HK1107539A - Analytical test element - Google Patents

Description

Analytical test element

The invention relates to an analytical test element, a test element magazine having a plurality of analytical test elements, and a liquid sample analysis system having at least one analytical test element.

In the analysis of samples, for example body fluids such as blood or urine, test element analysis systems are frequently used, in which the sample to be analyzed is applied to a test element and, if appropriate, reacted with one or more reagents located in a test field on the test element before it is analyzed. Optical, in particular photometric test elements are one of the most common methods for rapidly determining the concentration of an analyte in a sample. Photometry is commonly used in the fields of analysis, environmental analysis and most notably medical diagnostics. The field of blood glucose diagnostics from capillary blood is particularly important for test elements that can be measured photometrically.

In recent years portable measuring devices for blood glucose determinations have become more and more important. They make it possible to determine blood glucose measurements at any desired time by means of easy-to-use measuring instruments, piercing tools optimized with regard to the pain caused by the piercing and test elements for single-use, and thus to obtain precise insulin doses for stabilizing the blood glucose level of the patient. Most of the currently available blood glucose measuring devices involve separate, independent test elements, measuring devices and piercing tools. The patient removes the individual test elements from the moisture resistant individual package. Blood is obtained by piercing with a piercing tool. The minimum amount of blood required is then applied to the test element and measured with the measuring instrument.

There are many types of test elements. For example, substantially square slides (Blettchen) are known in which a multi-layer test zone is arranged in the middle. Diagnostic test elements configured in the form of strips are referred to as test strips. The prior art discloses capillary test elements for spatially isolating a test element's detection zone from a sample receiving point.

WO 99/29429 relates to an analytical test element for the determination of an analyte in a liquid, having an inert carrier, a detection element and a channel allowing capillary transport of the liquid, and having a sample application opening at one end and a vent opening at the other end of the channel for capillary transport of the liquid. The capillary transport liquid-permitting passage is at least partially formed by the carrier and the detection element and extends in a capillary transport direction from the sample application port up to an edge of the detection element nearest the vent port.

The package containing the individual test elements is designed to fulfill the basic task required for the long-term preservation of the function of the chemical and biological components on the test elements. These tasks are, in particular, protection against the action of light, protection against the entry of moisture, dirt, microorganisms and dust, and protection of the test elements against mechanical damage.

As an alternative to individual packaging, storage containers are known which accommodate a plurality of individually removable test elements and which provide a sufficient storage volume of desiccant to absorb the moisture introduced by opening and removal of the test elements, thereby ensuring a sufficiently long shelf life for all test elements in the container. Such storage containers are known from EP 0640393B 1. In this storage container, the test elements are as if they were contained in a arrow pouch, from which they can be removed when the storage system is opened.

Another suitable form of test element storage container is an aluminum or plastic tube that is plugged by a press-in or screw-in plug. A disadvantage of these storage containers is that the individual test elements have to be manually removed in a cumbersome manner. A patient, for example a person wishing to perform a blood glucose test, must carry not only the measuring device but also the piercing tool and a separate test element storage container. In addition to this inconvenience, a further disadvantage is that when the test element is taken out, this test element and/or another test element can become contaminated, which can lead to erroneous measurement results. There is also a risk that the test strip is contaminated by dirt sticking to the patient's hand or by dropping the test element.

Another known alternative is to store several test elements within the measuring device itself.

DE 19819407 discloses a container for a blood glucose measuring device or other measuring device which operates with a disposable test strip which can be supplied to a sensor for measurement, wherein the container consists of two parts, in a first part of which the test strip is stored and in a second part of which a used test strip is collected. The test elements may be arranged alongside one another to form a tape which may be wound like a magnetic tape in a cassette. Alternatively, they can also be arranged to form a disk on which they are arranged at a defined distance from one another in the region of the rim, so that a new test field is brought to the corresponding measuring position by rotating the disk. Another possibility is that the test strips form a stack from which they can be individually processed by some mechanism and that the test strips are brought one after the other to the respective measuring position and, after the measurement, to the collection chamber.

EP 0622119a1 discloses a substantially rectangular cartridge with mutually parallel chambers in line alongside one another.

When the test element is stored in the measuring device itself, the storage container, or the chamber in which the test element is located, is opened by an opening mechanism and the test element is brought to the sample receiving point by the transport mechanism.

DE 19854316a1 describes a storage container with a separate moisture-proof compartment for the test element. Each chamber has at least two openings opposite to each other and each opening is closed by a sealing film. To remove the test element, the test element is pushed out of its chamber by a ram. The ram cuts through the sealing membrane on one side of the chamber and then presses on the test element, which can be pushed out of the storage chamber due to the pressure from the ram cutting through the sealing membrane on the opposite side. EP 073866681 discloses a storage container for cartridge form, EP 066262681 and EP 0732590a2 disclose storage containers for tray form, WO 02/08753a2 discloses other mechanisms for automatic removal of test elements from storage containers for stacked storage of test elements.

After the sample (e.g. blood) has been applied to the removed test element, the test and measurement data evaluation takes place in the measuring device. After the test element has been removed by the patient or another mechanism integrated in the appliance, the storage container is automatically displaced for the next measurement.

In the prior art, moisture is generally prevented from entering the test element by sealing the storage container or sealing a separate compartment in the storage container of the test element. The seal is provided, for example, in the form of a suitable low water vapor permeability film-forming substance, such as an aluminum film coated with an adhesive plastic. Furthermore, the test elements are often protected from moisture by means of a desiccant placed in a storage container or chamber.

The integration of the devices known from the prior art for providing the test elements, for applying the test specimen and for measuring in the measuring device has the disadvantage that their construction is very complicated. This complexity is particularly such that each test element must be transported to a different location within the device (from the storage container to the sample receiving site, to the measurement site and then to the disposal site). Furthermore, the test elements of the prior art must also be protected against moisture, in particular in an expensive manner. The filling and sealing of storage containers integrated in the device for storing the test elements is a costly and time-consuming procedure.

DE 10057832C1 describes a blood analysis device of simplified construction, which constitutes a complete system comprising a puncturing element, a blood collection device, a test element comprising a test field and an evaluation device. The test elements are inserted into the magazine and, for a plurality of measurements, can be moved one by one to the operating position. The puncturing element can be inserted through the test element and into the skin surface of the user when positioning each test element in the operative position. The blood flowing from the skin surface acts directly on the test element. A disadvantage of such a blood analysis device is that the test field itself is pierced, with the result that toxic components of the test field may remain adhering to the piercing tool and may be carried over a puncture wound in the skin of the user.

It is therefore an object of the present invention to provide an analytical test element, a test element magazine and a liquid sample analysis system with at least one analytical test element, all of which eliminate the above-mentioned disadvantages of the prior art. In particular, moisture is prevented from entering the test element. Furthermore, the production of the test elements, test element magazines and analysis systems should be simplified and their complexity should be reduced.

According to the invention, this object is achieved by an analytical test element for analyzing a liquid sample, comprising a channel adapted for capillary transport of the liquid sample and having an inlet for the liquid sample and a vent for venting the channel, wherein at least one test zone is arranged within the channel at a distance from the inlet, the test element comprising a sample receiving point which is closed by a seal, and wherein the sample receiving point is designed in such a way that the sample receiving point and the inlet of the channel are simultaneously open to the environment outside the test element when the seal is opened, and the test element can receive the liquid sample via the sample receiving point and the inlet of the channel for analysis at the test zone.

The test element according to the invention has the advantage that the test element itself is closed by the seal in a manner substantially impervious to water vapour and preventing ingress of dirt, so that no separate storage means is required to prevent ingress of moisture or contaminants when used in an appliance. This makes it possible to dispense with the step of removing the test element before the measurement is carried out, thus simplifying the handling for the user and the design of the measuring device into which the test element is already integrated. By opening the seal at the sample receiving point, the inlet of the channel is also opened, so that the test element is ready in only one opening step. A channel adapted for capillary transport of a liquid sample and having an integrated test zone has the advantage that the liquid sample is automatically transported by capillary forces to the test element representing the detection zone. The sample to be analyzed can be placed directly on the sample receiving site.

The vent ensures that air is vented from the channel as the liquid sample is transported through the inlet in the channel to the capillary of the test zone. In the test element according to the invention, it is possible to open the environment outside the test element already before the seal is opened. Contamination of the test field by the venting opening can in this case be avoided by means of a suitable passage. In another embodiment of the invention, the vent opens into a sufficiently large hollow space that is closed off from the environment outside the test element, and it allows air to be released from the channel through the vent without opening the hollow space to the outside environment. It is furthermore possible that the air outlet is sealed separately, which is opened to the environment outside the test element by opening this separate seal. In a preferred embodiment of the invention, the sample receiving site, the channel inlet and the channel vent are all open to the environment outside the test element simultaneously by opening only one seal.

The test zone is disposed in the channel, preferably between the inlet and the exhaust. In a preferred embodiment of the invention, the inlet is provided at one end of the channel and the exhaust is provided at the other end of the channel. The liquid sample flows through the inlet into the channel and fills the channel at least until the test zone is wetted, whereupon one or more components of the liquid sample are preferably analyzed photometrically or electrochemically. In addition, the uniform wetting of the test field with a sample volume defined by the channel diameter is ensured, so that the accuracy and reproducibility of the measurement are increased. A further advantage of the test element according to the invention is that the test field is not destroyed or contaminated by the detachment residues of the seal when opened (by piercing, shearing or tearing).

In the test element according to the invention, the sealing member is made of a material which is substantially impermeable to water vapour, for example a polymer-coated aluminium film.

In a preferred embodiment of the invention, the inlet and, where appropriate, also the air outlet of the channel open into an empty space within the test element, said empty space being provided in such a way that it is open to the environment outside the test element when the seal is opened. In the non-use state of the test element, the free space is preferably delimited at least partially by a seal closing the sample reception point on a first side and at least partially by a second seal on a second side facing away from the first side. This has the advantage that the puncturing device (e.g. lancet, needle, knife, hollow needle, spike) can first open the second seal on the side remote from the sample receiving point and then pass through the free space, also opening the seal of the sample receiving point. This simplifies the construction of the integrated measuring system, since the application position of the liquid sample and the piercing means can be arranged on opposite sides of the test element, and thus the piercing means do not hinder the sample reception. Furthermore, the puncturing device can also serve as a puncturing device which, in addition to opening the two seals, punctures the skin of the patient in order to collect the sample, so that the body fluid emerging from the puncture in the skin can then flow directly into the test element as a liquid sample. For this reason, the patient does not have to perform any other operation steps or movements and does not need any additional equipment.

In a preferred embodiment of the invention, the channels in the test element have a U-shaped or V-shaped course. This arrangement has the advantage that the passage can be accommodated in the test element in a space-saving manner. In this case, the channel ends can be arranged one above the other or next to one another in the free space in the test element.

Since the channel has a substantially rectangular cross-section in the preferred case, one dimension of the channel, for example its height, is predefined by the physical constraints of capillary action, the volume of the capillary channel can be adjusted by suitably selecting the other two dimensions, for example length and width. In the case of aqueous liquid samples, the height is preferably less than 1mm, particularly preferably less than 0.5 mm. The width of the channel may preferably be less than 5mm, particularly preferably less than 2mm, and the total length of the channel may preferably be less than 5cm, particularly preferably less than 2 cm.

In a preferred embodiment of the invention, the sample receiving point is located at a distance from the inlet of the channel that is less than the distance of the sample receiving point from the outlet of the channel. This has the advantage that the liquid sample entering the test element at the sample receiving point flows into the inlet of the channel instead of the vent, since the vent should remain free of sample liquid to allow gas to escape when the channel is filled.

The channel preferably has better wetting properties with the liquid sample in the inlet region than in the outlet region. This measure is also intended to supply the liquid sample to the channel inlet and prevent it from entering the vent. Furthermore, in its interior, the channel preferably has better properties of being wetted by the liquid sample between the inlet and the at least one test zone than between the at least one test zone and the vent. This may be achieved by hydrophobic treatment of the vents and/or adjacent areas of the channel that do not require wetting.

In a preferred embodiment of the invention, the seal closing the sample receiving point has better wetting properties with the liquid sample on the side facing the interior of the test element than on the side facing away from the interior of the test element. This has the advantage that when the liquid sample is applied directly to the pierced seal of the sample receiving point, the outside of the seal is not heavily wetted by the sample. This therefore facilitates the transport of the sample to the inside of the better wetting seal and thus into the test element.

In a preferred embodiment of the invention, a desiccant is contained within the test element. This desiccant can further improve the water resistance of the test element because it can absorb moisture. The desiccant may be contained within the channels, for example, proximate the exhaust. The drying agent may be, for example, a solid drying agent. The desiccant preferably comprises a zeolite or silica gel. The zeolite or silica gel may be used in the form of beads or platelets, or as a hot melt adhesive which may be applied in the form of a film containing silica gel or zeolite filler, as is used in the packaging industry.

In a preferred embodiment of the invention, the test element comprises a waste zone for receiving an excess liquid sample in the test element. This waste region serves to avoid undesired filling of certain regions of the test element, in particular the vent region of the channel, with the liquid sample.

The seal closing the sample receiving point preferably has a pre-configuration arranged such that a defined ridge is obtained when the seal is opened. The defined ridges or protrusions should have sharp edges that promote the transport of the liquid sample into the test element. The prescribed geometry and dimensions of the ridges or projections will achieve a greater chance that the liquid sample will come into contact with the capillary channel and be drawn into the channel. One possible pre-configuration is a cross or star shape, with the addition of a surrounding rectangle or a surrounding circle to define the length of the protrusion.

In a preferred embodiment of the invention, the test element comprises a detection window which is directed towards the test zone and which serves for photometric analysis of the liquid sample on the test zone. Light emitted from the light source and light reflected from the test zone may pass through the detection window, the latter being transparent in the relevant wavelength range. The detector may detect the reflected light and the detected signal may be processed by the electronic device and the result displayed to the user on the display device.

In a preferred embodiment of the invention, the conductor tracks for the electrochemical analysis of the liquid sample on the test field are formed on at least one wall which delimits the channel. These conductor tracks are necessary for the electrochemical analysis of the liquid sample in the test field of the test element. It is also contemplated that both photometric and electrochemical analysis may be performed.

In a preferred embodiment of the invention, the test element is composed of a plurality of layers. This has the advantage that the manufacture can be simplified. Different properties of different areas of the test element, such as wettability, light transmission, stability and shape, can be achieved by corresponding structures of the layers connected to one another.

In a test element constructed layer-by-layer, the channel may extend through one or more layers. The entire channel or a partial region of the channel may be fabricated by removing a portion of one or more layers by digging or stamping. Correspondingly, u-shaped or v-shaped channels are produced by punching out or cutting out u-shaped or v-shaped regions from a single intermediate layer, or by removing correspondingly shaped regions from several layers stacked one on top of the other in sequence (for example by removing two rectangular regions in two intermediate layers between which a carrier layer is provided which connects the two rectangular channel parts via openings). The channel height is in this case determined by the thickness of the intermediate layer. It is likewise possible to create free spaces in the test element by cutting or punching out correspondingly shaped regions in one or more layers.

The analytical test element according to the invention, which is constructed layer by layer, comprises at least one closed layer. The first closure layer acts as a seal (having the properties described above) for the sample receiving site and allows it to be opened by piercing, cutting, tearing or the like (preferably by piercing) when the test element is in use. Other sealing layers, for example on the side of the test element remote from the first sealing layer or on its end face at 90 ° thereto, can be used to protect the test element from water or contaminants and, if desired, can also be partially opened in addition to the first sealing layer during use of the test element.

In a preferred embodiment of the invention, the closing layer has a hydrophobic coating. The first sealing layer preferably has a hydrophobic coating on its outer side to achieve the above-mentioned better wetting properties with the aqueous liquid sample on its inner side than on its outer side.

The test element according to the invention, which is constructed layer by layer, preferably comprises at least one carrier layer and at least one intermediate layer which at least partially contains the channels. The carrier layer may impart stability to the test element. They may, for example, define the channel as a bottom layer and a top layer and may include a test zone. These bottom and top layers may contain hydrophilic materials in selected areas (preferably between the inlet and the test zone) and/or have surfaces with hydrophilic properties. Here, the hydrophilic surface is a surface that can absorb water. Aqueous samples, including blood, spread well on such surfaces. The latter can be easily wetted by these samples. Such surfaces are characterized in particular by the fact that the water droplets form an acute edge angle (Randwinkel) or contact angle at the interface on them. In contrast, on a hydrophobic surface, i.e., a water-repellent surface, an obtuse edge angle is formed at the interface of a water droplet with the surface.

The edge angle due to the surface tension of the sample liquid and the surface to be measured is a measure of the hydrophilicity of the surface. For example, the surface tension of water is 72 mN/m. If the surface tension of the surface in question is much lower than this value, i.e. more than 20mN/m less, wetting is poor and the edge angle formed is obtuse. Such surfaces are referred to as hydrophobic. Wetting is good when the surface tension is close to the surface tension value of water, with the wetting angle being an acute angle. Conversely, if the surface tension is equal to or greater than the surface tension value of water, the droplets spread apart, forming a full dispersion of the liquid. The edge angle will no longer be measurable. Surfaces that form acute edge angles with the water droplet, or where full dispersion of the water droplet can be observed, are said to be hydrophilic.

The ability of the capillary to draw up liquid is related to the wettability of the channel surface by the liquid. For aqueous samples this means that the capillary should be made using a material with a surface tension close to 72mN/m or above.

Examples of sufficiently hydrophilic materials for constructing capillaries which can rapidly take up aqueous samples are glass, metal or ceramic. However, these materials are not so suitable for use in test elements because they have certain disadvantages, such as the risk of breakage of the glass or ceramic, and the change in surface properties of many metals over time. Therefore, plastic films or plastic mouldings are often used for the production of test elements. In general, the surface tension of the plastics used is almost never more than 45 mN/m. Even with the relatively most hydrophilic plastics, such as Polymethylmethacrylate (PMMA) or Polyamide (PA), capillaries with very slow suction forces (if any) can only be formed. Capillaries made from untreated hydrophobic plastics such as Polystyrene (PS), polypropylene (PP) or Polyethylene (PE) do not substantially pick up any aqueous sample. It is therefore required that the construction material of the test element with capillary channels must become hydrophilic when using plastic.

In a preferred embodiment of the analytical test element according to the invention, at least one of the faces constituting the inner surface of the channel for capillary liquid transport, but better both faces, most particularly preferably both opposite faces, are treated to be hydrophilic. If more than one face is rendered hydrophilic, the same or different methods may be used to render the face hydrophilic. Hydrophilic treatment is especially required if the materials forming the capillary channels, in particular the carrier layer, are hydrophobic in nature or only slightly hydrophilic, for example because they consist of non-polar plastics.

Hydrophilic treatment of the capillary channel surface is desirably achieved by using a hydrophilic material which is not or substantially not capable of drawing up sample liquid itself in its manufacture, particularly in the manufacture of the carrier layer. When this cannot be done, hydrophilic treatment of hydrophobic or only very slightly hydrophilic surfaces can be achieved by suitable application of a stable hydrophilic layer inert to the sample substance, for example by covalent bonding of a photoreactive hydrophilic polymer to the plastic surface, by application of a layer comprising a wetting agent or by application of a nanocomposite material to the surface by means of a sol-gel process. In addition, increased hydrophilicity may also be obtained by thermally, physically or chemically treating the surface.

Very particular preference is given to achieving the hydrophilic treatment by using a thin layer of oxidized aluminum. These layers are either applied directly to the desired portions of the test element, for example by vacuum vapor deposition of metallic aluminum onto the workpiece and subsequent oxidation of the metal, or are used in the construction of the test element in the form of a metallic film or a metal-coated plastic film, which must also be oxidized to achieve the desired hydrophilicity. Here, a metal layer thickness of 1-500nm is sufficient. The metal layer is then oxidized to form the oxidized form, particularly suitable methods, in addition to electrochemical anodization, have proven to be especially boil oxidation in the presence of water vapor or in water. Depending on the method used, the oxide layer obtained has a thickness of between 0.1 and 500nm, preferably between 10 and 100 nm. In practice, larger layer thicknesses can also be obtained, which include both the thickness of the metal layer and the oxide layer.

The support layer, which acts as the top or bottom layer of the channel, may also have a hydrophobic material in selected areas, preferably between the vent and the test zone, or contain a hydrophobic surface coating. This is intended to ensure a weak wetting of the surface of the support layer by the aqueous liquid sample, for example to avoid the sample entering the vent area of the channel and thereby clogging this area.

Within the scope of the present invention, an intermediate layer is understood to be a layer which is arranged between two carrier layers and which at least partially contains channels and whose thickness defines at least part of the capillary height of the channels. The intermediate layer may be a double-sided adhesive tape or may be attached directly or by means of an adhesion promoter to a carrier layer serving as a bottom or top layer. The intermediate layers may have hydrophobic fillers that reduce their water vapor permeability, thereby preventing moisture from entering the channels through the intermediate layers. Alternatively, the intermediate layer itself may be made of a hydrophobic material.

In a particularly preferred embodiment of the invention, the layers are arranged in the following order:

A) a first sealing layer comprising a sample receiving point,

B) a first carrier layer which is transparent and which is,

C) a first intermediate layer comprising a first portion of the channels,

D) a second carrier layer comprising openings, the second carrier layer,

E) a second intermediate layer comprising a second portion of the channels,

F) a third carrier layer, and

G) a second sealing layer is arranged on the first sealing layer,

wherein an opening in the second carrier layer connects a first part of the channel with a second part of the channel, and a test zone is provided in the first part of the channel, and an empty space extends through the layers B) -F) when the test element is not in use, the first and second parts of the channel opening into this empty space. The outer surface of the first closing layer, and the sides of the second and third carrier layers facing the second portion of the channel may have a hydrophobic coating. A desiccant may be disposed within the second portion of the channel. The first sealing layer may comprise a detection window for photometric analysis of a liquid sample on the test area. The intermediate layer is preferably hydrophobic. The first and second carrier layers are preferably hydrophilic or provided with a hydrophilic coating on the side of the first portion facing the channels.

In a preferred embodiment of the invention, the sealing or closing layer is a composite film comprising an aluminium film, an outer layer made of PE, PET or oriented PA and an inner layer made of PE, PP or lacquer or comprising a PET/SiOx high barrier composite.

The invention further relates to a test element magazine designed as a tape, cartridge, stack or tray. In the case of a tape, a number of test elements according to the invention are arranged next to one another so that they can be wound, for example, on a reel. By rotating the reel, a new test element can be brought into the working position (sample removal and/or measurement position). The reel may be driven manually or automatically.

The test element magazine designed as a cartridge is preferably shaped as a substantially cylindrical, elongated cartridge, wherein the chambers for receiving the test elements are arranged in a star-like manner about the longitudinal axis of the cartridge. The length of the cartridge is adjusted substantially to the length of the test element contained therein. The bottom and top surfaces of the cylindrical cartridge contain the chamber openings which do not have to be closed since the test elements according to the invention are individually sealed. However, appropriate measures should be taken to ensure that the test element is held within the chamber against slipping until it is removed from the cartridge.

In the stack, the individual test elements are stacked on top of one another in a storage container and individually moved to the respective measuring position. In the present invention, the storage container comprising the laminate does not require further measures to protect the test elements, since they are each already provided with a seal according to the invention.

In the case of a disc, the individual test elements are arranged radially and at a distance from one another on a substantially circular disc. The new test element can be brought into the working position by rotating the disc, which can be done manually or automatically.

The invention further relates to a liquid sample analysis system having at least one test element magazine according to the invention, having a piercing device for opening a seal of a test element located at a sample receiving point shortly before application of the liquid sample, and having a detector for analyzing the liquid sample in a test field of the test element. The detector is, for example, a device for photometric or electrochemical determination of the test element. A piercing device is understood here to mean a device which can be opened by passing through or shearing through the seal of the respective test element according to the invention. For this purpose, it has sharp or pointed edges. It may for example be in the form of a spike, needle, lancet, knife or hollow needle.

In one embodiment of the invention, the system comprises a puncturing device in the form of a lancet, hollow needle, knife or spike in addition to the puncturing device to create a small hole in the skin of the patient for collecting body fluid as the liquid sample. Alternatively, the piercing means itself may simultaneously act as said perforating means. The punch device is used to create an opening in the body through which bodily fluids can be discharged. In the case where the puncturing means itself acts as the puncturing means, it is advantageous that the test element comprises two seals arranged on opposite sides of the test element and requiring a slight puncturing force, and that there is an empty space between these seals within the test element, whereby the puncturing means acting as the puncturing means can pass through the test element (and said empty space) and can be inserted into the skin surface of the user. The body fluid coming out of the skin surface can act directly on the sample receiving point of the test element.

In the case of two separate piercing and perforating devices, the perforating device may be concentrically surrounded by the piercing device. This makes it possible to accommodate both devices in a space-saving manner in the analysis system according to the invention. A further advantage of this arrangement is that the test element is in the working position for both devices at the same time.

In a further embodiment of the invention, the piercing means and the perforating means are arranged adjacent to each other in a holder, which can be rotated to successively reach the working position.

The test element magazine is preferably designed in the form of a strip of test elements which are individually sealed in a sequential manner, and the system comprises a transport device which can transport one test element at a time in succession to the operating position, wherein the seal of the test element can be pierced by the piercing device. In a further preferred embodiment, the test element magazine is designed in the form of a disk on which the test elements are arranged radially, by rotating the disk one test element at a time being able to be rotated into an operating position in which the seal of the test element can be opened by the puncturing device.

The system according to the invention preferably comprises a pressurizing unit for increasing the pressure against the perforated skin of the patient when extracting body fluid. The pressurizing unit is used to facilitate the flow of body fluid from the opening in the body. It may be a pressurizing unit as disclosed in WO 01/89383. The user presses the body part of the sample to be collected against the optionally deformable pressure unit. The user maintains the body part in this compressed state during opening to the skin and/or during extraction of body fluid.

Furthermore, the invention relates to the use of an analytical test element according to the invention for the analysis of the glucose content in blood or interstitial fluid.

The invention will be described in further detail below with reference to the attached drawing figures, wherein:

FIG. 1 shows a cross-section of an analytical test element according to the invention in the sealed state, in the open state and with a liquid sample applied,

figure 2 shows a cross-section of an analytical test element according to the invention with a waste zone,

FIG. 3 shows a liquid sample analysis system according to the invention with a test element magazine in the form of a tape, a piercing device and a detector according to the invention, and

fig. 4 shows a liquid sample analysis system according to the invention with a cartridge of test elements according to the invention in the form of a tray.

Detailed description of the invention

Fig. 1 shows an analytical test element according to the invention in the sealed state, the open state and the state with the application of a liquid sample.

The uppermost view of fig. 1 shows the test element 1 in a sealed state. It is made up of a plurality of layers. It is sealed on both outer sides by first and second sealing layers (2 and 3) of low water vapor permeability. The first closing layer 2 closes the sample receiving point 4 and has a hydrophobic coating 5 on its outside so that the aqueous liquid sample does not wet the outside but enters the test element 1 when the seal is opened at the sample receiving point 4. In the test element 1 there is a free space 6, to which free space 6 an inlet 7 and an outlet 8 of a channel 9 suitable for capillary transport of a liquid sample open. The channels 9 are U-shaped and extend over a plurality of layers, namely the two intermediate layers 10, 11 (the first and second portions 30, 31 of the channels) and the carrier layer 12 (the openings 32). In addition to this second carrier layer 12, the test element 1 also comprises a transparent first carrier layer 13 and a third carrier layer 14 arranged adjacent to the second sealing layer 3. The carrier layers 12, 13, 14 constitute the top and bottom layers of the channel 9. The second carrier layer 12 and the third carrier layer 14 each have a hydrophobic coating 15, 16, respectively, on their side facing the channel 9, to prevent the aqueous liquid sample from entering the portion of the channel 9 facing the vent 8. In the channel 9, on the side facing the transparent first carrier layer 13, a test field 17 is provided, on which a liquid sample can be analyzed. On the side of the transparent first carrier layer 13 remote from the test field 17, a detection window 18 for photometric analysis of the liquid sample on the test field 17 is provided on the first sealing layer 2. A desiccant is also provided in the channel 9 near the vent 8 for absorbing possible residual moisture in the sealed test element 1.

The middle view in fig. 1 shows an open test element 1, in which both closure layers 2, 3 in the region of the free space 6 have been pierced or cut apart. The sample receiving site 4 is now open and ready to receive a liquid sample. With the first closing layer 2 open at the sample receiving site 4, the inlet 7 of the channel 9 and the vent 8 of the channel 9 are simultaneously open to the environment outside the test element 1.

The lower view in fig. 1 shows how the liquid sample 20 reaches the test zone 17. A sufficiently large drop of the liquid sample 20 at the sample receiving point 4 is applied to the test element 1, the liquid sample 20 flowing from the sample receiving point 4 through the free space 6 to the inlet 7 of the channel 9 and being drawn into the latter by capillary forces. In the channel 9 the sample 20 flows through the test zone 17 where it is analysed.

Fig. 2 shows a further analytical test element according to the invention, which corresponds in construction to the test element shown in fig. 1 and further has a waste zone 21 which can receive an excess portion 22 of the liquid sample 20. For the rest of the structure, the description of fig. 1 applies equally to the test element 1 shown in fig. 2, and the reference numerals have the same meaning as in fig. 1.

Fig. 3 schematically illustrates a liquid sample analysis system according to the present invention.

The top left view of fig. 3 schematically shows a top view of the system. The test element 1 according to the invention is located in a magazine in the form of a tape 23. The cone symbol acts as a pressurizing unit 24 for adding pressure to the area around the body opening of the patient's skin for transferring body fluids, such as blood or interstitial fluid, from the body opening. The pressure unit 24 is in this case arranged above the sample reception site 4 of the test element 1 in the operating position.

The lower left view of fig. 3 schematically shows a first side view of the same system according to the invention. The magazine in the form of a belt 23 passes through two transport rollers 25 to transport the test elements 1 each time to a working position, in which the pressure unit 24 is located directly above the sample receiving point. In the cylindrical device 26 shown in fig. 3, there are (not shown) piercing means and, optionally, perforating means, which can be brought successively into the operating position, for example by rotating a holder accommodating them, i.e. into a position in which the piercing means can pierce seals on both sides of the test element 1, in particular at the sample receiving point, and the perforating means can create a body opening in a body part placed on the pressurizing unit 24. The cylindrical device is preceded by a detector 27, for example for photometric analysis of the sample, wherein the detector 27 is directed to a detection window (not shown) on the test element 1 in the operating position.

The lower right view of fig. 3 schematically shows a second side view of the same system according to the invention. The cylindrical device 26, the detector 27, the strip-shaped magazine 23 and the pressure unit 24 can again be clearly seen.

Fig. 4 schematically shows a top view of another liquid sample analysis system according to the present invention.

The system comprises a magazine in the form of a disc 28, wherein the test elements 1 according to the invention are arranged radially on a substantially circular disc on said disc 28. By rotating the magazine 28 in the direction of rotation 29, it is possible to bring one test element 1 at a time into the operating position (sample receiving point 4 below the pressure unit 24). The system further comprises a piercing device (not shown) housed within the cylindrical device 26, and a detector 27.

List of reference numerals

1 test element

2 first sealing layer

3 second sealing layer

4 sample receiving point

5 hydrophobic coating

6 free space

7 inlet

8 exhaust port

9 channel

10 first intermediate layer

11 second intermediate layer

12 second carrier layer

13 first carrier layer

14 third carrier layer

15 hydrophobic coating

16 hydrophobic coating

17 test area

18 detection window

19 desiccant

20 liquid sample

21 waste zone

22 excess liquid sample

23 Belt form of Cartridge

24 pressure unit

25 transport roller

26 cylindrical device

27 Detector

28 tray type storehouse

29 direction of rotation

30 first part of the channel

31 second part of the channel

32 opening

Claims (40)

1. An analytical test element for analyzing a liquid sample (20), comprising a channel (9) adapted for capillary transport of the liquid sample (20) and having an inlet (7) for the liquid sample (20) and a vent (8), wherein at least one test zone (17) is arranged within the channel (9) at a distance from the inlet (7), characterized in that the test element (1) comprises a sample receiving point (4) which is closed by a seal, which sample receiving point (4) is designed in such a way that the sample receiving point (4) and the inlet (7) of the channel (9) are simultaneously open to the environment outside the test element (1) by opening the seal, and that the test element (1) can receive the liquid sample (20) via the sample receiving point (4) and the inlet (7) of the channel (9) for analysis in the test zone (17).

2. Analytical test element according to claim 1, characterised in that the inlet (7) is arranged at one end of the channel (9) and the exhaust (8) is arranged at the other end of the channel (9).

3. The analytical test element according to claim 1 or 2, characterised in that the sample reception site (4), the inlet (7) of the channel (9) and the vent (8) of the channel (9) are simultaneously open to the environment outside the test element (1) by opening the seal.

4. Analytical test element according to one of claims 1 to 3, characterised in that the inlet (7) and the exhaust (8) of the channel (9) open into an empty space (6) within the test element (1), which empty space (6) is arranged in a form which is open to the environment outside the test element (1) when the seal is opened.

5. Analytical test element according to claim 4, characterised in that in the non-use state of the test element (1) the free space (6) is at least partially delimited on a first side by a seal closing the sample reception point (4) and on a second side facing away from the first side by a second seal.

6. Analytical test element according to one of claims 1 to 5, characterised in that the channels (9) in the test element (1) run in a U-or V-shape.

7. Analytical test element according to one of claims 1 to 6, characterised in that the channel (9) has a substantially rectangular cross section and a width of less than 5mm and a height of less than 1 mm.

8. Analytical test element according to one of claims 1 to 7, characterised in that the total length of the channel (9) is less than 5 cm.

9. The analytical test element according to one of claims 1 to 8, characterised in that the distance of the sample reception point (4) from the inlet (7) of the channel (9) is smaller than the distance of the sample reception point (4) from the air outlet (8) of the channel (9).

10. Analytical test element according to one of claims 1 to 9, characterised in that the channel (9) has better wetting properties with the liquid sample in the region of the inlet opening (7) than in the region of the outlet opening (8).

11. Analytical test element according to one of claims 1 to 10, characterised in that in its interior the channel (9) has better wetting properties with the liquid sample (20) between the inlet (7) and the at least one test zone (17) than between the at least one test zone (17) and the vent (8).

12. Analytical test element according to one of claims 1 to 11, characterised in that the seal closing off the sample reception point (4) has better wetting properties with the liquid sample (20) on the side facing towards the interior of the test element (1) than on the side facing away from the interior of the test element (1).

13. Analytical test element according to one of claims 1 to 12, characterised in that a desiccant (19) is contained in the test element (1).

14. The analytical test element according to claim 13, characterised in that the desiccant (19) comprises zeolite or silica gel.

15. Analytical test element according to one of claims 1 to 14, characterised by a waste zone (21) for receiving an excess (22) of the liquid sample (20) in the test element (1).

16. Analytical test element according to one of claims 1 to 15, characterised in that the seal closing the sample reception site (4) has a pre-structure arranged such that a defined ridge is obtained when the seal is opened.

17. The analytical test element according to claim 16, characterized in that the pre-structure is cross-shaped or star-shaped.

18. Analytical test element according to one of claims 1 to 17, characterised in that the test element (1) comprises a detection window (18) which is directed towards the test zone (17) and is used for photometric analysis of a liquid sample (20) on the test zone (17).

19. Analytical test element according to one of claims 1 to 18, characterised in that a conductor track for the electrochemical analysis of the liquid sample (20) on the test field (17) is provided in at least one wall delimiting the channel (9).

20. Analytical test element according to one of claims 1 to 19, characterised in that the test element (1) consists of a plurality of layers.

21. Analytical test element according to claim 20, characterised in that the channel (9) runs through one or more layers.

22. Analytical test element according to claim 20 or 21, characterised in that the test element (1) comprises at least one sealing layer (2, 3).

23. Analytical test element according to claim 22, characterised in that the closing layer (2, 3) has a hydrophobic coating (5).

24. Analytical test element according to one of claims 20 to 23, characterised in that the test element (1) comprises at least one carrier layer (12, 13, 14) and at least one intermediate layer (10, 11) which at least partially comprises the channels (9).

25. Analytical test element according to one of claims 20 to 24, characterised in that the layers are arranged in the following order:

A) a first sealing layer (2) comprising a sample receiving site (4),

B) a transparent first carrier layer (13),

C) a first intermediate layer (10) comprising a first portion (30) of the channels (9),

D) a second carrier layer (12) comprising an opening (32),

E) a second intermediate layer (11) comprising a second portion (31) of the channels (9),

F) a third carrier layer (14), and

G) a second sealing layer (3),

wherein an opening (32) in the second carrier layer (12) connects a first portion (30) of the channel (9) and a second portion (31) of the channel (9), and a test zone (17) is provided in the first portion (30) of the channel (9), for unused test elements (1) a free space (6) extending through the layers B) -F), the first and second portions (30, 31) of the channel (9) opening into the free space (6).

26. Analytical test element according to claim 25, characterised in that the outer surface of the first closing layer (2) and the sides of the second and third carrier layers (12, 14) facing the second portion (31) of the channel (9) are provided with a hydrophobic coating (15, 16).

27. Analytical test element according to claim 25 or 26, characterised in that a desiccant (19) is provided in the second portion (31) of the channel (9).

28. Analytical test element according to one of claims 25 to 27, characterised in that the first sealing layer (2) comprises a detection window (18) for photometric analysis of a liquid sample (20) on the test field (17).

29. Analytical test element according to one of claims 25 to 28, characterised in that the intermediate layer (10, 11) is hydrophobic.

30. The analytical test element according to one of claims 25 to 29, characterised in that the side of the first and second carrier layer (13, 12) facing the first section (30) of the channel (9) is hydrophilic or provided with a hydrophilic coating.

31. Analytical test element according to one of claims 1 to 30, characterised in that the sealing or closure layer (2, 3) is an outer layer comprising an aluminium film, made of PE, PET or oriented PA and an inner layer made of PE, PP or lacquer or comprises PET/SiO_xA composite film of a high barrier composite material.

32. A test element magazine having a plurality of analytical test elements (1) according to one of claims 1 to 31, wherein the test element magazine is provided as a tape (23), cartridge, stack or disk (28).

33. A liquid sample (20) analysis system having at least one analytical test element (1) according to one of claims 1 to 31, piercing means for opening the seal of the test element (1) at the sample receiving point (4) shortly before receiving the liquid sample (20), and a detector (25) for analyzing the liquid sample (20) in the test zone (17) of the test element (1).

34. A system according to claim 33, characterized in that it comprises, in addition to the puncturing device, a puncturing device in the form of a lancet, a hollow needle, a knife or a spike for creating a puncture in the skin of the patient for obtaining body fluid as the liquid sample (20), or in that the puncturing device also acts as a puncturing device.

35. The system of claim 34, wherein the puncturing device is concentrically surrounded by the puncturing device.

36. System according to claim 34, characterized in that the piercing means and the perforating means are arranged adjacent to each other in a holder, by rotating said holder, the working positions being reached one after the other.

37. System according to one of claims 33 to 36, characterized by a test element magazine in the form of a strip (23) of test elements (1) in a sequential order, wherein the system comprises transport means which are designed to transport one test element (1) of the strip (23) to the operating position, respectively, wherein the seal of the test element (1) can be opened by the puncturing means.

38. System according to one of claims 33 to 36, characterized in that the test element magazine is in the form of a disc (28) on which the test elements (1) are radially arranged, by rotating said disc (28) the test elements (1) being rotatable individually into an operating position in which the seal of the test element (1) can be opened by the puncturing device.

39. The system of one of claims 33 to 38, comprising a pressurizing unit (24) for increasing the pressure on the perforated skin of the patient when extracting the body fluid.

40. Use of an analytical test element according to one of claims 1 to 31 for the analysis of the glucose content in blood or interstitial fluid.