DIAGNOSTIC TEST UNIT FOR ANALYSING BODY FLUID

Abstract

A diagnostic tester for analysing a body fluid includes a test tape having test zones configured to receive the body fluid. The tester further includes a chamber configured to contain the test tape and a seal. The tester further includes an opening of the chamber which is at least partially bordered by the seal. The tester further includes a face on the chamber that borders the opening, at least part of the face being formed by the seal. The tester further includes a closing leaf spring sealed onto the face, the closing leaf spring shielding the opening from an environment outside the chamber. The tester further includes an exit gap formed between the closing leaf spring and the seal through which the test tape is configured to exit the chamber.

Claims

1. A diagnostic tester for analysing a body fluid, the tester comprising: a test tape having test zones configured to receive the body fluid; a chamber configured to contain the test tape; a seal; an opening of the chamber which is at least partially bordered by the seal; a face on the chamber that borders the opening, at least part of the face being formed by the seal; a closing leaf spring sealed onto the face, the closing leaf spring shielding the opening from an environment outside the chamber; and an exit gap formed between the closing leaf spring and the seal through which the test tape is configured to exit the chamber.

2. The tester according to claim 1, wherein the opening is configured for installation of a roll of the test tape through the opening into the chamber.

3. The tester according to claim 1, wherein the test tape comprises: a carrier tape with test zones spaced at intervals; and a test zone-free area of carrier tape which is located in the exit gap during storage.

4. The tester according to claim 1, wherein the chamber is part of a cassette, the test tape is configured to be moved out of a storage chamber via an application site into a waste chamber, and the exit gap is located proximate to the storage chamber.

5. The tester according to claim 1, wherein the seal and leaf spring seal against the test tape.

6. The tester according to claim 1, wherein a rear side of the test tape facing away from a test field is configured to slide over the seal.

7. A diagnostic tester for analysing a body fluid, the diagnostic tester comprising: a plurality of test strips, each test strip having at least one test zone configured to receive the body fluid; a chamber configured to contain the test strips; a seal; an opening of the chamber that is at least partially bordered by the seal; a face on the chamber that borders the opening, at least part of the face being formed by the seal; a closing leaf spring sealed onto the face, the closing leaf spring shielding the opening from an environment outside the chamber; and an exit gap formed between the closing leaf spring and the seal through which test strips are configured to exit the chamber.

8. The tester according to claim 7, wherein the opening is configured for installation of the test strips into the chamber through the opening.

9. The tester according to claim 7, wherein the chamber is part of a magazine, and test strips are configured to be transported out of the chamber to an application site.

10. The tester according to claim 7, wherein when the closing leaf spring is applied, the gap is formed.

11. The tester according to claim 7, wherein the closing leaf spring is joined along a sealing line with the chamber or the seal.

12. The tester according to claim 7, wherein the closing leaf spring is composed of spring steel having a heat-seal coating.

13. The tester according to claim 7, wherein the seal is either (i) a single component injection-moulded part or (ii) in combination with the chamber as a co-moulded part composed of TPE (thermoplastic elastomer).

14. A diagnostic tester for analysing a body, the tester comprising: a test tape with test fields for applying the body fluid; a chamber configured to contain the test tape; a seal; a closing leaf spring; a gap formed between the closing leaf spring and the seal, the gap being configured to allow passage of the test tape in use; and an opening of the chamber which is at least partially bordered by the seal, the opening being shielded from an environment outside the chamber by the closing leaf spring, and configured to act as a passageway for installing components of the chamber before the closing leaf spring is applied.

15. A diagnostic tester for analysing a body fluid, the diagnostic tester comprising: a plurality of test strips, each with at least one test zone configured to receive the body fluid; a chamber configured to contain the test strips; a seal; an opening of the chamber that is at least partially bordered by the seal; a face on the chamber that borders the opening, at least part of the face being formed by the seal; a closing leaf spring sealed onto the face; and a gap formed between the closing leaf spring and the seal, the gap being configured to allow the test strips to be transported out of the chamber to an application site, wherein the opening is configured to allow components of the chamber to be installed before the closing leaf spring is applied.

16. A portable device for analysing a body fluid, the device comprising: a receiving bay configured to load a diagnostic tester, the comprising: a plurality of test strips, each with at least one test zone configured to receive the body fluid; a chamber containing the test strips; a seal; a face on the chamber bordering the opening, at least part of the face being formed by the seal; a closing leaf spring sealed onto the face; a gap formed between the closing leaf spring and the seal, the gap being configured to allow passage of the test strips to an application site; and an opening of the chamber which is at least partially bordered by the seal, the opening being shielded from an environment outside the chamber by the closing leaf spring, the opening being configured to allow components of the chamber to be installed before the closing leaf spring is applied.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Preferred embodiments of the present invention will be described hereinafter, by way of examples only, with reference to the accompany drawings, wherein:

[0026] FIG. 1 is a schematic perspective view of a first embodiment diagnostic test unit for analysing body fluid;

[0027] FIG. 2 is a further schematic perspective view of the diagnostic test unit of FIG. 1;

[0028] FIG. 3 is a schematic perspective view of a second embodiment diagnostic test unit for analysing body fluid;

[0029] FIG. 4 is a schematic cross-sectional view of a spring lid of the diagnostic test unit of FIG. 3;

[0030] FIG. 5a is a cross-sectional view of a housing and storage chamber of the diagnostic test unit of FIG. 3 after ultrasonic welding;

[0031] FIG. 5b is a schematic perspective view of the diagnostic test unit of FIG. 5a after the spring lid has been welded into position;

[0032] FIG. 5c is a schematic top view of a chamber of the diagnostic test unit for of FIG. 3 before ultrasonic welding;

[0033] FIG. 6 is a schematic top view of a third embodiment diagnostic test unit for analysing body fluid with test tape exiting its storage chamber; and

[0034] FIG. 7 is a schematic perspective view of the diagnostic test unit of FIG. 6 with a leaf spring with heat seal layer before heat welding and after heat welding over the storage chamber.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0035] In order to convey the concepts of preferred embodiments of the invention, reference will now be made to embodiments illustrated in the drawings and described herein. It is important to understand that no limitation to the scope of the invention is intended, and variations, modifications and further applications of the principles of the invention shown in the figures is contemplated as would normally be expected by a person who is skilled in the art relating to the invention. Several embodiments of the invention are shown in great detail, nevertheless some facets which are not relevant to the invention are omitted for the purpose of aiding understanding.

[0036] FIG. 1 depicts a storage chamber (2) located in a housing (1) with carrier tape (3) exiting over the top of a seal (8) that forms a ring around the opening to storage chamber (2). The carrier tape (3) is drawn from the storage chamber (2) by a drive (5) which can be either motor driven or hand turned, until a test zone (4) is over a reading head (not shown) where a sample is applied for analysis. Spring lid (6) is shown before being secured against a face (7) that borders the opening to storage chamber (2). Face (7) occupies a plane that lies below the top surface of the seal (8). The distance between the two planes is fixed by the mould that makes the co-moulded parts (housing and seal).

[0037] FIG. 2 shows spring lid (6) secured after loading a roll of carrier tape and a desiccant into the storage chamber. FIG. 2 shows spring lid (6) secured in position against face (7) by plastic rivets (10) that have been melted by a heat staking machine. Downward force is applied to spring lid (6) during heat staking causing it to contact face (7). Once the melted rivets have cooled the downward force is released. Spring lid (6) is held securely all around face (7) except at the tape exit area (9) where the spring is free to rise and fall as a test zone (4) exits. Despite being a thin sheet of metal, the spring lid does not transmit water vapour and provides a shield against water ingress into the chamber, whilst occupying very little space in the assembly. Seal (8) can be a TPE (thermoplastic elastomer) that is co-moulded with the housing. A very soft TPE (Shore A<40) is preferred to improve the seal around the tape as it exits via a gap formed between the leaf spring and the seal.

[0038] Strengthening ribs (not shown) may be embossed into spring lid (6) to increase its strength and maintain flatness. A groove for the seal may also be added. It can be seen that the spring lid is located in a set position against face (7) which allows a specific spring force to be applied against the seal. Moving the rivets closer to the tape exit (9) can increase the spring force as can changing the thickness of the metal spring.

[0039] FIG. 3 shows another embodiment of the invention. Here the spring lid (6) has plastic moulded over it to enable it to be ultrasonically welded against the rim of the opening (7 not shown). Before welding, a plastic edge (11) meets a sacrificial edge inside the chamber opening (17 not shown) preventing the spring lid from resting on face (7). An ultrasonic welding head is pressed against the top surface (12) transmitting waves of energy that cause the plastic surfaces to vibrate, heat and melt together, forming an air-tight weld. As the plastic surfaces melt the spring lid moves downwards, eventually resting flat on a face that borders the compartment opening (7).

[0040] FIG. 4 shows a cross section through the ultrasonically welded spring lid (6). Plastic edge (11) has melted against the inside of the storage chamber resulting in a weld that continues all around the rim to weld point (13). Spring lid (6) rests on the rim of the opening (7) and also presses onto the seal (15) which in this example only extends across the tape exit area, where there has been no ultrasonic welding.

[0041] FIG. 5a shows a cross section of the housing (1) and storage chamber (2) after ultrasonic welding. Spring lid 6 is resting on a face bordering the opening to the chamber (7) which puts it in the correct plane in relation to the top of the seal (8—not visible). This causes flexing of the spring at the tape exit area (9) creating a seal which sandwiches the tape (3) between the seal (15) and the spring lid (6) keeping moisture out of the storage chamber (2) that holds desiccant (16) and unused test tape (14).

[0042] FIG. 5b shows the test chamber and housing with spring lid welded into position.

[0043] FIG. 5c shows a top view of a chamber before ultrasonic welding. The seal (15) forms only a section of the face bordering the chamber opening and can be seen extending underneath the tape. Interference (17) in the form of a ledge borders the opening from one end of the seal around the chamber opening to meet the other end of the seal.

[0044] FIG. 6 depicts a housing (1) with test tape (3) exiting from a storage chamber (2) over a seal (15) that is integrated into the opening of storage chamber (2). Test tape (3) is drawn from storage chamber (2) by a drive (5) that can be either motor powered or manually turned, until a test zone is over a reading head (not shown) where a sample is applied for analysis. After analysis, used tests are stored on take up spool (18). Face (7) that borders the opening to storage chamber (2) provides a surface for the closing leaf spring with heat seal layer (19 not shown) to be heat welded, to seal storage chamber (2) protecting the unused test reel (14) and optional drying agent (16) contained therein. The spring may also be heat welded to the seal (15) but not the test tape (3) that lies over it.

[0045] FIG. 7 shows a leaf spring with heat seal layer before heat welding (20) over storage chamber (2) after loading a roll of test tape and optionally a desiccant material. Leaf spring (19) applies downward force on the tape at the exit point (18) pressing the tape into the seal and forming a barrier that keeps the chamber isolated from the outside environment. The spring force applied to the tape depends on the degree of deflection of the spring which can be varied by adjusting the height of the seal relative to the face that borders the opening of the chamber (7). The spring is welded securely to the face (7) and optionally to the seal (15), but not to the tape or the seal directly under the tape. The spring (19) rises and falls at the exit point (18) as each test zone (11) exits, reducing the friction at the exit. Despite being a thin material, the spring does not transmit water vapour and so provides a shield against water ingress into the chamber.

[0046] Although the invention is described above in relation to preferred embodiments, it will be appreciated by those skilled in the art that it is not limited to those embodiments, but may be embodied in many other forms.