Body fluid testing device

BODY FLUID TEST DEVICE

BACKGROUND OF THE INVENTION

The present invention relates to body fluid testing devices and more specifically but not exclusively to a body fluid testing device incorporating a test media cassette containing test media used for testing body fluid. .

General Fluid Test

Acquiring and testing body fluids is useful for many purposes and continues to grow in importance for use in medical diagnosis and treatment and other miscellaneous applications. In the medical field, it is desirable for unskilled operators to perform routine, rapid and reproducible testing outside a laboratory environment with rapid results and a reading of test information. 0 Testing can be performed on various body fluids and, for certain applications, is particularly related to blood and / or interstitial fluid testing. These fluids may be tested for a variety of fluid characteristics, or analytes contained within the fluid, to identify a therapeutic state, assess medical progress, determine treatment responses and the like.

General Test Steps Body fluid testing basically involves the steps of taking the fluid sample, transferring the sample to a test device, performing a test on the fluid sample and presenting the results. These steps are generally performed by a plurality of separate instruments or devices.

Acquisition - Vascular

One method of acquiring fluid sample involves introducing a hollow needle or syringe into a vein or artery to draw a blood sample. However, this direct sampling of vascular blood can have several limitations, including pain, infection, and bruising and other bleeding complications. In addition, direct sampling of vascular blood is not suitable for repeat on a routine basis, can be extremely difficult and patients are not recommended to perform it on their own.

Acquisition - Incision

The other common technique for taking a body fluid sample is to form an incision in the skin to bring the fluid to the surface of the skin. A lancet, knife or other cutting instrument is used to form the skin incision. The resulting blood or interstitial fluid sample is then collected into a small tube or other container, or placed directly in contact with a test strip. The fingertip is often used as a source of fluid because it is highly vascularized and therefore produces a good amount of blood. However, the fingertip also has a high concentration of nerve endings and lancing the fingertip can therefore be painful. Alternative sampling sites, such as the palm, forearm, earlobe, and the like, may be useful for sampling and are less painful. But they also produce smaller amounts of blood. These alternative sites are therefore generally suitable for use only for test systems requiring relatively small amounts of fluid or if measures are taken to facilitate the extraction of body fluids from the incision site.

Various methods and systems for making a skin incision are known in the art. Exemplary lancing devices are shown, for example, in US Pat. Nos. Re 35803, issued to Lange, et al., On May 19, 1998; 4,924,879, issued to O'Brien on May 15, 1990; 5,879,311 issued to Duchon et al. On February 16, 1999; 5857983, issued to Douglas on January 12, 1999; 6,183,489 issued to Douglas et al. On February 6, 2001; 6,332,871 issued to Douglas et al. On December 25, 2001; and 5,964,718 issued to Duchon et al. on October 12, 1999. A representative commercial lancing device is the Accu-Chek Softclix lancet.

Extraction

Patients are often advised to force fluid into the incision site, such as by applying pressure to the area surrounding the incision to squeeze or pump fluid from the incision. Mechanical devices are also known to facilitate the extraction of body fluids from an incision. Such devices are shown, for example, in U.S. Patent No. 5,879,311, issued to Duchon et al., On February 16, 1999; 5857983, issued to Douglas on January 12, 1999; 6,183,489 issued to Douglas et al. On February 6, 2001; 5,951,492 issued to Douglas et al. , on September 14, 1999; 5,951,493 issued to Douglas et al. , on September 14, 1999; 5,964,718 issued to Duchon et al. on October 12, 1999; and 6,086,545 issued to Roe et al. on July 11, 2000. A representative commercial product that promotes the extraction of body fluids from an incision is the Amira AtLast blood glucose system.

Sampling

Acquisition of produced body fluid, hereinafter referred to as fluid sampling, may take various forms. As soon as the fluid sample reaches the skin surface in the incision, a sampling device is placed in contact with the fluid. Such devices may include, for example, systems in which a tube or test tape is positioned adjacent to the incision site before forming the incision or is moved to the incision site shortly after the incision has been formed. A sampling tube may acquire fluid by suction or capillary action. Such sampling systems may include, for example, the systems shown in US Patent No. 6048352, issued to Douglas et al. On April 11, 2000; 6,099,484 issued to Douglas et al. On August 8, 2000; and 6,332,871 issued to Douglas et al. on December 25, 2001. Examples of commercial sampling devices include Roche Compact, Amira AtLast, Glucometer Elite and Therasense FreeStyle test strips.

General Test

The body fluid sample can be analyzed for a variety of properties or components, as is well known in the art. For example, this analysis may be directed to hematocrit, glycemia, coagulation, lead, iron, etc. Test systems include means such as optical (eg, reflectance, absorption, fluorescence, Raman, etc.), electrochemical and magnetic media for analyzing the sampled fluid. Examples of such test systems include those in US Patent No. 5,824,491, to Priest et al., Issued October 20, 1998; 5,962,215, issued to Douglas et al., October 5, 1999; and 5,776,719 issued to Douglas et al. on July 7, 1998.

Typically, a test system takes advantage of a reaction between the body fluid being tested and a reagent present in the test system. For example, an optical test strip is generally based on a color change, ie, a change in wavelength absorbed or reflected by the dye formed by the reagent system used. See, eg, US Pat. Nos. 3802842; 4061468; and 4,490,465.

Blood glucose

A common medical test is the measurement of blood glucose level. Blood glucose level can be determined directly by blood analysis or indirectly by analysis of other fluids such as interstitial fluid. Diabetics are usually taught to measure their blood glucose level several times a day, depending on the nature and severity of their diabetes. Based on the observed pattern of measured blood glucose levels, the patient and physician determine the appropriate level of insulin to be given, as well as issues such as diet, exercise and other factors. Proper blood glucose control prevents hypoglycemia, which can lead to insomnia and even sudden death, as well as hyperglycemia resulting in long-term disorders such as blindness and amputations. Blood glucose is therefore a very important analyte to watch.

When testing for the presence of an analyte, such as glucose, in a body fluid, test systems are generally used that take advantage of an oxidation / reduction reaction that occurs using a chemical oxidase / peroxidase detection. The test reagent is exposed to a body fluid sample for a suitable period of time and there is a color change if analyte (glucose) is present. Typically, the intensity of this change is proportional to the analyte concentration in the sample. The color of the reagent is then compared to a known standard which allows to determine the amount of analyte present in the sample. This determination may be made, for example, by a visual check or by an instrument such as a reflectance spectrophotometer at a selected wavelength or a blood glucose meter.

others are equally

Electrochemical systems known to test properties of body constituents.

well fluid

Test Means

As mentioned above, diabetics typically have to watch their blood glucose levels throughout the day to ensure that their blood glucose stays within an acceptable range. Some types of sampling devices require the use of test strips that contain a means for absorbing and / or testing body fluid, such as blood. After testing, blood-contaminated test media may be considered a biohazard and need to be disposed of quickly to prevent other individuals from being exposed to the contaminated test strip. This can be especially inconvenient when you are away from home, such as in the restaurant. In addition, individual test elements can easily be mixed with other test strips having different expiration dates. Use of outdated test elements may create false readings, which may result in improper treatment of the patient, such as inadequate insulin doses for diabetics. In particular, most of these test elements are moisture sensitive.

Test Cassettes

Analytical systems with test media cassettes that allow multiple tests have been described in the prior art.

There are distributors available that contain a limited number of test elements such as 1 to 2 dozen strips that are individually sealed. Blood glucose meters using this test strip dispenser are on the market under the names AccuChek Compact (Roche Diagnostics GmbH) and DEX (Bayer Corporation). Consumers, however, require systems that contain even more straps to reduce the loading actions to be performed by the user. A suitable way to package a larger number of test elements is test film as, eg, described in US 4218421 and US 5077010. These test systems, however, are designed for use in the automated laboratory system environment and are designed to be used. therefore not suitable for the patient's self-diagnosis environment. DE 19819407 describes a test element cassette that employs a test media tape for use in the patient's self-diagnostic environment. However, a number of practical problems remain to be resolved based on the device described in DE 19819407. Test media used for blood glucose testing as well as other analytes are susceptible to deterioration by ambient air humidity. It is therefore a serious problem to keep unused test media free of moisture to avoid deterioration that would lead to incorrect analytical results. US 5077010 discloses test media tape containers having a tape outlet which is sealed by a locking element or an elastic element (see, in particular, Figures 21 to 33 and the corresponding disclosure). This form of seal is comparable to the known seal type of photographic film enclosures. The automated analytical instruments of US 5077010 have a high throughput and therefore the stability required after loading is short (typically one or two days only). Contrary to that, the stability after charging required in the home diagnostics market is much longer. Considering a patient performing two tests per day and the capacity of a test media cassette at around 100, the stability of the test media cassette after introduction into a measuring device (ie stability after loading) requires, at least 50 days long. The situation, however, may be even worse considering that the patient may have a second measuring device and use the present measuring device only from time to time. In the field of blood glucose testing, stability after loading must therefore be demonstrated for at least three months. The type of seal as disclosed in US 5077010 has been shown to be insufficient to achieve stability after loading as required in the domestic.

surveillance environment

It was an object of the present invention to propose body fluid test devices and test media cassettes containing a larger number of test media than body fluid test systems currently on the market and ensuring long stability after loading media. test. In addition, it was an objective to propose multi-test measuring devices that were easy to operate and had a size suitable for holding in hand.

SUMMARY OF THE INVENTION

The present invention encompasses a body fluid testing device according to claim 1, a test cassette according to claim 10 and a method for providing a test medium for body fluid testing according to claim 15.

In accordance with the present invention, it has been found that the concept of test tape measuring devices can be greatly improved. And employ a test media tape in which the individual test media are spaced apart so that the free tape portions are positioned between successive test media. This test media tape is contained in a supply container that protects the test media tape from moisture. The test means may be withdrawn from the container through an opening using the tape as a means of transport. Test means that are still positioned within the supply container are protected from moisture using a sealing means to seal the container opening while a free portion of tape is positioned between the sealing means and a surface of the supply container. . This type of seal allows very practical test devices which can provide numerous test means without the need for the user to load the test device with separate individual test elements.

Due to the spacing of test media, the material of the free tape portion can be chosen almost entirely independently of the test media material to obtain a suitable seal with the described sealing means. Typically, the test media tape is the width of test media or even wider. But it is also possible that the width of the tape is smaller than the width of test media and may even have the shape of a wire connecting individual test media. For reasons of positioning or orientation of test media, in the case of short width tapes it is preferred to have two tape lines at opposite edges of the test medium. In all embodiments, however, the tape serves to carry test media in an orderly manner.

Tape materials such as, for example, plastic for audio cassettes have been shown to be very suitable for this purpose. Suitable tape materials are plastic sheets of polyester, polycarbonate, cellulose derivatives and polystyrene. It is preferred, however, to choose non-hygroscopic materials which do not carry water or water vapor to a high degree. Accordingly, tapes without tape-free sections between successive test media cannot be sealed properly, as the test media material is porous and thus would allow moisture to flow into the supply container, even when the tape is sealed according to the present invention. In addition, the thickness of the tape on the free part of the tape is an important parameter to control proper sealing. It has been shown by the inventor of the present invention that moisture infiltration into the storage enclosure decreases with decreasing tape thickness. Although there are a number of interactive parameters, the particular effect of tape thickness can be seen from Figure 1. The tape (T) is positioned between a sealing means (S) having a deformable gasket (G) and a surface of the tape. container housing (H). 0 The sealing means applies pressure towards the housing, thereby compressing the seal against the tape and the surface of the housing. The seal is compressed more strongly in the tape region than on the right and left of the tape. Infiltration regions (L) that are not filled by tape or sealing material allow the influx of moist air. Decreasing the thickness of the tape thus reduces the cross section of the infiltration regions. A tape having a thickness below 100 microns has been shown to be very suitable for limiting the influx of moisture into the shell even if the seal is relatively rigid. Even more preferred are tape thicknesses below 50 microns.

The sealing means is a means that closes the opening of the shell (container) in which the uncontaminated test media tape is stored. The sealing means is preferably a body of a sealing material or a body of a material to which a joint is attached. Alternatively the seal may be fixed to the surface against which the sealing means presses to close the opening of the container. Also, embodiments are possible where the sealing material is present on the surface as well as on the body of the sealing means. Moreover, it can be understood from Figure 1 that increased seal flexibility reduces the influx of moisture. Seals having a (A) Shore hardness of less than 70, preferably within a range of 30 to 50 and even more preferably below 30, have been shown to be very suitable. Shore hardness (A) is defined by DIN 53505 (June 1987). Sealant materials which are very suitable for practicing the present invention are thermoplastic elastomers and vulcanized rubbers. Especially suitable are elastomers comprising polystyrene as the hard component and polymerized butadiene or isoprene as the soft component. Suitable sealing materials may be obtained under the trade names Kraton D, Kraton G and Cariflex TR from Philips and Philips Shell. In view of the purpose of the low water permeability of the seal, elastomers based on olefin thermoplastic polymers are preferred.

Seals having an annular shape are preferred to surround to annul the opening of the container. It has been found that with these annular seals a suitable seal can be obtained, while proper sealing with non-annular seals (eg rectilinear seals) is much more difficult to obtain as infiltration at the ends of these is more difficult to deter. seals.

As an alternative to the present invention it is even possible to have sealing means without a flexible joint. The sealing means may be designed to provide a shape fit between a sealing means surface, a housing surface and the tape. In this way, the section of the infiltration channels may be reduced to a size where vapor spillage / transport of

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Shape adjusting The sealing means is opened to extract test means by moving the tape and the sealing means is closed in a shape-adjusting state to protect unused test means in the supply section.

Additional hydraulic sealing means may be employed. In these embodiments a fluid or gel-filled deformable pouch is positioned in a channel through which the tape exits from the interior of the supply casing to the outside. The pouch is mechanically or hydraulically actuated to deform from an open position (in which the tape can be extracted) to a closed position where the shape of the pouch properly seals the tape. The hydraulic bag is also advantageous because of the potential of a hydraulic transmission that allows easier adaptation to an actuating mechanism.

The body of the sealing means as well as the body of the storage container should be made of materials that are almost completely impervious to moisture. This can be achieved by many materials. Due to production aspects, plastics such as polypropylene and polyethylene are however preferred. The materials, however, do not need to be completely impermeable to moisture, as it is possible to capture moisture that has spread by drying agents.

The sealing means further comprise pressure means for applying pressure to the body of the sealing means to achieve sealing. These pressure means are, eg, coil springs, pneumatic actuators, motors, electromagnets, compressed materials or materials under tension. From the preferred embodiments it will become clear that, in particular, elastic sealing means which in their resting position exert pressure on the body of the sealing means is easy and economical to manufacture.

The pressure required for proper sealing depends primarily on the hardness of the sealant employed, as well as the area to be sealed. The required pressure, however, is typically in the range of a few Newton or less.

Other optional measures to increase stability after loading of test media will be described later in connection with the specific embodiments.

A first general concept of the present invention relates to a body fluid testing device incorporating a test media tape. The test media tape holds test media that is used to take body fluid samples that are analyzed with a sensor. The test media tape is advantageously housed in a cassette so that, after the test media of a cassette has been used, a new test media cassette can be inserted into the test device. The test media tape is positioned before or after each test, so that successive tests can be performed without requiring the disposal of used test media. The test means can be positioned manually or automatically.

Test medium is a medium containing a test chemistry which, with the analyte of a sample, leads to detectable results. For more details on test chemistry and testing, see the General Testing section. The test means is preferably designed to soak the test fluid sample. This prevents the test device from becoming contaminated by the body fluid sample. As will be described in more detail later, a test medium tape is employed which comprises a tape wherein the test media is arranged with tape free regions between successive test media. The arrangement therefore has a structure with regions as follows: tape with test media - tape without test media - tape with test media - etc. The tape may be made eg from conventional plastic tape as used for audio cassettes. The test means are attached to the tape, eg by gluing, welding or using an adhesive tape.

According to one aspect of the present invention, there is provided a body fluid testing device for analyzing a body fluid. The test device includes a test media cassette including a test media tape adapted to collect body fluid. The cassette includes a supply portion that stores an uncontaminated section of the test media tape. A storage portion for storing a contaminated section of the test media tape may further be employed. In contrast to the supply portion which is designed to protect the test strip from ambient humidity, it is preferred to design the storage section so that the contaminated strip is open to a certain extent so that the test means which are soaked in sample may dry out. This open design can be realized by a plastic container having slots or recesses for gas exchange with the environment.

An important measure which may advantageously be used with embodiments of the present invention is a desiccant within the test media tape supply container. Moisture that has entered the container by diffusion through the wall materials or during an opening cycle is absorbed and cannot deteriorate the test media. The sealing concepts of the present invention are not, however, obsolete due to the use of the desiccant, since the amount of moisture entering without sealing means during the period after loading would be too high to be solved with rational amounts of drying material. / desiccant. Suitable desiccants are well known in the art, these are eg molecular sieves, silica gel, etc.

The present invention further proposes single use devices, where the test media tape belongs to the test device, such that the entire device is discarded when the test media tape is worn. Alternatively the test media tape may be disposed in a disposable cassette which is removably received in the test device. The designation body fluid testing device will be used for both embodiments (eg , with and without the cassette) in this patent application. However, when referring to embodiments employing a test media cassette, the designation will also be used to designate the device into which the cassette is inserted.

As described in European patent application EP 1424040 A1, the test media tape to which body fluid will be advantageously applied may be exposed to a tip shape to simplify the application of body fluids to a test medium. To this end, the test media tape may be guided over a convex tip portion that may belong to the test device or the test media cassette.

The test device may further comprise a penetrating unit for pricking a body part. Also, the lancet opening of such penetrating unit may advantageously be disposed at or near the convex portion so that the tip portion (if present) may also be used to prick. Convenient mode. The penetrating unit may be disposed under the test media tape and a lancing device may penetrate the test media tape or may extend through a recess in the test media tape.

The test device may further employ visual guidance of the user for applying body fluid samples. According to this embodiment, the test device comprises a lighting unit which indicates by illumination a part of a test element to which body fluid has to be applied. The illumination serves for the user's temporal and / or spatial orientation to apply body fluid. In addition, the lighting can be used to indicate where to position a body part to sting. An illuminated area on the test medium may further indicate the amount (or droplet size) of body fluid that is required by the test device.

Another aspect of the present invention relates to a test cassette for collecting a body fluid sample. The cassette includes a housing having a supply portion in which the uncontaminated test media tape is enclosed. The enclosure further includes a storage portion in which a contaminated section of the test media tape is enclosed after contamination. For sealing unused moisture testing media, a tape having tape-free portions between successive testing media is employed, as described above, such that the sealing concept of the present invention may be employed. The sealing means of the present invention may belong to the test media cassette or test device. Other embodiments are possible where parts of the sealing means, such as eg a pressure application plate belongs to the test device while other parts, such as a gasket, belong to the cassette. Advantageously, the container housing the strip of uncontaminated test media is closed against moisture except for the opening which may be closed by the sealing means. The cassette may further include a convex tip portion over which the test media tape extends and on which the test media tape is exposed to body fluid. In a particular embodiment, a supply spool is disposed in the supply portion of the wrapper around which the uncontaminated section of the wound media tape and a storage spool is arranged for storage of the wrapper around which the contaminated section of the tape. of test means can be rolled up. In embodiments employing a spool for storing uncontaminated test media tape, it is preferred that the spindle of this spool

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the envelope of the moist air infiltration container in the

Most test media are destroyed or altered by moisture, sunlight, etc. Therefore, measures must be taken to protect the test media before being loaded and used in a test device. A first measure is to pack the entire test media cassette prior to use so that contact with ambient humidity is prevented. This can be obtained, eg, by a blister pack. Alternatively, the cassette housing may be made closed against moisture except in the region where the test means are exposed for the application of body fluids. Embodiments may be contemplated which employ a moisture proof covering over the exposure region which may be removed prior to use of the cassette.

Furthermore, this invention relates to a method according to claim 15.

The method may further include the steps of actuating the sealing means to close said container and test opening. Acting preferably means pressing the sealing means onto a surface of the supply container. Another step may be included in the above method regarding a prick to generate an opening in the body prior to testing.

It is preferred when the closure means may assume two distinct positions. In a first closed position, the sealing means engages tightly on a surface of the supply container to close it and protect the test means therein from moisture. In a second open position, the sealing means is opened to allow the test media tape to exit the supply container. The aperture must be wide enough to allow portions of the test media tape with test media (which are usually thicker than the tape alone) to pass through it. A method for providing test means may therefore comprise the following steps:

Providing a supply container in which the uncontaminated test media tape is contained, said container further having an opening for extracting the test media tape from the container,

- providing a sealing means that isolates said opening from the environment,

- moving the sealing means from a first closed position to a second open position to open said container opening,

- remove a portion of the test media tape from the container to expose unused test media,

moving the sealing means from said second open position to said first closed position to close said container opening:

Again, it should be understood that when the sealing means is closed, a free portion of tape is positioned between the sealing means and a surface on which the tape rests. Said surface is typically a surface of the supply container.

Closure through the sealing means preferably means that the sealing means is pressed onto another surface (typically a container surface) to produce a seal of the uncontaminated moisture testing tape.

Other embodiments, embodiments, objects, features, advantages, benefits and aspects of the present invention will become apparent from the detailed drawings and description herein.

Brief description of the figures:

Figure 1: Schematic drawing showing infiltration regions

Figure 2: Perspective view of a test device

Figure 3: Perspective view of a fence concept.

Figure 4: Cut along line AA of figure 3

Figure 5: Test media cassette with trapezoidal sealing medium

Figure 6: Shape Adjustment Sealing Media Test Cassette

Figure 7: Test media cassette having a lever for opening the supply container by applying tension to the test media tape

Figure 8: Test media cassette having a lever for opening the supply container by applying tension to the test media tape

Figure 9: Test device and operating steps

Figure 10: Test Feeder with Self-Sealing Sealing Medium

Figure 11: Hydraulic sealing means

DESCRIPTION OF SELECTED EMBODIMENTS

For purposes of furthering and understanding the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe it. However, it will be understood that no limitation on the scope of the invention is thus intended as these changes and further modifications to the illustrated apparatus and these other applications of the principles of the invention as illustrated herein, being contemplated as would normally occur. one skilled in the art to which the invention relates. It will be apparent to those skilled in the art that some of the features that are not relevant to the invention may not be shown for clarity.

The principle of sealing moisture is shown in figure 1 which has already been described above. On the surface (H) of the shell, which preferably has a low roughness, the test strip (T) is pressed by the sealing material (G). The sealing force (F) presses the flexible seal around the test media tape. The remaining infiltration channels (L) are minimized by the selection of sealing material, tape thickness, sealing force and time pattern in which the sealing means moves.

A body fluid testing device (10) is shown in Figure 2. The drawing of the device shows a housing (11) and a screen (12) for displaying the test results as well as instructions for use. At the front end of the device can be seen a portion (20) of the tip over which the test media tape (30) extends. A test medium at the front end of the test device is exposed by the tip portion in the manner of a tip, which facilitates the application of body fluid. The tip portion therefore at least partially protrudes out of the contour of the test device housing (11) to be accessible to a body part (eg finger or arm). At the tip part can be seen an illuminated area 30 'indicating the position for sample application.

Figure 3 shows an improved embodiment of the sealing concept of the present invention. A portion of the test media tape (30) is positioned outside the supply part housing (50). The housing has an opening (51) through which the tape can be removed. The squares (52, 53) shown in the housing show the positions on the surface of the housing over which sealing means seals (not shown) press during sealing of the opening. Using two (or more) seals for sealing improves protection against infiltration. It is preferred to employ annular seals, as shown, which annularly press upon a region around the opening (51) to include the opening within the section area of ​​the annular seals. When two or more annular seals are employed, it is preferred when an annular gasket fully encompasses the next smaller annular seal.

Figure 4 shows a section through figure 3 along line AA. It can be seen that the seals are not vertically aligned with the surface of the housing (50) but are inclined relative to the vertical. The outer seal (53) towards its base portion (53b) towards its free end (53e) is angled away from the opening (51). The inner seal (52) is inclined towards its base portion (52b) towards its end portion (52e) towards the opening. The inclination of the outer seal serves to block incoming air more effectively than what a joint without this inclination would achieve. Due to the inclination, the seal is reinforced when air attempts to enter the enclosure (this is the case when the pressure within the enclosure is less than the outside pressure) as the air pressure increases the pressure of the seal end portion (53e). on the surface (54) of the container (50). The same principle applies to the inner seal in the reverse case when the pressure inside the housing is higher than the outside pressure.

As can still be seen from figure 4, it is advantageous when the seals taper from their base portion to their free end portion. The smaller the seal on the end portion, the more flexible the shape of the tape is, thereby reducing the section of the infiltration areas. The smaller the area covered by the annular seal around said lower opening (51), the less force required to achieve a small infiltration channel (L). In this embodiment the pressure means (55) (not described in figure 3) is in the form of a plate to whose underside the seals are attached. It is particularly preferred to secure the seals to the plate by molding it into two components of the plate and seal. A spring means (not shown) for applying pressure to the pressure plate (55) belongs to the test device.

Moreover, in Figure 4 it can be seen that the test media tape need not necessarily be wound on a spool. Arrangement of the tape within the storage container is more or less arbitrary, but misfeeds or locking must be avoided.

Figure 5 shows a section through one embodiment having a trapezoidal sealing means (60) that exerts pressure on an inclined surface (62) of the supply container (50). The sealing means itself may be made of a sealing material (eg rubber) or a sealing (sealing) material may be present on the surface of the sealing means which exerts pressure on the surface of the supply container. Sealing in this embodiment is again performed when a free portion of tape is positioned in the region where the sealing means exerts pressure against the test media tape. The angle shown in figure 5 is preferably in the range of 0 to 45 degrees.

Fig. 6 is a similar embodiment as shown in Fig. 5. Instead of a trapezoidal sealing means a shape-fitting sealing means (61) is employed. The surface of the housing (50) has a contour (62) in the opening that fits a contour (63) of the sealing means (61). The contours of the sealing means may be made of a material itself functioning as a gasket (eg rubber) or a gasket may be present on the surface of the sealing means. However, even the principle of reverse sealing with a gasket fixed to the surface of the housing can be employed.

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<td>free tape</td><td colspan="2">is positioned</td><td>between the</td><td>seal and</td><td>The</td>

Figure 7 shows a section through a test media tape container (50) having a sealing means. The test media tape (30) is wound on a spool (57). From the spool, the tape is guided through a diffusion channel (70) and leaves the container through the opening of the container. At rest, the opening is sealed by an annular gasket (53) which is attached to a first lever arm (80). This lever is also known in the art as a dancer. The lever has a center (81) of rotation. A spring member (82) keeps the seal pressed onto the surface of the container. The sealing tape and the e. a surface part of the container). The tape positioned outside the container is guided on a wheel on the other lever arm. When the tape is pulled in the direction as shown in Figure 7, the tension of the tape turns the lever (80) against the spring force (82) around (81). This movement reduces the contact pressure of the seal (53). The tape begins to slip through the seal. In this way, the tape section within the housing begins to come under tension. In subsequent movement, friction of the spool increases the tension of the tape and thus causes the seal to rise higher. The opening created is large enough for a test medium to come out without touching the seal. The tape can now be extracted from the container. When a sufficient portion of tape has been removed from the container, the test device (or a user) ceases to tear the tape and the seal is closed due to a lever movement caused by the spring element. In this embodiment it is advantageous when the spool 57 is frictionally loaded as the force acting on the lever is created by retaining the tape. In other embodiments, a frictional loading of the supply reel is also advantageous as it can prevent uncontrolled unwinding of the tape which may lead to jamming. In addition, a correctly wound tape on a spool has the advantage that the test means under the outermost layer of the tape is protected from moisture that may already have entered the wrapper.

Another important (but optional) measure to keep moisture away from unused test media is the diffusion channel (70) of Figure 7. This channel serves to decrease convection air exchange between the interior of the container and the environment. surrounding during opening of the seal. The channel limits the air exchange at the opening and thus the amount of moisture entering during the time of removing a new test medium from the container. The channel has a decrease in humidity along the opening to the spool path. Preventing air convection through the channel limits the ingress of moisture into the container, especially by diffusion, which is a much slower means of transport than convection.

Figure 8 shows another embodiment of a self-sealing test media cassette. Self-sealing in this context means that the cassette itself closes its opening without the need for outside forces acting on it to close its seal. The cassette further opens the seal by stressing the test media tape, which is a preferred embodiment. The lever of this embodiment has a first lever arm mostly within the test means supply container (50). As in the previous figure, the test media tape 30 is guided on a roll on one lever arm while the other lever arm holds an annular sealing gasket to seal the container opening. When the test media tape is tensioned, the lever is actuated and opens the seal to give the tape freely so that a new portion of test media tape with an unused test medium can be removed. Thereafter, the tensioning force applied to the tape may be reduced and the lever rotated, driven by the cassette spring means 82 ', to close the container opening.

Figure 9 shows a test device (10) with a test media cassette (50) inserted, as well as steps of using this device. As can be seen from Fig. 9A, the test device comprises a housing (100) in which the cassette is received. The cassette has a supply portion (50a) containing a supply spool (57) in which the uncontaminated test media tape (30) is wound. Figure 9 represents the parts (31) of test means such as pads which are attached to a tape. The test pads are attached to the tape by double-sided adhesive tape. Production of the test media tape can therefore easily be achieved by firstly removing a protective sheet from a first side of a double-sided adhesive, applying a test medium pad thereto, and then removing a protection sheet of a second side of the double-sided adhesive and applying the composite pad structure and the test medium adhesive to the tape. This process can be very automated. Alternatively, a double-sided adhesive may first be applied to the tape and then a test medium pad is applied to the adhesive. Other production methods such as gluing test media to tape are also possible. Used (contaminated) test media tape is wound onto a storage spool (58) in the storage section of the test media cassette. 0 Transport of the test media tape is by a motor (101) of the test device (10) which has a sprocket to engage the storage reel gears and to rotate the storage reel. It is usually sufficient to employ only a single motor to wind the storage reel in one direction to move the supply reel tape to the storage reel. For proper positioning of test means for sampling and / or testing, it may be advantageous to move the tape in the opposite direction as described above. This can be achieved by a separate motor winding the supply spool or a mechanical system allowing movement of the supply spool with the motor to rotate the storage spool. Further, it is possible to employ a spring mechanically coupled to a friction loading means that is coupled to the supply reel. When the ribbon is extracted from the supply spool by winding the ribbon into the storage spool, the spring is loaded and spring tension can be used to move the ribbon back a little. This can be achieved by turning the motor backwards and the supply spool will also rotate backwards due to spring tension, so that the tape is further retained under sufficient load to compress it over the tip for proper detection, as well as preventing jams caused by loose tape. By such a mechanism, it is possible to correctly position a test means for evaluation (eg, at tip 20) when it was initially moved too far. However, it is preferred to avoid such a process by positioning the test means by proper movement in only one direction (the transport direction). The positioning of test means on the tip may be achieved by the same optical system employed to read the test means. It is, however, also possible to employ a separate positioning sensing means that preferably operates optically. Detection of proper positioning can be achieved by employing different reflectance tape and test means, so that a vigilance of the reflectance during tape transport indicates, by a change in reflectance, when a test medium reaches the reading position. However, it may also be advantageous to employ indicator marks - such as eg black bars - on the tape which are optically detected when they are detected by the positioning sensing means.

The test device further comprises a control unit that controls the steps of tape transport, opening and closing of the seal and reading of the test medium. The control unit or a separate calculation unit is further employed for the calculation of analytical results from the readings obtained. The position sensing means may also be controlled by the control unit.

The cassette further comprises a tip (20) over which the tape is guided. This tip (optional) is for convenient sample application, eg by the fingertip. For details of the tip and how the tape is prevented from tipping, reference is made to co-pending European patent application EP 1424040 A1. The cassette further has a recess for receiving an optical measuring system (102) belonging to the device. of test. The visible optical system portion of FIG. 9 is a light coupling member for coupling light to the tip (20) to illuminate a test means positioned at the tip. When the sample is applied to this test medium, the intensity of light reflected backwards from the underside of the test medium changes and the intensity of reflection (preferably at a particular wavelength range) can be read by a detector (not shown) and the intensity can be converted by the control unit or a calculation unit to an analytical concentration. For the purpose of obtaining optical readings from the test medium, it is preferred to employ a tape material that is almost completely transparent so that light is detected or to employ a tape with a recess under the test medium as known from the optical elements. as eg sold under the trademark Glucotrend®. (Starting from the embodiment shown in Fig. 9, however, it is also possible to employ test means which function as known from electrochemical test elements. In these embodiments, the test device contacts the test medium in use with electrodes and employs a test device to control the application and measurement of current or energy to obtain readings that can be converted to analyte concentrations). Optical concentration measurement as well as electrochemistry with disposable test elements is, however, well known in the art and therefore will not be described in more detail.

Figure 9Α shows the test device (could also be called a test system as the test device houses a test media cassette) in its storage position with the seal (52, 55) closed (position closed). The test device comprises a pressure actuator (eg a coil spring) which presses the sealing plate (55) having an annular gasket (52) facing away from the actuator for an opening of the cassette (50). It can be seen that a free portion of tape is positioned between the cassette opening and the seal when the seal is closed. This embodiment has a diffusion channel (70) connecting the opening with the supply section, in which the uncontaminated test media tape is contained. It may further be seen that the supply section 50a is closed against the environment when the seal is closed, while the storage section 50b is partially open to the environment. The test media cassette further has rollers or pins (59) over which the tape is guided. Figure 9B shows the test device in an open position with the seal open. Opening may be achieved by moving the pressure plate (55) away from the opening against the force of the pressure actuator. This can be done by a reverse attraction device that pulls the pressure plate from the opening (eg an electromagnet attracting the pressure plate). Figure 9B also shows that the test means 31a has been moved from a position on the supply reel (see Figure 9A) to a position within the diffusion channel but still located within the supply section. . It will be understood that Figure 9B is a snapshot of an intermediate phase of transporting the test medium. The represented position of the test medium is not a typical hold position, but a position to last only briefly to keep the seal opening time as short as possible. The arrow shows the transport direction of the tape. 9C can be seen the sampling position for the sampling body fluid. The test medium 31a is positioned at the tip and the seal is closed again. After applying body fluids to the test medium at the tip, the test device reads the reflected light from the underside of the test medium to obtain a reading that can be converted to analyte concentration. It should be understood that it is preferred that body fluid application and reading be conducted in the same tape position, so that no additional tape transport requiring the opening of the seal is required. However, it may also be advantageous to employ a reading position that is independent of the sampling position, as this allows for an optical or electrochemical reading analysis unit within the test device in a different location. The closed seal of figure 9C can be obtained by deactivating the reverse actuator so that the pressure actuator presses the pressure plate again to open the fill section. Figure 9D is again a snapshot taken during transport of the test medium used for storage section 50b. When the test medium used is positioned within the storage section, the seal is closed again. As shown in Fig. 9D, it is preferred when the distance between two successive test means is so large that a subsequent test medium is still positioned within the supply section when the preceding test medium is already within the storage section. . It is even more preferred when the subsequent test medium is still on the spool, covered by a layer of tape, so as to be protected from moisture.

Figure 10 shows a test media cassette (50) with a supply section (50a) in which a supply spool (57) is being positioned. The test media strip exits the supply section through a diffusion channel (70). At the opening of the supply section, which is positioned at the outer end of the diffusion channel, the sealing means (80 ') is positioned. This sealing means has a shaft 81 'whereby it is rotatably attached to the cassette housing. The sealing means has a sealing section to which an annular gasket is attached (not shown). When the cassette is at rest (ie no breaking force is applied to the tape) the sealing section presses onto a surface surrounding the cassette opening (ie at the outer end of the diffusion channel in this embodiment). The force to achieve this pressing action is applied to the sealing means 80 'through a spring means (59) which is integrally with the cassette (a non-integral or even non-cassette spring means may also be contemplated). The integral spring means in the case shown is a protrusion of plastic material that can be produced in the same production step as the cassette shell (eg, by injection molding). When the sealing means 80 'is mounted on the boss (59) it is deformed and spring tension acting on the sealing means is created by the boss trying to return to an unstressed condition. When the tape 30 is extracted from the supply section, the tape needs to be tensioned to overcome the retaining force of the sealing means and / or the friction of the supply spool. As can be seen, the sealing means has a rounded section which, together with the cassette shell, creates a winding channel in which the tape extends. When the tape is forced it attempts to take a straight direction and therefore acts on the rounded section of the sealing means to move the sealing means against the force of the spring means (59). This movement opens the seal and lets the tape pass yet further shows a connected chamber is filled with a molecular agent (71) in the case described.

of the test medium. Figure 10 to the drying section which is a sieve

Figure 11 shows the hydraulic sealing concept. The housing has an upper section 100a and 1 lower section 100b which form a channel at the outlet of the storage section through which the test medium tape extends. Within this region of the channel is a fluid-filled pouch 105. The pouch is made of a flexible material (eg polyethylene) which, in its resting position, has the shape as shown in figure 11. In this position, the channel is opened so that the test medium strip can be extracted from the supply section and the test medium (31) can pass. When pressure is applied to a portion of the pocket located outside the channel, the portion of the pocket located in the region of the channel expands and, by shape adjustment, engages the tape within the channel. Pressure may be applied eg by a gasket (110). To obtain a moisture-tight seal from the fill section, the channel is closed by the pouch when no unused test medium has to be extracted. In this closed position, a tape free region between two successive test means is positioned in the channel and is properly sealed by the hydraulic sealing means.