HK1116541B - Diagnostic test band cassette - Google Patents

Description

Diagnostic tape cassette

Technical Field

The invention relates to a diagnostic tape cassette, in particular for blood glucose testing, having a test tape which is provided with a plurality of test fields for testing body fluids; a housing is also provided for receiving the test strip. The subject matter of the invention also relates to a method for producing such a tape cassette.

Background

For self-diagnosis of diabetic patients, individual test strips have been used in practice which, after the use of a small amount of sample, are tested photometrically or electrochemically in order to determine the blood glucose content (blood or interstitial fluid) in the sample as accurately and reliably as possible. In order to improve user friendliness, it has been proposed: a number of tests are provided in the form of cassettes on a test tape. Such a cassette should be able to be installed as a disposable component in a compact hand-held device in order to be able to carry out all necessary test steps automatically and quickly. It must be noted here that: the sacrificial part is a mass product for which high demands are made due to the necessary reliability.

Disclosure of Invention

Starting from this, the object of the invention is to further develop the tape cassette proposed in the background art for efficient use and to achieve a high storage and use stability while ensuring simple production.

To achieve this object, some combinations of the features specified in claim 1 or 18 are proposed. Advantageous embodiments and refinements of the invention are specified in the dependent claims.

The idea of the invention is to ensure the function of the cassette with as few separate components as possible. Accordingly, according to the invention: the housing has an injection-molded part (outlet-molding-Teil) which, in the injection-molding technique, consists of a metal carrier and a plastic which has been injected. Injection molding techniques can allow a cost-effective production of the metal-plastic composite, wherein the material webs and undercuts ensure a fixed connection. In view of the diagnostic tape cassette, the functional elements integrated in the housing can thus be designed (for special purposes also in the metal carrier, without having to machine and handle separate components). In particular, the metal carrier prevents shape changes, which occur in purely plastic parts, even during long-term storage or use of the device, wherein high housing strength can be achieved even with small wall thicknesses. In the case of a high storage density of the test strip, a compact design can be achieved from a production point of view.

The functional elements integrated in the injection-molded part preferably comprise spring elements, connecting elements and/or guide elements for a particularly practical cassette design.

A particular advantage is produced in terms of the effect of the functioning of the cassette by the following method: the functional element comprises at least one spring element arranged on a metal carrier. The spring element must no longer be separately inserted into the housing, but can be integrated into the injection-molded part at the desired location in one process step.

Another advantageous embodiment provides that: the metal carrier is preformed from a cut-out sheet, so that a thin but load-bearing housing wall can be realized.

A cut-out portion of the cutting plate is more advantageously bent into a spring element which is elastically resettable. It is particularly advantageous if a functional element in the form of a leaf spring is provided for the sealing function for the test strip.

Another simplified form provides that: the leaf spring is releasably held at a free end by a wall made of injection-molded plastic in a prestressed position and, under certain conditions, only reaches the defined functional position during final assembly.

It is also preferred if a functional element in the form of a helical spring is used for spring loading of the tape roll. It is advantageous here that: if the helical spring is deepened relative to a plane of the metal carrier and is bent helically into the interior of the housing. Another advantage, which also serves to protect the housing interior from contamination, can be achieved as follows: the coil spring is protected against external influences by a cover made of injected plastic.

In order to be able to manipulate the spring function and position it, it is advantageous: the injected plastic has at least one wall opening in the region of the spring element for an ejector and/or a centering pin acting on the spring element.

A further advantageous embodiment provides that: the functional element comprises at least one anchoring element for the injection-molded part. This can be achieved particularly simply by: the hooks projecting from the metal carrier are encapsulated in the form of a positioning element by injection molding with plastic.

Another advantageous housing function is achieved by the following method: the functional element comprises a cover for the test tape transported between the two tape reels. This cover can be formed more advantageously by a plastic injection-molded, preferably undercut, web of the metal carrier.

In order to ensure that the belt runs with as little friction losses as possible, it is advantageous: the functional element comprises a strip guide for sliding guiding the test strip.

The injection-molded part advantageously forms a housing part, in particular a lid or a housing for a tape cassette.

In terms of the method, the object mentioned at the beginning is achieved by: a metal carrier is preferably preformed as a cut-out plate and the injection-molded plastic part is provided by injection molding in the injection molding technique, wherein the functional elements for the tape cassette are integrated in the injection-molded part thus formed.

Disclosure of Invention

The invention will be described in detail below on the basis of an embodiment which is schematically shown in the drawing. The attached drawings are as follows:

FIG. 1: a perspective view of a cartridge for blood glucose testing;

FIG. 2: a perspective inside view of a metal carrier for a cassette cover member;

FIG. 3: a corresponding view of the lid component formed in an injection molding technique is shown in fig. 2.

Detailed Description

The cassette 10 shown in the drawings can be used to perform some blood glucose tests on blood samples taken by the patient himself at the site. For this purpose, a housing 12 is provided for receiving a test strip 14, which is provided with a plurality of test fields 16, which can be successively filled with blood at a filling tip 18. The tape is transported through two tape reels 20, 22 housed in the housing 12. The principle test procedure can be found, for example, in WO 2004/056269, which is expressly incorporated herein by reference.

The housing 12 comprises an injection-molded part 24 designed as a cover part and a box body 26 connectable to the part 24. In the injection molding technique, the injection-molded part 24 is formed from a metal carrier 28 according to fig. 2 and a plastic 30 according to fig. 3 injected thereon. In this way, the individual functional elements 32 can be integrated into the finished part, which is advantageous from a production and application point of view. In the injection molding technique, the metal carrier 28 is inserted into a mold cavity of a closable molding tool and is encapsulated, preferably by injection molding, with a hardenable plastic material. The plastic is firmly anchored to the metal carrier by means of undercuts and through-holes. Such methods are well known to the skilled person and further details concerning the method need not be described here.

Fig. 2 shows the metal holder 28 formed as a cut sheet metal part 34 by stamping and bending. The cut-out part 34 has a flat bottom surface 36, from which various functional elements, in particular spring elements 38, 40 and support elements 42, 44, are bent out.

A leaf spring 38 is provided on a bent side for a better sealing function with respect to the test tape 14 guided past a sealing mechanism, not shown. In order to apply the band 22 with a spring force, a helical spring 40 is provided in the region of the base 36, wherein the formed spring end is deep-drawn in a circular shape and the free end of the spring is bent in a helical shape towards the interior of the housing.

In order to ensure the stability of the injection-molded anchoring element, a plurality of angled undercut supporting hooks 42 are distributed on the base surface 36. The edge side is provided with a web 44 as a lateral support element on the bottom 36.

The finished injection-molded part 24 has, according to fig. 3, side walls 46 supported by webs 44, which cover the test tape 14 except for the region of the loading tip 18. For the purpose of engaging with the cassette 26, a positioning hook 48 made of plastic is molded onto the support hook 42. The helical spring 40 is covered in the plane of the bottom face 36 by a cover 50 made of plastic, protected against external interference. This cover 50 is held firmly connected to the metal support 28 on the inner face of the bottom face 36 by means of an opposing injection point 52.

The leaf spring 38 is preloaded in the region of the adjacent side wall 46 in the injection molding tool and is fixed there by centering pins until the solidified plastic has a fixing effect due to its shrinkage properties. In this case, the centering pin then forms a wall through opening 54 in the plastic, as can be seen in fig. 1 on the side of the cover part 24. During final assembly, the spring 38 can be pushed inward into the active position by means of an ejector through the through-opening 54. A corresponding through-hole 56 is also present in the region of the cover 50 of the helical spring 40.

In principle, it is also possible to form other parts of the cassette 10 by injection molding, and the cassette body 26 can in particular have a metal carrier on which the tape guides for the test tape 14 are molded. These guides can be left free on the outside after injection of the plastic box part, so that the test tape guided between the tape rolls 20, 22 through the tip 18 slides with little friction on the metallic tape guide.

Claims (19)

1. A diagnostic tape cartridge having a test tape (14) with a plurality of test zones (16) for testing body fluid; and having a housing (12) for receiving the test strip (14), characterized in that the housing (12) has at least one injection-molded part (24) consisting of a metal carrier (28) and an injection-molded plastic (30), wherein the injection-molded part (24) has at least one integrated functional element (36), and the functional element (36) comprises at least one of the following elements:

-a spring element (38, 40) arranged on the metal holder (28);

-an anchoring element (48) for the housing piece;

-a cover (46) for the test strip (14);

-a tape guide for slidably guiding the test tape (14).

2. The cartridge of claim 1, wherein said cartridge is for blood glucose testing.

3. A cassette as claimed in claim 1 or 2, characterised in that the metal holder (28) is preformed from a sheet cut (34).

4. A cassette as claimed in claim 3, characterised in that a cut-out portion of the plate cut-out (34) is bent into the resiliently return spring element (38, 40).

5. A cassette as claimed in claim 1 or 2, characterized in that the spring element is provided as a leaf spring (38) for performing a sealing function with respect to the test tape (14).

6. A cassette as claimed in claim 5, characterised in that the leaf spring (38) is releasably held at a free end in a pretensioned position by a wall made of injected plastic (30).

7. A cassette as claimed in claim 1 or 2, characterized in that the spring element is provided as a helical spring (40) for spring-loading the tape roll (22).

8. A cassette as claimed in claim 7, characterised in that the helical spring (40) is deepened relative to a plane of the metal holder (28) and is bent helically into the housing interior.

9. A cassette as claimed in claim 7, wherein the coil spring (40) is covered by a cover made of injection-moulded plastic (30) to prevent disturbing influences from outside.

10. A cassette as claimed in claim 1 or 2, characterised in that the injected plastic (30) has at least one wall passage opening (54, 56) in the region of the spring element (38, 40) for an ejector and/or a centring pin acting on the spring element (38, 40).

11. A cassette as claimed in claim 1 or 2, wherein the support hooks (42) projecting from the metal holder (28) are encapsulated in the form of a positioning element by injection molding with plastic.

12. A cassette as claimed in claim 1 or 2, wherein said test tape (14) is transported between two tape reels.

13. The cartridge as claimed in claim 12, characterized in that the cover (46) for the test tape (14) is formed by a connecting plate (44) of the metal holder (28) which is encapsulated by injection molding with plastic (30).

14. The cartridge as claimed in claim 12, characterized in that the cover (46) for the test tape (14) is formed by an undercut web (44) of the metal holder (28) which is encapsulated by injection molding with plastic (30).

15. A cassette as claimed in claim 1 or 2, wherein the injection moulded part (24) forms a housing part.

16. A cassette as claimed in claim 1 or 2, characterised in that the injection moulded part (24) forms a lid or a housing (26).

17. Method for producing a cassette (10) according to one of the preceding claims, in which method a metal carrier (28) is preformed and the plastic part is injection-molded by means of an injection-molding method in the injection-molding technique, wherein the functional element (36) for the cassette (10) is integrated in the injection-molded part (24) formed in this way.

18. The method of claim 17, wherein said cartridge is used for blood glucose testing.

19. The method of claim 17, wherein the metal holder (28) is preformed into the blank (34).