Abstract:
A method for manufacturing a carrier tape comprising lancets and corresponding products in which a plurality of disposable lancets having a lancet tip for piercing a user&#39;s skin are provided on a carrier tape that is or can be wound onto a spool and used for obtaining a sample of body fluid. The lancets can each be arranged in a package and the lancet packages formed in this manner can be applied individually to the carrier tape and fastened thereon.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Patent Application No. PCT/EP2008/055689, filed May 8, 2008, which claims priority to European Patent Application No. 07108252.3, filed May 15, 2007. 
       FIELD OF THE INVENTION 
       [0002]    The invention concerns a method for storing lancets and optionally test elements in particular, for blood glucose analyses in which a plurality of disposable lancets provided with a lancet tip for piercing the skin are provided on a carrier tape which is wound onto or can be wound onto a spool for obtaining a sample of body fluid. The invention additionally concerns a tape magazine manufactured by such a method. 
       DESCRIPTION OF RELATED ART 
       [0003]    An arrangement of lancets on a carrier tape is known from International Patent Application WO-A 2005/107596 where the individual lancets can be successively brought into use and also disposed of again by tape transport. The lancets should be integrated on the tape by a direct connection in the course of the manufacturing process. In addition an additional provision of a test medium on the tape is also disclosed. This can simplify the handling for the user when carrying out self tests especially for blood sugar monitoring. 
         [0004]    Based on this, the inventors desired to further improve the manufacturing methods and products of the methods known in the prior art and to design them such that a low-priced mass production with high product quality is possible. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    It is against the above background that the present invention provides certain unobvious advantages and advancements over the prior art. In particular, the inventors have recognized a need for improvements in manufacturing methods for carrier tapes comprising lancets and in tape magazines for storing lancets. 
         [0006]    Although the present invention is not limited to specific advantages or functionality, it is noted that the present invention is based on the idea of packaging the disposable elements separately on a first carrier and then to apply them like a label on a second carrier. Accordingly it is proposed according to the invention that the lancets are arranged each in a package and are thereby tightly enclosed in a sterile manner at least in the area of their tip which penetrates into the skin, and that subsequently the lancet packages formed in this manner are separated and applied individually to the carrier tape and attached thereon. This results in special advantages for storing lancing elements that have to be kept sterile. The prepackaging allows a sterile protection even in a manufacturing environment and at the same time simplifies the mechanical handling when they are joined to the carrier tape. Moreover, the packaging also results in an increased storage stability. 
         [0007]    In order to create a flat structure that can be rolled up, it is advantageous when the packages consist of a base foil and a cover foil that is joined thereto. The base foil and cover foil can be brought into contact with one another and joined while enclosing the lancets. 
         [0008]    Additional components can be avoided due to the fact that the base foil and the cover foil are joined together by a hot-melt adhesive join wherein a layer of hot-melt adhesive which is preferably on the base foil is activated by a hot stamp. 
         [0009]    There are advantages for the manufacturing due to the fact that a plurality of lancet packages are manufactured in a connected manner as a package tape and are separated before application to the carrier tape. Another simplification of the manufacturing process provides that the package tape is formed by bringing together and joining a base foil strip and a cover foil strip. Alternatively it is also possible that the package tape is manufactured by folding down a foil strip and forming lancet pockets in the folded foil strip. 
         [0010]    A sterile packaging can be achieved in that the packages are at the same time cut and the border sealed while enclosing the lancets by means of a hot cut. 
         [0011]    In order to simplify the device handling it is advantageous when the lancets are permanently joined to the package, preferably at a proximal end section of the said lancets, and are preferably joined to the base foil. 
         [0012]    A particularly preferred embodiment provides that the lancets and at least the tip area thereof are protected against damage and/or are kept sterile in the package. 
         [0013]    The lancet tips are advantageously arranged in a pocket formed by the package. It is also conceivable that the packages are formed by a base foil and a biocompatible sealing compound applied thereon and especially consisting of silicone or TAE which encloses at least the lancet tip. In any case the pocket or the sealing block should be easy to penetrate in order to release the lancet tip for use. 
         [0014]    Another advantageous embodiment is that at least the tips of the lancets in the lancet packages are sterilized preferably by high-energy irradiation before they are applied to the carrier tape. This enables a large number of them to have a targeted sterile protection as well as enabling the lancet packages to be subsequently handled outside of a sterile zone. 
         [0015]    The application onto the carrier tape can be simply realized by fastening each of the lancet packages on the carrier tape at a joining surface that faces away from the lancet. The lancet packages are particularly preferably applied to the carrier tape in the form of labels or stickers. In this case it is advantageous when the lancet packages are provided with a piece of adhesive tape to glue them onto the carrier tape. 
         [0016]    Basically it is also possible that the lancet packages are held on the carrier tape by mechanical connecting means or by welding (e.g. by ultrasound or laser). 
         [0017]    A particularly preferred variant of the invention provides that test elements to which a sample of body fluid can be applied are applied to the carrier tape preferably alternating with the lancet packages. Accordingly it is proposed that the lancets and the test elements are prefabricated separately as package units and that subsequently the package units are applied to and fastened on the carrier tape in a common assembly process. In this manner it is possible to uniformly handle completely different disposable units when they are applied to the tape. In this connection the similar prepackaging which, however, is carried out separately enables different requirements with regard to the sterile protection of the lancets and the protection of the test chemistry to be especially taken into consideration. 
         [0018]    The manufacturing is further simplified due to the fact that the flat lancet and test element package units have an essentially corresponding width which preferably corresponds to the width of the carrier tape. 
         [0019]    Further handling advantages can also be achieved due to the fact that the carrier tape is arranged in a cassette such that it can be pulled off a take-off spool and wound onto a take-up spool. 
         [0020]    With regard to a tape magazine as a product, a carrier tape that can be or is wound onto a spool and a plurality of disposable lancets arranged on the carrier tape are provided wherein the lancets are arranged each in a prefabricated or separate package and wherein the lancet packages are fastened on the carrier tape spaced apart from one another. 
         [0021]    The invention also concerns a tape magazine for storing lancets and test elements especially for blood glucose analyses wherein the lancets and test elements are arranged each in a prefabricated package unit and wherein the lancet and test element package units are fastened on the carrier tape preferably in an alternating manner at a distance from one another. 
         [0022]    These and other features and advantages of the present invention will be more fully understood from the following detailed description of the invention taken together with the accompanying claims. It is noted that the scope of the claims is defined by the recitations therein and not by the specific discussion of features and advantages set forth in the present description. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0023]    The following detailed description of the embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which: 
           [0024]      FIG. 1  shows a lancet tape in an interrupted perspective view. 
           [0025]      FIG. 2  shows an enlargement of a section of the lancet tape according to  FIG. 1 . 
           [0026]      FIG. 3  shows the layer structure of the lancet tape in an exploded, sectional diagram. 
           [0027]      FIGS. 4 and 5  show a section through the lancet tape longitudinally to the lancet and in the transverse direction to the lancet, respectively. 
           [0028]      FIGS. 6 and 7  show a diagram of various steps for manufacturing lancet packages. 
           [0029]      FIG. 8  shows a stamp for heat sealing lancet packages in a top-view. 
           [0030]      FIG. 9  shows a section taken along the line  9 - 9  of  FIG. 8 . 
           [0031]      FIG. 10  shows a tape cassette with a test tape furnished with lancets and test elements in a partially cut-open perspective view. 
           [0032]      FIGS. 11 and 12  show a lancet being put into use in a perspective and sectional view, respectively. 
       
    
    
       [0033]    Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the embodiments of the present invention. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    For the purposes of describing and defining the present invention it is noted that terms like “preferably”, “commonly”, and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention. 
         [0035]    The lancet supply tapes  10  shown in the drawing enable storage or provision of a plurality of lancets  12  as single-use articles for blood glucose determinations or other analyses in which a sample of body fluid is to be obtained for diagnostic purposes by a skin puncture. In addition, combinations of lancets and diagnostic test elements are also possible on a common supply tape. In both cases, prefabricated package or carrier units are prepared which are stored on a carrier tape in the form of a tape spool. 
         [0036]    As shown in  FIG. 1 , the lancets  12  are each arranged in an allocated package  14  wherein the package units or lancet packages  16  formed in this manner are fastened on the carrier tape  18  like labels at a distance from one another. Since the lancet packages  16  are flexible and flat, this results in a tape magazine that can be rolled up and can be used in a hand-held device that is not shown for automatic handling. 
         [0037]    In the enlargement of  FIG. 2  it can be seen that the respective lancet  12  is protected in a pocket  20  formed by the package  14 . The pocket  20  is formed by a foil laminate consisting of a base foil  22  and a cover foil  24 . The lancet tip  28  is accommodated in an enlarged pocket area  26  in which it lies freely whereas the proximal shaft section  30  of the lancet  12  is tightly enclosed. Mechanical handling is thus facilitated even in the case of very small needle elements without having to be afraid that the very sensitive tip will be damaged or its sterility impaired. In the embodiment shown a round lancet aligned in the tape transverse direction is provided. Other orientations and designs are also conceivable for example in the form of a flat lancing element provided with a groove-shaped capillary collecting channel. 
         [0038]      FIG. 3  shows the individual components of the foil structure according to  FIG. 2 . An approximately 10 μm thick and about 5-10 mm wide PET foil can for example be used as the carrier tape  18 . A section of a double-sided adhesive tape  32  which has a first adhesive face  34  for the carrier tape  18  and an opposing second adhesive face  36  for the base foil  22  mediates the joining of the label-like lancet package  16 . Alternatively it is also possible to use a piece of adhesive tape which adheres on one side and at the same time forms the base foil. Instead of an adhesive bond an integral bond or mechanical connection (e.g. a Velcro fastener) are also conceivable. The base foil  22  and cover foil  24  are laminated with inclusion of the lancet  12  by means of a layer of hot-melt adhesive  38  on the base foil which is activated by a hot stamp as elucidated in the following. 
         [0039]      FIGS. 4 and 5  show the final product according to  FIG. 2  in a section at right angles and longitudinal to the lancet  12 . The thin cover foil nestles over the lancet cross-section thus making a seal around the lancet  12 . In this connection it can also be seen that the proximal section of the lancet  30  is fastened on the base foil  22  by means of the layer of hot-melt adhesive  38  whereas the distal section of the lancet  28  is kept free for use in the enlarged unwelded area  26  of the pocket  20 . Especially in the transverse orientation of the lancet  12  that is shown at right angles to the longitudinal direction of the tape, it is advantageous when the lancet packages  16  have dimensions that correspond to the width of the carrier tape  18  taking into account manufacturing tolerances. 
         [0040]      FIG. 6  illustrates the prefabrication of a package tape comprising a plurality of connected lancet packages. For this purpose a base foil strip  40  and a cover foil strip  42  are brought together and permanently joined to one another with enclosure of the lancets, which are in this case flat lancets  12  with a lancet tip  28  and a planar proximal holding member  30 . An approximately 20 μm thick PET foil can for example be used as a base foil strip  40  which is coated on one side with a hot-melt adhesive made of a low-melting polyester, e.g., an ethylene vinyl acetate copolymer. The cover foil strip  42  is advantageously configured to be thinner than the base foil strip  40  and is for example a PET foil of 5 μm thickness. 
         [0041]    As shown in  FIG. 7 , the package tape  44  can be provided with transverse perforations  46  which simplify the separation of the lancet packages  16  before they are applied to the carrier tape  18 . It is also possible to divide and at the same time weld individual packages along the cutting line by a hot-cutting means in which case thermoplastic foil material is used. Another variant provides that a foil strip that is longitudinally folded is fitted with lancets and is transversely divided into individual packages (not shown). In this case one longitudinal half of the foil strip forms the base region for applying the lancets whereas the other longitudinal half is subsequently folded over and joined to the base region. 
         [0042]      FIGS. 8 and 9  show the scaling of the individual lancet packages by a hot stamp  48  which acts on the hot-melt adhesive. The stamp face  50  of this stamp that presses against the respective lancet package  16  is provided with a stepped recess  52  which tightly encloses the proximal needle section  30  and due to a corresponding depression provides the enlarged unwelded region  26  of the pocket  20  in the area of the needle tip  28 . In this case the proximal needle section  30  is preferably permanently glued to the base foil  22  such that the needle  12  can be re-stored in connection with the carrier tape  18  after a later use. 
         [0043]    Although not shown specifically the lancets  12  sealed into the lancet packages  16  can be sterilized by irradiation for example with a high-energy electron beam. The material-tight seal ensures that it keeps sterile even in the subsequent processing sequence. 
         [0044]    The lancet packages  16  are stuck onto the carrier tape  18  at a labeling station. In this connection it is also possible to apply additional test elements in the form of test field labels  54  as shown in  FIG. 10  with the tape cassette  56  as an example. The test field labels  54  are provided with a reagent layer  58  to which body fluid (blood and/or tissue fluid) obtained by a skin puncture can be applied in order to detect an analyte (e.g., glucose). The analyte is preferably detected by means of a color change but it can also be detected electrochemically. The mechanical handling of the various disposable units  16 ,  54  at the labeling station can thus be carried out in a common labeling process as described in European Patent Application No. 1 593 434 A only for test field labels to which reference is herewith made. 
         [0045]    The cassette  56  has a supply spool  60  for unused tape material and a take-up spool  62  for re-storing or disposing of used units  16 ,  54 . They are provided by successively advancing the tape preferably in a handheld device in order to enable a substantially automatic measuring process. 
         [0046]    In the course of such a measurement which can be carried out locally by the patient himself; the respective lancet  12  according to  FIGS. 11 and 12  is brought into use. The thin cover foil  24  is slit open by the lancet  12  by bending the lancet package  16  at a deflection point  64  thus exposing the lancet tip  28 . A lancing movement can then be carried out by a suitable actuator in order to for example prick a finger. The proximal lancet section  30  advantageously remains joined to the foil laminate in this process in order to simplify the subsequent disposal of the lancet  12  on the carrier tape  18 . 
         [0047]    Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention.