the test strip. . A device according to any one of claims 8-11, wherein the test strip comprising a recessed area for containing samples. . A device according to claim 13 , wherein the test strip comprises sampling carrier material covered by an open windowed top layer. . A device according to claim 14, wherein the test strip further comprises a bottom layer. . A device according to any one of claims 10-15, wherein the test strip comprises sampling carrier material having an adhesive surface so that skin sguames will adhere to the surface, wherein the carrier is provided with a colour for contrasting between the skin sguames and the carrier.

. A device according to claim 16 , wherein the carrier is provided with a transparent foil between the adhesive surface and the carrier, so that on illumination with parallel light at an angle, light is reflected from the sampled material, and/or so that on illumination with parallel light at an angle, other light components are refracted and absorbed. . A device according to any one of claims 8-14, wherein the test strip comprises a layer of micro-porous

material for absorbing skin lipids, the voids of the microporous material being partly filled with a filler material so as to reduce the total volume of the voids and so as to ensure that the absorbance of even small volumes of the skin lipids result in visible change in the surface of the material even when the lipids are not absorbed throughout to the other side of the material. . A device according to claim 18, wherein the layer of microporous material is a polyethylene or polypropylene membrane film. . A device according to claim 18 or 19, wherein the filler material is a mineral oil, petroleum jelly, low molecular weight polyethylene, polyethylene glycols (PEGs), talc, calcium carbonate, titanium dioxide, barium sulfate or a mixture thereof. . A device according to anyone of the previous claims, wherein the measurement system is provided in a

measurement chamber, the probe chamber and the

measurement chamber being connected by a channel which is thin relative to the dimensions of the probe chamber, wherein the probe pin is provided with a thin part for presenting to the measurement system through the channel a displacement of the probe pin. . A test strip reader for receiving a test strip in a light path between at least one visible or invisible light source and at least one light sensor, the test strip being for collecting sample material from skin or scalp . . A test strip reader according to claim 22, wherein the reader is arranged for assessing that a test strip has been fully inserted when at least one predetermined light sensor no longer receives light from at least one predetermined light source, receives less than a

predetermined amount of light, or registers more than a predetermined reduction in light. . A test strip for collecting sample material from skin or scalp, wherein the test strip is provided with at least one optical absorbance or optical area for

identifying the test strip. . A test strip reader according to claim 23, wherein the device comprises at least one visible or invisible light source for facilitating identifying a test strip according to claim 24. . A test strip for collecting sample material from skin or scalp, wherein the test strip comprises a recessed area for containing samples.

. A test strip according to claim 26, wherein the test strip comprises sampling carrier material covered by an open windowed top layer. . A test strip according to claim 27, wherein the test strip further comprises a bottom layer. . A test strip for collecting sample material from skin or scalp, wherein the test strip comprises a carrier having an adhesive surface so that skin squames will adhere to the surface, wherein the barrier is provided with a colour for contrasting between the skin squames and the carrier. . A test strip according to claim 29, wherein the carrier is provided with a transparent foil between the adhesive surface and the carrier, so that on

illumination with parallel light at an angle, light is reflected from sampled material, and/or so that on illumination with parallel light at an angle, other light components are refracted and absorbed. . A test strip for absorbing skin lipids, having a sampling carrier material which is provided with a layer of micro-porous material for absorbing the skin lipids, voids of the microporous material being partly filled with a filler material so as to reduce the total volume of the voids and so as to ensure that the absorbance of even small volumes of the skin lipids result in visible change in the surface of the material, even when the lipids are not absorbed throughout to the other side of the material.

. A test strip according to claim 31, wherein the layer of microporous material comprises polyethylene or polypropylene membrane film. . A test strip according to claim 31 or 32, wherein the filler material is mineral oil, petroleum jelly, low molecular weight polyethylene, polyethylene glycols (PEGs) , talc, calcium carbonate, titanium dioxide, barium sulfate or a mixture thereof .