HK1126105B - Assembly for receiving body fluids, and method for the production thereof - Google Patents

Description

Device for receiving body fluid and method for producing the same

The invention relates to a device or apparatus for receiving body fluids, such as blood, having a sample receiving element, preferably provided with a piercing section for insertion into a body part, having a collecting region for collecting body fluid obtained by piercing, and having a sample absorbing element which can absorb body fluid through the collecting region, preferably provided with a test field for an analyte in the body fluid. The invention further relates to a method for producing such a sample receiving element.

An apparatus for collecting body fluids for analytical purposes, in particular for blood glucose concentration determination, has been described in an earlier application PCT/EP2005/002357 in the name of the applicant. This leads to a lancing element with a collecting region for receiving body fluid, wherein the collecting region can be formed by a lateral opening. The liquid transfer to a sample absorption element which is placed in fluid contact can thus be effected perpendicularly to the needling direction, so that a microvascular transfer with a high dead volume over a visual distance can be avoided.

The object of the invention is to further develop the systems known from the prior art and to optimize the device of the initially defined type with respect to the sample reception, wherein an object of the invention is also to facilitate production.

To solve this object, the combination of features described in the independent claims is proposed. Preferred embodiments and further developments of the invention emerge from the dependent claims.

The idea of the invention is that a capillary gap which is open on both sides makes it possible to achieve a capillary sample receiving structure which is as reliable as possible. In accordance with the invention, the collection area is formed by a longitudinal slot which extends as a capillary structure and is open on both sides of the sample collection element via side openings, wherein the longitudinal slot is separated from the sample absorption element in the collection position of the sample collection element, so that no body fluid is transported and is in fluid contact or fluid connection with the sample receiving element in a transport position of the sample collection element. This ensures a rapid sample reception from both sides in a uniform volume, wherein no external activation is required due to capillary action. It is particularly preferred that the slot extends in the longitudinal or needling direction of a sample extraction element designed as a needling element. However, a sample reception after a puncture has been produced by means of a separate needling device is also conceivable. The risk of obstruction by tissue components is additionally reduced by this open aperture structure as compared to a tubular or semi-open capillary tube. Furthermore, the two-sided opening also substantially improves the further sample processing, and a transfer without dead volumes to a considerable extent is possible. For further integration in the analysis, a sample absorption element is provided which can be loaded with a body fluid via the collection area, preferably a test field for an analyte in the body fluid. A rapid and substantially loss-free liquid transfer to the previously separated absorption element can thus be achieved, allowing an analysis at a defined point in time.

According to a preferred embodiment of the invention, the length of the longitudinal slot is dimensioned such that, in the collection position of the sample collection element, the longitudinal slot is partially inside the body region and partially outside the body region. In this way, a venting function of the gap can be achieved upon liquid reception, and it also provides additional collection volume. In this respect, it is advantageous if the longitudinal slit, when collecting body fluid, has a distal receiving section which projects into the skin of the body part and a proximal venting section which is outside the skin.

Preferably, the longitudinal slot has a length of 0.5-4mm, preferably 1-2mm, and a width of less than 500 μm, preferably less than 100 μm. Advantageously, the longitudinal slit is preferably spaced from the distal tip of the sample extraction element constituting the needle-punching portion by a distance of about 50-200 μm.

In order to reduce the pain felt during the insertion and at the same time to provide a sufficient receiving volume, the sample collection element can have a distal shaft section with a reduced cross section and a proximal shaft section with a gradually enlarged cross section in the region of the longitudinal slot.

A further development in this direction is achieved in that the longitudinal slot is spatially and/or fluidically separated from the sample absorption element in the collection position of the sample collection element and is coupled to the sample absorption element via a lateral opening in the transport position of the sample collection element for the transport of body fluids.

It is also advantageous if the lateral opening of the longitudinal slot opposite the outlet opening is connected to an actuator in a transfer position for actively transferring body fluid to the sample absorption element.

Preferably, the actuator acts on the body fluid in the longitudinal slot by means of a pneumatic and/or mechanical pressing device, wherein a mechanical actuator can be formed by a membrane which is deformable toward the longitudinal slot. It is also advantageous if the actuator has a pressure air channel which can be coupled to a side opening of the longitudinal slot facing away from the sample absorption element.

In order to achieve as complete a liquid transfer as possible, it is advantageous if the sample absorption element has a capillary suction which is at least greater or greater than the longitudinal gap for body fluids.

A further preferred embodiment provides that the sample collection element is mounted in a guide structure so as to be movable relative to the sample absorption element. For protection and hygiene reasons, it is therefore advantageous if the sample absorption element forms a sleeve-like structure which receives the sample receiving element.

Further advantages for the user can be achieved by storing sample extraction elements in a first cassette and sample absorption elements in a second cassette, wherein the cassettes can be connected to one another as separate units for mating coupling of the sample extraction elements and the sample absorption elements.

An advantageous embodiment is possible in which a plurality of sample extraction elements are arranged axially pushable in a magazine, preferably a drum magazine, and correspondingly configured sample absorption elements are arranged in front of the magazine in the push-out direction, preferably in the through-chambers.

The subject of the invention is also a portable blood analysis apparatus for receiving at least one collection device according to the invention, preferably provided as a disposable item.

The invention also comprises a system for analyzing a body fluid, such as blood, having a sample-collecting element, preferably provided with a piercing section for piercing into a body part, having a longitudinal slot extending as a capillary tube and open on both sides through lateral openings as a collecting region for collecting the body fluid obtained by the piercing, and having a sample-absorbing element which can be loaded with body fluid through the collecting region and is preferably provided with a test field for an analyte in the body fluid, wherein an actuator is provided for transferring the body fluid from the sample-collecting element to the sample-absorbing element. In order to utilize the advantage of this slit opening on both sides in a particularly space-saving manner, it is advantageous if the actuator acts from one side opening onto the body fluid in the longitudinal slit and, on the side of the sample extraction element facing away therefrom, tests for the analyte in the body fluid are carried out, wherein the sample extraction element is in fluid connection with the sample absorption element via the side opening facing away from the actuator in a transfer position. In such an apparatus with a preferably disposable fluid-handling element, a preferably optical test element is provided for detecting the analyte on the test field loaded with body fluid.

In a related method aspect, the object stated at the outset is achieved in that a longitudinal slot which is open on both sides is formed in the sample collection element as a collection area for the body fluid by laser cutting.

In this way, the boundary surfaces of the longitudinal slot are hydrophilized during laser cutting.

A further development provides that the laser energy and/or the speed of the laser beam are adjusted during the laser cutting in a position-dependent manner, so that different material thicknesses can be taken into account better.

The machining time during laser cutting is preferably less than 2s, preferably about 1 s.

It is also advantageous for an increased capillary action that the boundary edge of the longitudinal slot is provided with an edge angle of less than 100 °, preferably about 90 °.

A further preferred method variant provides that a sharp needle-punched area is produced on the sample extraction element by grinding, so that the needle-punched area is delimited by at least one flat grinding structure. This also has the advantage that a wire or a flat strip is processed as starting material.

The invention will be explained in more detail below with the aid of specific embodiments which are schematically illustrated in the drawing. Shown in the attached drawings:

figure 1 is a perspective view of a hand-held device for blood glucose testing,

figure 2 is a perspective view of a lancing element having a longitudinal aperture for blood reception,

FIG. 3 is a perspective view of an integrated test device with a lancing element and a test element in different operating steps,

figure 4 is an axial cross-sectional view of a testing procedure corresponding to figure 3,

FIG. 5 is an exploded view of a cartridge structure for a blood glucose detecting device,

FIG. 6 is a longitudinal cross-sectional view of the detection process when the cartridge of FIG. 5 is applied,

fig. 7 is a partial enlarged view of fig. 6 c.

The device 1 depicted in the figures comprises at least one sample extraction element 10 having a collection area configured as a longitudinal aperture 12 for collecting body fluid obtained from a body site 14 in a puncturing position, and a sample absorption element 16 which is in fluid connection with the longitudinal aperture for blood glucose assessment.

Fig. 1 shows a portable blood glucose meter 18 for use with a test device 1 of the type described above, which is used for so-called "Spot-Monitoring", i.e. the self-determination of the blood glucose concentration by a test subject over a certain period of time. For this purpose, the instrument 18 has an inwardly tapered seat 20 for positioning the fingers over a through-opening 22 for the sample extraction or lancing element 10. The individual device components are activated in a completely automatic detection process, so that in conjunction with the device 1 installed in the device, preferably disposable, the user finally obtains a measurement value on a display 24 concerning his instantaneous blood glucose level, without a cumbersome operation. In general, with the aid of such a system, the detection can be carried out on other body regions, for example on the arm or abdominal region with less painful sensations, wherein the body fluid taken as a sample can also be tissue fluid or a mixture thereof in addition to the capillary blood from the skin.

As can be seen from FIG. 2, the longitudinal slot 12 extends in the longitudinal direction of the rod-shaped piercing element 10, for example over a length of 1-2mm in the case of a width of 100 and 200. mu.m. The spacing from a tip 26 forming the lancing portion may correspond approximately to the width of the slit. In this way, a capillary receiving structure can be formed into which the body fluid that is accessible when the body part 14 (fig. 4) is penetrated automatically flows by capillary action.

The liquid is received on both sides via the opposite lateral openings 28, 30 of the longitudinal slot 12. The slit length is determined in the needle insertion direction such that a distal slit section 32 projects into the skin of the body part 14 and a proximal slit section 34 is located outside the skin. In order to reduce pain, the distal shaft section 36 inserted into the body can be provided "thin", i.e. with a constricted cross section, while the proximal shaft section 38 remaining outside the body has, in contrast, an enlarged cross section or a comparatively large thickness in order to be able to collect a sufficiently large amount of liquid. By way of example, the amount of liquid may correspond to an aperture volume of 10-20 nanoliters (nanoliters), wherein the partial volume of the longitudinal aperture 12 in the body comprises, for example, a volume fraction of 20%.

In the production of such a needle-punched element 10, first a wire is machined as starting material in a defined orientation by means of a grinding operation, whereby differently chamfered grinding surfaces 40, 42 are produced. The longitudinal slot 12 is then machined in this surface structure by means of a suitably positioned laser, provided that the rotational orientation is maintained in the same machining station as required for the purpose. An important manufacturing detail is that the laser energy and/or the speed of operation of the laser beam is adjusted depending on the cutting position. In this way, tapered openings can be formed or different material thicknesses can be compensated for.

Only a few movements of the laser beam are required for the slot opening, and the processing time can be kept sufficiently short for a mass production, for example in the range of 1 second. Likewise, the mechanical tolerances can also be kept small, for example in the range of 10 μm, wherein the wall steepness can be achieved at almost 90 °. Furthermore, by suitable laser treatment of the applied layer, in particular under protective or special gas conditions, an activated and/or hydrophilic surface is provided, which can be further improved by a physical or wet-chemical aftertreatment.

The lancet 10 thus created can be oriented into a plastic holder. It can come, for example, from a roller and, by clamping, heat deformation or the like, the connection to the lancet can be realized positionally correctly. The plastic holder may have a coupling so that the lancet can be grasped in the instrument 18 and moved.

Fig. 3 shows a unit consisting of a sample collection element (lancing element 10) and a sample absorbent element 16. The sample is withdrawn by a reciprocating needling movement of the needling element 10, wherein a suitable drive is coupled to the proximal shaft portion 44 in a form-fitting manner. The sample absorbing element 16, which is held stationary with the instrument during the needling process, is part of a feed guide for the lancing element 10, which is designed as a sleeve, and has a test field 46 for receiving body fluid 48 previously collected in the longitudinal slot 12. The sleeve, which acts as a linear guide, thus surrounds the needle-punching element in a rectangular-flat configuration, with the broadside facing the lateral openings 28, 30 of the longitudinal slot 12. In addition to the advantageous liquid transport, protection of the lancing element 10 and a hygienic removal can thus be ensured.

The lancing element 10 can thus perform a transport function as a "shuttle" during sample acquisition, while the actual identification of the analyte takes place on the sample absorbing element 16 which is not in contact with the body part 14. It can also be provided as an assembly of a cartridge comprising a plurality of separate sub-cartridges 50 which can be installed as consumable items in the instrument 18 and can be removed again together with the used needle elements. The glucose identification in the test field or reaction agent carrier 46 can be done photometrically by reflection through the transparent cover window 52, so that the blood 48 in the sub-cassette 50 is separated from the instrument components in a hygienic manner. Other identification techniques are also contemplated, such as by fluorescence or electrochemical detection.

The basic steps of this sample transfer are again detailed in fig. 4. In the home position (4a), the lancing element 10 is held in the cartridge compartment 50 in a protected manner, and the compartment can be closed on the front side by a piercing film. The pricking movement to the body part 14 (for example a fingertip) is then to be effected as quickly as possible for pain reasons and to be optimized in terms of movement, in which case a slightly retracted collecting position can be triggered by the maximum pricking depth. Preferably, the distal slit section 32 extends into the skin for the collection procedure corresponding to (4b), while the proximal slit section 34 performs a venting function out of the skin. In this way, blood obtained in the puncture channel can flow into the collecting slit 12 on both sides in a short collection time and effectively fill the entire slit volume. In the collecting position, the slit 12 and the sample absorption element 16 are spatially separated in such a way that no fluidic connection exists between them and the identification reaction agent cannot reach the interior of the body. This also allows the authentication process to be started as intended and the test process to be evaluated as this authentication process. For this purpose, the lancing element 10 is pulled back again, corresponding to fig. 4c, until the lateral opening 28 above the slot 12 reaches below the test field 46. This test zone 46 may have a greater capillary attraction than the slit 12, for example by a fleece structure, for automatic transport of the received blood. Preferably, however, the liquid transfer can be assisted in that, according to fig. 4d), a membrane 54 is pressed in as a pressing device for the collected liquid on the lower aperture opening 30. The fluid transport is thus effected over the entire gap length with a short-circuit path transverse to the needling direction of the needling element 10.

Also the specific embodiment illustrated in fig. 5-7 implements this principle solution, wherein a special cartridge storage and activation structure is provided. According to fig. 5, the lancing element 10 is stored in a lancet roller 56, the coupling element 44 for driving the coupling being extended on its rear end face, while the front (distal) end face is sealed by a lancing film 58. A separate test strip roller 60 can be fitted with test strips 46 via the push-in slit, which is then shielded from the environment, in particular against moisture, by a membrane 62 and an end cover 64. The end cover 64 is mounted on a hollow drum shaft 66 which at the same time forms an air channel 68 for pneumatic activation via a peripheral air opening 70. Different application requirements can be taken into account by this separate magazine storage. The lancing element 10, which is in contact with the body, can be sterilized in the lancet roller 56 by means of radiation of sufficient energy, while the radiation-sensitive test chemical is held in the test strip roller 60 independently of it from external influences and does not come into contact with the body during the lancing process.

As can be seen from fig. 6, the cartridges 56, 60 are axially coupled in the mounted state on the roller shaft 66, so that the lancing element 10 and the test strip 46 are each arranged in correspondence with one another. A magazine receiver 72 in the instrument 18 enables a pressurized air application to the air channel 68 and a needle drive for coaxially orienting the needle-punching elements 10 connected in each case to the drive ram 74 relative to the finger cone 20 (FIG. 6 a). As the lancing advances, the actuated lancing element 10 passes through the front-located chamber 76 of the correspondingly configured test strip 46 and through the cone aperture 22 to this maximum advanced position (line 78 in fig. 6 b) with a stroke of about 10 mm. Blood reception through the aperture 12 is then achieved as described above. In the case of a return movement of the lancing element 10, it is then moved into the transport position illustrated in fig. 6c, in which the slot 10 is aligned with the test strip 46 in its direction of passage.

As can best be seen from the enlarged view of fig. 7, a targeted transfer of the collected liquid onto the test strip 46 can be achieved in this transfer position. For this purpose, an air displacement is initiated via the air channel 68 in the direction of the arrows 80, 82, which loads the slot 12 at the facing side opening 28, so that blood is displaced via the opposite side opening 30 onto the test strip 46 and is detected there. The glucose determination can then be effected in a reflectometry manner by means of an instrument optical component, not shown. The contaminated lancing element 10 is then completely pulled back into the receiving chamber 84 of the drum magazine 56 and brought into the ready state by drum rotation of the next functional pair 10, 46.

Claims (1)

1. A device for receiving a body fluid, having a sample extraction element (10) with a collection area (12) for collecting a body fluid obtained by a puncture, wherein the collecting region is formed by a longitudinal slot (12) extending as a capillary tube and opening on both sides of the sample extraction element (10) through lateral openings (28, 30), and the device has a sample absorption element (16) which can be loaded with body fluid via the collection area (12), wherein the longitudinal slot (12) is separated from the sample absorption element (16) in the collection position of the sample extraction element (10) and is in fluid contact with the sample absorption element (16) in the transport position of the sample extraction element (10), wherein the sample extraction element (10) is movable relative to the sample absorption element (16) between the collection position and the transfer position.

2. The apparatus of claim 1, wherein:

the longitudinal slot (12) is dimensioned such that, in the collection position of the sample collection element (10), the longitudinal slot (12) is located partially inside the body region (14) and partially outside the body region (14).

3. The apparatus of claim 1 or 2, wherein:

the longitudinal slit (12) has a distal receiving section (32) which projects into the skin of the body part (14) and a proximal venting section (34) which is located outside the skin when collecting body fluid.

4. The apparatus of claim 1 or 2, wherein:

the longitudinal slot (12) has a length of 0.5mm to 4 mm.

5. The apparatus of claim 1 or 2, wherein:

the longitudinal slot (12) is arranged at a distance of 50-200 μm from the distal tip (26) of the sample receiving element (10) forming the needle-piercing section.

6. The apparatus of claim 1 or 2, wherein:

the sample extraction element (10) has a distal shank section (40) with a reduced cross section and a proximal shank section (42) with an enlarged cross section in the region of the longitudinal slot (12).

7. The apparatus of claim 1 or 2, wherein:

the lateral openings (28, 30) can be used as discharge openings for the longitudinal slots (12) and can be in fluid contact with the sample absorption element (16).

8. The apparatus of claim 1 or 2, wherein:

the lateral openings (28, 30) of the longitudinal slot (12) are connected to an actuator (54; 68) in the transfer position in order to transfer the body fluid into the sample absorption element (16).

9. The apparatus of claim 8, wherein:

the actuator (54; 68) acts on the body fluid present in the longitudinal slit (12) by means of a pneumatic and/or mechanical squeezing device.

10. The apparatus of claim 8, wherein:

the actuator is formed by a membrane (54) which can be deformed into the longitudinal slot (12).

11. The apparatus of claim 8, wherein:

the actuator has a pressure air channel (68) which can be connected to the lateral openings (28, 30) of the longitudinal slot.

12. The apparatus of claim 1 or 2, wherein:

the sample-absorbing element (16) has a greater capillary absorption for body fluids than the longitudinal slit (12).

13. The apparatus of claim 1 or 2, wherein:

the sample collection element (10) is mounted in a guide structure (50) so as to be movable relative to the sample absorption element (16).

14. The apparatus of claim 1 or 2, wherein:

the sample absorbing element (16) forms a sleeve that can receive the sample extraction element (10).

15. The apparatus of claim 1 or 2, wherein:

a plurality of sample extraction elements (10) are stored in a first cassette (56) and a plurality of sample absorption elements (16; 46) are stored in a second cassette (60), wherein the first cassette (56) and the second cassette (60) can be connected to each other as separate units for mating coupling of the sample extraction elements and the sample absorption elements.

16. The apparatus of claim 1 or 2, wherein:

a plurality of sample extraction elements (10) are arranged in the cartridge (56) such that they can be pushed out axially, and a correspondingly arranged sample absorption element (46) is arranged in the direction of push-out before the cartridge (56).

17. Portable blood analysis instrument for receiving at least one device (1) according to any one of the preceding claims.

18. A system for analyzing a body fluid, comprising a sample extraction element (10) having a longitudinal slot (12) extending as a capillary and open on both sides via lateral openings (28, 30) as a collection area (12) for collecting the body fluid obtained via a puncture, and comprising a sample absorption element (16) having a test field (46) that can be loaded with the body fluid via the collection area (12), wherein an actuator (54; 68) is provided for transferring the body fluid from the sample extraction element (10) into the sample absorption element (16).

19. The system of claim 18, wherein:

the actuator (54; 68) acts from the lateral opening (28, 30) on the body fluid in the longitudinal slot and effects a test for the analyte in the body fluid on the side of the sample receiving element (10) facing away therefrom.

20. The system of claim 19, wherein:

the sample collection element (10) is in fluid connection with the sample absorption element (16) in the transport position via a side opening facing away from the actuator (54; 68).

21. A system according to any of claims 18 to 20, wherein:

the test element is provided for detecting an analyte on a test field (46) loaded with a body fluid.

22. Method for manufacturing a sample extraction element (10) for receiving a body fluid for a device (1) according to any one of claims 1 to 16, wherein the contour is manufactured by laser machining, characterized in that: a longitudinal slot (12) which is open on both sides is formed in the sample-extraction element (10) by laser cutting as a collecting region (12) for the body fluid.

23. The method of claim 22, wherein:

the boundary surface of the longitudinal slot (12) is activated and/or hydrophilized during laser cutting to form a layer structure.

24. The method of claim 22 or 23, wherein:

the laser energy and/or the speed of the laser beam are adjusted in a position-dependent manner during the laser cutting.

25. The method of claim 22 or 23, wherein:

the machining time during laser cutting is measured to be less than 2 s.

26. The method of claim 22 or 23, wherein:

the boundary edges of the longitudinal slot (12) are formed with an edge angle of less than 100 °.

27. The method of claim 22 or 23, wherein:

a distal needle-punched section (26) is produced on the sample extraction element (10) by grinding, said section being delimited by at least one planar grinding structure (36).

28. The method of claim 22 or 23, wherein:

wire or flat strip is processed as a starting material.