System for withdrawing blood

The present invention relates to a system for withdrawing body fluid from a Body part, in particular the finger pad, by producing a small puncture wound.

In the field of clinical diagnosis, it is necessary, samples of body fluid, especially to attract blood samples in order to detect therein ingredients can. If a larger amount of blood required, this will be like a rule with a syringe or taken, including a blood vessel is deliberately punctured. However, the present invention falls in an area where only sample quantities in the range less ul or less necessary are to determine analytical parameters. Such a procedure is particularly suitable for Measurement of blood glucose widespread, but they are also found, for example, application to determine coagulation parameters, triglycerides, HBA 1c or lactate. Around Diabetes has prevailed that diabetics self monitoring of Blood sugar level make (so-called. Home monitoring). This is required to targeted Insulin doses set a blood sugar level, which is in the normal range. device Diabetics, however in a blood sugar (hypoglycaemia) so this can be a loss of consciousness and even pull a patient's death by itself. Does the patient on the other hand too high Blood sugar levels, so it attracts serious sequelae such blindness and gangrene after themselves. For required to measure the blood glucose level blood have small, Handy Blood testing equipment, so-called. lancing devices, naturalized, the user, hospital and nurses can be operated simply and reliably. More recently, are also Systems for the extraction of interstitial fluid is known, with the corresponding in principle Analyzes can be carried out.

A in this field strengthens abzeichnendes problem is the contamination and Injury by used lancets. Many of the equipment on the market is the taken lancet after the sting operation or ejected. The exposed in such a case Needle of the lancet can lead to injury, the infection may entail. In some countries there are therefore already aspirations, blood collection systems, in which the needle tip is freely accessible after use, to prohibit.

In documents of the prior art, various variants of blood collection systems been described in which the needle is protected after the sting operation. In the Document US 5,314,442 describes a cap in which a lancet is disposed. to Carrying out a sting operation, the lancet by a plunger or the like. So within the cap shifted so that the needle passes through an opening to the outside. After stitch pulled back the lancet inside the cap and flexible elements on the lancet ensure that the lancet needle without the action of the plunger is no longer outwardly can penetrate. In principle, similar systems are described in US Patents 4,990,154 and 5,074,872, and International Application WO 00/02482 describes. Another system, wherein the retraction of a lancet is carried out in a cap with a built-in spring, is in Document DE 198 55 described 465th While the documents mentioned already, the solve problem of contamination or injury to the user, then a coupling of only achieved driving mechanism to the lancet by an interference fit. Here, the Piercing the needle is limited by a stop. However, it has been found that the Impact of the lancet leads to stop vibrations of the needle, which when the pain increase penetration. For more information on this problem is described in EP 0,565,970.

The object of the present invention to provide a system for removal of propose body fluid by one hand contamination or infection used lancet avoids on the other hand the user a very painful poor grooving allows. Another task was the systems of the prior art to simplify, to make more cost-effective and in particular to propose a concept that can be reduced. The latter point is particularly important in a system available question about working with a magazine, lancets and the user to a change in yet unused lancet allows without him here to complicated handling steps must be done.

The aforementioned objects are achieved by embodiments of systems for taking dissolved liquid body, having a drive unit having a plunger which for execution a lancing process is moved from a resting position into a lancing position. furthermore include the systems of a lancing unit in which a lancet is with a needle that is arranged in the rest position of the plunger within the lancing unit and by the Plunger is moved in movement in the puncturing position so that the needle is at least partially emerges through an exit opening of the lancing unit. An essential feature of the system is that the plunger and lancet to carry out the lancing process by positive locking are coupled together.

For a form fit in the context of this invention is characteristic that through him Coupling of the lancet and driving plunger by means of a low expenditure of energy is possible. It are two basic variants to achieve a positive connection. includes In the first variant is for coupling the lancet and driving plunger a mold in such a way that a enclosed retainer. The closing is mold in the invention as Holder designates. the holding device is located on the lancet, so has the Plunger drive a holding element, on the other hand is located on the holding device Drive plunger, the holding element on the lancet is arranged. The figures show 1 and 2 practical configurations. Preferably, this variant of the form-fit is achieved by that by a longitudinal movement in the puncturing direction transverse movement of retaining elements of a (First opened) holding device is achieved that this is a holding area conclude. Preferably on closing of the holding device wid the holding element (at least partially) engaged behind, so that the lancet during the retraction of the drive ram - at least is taken - until the eventual opening of the holding device. Furthermore, it is preferred when retaining device and retaining region are geometrically coordinated with one another that, after erfolgtem positive engagement in the direction of the pricking movement no or only a low tolerance exists and the movement of the drive ram in both stitch direction and opposite direction is backlash converted into a movement of the lancet. This can be achieved in that the longitudinal extension of the chamber in the closed Haltevrrichtung coincides with the longitudinal extent of the holding area, or is only insignificantly larger (See Figure 1). In another embodiment of this variant, a recess are in Holding area and retaining elements on the holding device in its longitudinal extent so matched that a transport in the puncture direction is substantially free of play possible (See Figure 2).

In a second variate the positive engagement are both holding device and holding area substantially dimensionally stable and enclosing the holding portion by the holding device is performed by moving the mesh given by these two units forms. Since the Units are dimensionally stable, no complete enclosure is possible, but the forms must be open to such an extent that they can be reciprocally moved. The mesh Move takes place (at least with a travel component) transversely to the puncturing direction and there is a Coupling which is substantially free of play is also in the puncture direction (see Figure 4). It is Finally, a coupling by a movement possible that both components transversely as has also parallel to the puncturing direction (see Figure 7).

The inventive system for blood collection has a drive unit with a plunger, through which a lancet is moved from a resting position into a lancing position. In the prior Technology, a number of drive mechanisms known in the field of blood sampling devices can be used. In particular, large-scale drive mechanisms used that draw their energy from a previously tensioned spring. In the present Invention drive units are preferably used, the guided movement the plunger and the lancet, due to the form-locking coupling, allow. with a guided movement is meant that the lancet in both a predetermined path engraved the body as withdrawn via a predetermined path-time course from the body becomes. In the conventional, on a combination of a spring and a Stop based system of the prior art is the path-time course by a plurality parameters such as manufacturing tolerances (friction conditions in the system, strength the spring) .As also affect the skin surface. It has been found that a guided movement the lancet, as described, for example, via a guide link as described in EP 565 970, advantageous with respect to the puncture pain is. With regard to the drive unit incorporated herein 4,924,879 made to the preferred drive mechanisms of EP 565970 and the US.

An important aspect of the invention provides a detachable from the drive unit Lancing unit is, in at least one lancet is located. The lancing unit comprises a Housing in which the lancet is arranged in the rest position. This can be avoided be that caused by the lancet before or after use injuries or that contamination occur. The housing may be configured so that therein a single Lancet is arranged or the housing may take the form of a magazine with several have lancets. As a rule, will the lancet within a magazine in one another separated chambers are to contamination of unused lancets by already used to prevent. The housing of the lancing unit is advantageously designed in such a way that it can be attached to the drive unit. For this purpose, the lancing unit for example, have the shape of a cap, which is plugged onto the drive unit. Such embodiments are disclosed in the documents US 5,314,442, US 4,990,154 and US 5,074,872 described. There are also embodiments are possible in which the lancing unit is firmly connected to the drive unit, or an integral forms part of the drive unit. This can for systems with magazine be advantageous, so that the entire unit is discarded after consumption of the magazine. in the The case of a lancing unit in the form of a magazine, this example next to each other have arranged chambers in which there are lancet and the chambers are sequentially positioned relative to the drive unit so that the lancet to the plunger the drive unit can be coupled. Also particularly advantageous is a magazine in The form of a drum having arranged in parallel to the longitudinal axis of the drum chambers in which Nearby lancet. Similar to a revolving drum can such a magazine repeatable be attached to the drive unit.

A further requirement of the lancing unit is located in the sterility of the lancet, over a long period must be ensured. A sterility of the lancing unit, as in the prior Technology customary be achieved by gamma irradiation. To maintain the sterile conditions can the lancing unit in an outer packaging, such as a polyethylene bag are welded. In another embodiment, the openings are the Lancing unit (for entry of the plunger and for the exit of the needle tip ) by sealing films closed. This may for example be peelable sealant films, the user of the front Use away. Advantageously, however, also thin films can be used, which at the Use are pierced by the plunger or the needle tip so that the user additional handling steps spared. Such films may already integral in Manufacturing process of the lancing unit, which is an injection molding process as a rule, are generated.

In a further advantageous embodiment, the needle tip through an elastomer before Contamination protected, which is taken off prior to the closure or during Engraving process is pierced to release the needle tip. Such protection of Needle from contamination as described in the application WO 01/66010 which is hereby By reference.

Within the lancing unit are one or several lancet with a needle. apart of possible devices on the lancet, which in a form-fitting coupling a allow plunger, can be used in this invention lancets, as they are well known in the art. As a rule, has such a lancet Basic body made of plastic, in which a metal needle is placed. However, it is also Lancets without a separate greenbody possible (for example, metal needle with a Thickening at the rear end as a holding area).

In the present invention, it is important that the plunger of the drive unit and the lancet are coupled for carrying out the lancing process by positive engagement with one another. Herein, the invention differs substantially from the prior art, where a mechanical Coupling between the lancet and drive via an interference fit (US 5,314,442, US 4,990,154, US 5,074,872), a catch (WO 00/02482), jamming (US 3,030,959) or via a simple contact pressure (DE 198 55 465) is performed. A form-fit being characterized by that a mechanically reliable coupling between the drive and the lancet is performed, without requiring a significant contact force to the lancet in the direction Lancing movement. In the devices of the prior art, which with a press fit work must in the cap, which includes the lancet, a spring element (z. B. DE 198 55 465) or a retaining element (eg., WO 00/02482) can be provided which is so designed that the Lancet when docking the lancing unit to the drive unit does not leak out of the cap. However, spring elements in the lancing unit lead to increased manufacturing costs, which is particularly is serious, because it is a consumable item during the lancing unit. to overcome a retaining member on the other hand is an additional force on the part of the drive unit necessary and overcoming also leads to vibrations of the needle, negative impact on the up Stitch pain affect. Incidentally, in systems which work with a press fit, a guided movement, which involves retraction of the lancet problematical, since the interference fit can be solved. The catches at described in WO 00/02482 solves this Problem though, but it is difficult to obtain. In particular, it is difficult to a Such catches at establishing in a continuous manufacturing process, as already slight variations of the material or process conditions inoperability Pull the device by itself. Another disadvantage of the described in WO 00/02482 Device is that the latching of paths takes place in a region that to the Puncture in the body is used. The force variations occurring in the catches at and Vibrations are detrimental from the lancing pain. A disadvantage of the device further characterized in that the needle remains after the puncture in the body and not actively withdrawn becomes. A needle retraction occurs only when the cap is removed from the drive mechanism. In a positive locking of the drive plunger and lancet according to the present Invention, however, can be achieved a connection between the plunger and lancet without that this special force would be expended in the direction of the stitch and above addition, the positive connection advantageously be used, the needle the puncture actively withdraw. This ability to actively manage the travel-time curve the needle on the drive unit, it is possible the lancing process very painless to design.

In Figure 8 are schematic force (F) pathway (s) procedure of sessions for coupling processes of the drive for a press fit to the lancet (a), latching of (b) and positive locking (c). It's closed recognize that when using the press fit, the force increases sharply until the lancet from the position in which it is held by a holding member or a spring, triggers. At a Catches at increasing the force on the locking and decreases after successful conclusion again. at a positive engagement are only very small forces for moving together of the retaining elements necessary.

Another characteristic of form closure according to the invention by comparison with the Document US 3,030,959 clearly. In an apparatus according to this US patent, needles, which are arranged in a tube one after the other supported by a clamping device which is similar to a mechanical pencil. In addition to the contamination problems with used needles, which makes this apparatus unresolved, it can be seen that the positioning of the needles in axial direction (ie, in the puncturing direction) is not defined. Just as in a mechanical pencil, the Length of protruding pencil tip by the user can be chosen also depends Here, the axial positioning of the needle from the setting by the user. At a Form-fitting principle, however, feature lancet and drive unit coordinated Holding areas and holding devices. The geometric configuration of the holding area and retaining device can be achieved in that the axial positioning of the lancet well is defined and hence the insertion depth can be accurately controlled. By using a form-circuit can thus both a peak force in the axial direction when coupling Lancet and driving plunger are avoided as achieved an exact axial positioning will. With a form-fitting to a shape (holding device) includes a different type (Holding area). Under a self-close in this sense is both a movement of Device parts transversely to the puncturing direction and alternatively a form-fitting Interlocking two meant in their form unchanged body. At a preferred embodiment, the holding device opens and closes around the Holding portion when this is introduced into the holding device. In particular, this Close by longitudinal movement take place in which the longitudinal movement into a movement of Holding elements of the holding device with components transverse to the longitudinal direction of movement is converted. A practically advantageous possibility of this transformation of a length to achieve movement into a transverse movement is to the holding device with the in a tapered channel introduce longitudinal movement (eg in a sleeve) or in To move this (see Figure 1). rejuvenating Among themselves this will not only understood continuously tapering channels but generally channels whose clear width is decreases in the longitudinal direction. A channel needs in this context not a to be closed circumferential surface body. When the holding device, for example as described in Figure 1 comprises two opposing hooks, satisfy two walls whose inner Distance is reduced to one another. There is on the other hand also the possibility of the retaining device by lifting one to suggest tensioned state (see Figure 2), which, for example, by moving the Holding device in an expanding channel.

The present invention is further illustrated by means of figures:<sl><li>Figure 1: Cross-sectional view of a lancing unit having a holding device at the lancet</li><li>Figure 2: Cross-sectional view through a system clipping with a retaining device at the drive unit</li><li>Figure 3: Cross-section through a complete system and steps of use</li><li>Figure 4: System segment with dimensionally stable holding device to the drive unit</li><li>Figure 5: Magazine of lancing units</li><li>Figure 6: System of drive unit and lancing unit</li><li>Figure 7: System with a dimensionally stable holding device</li><li>Figure 8: force-path diagram for different coupling types</li><li>Figure 9: lancing unit with sterile protection</li><li>Figure 10: drum-shaped magazine</li></sl>

1 shows a blood collection system according to a first embodiment of the invention in the Actuating phases I, II and III. 1 shows only partial aspects of the system are shown. In the illustration, the drive unit for the plunger (10) and the housing of the drive unit is absent, at which the lancing unit (20) is attached. The drive unit for the plunger (10) is the particularly useful in the described EP 0565970 drive device.

The stages shown in Figure 1 show the realization of the positive coupling between the drive ram (10) and the lancet (30), and the actual lancing process. For each of the three phases in each case 2 cross-sectional views along the longitudinal axis are of the system shown in mutually perpendicular planes. From the left of the phase I It can be seen that the lancet (30) is arranged within a sleeve (40). The illustrated A lance (30) has a base body which is made of plastic and an injected therein Needle (31) consist of steel. At the needle tip side facing away from the lancet a Holding device with holding elements in the form of two hooks (32a, 32b). During retraction of the Plunger (10) in the lancet enters a thickened region at the front end of the plunger, as the Holding area (11) is used between the hooks (32a, 32b) and finally collides with the rear Needle end (Phase II). It is also possible, instead of the plunger to the rear needle end to the Main body of the lancet impinge allow. A direct contact with the needle is, however, Advantage, because the needle length can be controlled very precisely production technology and thus precise control of the insertion depth is possible. Upon further advancement of the plunger he pushes the lancet inside the sleeve (40) in the direction of the outlet opening (41), so that finally is the needle tip through the outlet opening and into an underlying Tissue punctures. From the transition from phase 11 to phase III is to recognize that the Holding devices (32a, 32b) on the lancet to the holding area (11) close the ram, when the lancet is moved within the sleeve (40). The holding device at the Lancet surrounds the holding element of the ram so that a positive connection is formed, with not only a forward movement of the lancet to execute a stitch but also an active, controlled by the drive unit retracting the lancet substantially is no play possible. This is on the one hand ensured that the end of the holding area on the end of the needle is seated and by the hooks (32a, 32b) of which the rear end Holding area engage behind. The length of the holding area and the longitudinal extent of the Chamber in the closed holding device are coordinated so that a backlash-free drive of the lancet is placed in the puncture direction. By arranging the lancet or the holding device in a tapered sleeve is a conversion of a Longitudinal movement of the lancet in the puncture direction in a transverse movement of the elements achieved retaining device, which allows a form fit with the holding portion of the drive. As can be seen from the figures, the sleeve (40) has a central region (40b) relative to the upper portion (40a) is tapered. By this tapering the hooks (32a, 32b) of the lancet when moving the lancet in the sleeve in the direction of the compressed longitudinal axis, so that an enclosing of the holding area (11). particularly It is preferred to the lancing unit (20) in such a way that the lancet is held within the sleeve when there is no action of the ram is present. In this way, to ensure that the needle is in the unactuated state within the sleeve (40) is thus no injuries or contamination by an outstanding Needlepoint is caused. A sliding through the lancet through the sleeve in the direction of Outlet opening (41) is effectively prevented in that the hooks (32a, 32b) a shoulder comprise, resting on an edge of the central region (40b). The inclination of this edge and the flexibility of the hooks can be so adapted to one another that an insertion in the taper on the one hand can take place with little force and on the other hand an unwanted Sliding through is effectively avoided. To slipping out of the lancet out of the sleeve, in the puncture direction opposite direction to avoid, in the illustrated Embodiment, a widened portion (40c) at the lower end of the sleeve as well as a so corresponding widened portion (30a) at the lower end of the lancet body provided.

As shown in Figure III, the needle tip is when striking the holding area (11) on the needle end is still within the sleeve (40). This is advantageous since the by the Impact vibration generated has no influence on the casting process in the tissue, thereby will puncture pain avoided by such vibration.

According to the invention, it is preferred if the system is designed so that after passing through the occurs phases I, II and III, a return movement of the plunger (10) in the reverse direction, so that the plunger is uncoupled from the lancet and the lancet again completely within the sleeve is. For coupling of the ram to the lancet there are two main variants. In the first variant housing, drive unit and lancing unit are adapted to each other, that the plunger in the initial state is completely outside of the lancing unit (20) (Prepared as described for Phase I). A disadvantage of this embodiment is that the ram for Performing a stitch a relatively long way must be covered. An advantage it is, however, that the tappet is located completely outside of the sleeve so that a transverse movement is possible. Accordingly, the first variant can be beneficial for systems with a Lancet magazine are used, in which successively different under the sleeves Tappets are moved. In a second variant is by coupling the lancing unit at the Drive unit already positioning according to phase II or even better in Direction achieved in phase III. In such an embodiment, the distance which the must be done by ram, can be kept very small, which is constructionally favorable.

Figure 2 shows a second embodiment of the invention, wherein the lancet (130) has a holding area (131) and the drive unit having a holding device (132a, 132b). In the Figure 2 is, in turn, the range of the system shown, which serves to hold the lancet, not However, the drive unit. Also in connection with this embodiment it is advantageous to use a drive unit that moves out the plunger (110). The ram carries at its front end a holding device with holding elements in the form of two hooks (132a, 132b) connected by a flexible bridge (133) (or joint) are interconnected. The arrangement forms a spring element. In Phase I, these hooks are spread because their rear ends are held together by a sleeve (140). When pushing the Lancet (130), the sleeve is simultaneously moved against a spring (141), so that the rear Ends of the hooks are released and the front ends of the hook form-fitting manner to the holding portion (131) of the lancet close. The holding area of ​​the lancet has a Recess (recesses) into which the hook of the retaining device. The Longitudinal extent (in the puncturing direction) of the engaging ends of the retainer and the Longitudinal extension of the recesses are substantially equal, so that with this arrangement, a guided, essentially free of play piercing movement can be performed. Also in this embodiment there is a conversion of a longitudinal movement of the Holding device into a transverse movement of the retaining elements.

Figure 3 shows an inventive system, based on the positive Coupling principle according to FIG 2. The drive unit 100 based on the device Softclix®, which is described in EP B 0,565,970. From this document it is clear in particular, as mediated by the drive spring 170 rotational movement of the sleeve 171 in a Translational movement of the push rod 110 is implemented. The tensioning of the drive spring by are depression of the push button 172, and a mechanical transmission suitable for this purpose described in the European patent application with the application number EP 0 O10 2503.0. The The drive unit has at its front end a holding device with two holding elements, in this particular case hook (132a, 132b) on. As already explained to Figure 2, these hooks are in a central region via a flexible bridge (133) or a hinge with each other connected. On the hook relative to the bridge (133) facing away from the Holding device via a sleeve (140) supported so that the hooks are open. The sleeve (140) is held via a spring located in the driving apparatus (141) in position. a lancing unit can also be seen from Figure 3 I, in which a lancet (130) in a cap (121) is arranged. The lancet has at its rear end a retaining portion (131), the from the holding device (132a, 132b) is gripped. The outer body of the lancet has a front, narrow area and a flange (122) between this narrow range and the holding portion (131). The tip of the lancet is twist-off by a protected plastic body (123) from contamination and mechanical damage. The Cap (121) has in its interior a passage for the narrower region of the lancet and an enlarged cross-sectional area which for receiving the flange (122) suitable is. Within this widened channel of the cap, a bead (124) is disposed, which prevents unintended slipping of the flange in the extended channel. The cap further having a sleeve (125), which serves the sleeve (140) of the drive unit when Replacing the lancing unit to push back on the drive unit. This process can be seen by viewing FIGS 31 and 3II. By pushing away the sleeve (140) by means of the sleeve (125), the holding device is released, so that they hold the field the lancet comprises, as can be seen from Figure 3II. By pressing the button (172) and Trimming the guard member (123) of the lancet, the system is now available for use prepared. With the device shown in FIG 3II now is a lancing process carried out, in the mounted, the front end of the cap (120) to a tissue portion and by Actuating a trigger mechanism, the drive unit is activated. After the Lancing process is withdrawn, the cap of the drive unit along the longitudinal axis, wherein said flange (122) is retracted behind the bead (124) so ​​that the contaminated Needle tip can not leak out of the cap. The lancing unit in the state of FIG 3 III can be discarded, or coupling to the drive unit for more Removal procedures are used.

Figure 4 shows a third embodiment of the invention in which the positive engagement between lancet and driven by a positive connection of geometrically adapted to each other Holding portions and holding devices is achieved. In Figure 4A is a lancing unit (220) shown that comprises a sleeve (240) in which there is a metal needle (231). The sleeve (240) has a thin transverse wall (250) which supports the metal pin relative to the sleeve. These Transverse wall is preferably the same shape during encapsulation of the needles with plastic. by virtue of the relatively small thickness of this wall, the mechanical connection of the sleeve and Needle be solved when lancing process, so that the needle slides past the wall (250). At the exit opening of the sleeve is sealed with a thin film (260) when Engraving process is pierced. At its upper end, the needle (231) carries a molded Holding area (232). For mechanical stabilization, the needle has a taper, around which the holding area (232) is injected so that an axial sliding through avoided becomes. A mount the needle in the sleeve may also by roughening the needle at its Outer surface, a thickening or curvature of the needle in the sleeve can be achieved. The actuator stem (210) of this embodiment has at its lower end a holding device (211), which form-fit comprises the retaining portion (232), as shown. The Holding device (211) is open at the side, so that the plunger displaced parallel to the needle with the Holding device (211) to the height of the holding area (232) and be driven by displacement transversely to the needle axis and to the puncturing direction with the holding portion of the needle in Engagement can be brought. After this positive engagement thus obtained, the needle both are driven in the puncture direction of the plunger (210) as well as active retired. In the illustrated example, the holding area of ​​the lancet on a recess (depression), in the coupling with a projection of the holding device engages, so that the two bodies in Reference are connected largely without play together in the puncture direction.

In Figure 4B, a magazine is shown, which composed of lancing units (220) in accordance with Figure 4A is. With respect to the illustrated coordinate system by the drive ram (210) Movement in the Y-direction (perpendicular to the drawing plane) to the holding area of ​​the lancet in Engagement be brought or the positive connection are also canceled. With uplifted Form-fitting, the drive ram in X direction (right / left) at the level of another Lancet moves and brought by motion in the Y direction again engaged therewith be such that the lancet of the magazine can be successively processed. at existing form-locking is an active movement of the needles in both the positive and negative Z direction (up / down) possible.

As an alternative to the coupling shown in FIG 4B having both a movement of the drive ram in x as required in γ-direction, can also be a coupling motion a movement only in the x direction. The drive ram has for this purpose, for example, two opposite hooks, between which in the x-direction, a passage for the Holding area of ​​the lancet is provided. By movement in x-direction, the plunger will now be moved from lancet to lancet to a sting operation in the z direction perform. the drive ram is in the x-direction at the level of a lancet, so includes the holder of the ram the holding area of ​​the lancet can positively and this be moved out by the plunger in the z direction, the tappet therefore results in a Pricking movement and also draws the lancet back active.

In Figure 5, an automatically operating system is shown with lancing units according to FIG. 1 As can be seen from the top view (Figure 5B), the piercing units (20, 20 'etc) mounted side by side on a conveyor belt. The conveyor belt (301) passes around two spaced- spaced rollers (302, 303). One of the rollers is driven by a motor, so that the lancing units successively by a coupling position (305) moved through will. , As shown in Figure 4a in this position, a positive coupling of an Drive the plunger (10) located on one in the puncturing position (305) lancing unit (20) possible.

Figure 6 shows a drive unit to which a lancing unit analogous to the embodiment in Figure 1 is coupled. The illustrated drive system corresponding to the European Patent Application File number 00102503.0. In this drive system is by pressing a against the tension of a spring (418) comprises a sleeve (414) is rotated axially push button (420), so that a second spring (415) is tensioned. The sleeve (414) is locked in an end position, so that the second spring (415) remains tense. If the user cancels the locking, relaxed the spring (415) and the sleeve (414) is in the opposite direction as when Tensioning process rotated. In the sleeve (414) is a groove that to a guide link for Propulsion cylinder (408) is used, which carries on its outer surface a pin or the like, which engages in the groove. The rotation of the sleeve (414) is in a translation of the Propellant cylinder implemented. The jacking cylinders transfers its traction on the drive ram (480) having a holding area at its front end.

The drive unit further includes a holding area (450) on to which a lancing unit can be plugged or turned. The lancing device includes a cap (470) having a Surface has to the skin surface for pressing. The cap is a sleeve (471) arranged in which a lancet (472) with holding devices on its, the needle tip side facing away. The holding device of the lancet corresponds to the Holding devices (32a, 32b) of the figure 1. From figure 5 can also be seen that a positive connection of the lancet and driving plunger already by attaching the cap (470) is obtained at the drive device.

Figure 7 shows a system for withdrawing body fluids, a plurality of the has similarities to the system shown in FIG. 3 In particular, in the refer Figure 3 and Figure 6 was made describing the drive and clamping mechanism. The System according to Figure 7 has a piercing unit (120 ') with a cap (121') and a lancet (130 ') on. In the cap (121 ') is an axial passage through the Lancet body can pass during the lancing process. Preferably, both through and lancet body adapted to each other that an axial guide of the lancet when Lancing process is given with only slight play in the transverse direction. At its rear end the cap has a thread (126), which on a corresponding thread (127) of the Drive unit (100 ') can be screwed. At the tip of the needle opposite End of the lancet has one or more (in the case 2 shown) pin (131 '), the when placing or unscrewing the cap on the drive unit in the form of an end to the Retaining means (132 ') reach. The holding device has for this purpose a recess or groove to having an axial portion (134a) and a part arranged transversely thereto (134b). At the The cap is placed on the driving unit move the pin (131 ') in the axial portion of the Groove (134) and pass through this to the level of cross arranged part of the groove. By Unscrewing the cap (120 ') on the drive unit (100'), the pin (131 ') from the end of the axial part in the cross-section of the groove proceed to the opposite end. As seen from Figure 7II be seen, the lancet by means of the pin by the retaining device (132 ') is axially supported, so that a guided puncturing movement can be performed with the lancet. By Mounting of the journals in the cross section of the grooves can with the lancet both a motion for Leakage of the needle tip and retraction occur. As is apparent from Figure 7, , the positive connection between the lancet and retaining device can be achieved, without jamming or locking occurs. The coupling principle illustrated in Figure 7 of lancet and driving plunger is of course reciprocal, ie with a corresponding holding device on the lancet and a retaining portion on the plunger or Drive possible.

Figure 9 shows a further development of the system of Figure 1. The drive plunger (10 ') has a holding area (11 ') which has a peripheral inclined surface on its upper side, which As can be seen in Figure 9B, during the lancing process in fit with inclined surfaces of the hooks (32a ', 32b') comes. The end of the drive plunger is seated on the needle end, while the Compressing in itself flexible hooks (32a ', 32b') causes bevels on the Hook inside are pressed against chamfers at the top of the holding area, so that the Holding portion is pressed on the needle end and a backlash in the puncturing direction connection arises from holding area and lancet. This fit can be a very accurate positive retention between the lancet and plunger drive are achieved, (Manufacturing) compensates tolerances, so that both the stitch and in the Retracting movement a game is avoided. The holding device in the form of hooks (32a ', 32b') is further designed so that the free ends engage the hooks in cutouts in the sleeve (40 '). This avoids that the Lancet (30 ') from the sleeve (40' may slip unintentionally). As from the transition from 9A can be seen on Figure 9B, the free ends of the hook at the beginning are the Lancing process first dissolved from the recesses and the hooks at Pushing compressed in the tapered sleeve so as of the holding area Drive ram enclose.

In the Figure 9 can also be seen that the needle tip (31 ') in a material (35) is arranged. This material (35) is preferably an elastomer, which tightly the needle tip surrounds, so that contamination of the needle tip is effectively changed. suitable Elastomers are: styrene oligoblock copolymers, thermoplastic polyolefins, thermoplastic polyurethanes, thermoplastic copolyester and thermoplastic Copolyamides. For further details on this procedure, contamination of avoid lancet tip, is hereby to the international application WO 01/66010 Referring. In the initial position shown in Figure A prior to the closure, is the Needlepoint in the elastomer and, in performing a stitch of the needle pierced, as can be seen from Figure B. For this purpose, the sleeve (40 ') on its underside a Plate (36) on with a central opening. The plate prevents leakage of the elastomer by the opening so that it is pierced, while the needle through the central aperture exits. Upon retraction of the lancet now remains the elastomer to the needle, the Needle tip is exposed (see Figure C).

Figure 10 shows in cross section (Figure A) and in perspective view (Figure B) cylindrical magazine based on the lancet of Figure 1 and Figure 9. With such a Magazine it is possible to attach easily new lancet to the drive. To this end, For example, the drive ram be stationary with respect to a lancing device and the represented in Figure 10, drum-shaped magazine is similarly turned a revolving drum, so that unused lancet reach the position for coupling the drive ram.