HK1125017B - Test element for examining a body fluid - Google Patents

Description

Test element for examining a body fluid

Technical Field

The invention relates to a test element for testing body fluids as a disposable article, having a piercing element which can be pierced into a body part, an acquisition region which is arranged on the piercing element for body fluids obtained by a piercing action, and at least one light guide for optical measurement in the acquisition region. The invention also relates to a test system for using such a test element.

Background

In the context of insulin therapy, in the case of blood glucose self-tests, which are usually carried out several times a day, it is desirable to reduce the number of operating steps undertaken by the relevant person as far as possible and at the same time to ensure a low-pain and reliable measurement. For hygiene reasons, disposable articles are used here, which, as a mass product, should be producible at the lowest possible cost. Conventional solutions provide for the blood, which is usually withdrawn from the finger tissue area by a lancet prick, to be transferred to a separate sensor element, for example in the form of a test strip, in order to then initiate the actual measurement process.

For extensive system integration, a combined device has already been proposed in DE 10325699B3, in which a light-conducting hollow fiber is arranged concentrically around a coaxially movable lancet. The hollow fibers have a reagent layer on the distal end face, which is loaded with the exiting blood when the lancet penetrates the body part, while the light of the analysis unit can be fed into or out of the proximal hollow fiber end. In a complementary embodiment, the system has a hollow cannula with a light guide movable therein, the distal end of which, arranged in the opening of the cannula, is likewise coated with a reagent specific to the analyte. For the purpose of facilitating sampling, the light conductor end is pushed out of the cannula opening after the puncturing operation until it protrudes beyond the cannula opening and thereby brings the test field into contact with the patient's blood without any problems. However, an additional drive control is required for the relative movement between the puncturing element and the light-conducting element, wherein the function of checking whether blood contact is successful is not provided.

Disclosure of Invention

The object of the invention is to further develop the systems disclosed in the prior art, in particular to avoid the disadvantages of troublesome sample transport and to increase the operator friendliness by reliable means.

To solve this object, the test element according to the invention for the examination of body fluids as a disposable article is proposed, as well as preferred embodiments and improvements.

The test element according to the invention for testing body fluids as a disposable article has a piercing element which can be pierced into a body part, an acquisition region provided on the piercing element for body fluids obtained by a piercing action, and at least one light guide for optical measurement in the acquisition region, characterized in that the acquisition region is formed by an acquisition recess of the piercing element which extends in a piercing direction, and the light guide is integrated in the piercing element and is arranged with its distal end in a measurement region of the proximal end of the acquisition recess.

The invention is based on the idea of automatically and largely dead-volume-free drawing off the liquid in the collection line of a short capillary tube and deriving therefrom an optical measurement signal. Accordingly, it is proposed according to the invention that the collection area is formed by a collection recess of the piercing element extending in the piercing direction, and that the light guide is integrated in the piercing element in a manner that it is not displaceable relative to one another and is arranged with its distal end in a proximal measuring area of the collection recess. A certain (minimum) blood volume is accommodated in the collection space, so that the examination is not interfered with by interfering tissue components penetrating the wound and/or by uncontrolled mechanical pressure loading. By virtue of the preferably fixed or even non-displaceable mounting of the at least one light conductor, an integration which is also simplified in terms of production is achieved, wherein the arrangement in the region of the proximal end enables a check to be made as to whether the acquisition process was successful.

In order to ensure a reliable measurement, the light guide, with its distal end, forms a probe for detecting the body fluid filling the collection space. In order to ensure sufficient filling of the collection volume, the light guide preferably detects contact with body fluid in the final phase of the reception of fluid in the collection recess.

Alternatively or in addition to the optical detection, it can also be provided that at least one voltage-loadable electrode for liquid contact detection or analyte detection is arranged in the region of the collection space, wherein the electrode can be formed by an electrical line integrated in the piercing element.

The light guide and/or the electrodes provide a measuring signal for controlling the movement of the piercing element as a function of the detected contact with the body fluid, thereby resulting in a further development.

According to a preferred embodiment, a test field which responds to an analyte in the body fluid, in particular irreversibly chemically reacts, is arranged in the region of the distal end of the light guide. A further miniaturization can be achieved by providing the distal end of the light guide with a test field for an analyte in a body fluid, preferably arranged fixedly as a reagent layer, on the end face.

In order to further increase the reliability just when checking the minimum amount that is not felt by the user, at least two, preferably three, individual light conductors for parallel measurement are preferably integrated in the piercing element, wherein the distal ends of the light conductors are arranged laterally spaced apart from one another.

For a very robust structure despite miniaturization, the distal ends of the light conductors are preferably optically coupled via a carrier film to a common test field, wherein the test field is formed by a reagent layer arranged on the free front side of the carrier film facing away from the light conductors. For optical measurements with high signal quality, a reflection path between the transmitter-side and receiver-side light conductor ends on the back-side irradiated test field is particularly advantageous. For this purpose, the thickness of the carrier film should be 0.5 to 1.5 times the mutual distance of the center lines of adjacent light conductors. A further development is achieved in that the light guide, the carrier film and the reagent layer have mutually matched, substantially identical refractive indices. This can be optimized by the test field containing a reaction-neutral auxiliary material, in particular a salt such as common salt, in the reagent layer, which in solution in a body fluid matches the refractive index of the reagent layer to the refractive index of the at least one optical waveguide.

The light guide can be releasably connected to an optical transmitting and/or receiving unit of the measuring device by an optical plug connection. This can be achieved by the fact that the lancing element can be coupled to a coupling unit of the lancing drive, preferably in a form-fitting manner, wherein the coupling unit has an optical or optoelectronic interface for connecting the light guide to the evaluation unit, which interface can be moved together during the lancing movement.

According to a further preferred embodiment, the length of the collecting recess, as seen in the puncturing direction, is designed such that the proximal end section of the collecting recess remains outside the body part during puncturing, so that contact of the body with the test chemical is avoided in any case and interfering cell components can be avoided.

In order to be able to extract the liquid quickly and thereby also to minimize pain sensation, it is preferred that the collecting void has a volume of 1 to 100 nanoliters, preferably 5 to 50 nanoliters. In this case, the collecting space preferably forms a capillary for the capillary-active extraction of the liquid. Liquid extraction can also be further improved by configuring the collecting void as a slit open on at least one side, preferably both sides.

For the positioning of the light guide, the collection recess preferably has a proximal end section that widens in cross section as a measuring region.

Preferably, the light guide is formed by an optical fiber or fiber bundle. It is also conceivable for the light guide to be formed by a part of the piercing element which is formed from a light-conducting material. For optimum light transmission, the light guide preferably has a larger cross-sectional area at its proximal end than at its distal end.

This can be simplified in terms of production by the fact that the holder made of plastic is formed on the piercing element, preferably by a two-component injection molding technique. According to another embodiment, which is preferred in terms of production, the penetrating element is formed by a plurality of flat material layers, wherein the light guide is preferably arranged in a receiving groove between two flat material layers.

For a precise puncturing process, it is preferred that the puncturing element has a puncturing mechanism sharpened by a grinding plate and/or hardened by a coating. Likewise, as is also known from blade production, laser-optical material processing methods, in particular ablation methods, can be considered for sharpening the edges.

To improve the liquid extraction, the collecting void may be provided with a hydrophilic coating.

The collection process of a small but sufficient amount of body fluid obtained by skin penetration can be carried out automatically by the collection gap forming a capillary for the automatic filling of the body fluid, wherein the length of the capillary is a multiple of its diameter. For the analysis of minute amounts of liquid, a device is particularly preferred in which the test field is oriented transversely to the longitudinal extent of the collecting recess, so that the body fluid flows in front to the test field.

Another aspect of the invention relates to a test element for use as a disposable article for the examination of body fluids, the test element has a piercing element that can be pierced into a body part, a collection area arranged on the piercing element for body fluid obtained by a piercing action, and at least one signal line, preferably in the form of a light guide or an electrical conductor track, for optical or electrochemical measurement in the collection area, wherein the acquisition zone is constituted by capillary acting acquisition voids of the piercing element extending longitudinally in the direction of penetration, and the signal conductor is integrated in the piercing element and coupled to a test field that reacts to an analyte in a body fluid, the test field at least partially delimits the capillary cross section in the measurement field at the proximal end of the collecting recess on the front side in order to prevent inflowing body fluid. In this way, the liquid can be transported by capillary forces over a short flow path, in order to ensure that no interfering substances, such as cell components, influence the measurement, wherein the actual measurement process can be carried out in the device separately from the penetration process without the test field first influencing the liquid transport. When the flow front of the body fluid hits the test field, a very small volume of fluid can be measured at a given moment.

According to a structurally preferred embodiment, the piercing elements have a bent shaft or the light or signal line extends in a stepped manner, so that the piercing elements can be coupled to the piercing drive in a first plane and the signal line/light guide is coupled to the transmitting element and/or the receiving element in a second plane.

A test system for examining body fluids, in particular blood, having a receiving opening for at least one test element according to the invention is also subject matter of the invention. A large number of test elements are stored in the magazine, so that the user comfort is increased.

For the measurement process, the test element can preferably be driven by the lancing drive device with a back-and-forth lancing movement, and the transmitter element and/or the receiver element of the evaluation unit can be connected to the light guide or the signal line of the test element during the lancing movement. This can be achieved by the fact that the transmitting element and/or the receiving element, preferably as a mounting of the drive ram, can be moved together with the test element during the puncturing movement.

The test system in the form of a portable, hand-held instrument is preferably used for blood glucose measurements or also for other monitoring operations close to the individual, for example for blood coagulation diagnosis.

Drawings

The invention is explained in detail below with the aid of exemplary embodiments which are schematically illustrated in the drawing. Wherein:

FIG. 1 is a diagrammatic view of a blood glucose measuring instrument;

FIG. 2 is a perspective view of the instrument according to FIG. 1;

FIG. 3 is a side view of a test element provided with a light conductor;

FIG. 4 shows the test element coupled to the lancing drive device according to FIG. 3;

FIG. 5 is an enlarged view of the broken out cutaway portion of FIG. 4;

FIG. 6 is a broken side view of another embodiment of a coupling unit for an optical conductor of the test element;

fig. 7 and 8 are a side view and an enlarged view, respectively, of another embodiment of a test unit.

FIG. 9 is an exploded view and a perspective view in the assembled state of a test element as a film composite;

fig. 10 is a longitudinal section through a cut-out of the test element in the region of the acquisition of measured values on the acquisition interspace; and is

FIG. 11 is a perspective view of another embodiment of a test element with a bent piercing element.

Detailed Description

The test element 10 shown in the figures can be inserted as a disposable item for blood glucose measurements into a hand-held device 12 provided for this purpose. For this purpose, the test element 10 comprises a piercing element 14 which can be pierced into a body part during a piercing movement, a collection area 16 which is arranged on the piercing element 16 and is intended to receive a blood sample obtained by the piercing movement, and at least one light guide 18 for optical measurement in the collection area 16.

As shown in fig. 1, a large number of test elements 10 arranged in respective magazines 20 of a stack or reel-shaped magazine 22 can be placed one by one in an activated position of use with respect to a support 24 provided with piercing holes for positioning a user's fingers. The piercing drive 26 engaged in the magazine 20 can thereby move the piercing elements 14 back and forth along the piercing axis or piercing direction. In a collection position of the piercing element 14, which is optionally slightly withdrawn into the body part, blood is then received in the collection region 16.

A successful blood withdrawal and/or analyte (glucose) content can be detected by the light guide 18 as if it were on site with a very small blood volume, without the need to accept larger transport distances and dead volumes. The current blood glucose level can be analyzed and displayed by a microprocessor assisted processing unit 27 and output unit 28. According to fig. 2, all device functions are implemented in a compact battery-operated hand-held device, so that the blood glucose concentration can be determined automatically and reliably with great operating comfort even for laymen during a fully automatic measurement process.

Such measurements can also be carried out in other body regions, for example in the less pain-sensitive arm region or abdominal region, in which case tissue fluids or mixtures of these two fluids can also be used as the body fluid for sampling in addition to capillary blood from the skin.

Fig. 3 shows a single test element 10 with a rod-shaped, longitudinally extending piercing element 14, on the distal end of which piercing element 14 a tip 30 sharpened by a grinding plate 28 is provided as a piercing means. The collection region 16 is then formed as a longitudinal slit 32 which is open on one or both sides and which longitudinal slit 32 serves as a passage for capillary action to enable a small sample volume to be transferred into a proximal measurement region 34 located outside the skin. For this purpose, the length of the gap 32 is dimensioned such that the measuring field 34 remains outside the body part even when the lancing means 30 has reached its maximum lancing depth. At the same time, the longitudinally extending slit opening ensures an effective extraction of the liquid without the risk of clogging due to cell components. The lateral passage openings thus preferably extend over the length of the collecting interspace 16.

In order to extract the blood as carefully and as painlessly as possible, the volume of the collecting region 16 is only a few tens of nanoliters. In this case, the hydrophilic coating of the collecting spaces 16 and, if necessary, the hydrophobic nature of the adjoining regions preferably allow the liquid to reach substantially only where it is needed. The different hydrophilic and hydrophobic regions can be produced, for example, in such a way that the coating material is applied by an embossing method (tamproduckverfahren) and/or is also functionalized by a photochemical method.

As can be further seen from fig. 3, two parallel light conductors 18 are fixedly integrated in the insertion element 14, so that distal light conductor ends 36, which are spaced apart from one another laterally, project into a proximal measuring region 34, which widens in cross section, of the collection region 16. In general, for an "on-line detection" of a successful blood withdrawal, it is important that the light guide at least partially delimits the collection region in an end region facing away from the body, i.e., in the proximal end. Since only a few nanoliters of blood enter this end region, a higher measurement reliability is achieved by means of the parallel light conductors 18 by means of a double detection. This is particularly advantageous for the user, since he not only obtains one measured value, but additionally also knows quality-ensuring information from a comparison of the two measured values.

A special function of the light conductor 18 is that its end 36 is designed as a probe for detecting the successful filling of the collection interspace 16. A signal can be derived exclusively from the refractive index change occurring in the final phase of blood extraction upon liquid contact, which signal can be used for a flexible control of the lancing movement for a successful collection process. Thus, regular acquisition intervals of, for example, 0.1 seconds can also be extended in particular cases to, for example, 1 second, in order not to have to interrupt the measurement process in the event of an unsuccessful event. In principle, it is also possible to arrange for such a liquid contact to be detected by an integrated electrical probe, in particular a wire electrode (Drahtelektrode), instead of the optical waveguide (not shown).

The light guide 18 may be formed from individual fibers or fiber bundles. Here, it is also possible to use so-called drawn fibers, the cross-section of which at the proximal end is smaller than at the distal end, in order to ensure good optical connection to the coupling site.

For the direct detection of the analyte in the measurement zone 34, the distal end 36 of the light guide 18 is provided with a reagent layer as a test zone 38 on the end face. The test chemical, as an enzyme known per se, can be immobilized by polymerization on the end of the light guide, so that it reacts irreversibly with blood glucose in the event of a color change. By means of the particles dispersed within the chemical system, optical detection can be carried out on the instrument side with back scattering of the measurement light incident via the light guide 18.

For a drive coupling of a form-fitting connection, the test element 10 is provided with a base part 40 which supports the piercing element 14. This base member 40 can be made of plastic and formed on the piercing member 14 made of metal in a two-component injection molding process. Of course, it is also conceivable for the piercing elements 14 to likewise be made of plastic and additionally hardened in the region of the piercing means, for example by a diamond-like carbon coating.

As can be seen most clearly in fig. 4, the puncturing element 10 is guided linearly inside its magazine 20 by the base member 40. The pierceable sealing film 42 provided at the end of the receptacle 20 serves as an anti-microbial and moisture-proof seal. During the puncturing movement, the drive tappet 44 penetrates the facing sealing film and engages with its pincer-like end 46 with the base part 40. In this case, the light guide 16 is releasably connected to an interface 48 arranged in the tappet 44, as explained in more detail below. The interface 48 is connected to the processing unit 27 via a flexible line 50 which is carried along during the puncturing movement, so that signal processing and evaluation can take place there.

The puncturing process itself can comprise, in a controlled movement profile, a rapid puncturing phase, a longer dwell phase or collection phase, which is optionally slightly retracted, and also a rapid retraction phase. In this case, it can be provided that the detection is also carried out in several phases by means of the light guide 18, i.e. only blood contact is detected during the collection phase, and the actual analysis takes place in the device 12 only later during or after the retraction phase. It is also conceivable to transfer the blood sample in the gap 32 to a separate test field, as described in detail in european patent application nr.05019055.2. In this case, the light guide 18 is only intended for blood contact detection.

Fig. 5 shows an exemplary embodiment of an optical interface 48, which interface 48 is used for coupling the test element 10 by means of an optical plug connection, as is known, for example, from the field of telecommunications applications. The light conductor 18 of the test element 10 is in contact with its proximal end with an associated interface-side light conductor 52 in a butt-joint manner (Sto β auftsto β), which interface-side light conductor 52 is connected to a transmission/reception module fixed to the device by means of a flexible line 50. It is obvious that the mechanical tolerances of the plug connection should be small in order to obtain the necessary transmission quality for the measurement signal.

In order to reduce tolerance requirements, an optoelectronic interface 48 can be integrated into the lancing drive according to fig. 6. Two electrically activatable light-emitting diodes 54 are provided as light emitters, which light-emitting diodes 54 are directed by means of a baffle 56 toward the light guide 18 of the test element 10. The optical receiver is then formed by a photodiode 58 which is protected against crosstalk towards the transmitting side by means of said baffle 54, behind which photodiode 58 a preamplifier 60 is arranged. In this way, an intensified electrical measurement signal can be transmitted from the interface 48, which moves together during the puncturing operation, to the processing unit 27.

It is also possible to use two leds incident at different wavelengths for performing different measurement tasks (e.g. detecting test area wetting separately from the actual measurement task).

In the embodiment shown in fig. 7 and 8, three parallel optical waveguides 18 are provided for further improving the decoupling between the transmitting side and the receiving side. At the coupling point, the two outer light conductors for transmitting light are completely separated from the receiver 58 by the baffle 56, the receiver 56 thus being oriented only toward the outlet cross section of the central light conductor. In contrast, in the measuring region 34, the light conductors 18 merge into a common end 62, which end 62 is coated with the test chemical on its free end face. The receiving cross section for the back-scattered light is optimized by the Y-shaped widening of the central light guide body towards the test field 38. It is also conceivable to replace the light-emitting diodes 54 in the interface 48 with optical conductors and to perform the photoelectric conversion only on the reception side in the moving part.

In general, for optical measuring devices, it is preferred to orient the distal end section of the optical fiber 18 perpendicular to the test field 38 and to orient this test field 38 again perpendicular or transversely to the flow direction of the body fluid in the collecting recess 32.

Fig. 9 shows a production-technically advantageous variant of a piercing element 14 in the form of a composite body. The light conductor 18 can in this case be inserted into a receiving groove 64 of a lancet element 66. The lancet element 66 can be formed from a high-quality steel plate and is provided immediately behind its tip 30 with a recess 32 and a measuring region 34 widened as a break. The light conductor 18 is fixed by a cover film 38 laminated on the lancet element 66.

Fig. 10 shows an embodiment similar to fig. 8 with three parallel light conductors 18, the light conductors 18 being oriented at least in the distal end section with their center lines or optical axes perpendicular to the test field 38. The light guide 18 is optically coupled to the rear side of the test field by means of a carrier film 62, the carrier film 62 being fixedly connected to the light guide end for reducing reflection losses to a large extent. For this purpose, the carrier film 62 has a refractive index matched to the light guide 18, i.e. a deviation of a few percent. Likewise, the reagent layer provided as test field 38 on the free front side of carrier film 62 is matched to the uniform refractive index of the boundary of carrier film 62. This can be achieved by suitably adjusting the refractive index by adding a reaction-neutral additive such as common salt to the blood-loaded reagent layer. As soon as the liquid received in the capillary channel 32 at the distal end, as a result of the transport of the capillary action in the flow direction 68, strikes the test field, which closes at least one partial cross section of the capillary channel at the proximal end, it is wetted with blood at a specific point in time on the test field surface in this case. For this purpose, a short flow path is sufficient, without the need to flow past the lateral measuring surface. The sensitive surface of the test field can thereby also be lowered to the flow cross section, so that only a small sample volume is required for the actual measurement process and the liquid supply to the measurement site is not impaired. The optical arrangement between the central input light guide and the two laterally adjacent output light guides is selected in such a way that a direct reflected light path 70 can be generated on the rear side of the test field by the carrier film 62. For this purpose, the thickness of the film 62 corresponds approximately to the center distance of the adjacent light conductors 18.

The embodiment according to fig. 11 shows a puncturing element 14 with a bent shank 71, the shank 71 being slotted in the region of the bend for receiving a holder for a signal line 18. This holder can be inserted together with the shaft 72 into an opto-mechanical holder, in which an optical or electrical interface 48 can be coupled. In this way, two planes are provided, preferably one above the other, namely a first plane for the mechanical actuation of the piercing elements 14 and a second plane for the input and output of measurement signals. This makes it possible, in particular in the case of flat designs, for example, to simplify the design of disk-shaped cartridges from which the relatively long puncturing units 14 are radially ejected. It is also conceivable to provide a double plane for an advantageous coupling by means of a bent wire holder and a straight piercing rod.

In the embodiments explained above, instead of the optical signal lines, electrical conductor tracks can also be provided, which enable the best known electrochemical glucose measurement to be carried out in conjunction with the reagent layer electrodes.

Claims (26)

1. Test element for the examination of body fluids as a disposable article, having a piercing element (14) which can be pierced into a body part, an acquisition region (16) which is arranged on the piercing element (14) for body fluid obtained by a piercing action, and at least one light guide (18) for the optical measurement in the acquisition region (16), characterized in that the acquisition region is formed by an acquisition recess (16) of the piercing element (14) which extends in the piercing direction, and in that the light guide (18) which is integrated in the piercing element (14) in a manner such that it cannot be moved is arranged with an end (36) distal to the light guide (18) in a measurement region (34) proximal to the acquisition recess (16).

2. Test element according to claim 1, characterized in that the light conductor (18) forms with its distal end (36) a probe for detecting a body fluid filling the collection recess (16).

3. Test element according to claim 1 or 2, characterized in that at least one voltage-loadable electrode for liquid contact detection or analyte detection is arranged in the region of the collecting interspace (16).

4. Test element according to claim 1 or 2, characterized in that the light conductor (18) provides a measuring signal for the movement control of the piercing element (14) as a function of the detected contact with body fluid.

5. A test element according to claim 3, characterized in that the electrodes provide measuring signals for the movement control of the piercing elements (14) in dependence on the detected contact with body fluid.

6. A test element according to claim 3, characterized in that the light conductor (18) and the electrodes provide a measuring signal for the movement control of the piercing element (14) as a function of the detected contact with body fluid.

7. Test element according to claim 1 or 2, characterized in that a test field (38) which responds to an analyte in a body fluid is arranged in the region of the distal end (36) of the light guide (18).

8. Test element according to claim 1 or 2, characterized in that the distal end of the light guide (18) is provided on the end face with a fixedly arranged test field (38) for the analyte in the body fluid.

9. Test element according to claim 1 or 2, characterized in that at least two light conductors (18) for parallel measurement are integrated in the piercing element (14), wherein distal ends (36) of the light conductors (18) are arranged laterally spaced apart from one another.

10. Test element according to claim 9, characterized in that the distal ends of the light conductors (18) are optically coupled to a common test field (38) by means of a carrier film (62), wherein the test field (38) is formed by a reagent layer arranged on the free front side of the carrier film (62) facing away from the light conductors (18).

11. Test element according to claim 10, characterized in that the thickness of the carrier film (62) is 0.5 to 1.5 times the mutual distance of the center lines of adjacent light conductors (18).

12. The test element according to claim 10, characterized in that the light guide, the carrier film (62) and the reagent layer have matching, corresponding refractive indices.

13. The test element according to claim 10, characterized in that the test field (38) contains a reaction-neutral auxiliary material in the reagent layer, which auxiliary material in solution in a body fluid matches the refractive index of the reagent layer to the refractive index of the at least one optical waveguide.

14. Test element according to claim 1 or 2, characterized in that the optical waveguide (18) is releasably connected to an optical transmitter unit (54) and/or receiver unit (58) of the measuring device (12).

15. Test element according to claim 1 or 2, characterized in that the piercing element (14) is coupled to a coupling unit (46) of the piercing drive (26), wherein the coupling unit (46) has an optical or optoelectronic interface (48) for connecting the light conductor (18) to the evaluation unit (27).

16. Test element according to claim 1 or 2, characterized in that the length of the collecting interspace (16) seen in the puncturing direction is designed such that a proximal end section of the collecting interspace (16) remains outside the body part during puncturing.

17. Test element according to claim 1 or 2, characterized in that the collecting interspace (16) has a volume of 1 to 100 nanoliters.

18. Test element according to claim 1 or 2, characterized in that the collecting recess (16) has a proximal end section which widens in cross section as a measuring region (34).

19. Test element according to claim 1 or 2, characterized in that the light conductor (18) is formed by an optical fiber or fiber bundle.

20. Test element according to claim 1 or 2, characterized in that the light guide (18) is formed by a part of the piercing element (14) which is shaped from a light-conducting material.

21. Test element according to claim 1 or 2, characterized in that a holder (40) made of plastic is formed on the piercing element (14).

22. Test element according to claim 1 or 2, characterized in that the piercing elements (14) are formed by a plurality of flat material layers (66, 68).

23. Test element according to claim 1 or 2, characterized in that the collecting interspace forms a capillary for the automatic filling of body fluids, wherein the length of the capillary is a multiple of its diameter.

24. The test element according to claim 7, wherein said test zone is oriented transversely to the longitudinal extension of said acquisition void so that body fluid flows in front direction to said test zone.

25. A test element for examining body fluids as a disposable article, having a piercing element (14) which can be pierced into a body part, an acquisition region (16) arranged on the piercing element (14) for body fluids obtained by a piercing action, and at least one signal line (18) for optical or electrochemical measurements in the acquisition region (16), characterized in that the collection zone is formed by a collection space (16) of the piercing element (14) extending longitudinally in the piercing direction and acting as a capillary, and the signal line (18) which is integrated in the piercing element (14) in a non-movable manner is coupled to a test field (38) which reacts to an analyte in a body fluid, the test field (38) delimits the capillary cross section in a measurement field (34) at the proximal end of the collecting recess (16) at least in sections on the front side in order to prevent inflowing body fluid.

26. Test element according to claim 25, characterized in that the piercing elements (14) have a bent shank or the signal lines (18) extend in a stepped manner, so that the piercing elements (14) can be coupled to the piercing drive (26) in a first plane and the signal lines can be coupled to the transmitting and/or receiving elements (54, 58) in a second plane.