Abstract:
The invention relates to a pricking device ( 1 ) for taking a blood sample, comprising a movable holding device ( 10 ) for pricking means ( 5 ), a linear guide element ( 11 ) for guiding the movable holding device, means ( 12 ) for driving the movable holding device and a release device ( 31 ) for releasing the pricking movement ( 6 ) of the pricking means. When the release device has been manually actuated, the movable holding device can be moved in a translatory manner by the drive means. Said drive means comprise a curved path ( 20 ) in which the movable holding means is directly engaged, enabling the pricking device to have a particularly simple structure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Stage Application under 35 U.S.C. §371 of International Application No. PCT/EP2009/056594, filed May 29, 2009, which claims the benefit of German Application No. 102008027267.1, filed Jun. 6, 2008 and German Application No. 102008039111.5, filed Aug. 21, 2008. All three of these applications are hereby incorporated by reference in their entireties. 
     DESCRIPTION 
     The invention concerns firstly a pricking device for taking a blood sample with a moveable holder device for a pricking means, with a linear guide to guide the moveable holder device, with means for driving the moveable holder device and with a trigger device to trigger the pricking movement of the pricking means, wherein after manual activation of the trigger device the moveable holder device can be moved translationally by means of the drive means. Secondly the invention concerns a method for taking a blood sample in which a pricking means is moved forward and then immediately backward, whereby the pricking means can briefly penetrate a body at least with its tip, wherein the pricking aid is guided translationally in a moveable holder device and wherein the moveable holder device is driven by a spring drive. 
     Generic devices are well known from the prior art. They are used preferably for taking blood samples in order to be able to perform medical tests on the blood drop, for example measuring the blood sugar. For this such a device can be placed on a patient&#39;s skin area in order to allow insertion in the skin of a suitable pricking means, such as an interchangeable lancet of the device, whereby after pricking by the pricking means one or more drops of blood can be taken from the damaged capillary vessels in the upper skin layers. In order to reduce the damage to the skin layers as far as possible, such pricking means are often moved forward and back translationally along a pricking axis. For example patent specification U.S. Pat. No. 5,527,334 describes a generic pricking aid in which a needle or lancet is held by a needle holder, wherein the needle holder is mounted mobile linearly between two guide ribs inside the pricking aid. The needle is driven by a tensionable torsion spring which is attached firstly with a first leg end in the housing of the pricking aid and secondly with a second leg end in a moving coupling part of the pricking aid. The coupling part is connected by a first end area by form fit but resiliently with the needle holder and mounted by a second end area in a guide slot. When the torsion spring is released by manual activation of a corresponding trigger device, the second end area of the coupling part can be moved along the guide slot, whereby the coupling part can move the needle holder linearly forward and back. As a result the needle can in turn execute a pricking movement in which the needle tip can briefly accelerate out of the housing of the pricking aid. 
     The object of the invention is to refine such generic pricking devices, frequently also called pricking aids, for taking blood samples. 
     The object of the invention is achieved by a pricking device for taking a blood sample with a moveable holder device for a pricking aid, with a linear guide for guiding the moveable holder device, with means for driving the movable holder device and with a trigger device for triggering a pricking movement of the pricking aid, in which after manual operation of the trigger device the moveable holder device can be moved translationally by means of the drive means, whereby the pricking device is characterised in that the drive means have a curved track in which the moveable holder device engages directly. 
     If the holder device engages directly in a curved track of the drive means, the construction of the pricking device can be kept very simple. Thus the pricking device can be constructed particularly flat. In particular no additional coupling devices are required between the holder device and the drive means, so that smaller masses must be accelerated and/or decelerated during the pricking movement of the pricking aid or holder device. As a result a pricking movement can be performed substantially faster, whereby the puncture pain can be reduced. Advantageously the holder device is driven translationally by means of the curved track so that a translational pricking movement, such as of a lancet, can be achieved by means of the curved track. The curved track serves here as a guide curve for the holder device concerned. 
     Suitable pricking means can be any structure such as lancets or needles which can penetrate suitably easily into the upper skin layers. A pricking means can for example be moved forward and back only along a straight track and/or along a curved track. 
     Evidently the course of the curved track here can be selected and designed in many ways in order to move the holder device advantageously. A movement course along the curved track is particularly simple if the curved track is formed in a closed loop. Consequently an excellent embodiment also provides that the curved track is an endless curved track. In particular the benefits explained in connection with the curved track can also be transferred to the endless curved track. In particular with an endless curved track, the drive means can perform a particularly even drive movement, whereby the pricking result of the pricking means in relation to the body, such as on the upper skin layers, can be substantially improved. 
     In this connection the object of the invention is also achieved by a method for taking a blood sample in which a pricking means is moved forwards and then directly back, whereby the pricking means can penetrate briefly into a body at least with its tip, wherein which the pricking means is guided translationally in a moveable holder device, and wherein the moveable holder device is driven by a spring drive, wherein the moveable holder device is guided directly inside and along an endless curved track of a control curved track element. 
     Advantageously in such a closed endless curved track the holder device moves only in a single peripheral direction, whereby the entire movement kinematics of the mobile components within the pricking device can be simplified. In particular because of such movement kinematics, the reverberation of the pricking means on the pricking movement can be reduced or ideally even fully excluded, whereby the risk of secondary pricking by the pricking means can be further reduced. As a result the pricking process can take place substantially less painfully. To this extent the taking of a blood sample can be made substantially more comfortable for the patient. 
     The spring drive can be provided easily and very compactly if the drive means comprise a spring element for storage of energy. 
     Preferably the spring element can be constructed relatively flat as a leg spring. 
     Furthermore an advantageous method variant provides that the holder device is moved only in a single peripheral direction along the curved track both on the forward movement of the pricking means and on the return movement of the pricking means. In particular this extremely effectively reduces the risk of reverberation of the moveable holding device. 
     A preferred embodiment variant in this respect thus provides that the drive means comprise a curved track element which comprises the endless curved track. This allows particularly good guidance of the endless curved track. 
     If the control curved track element of the drive means is mounted swivelably about a swivel axis, the holder device can be mounted so that it is easily moveable translationally on the linear guide. 
     Therefore with regard to a further advantageous method variant, it is provided that the curved track is swivelled along an arc section about a swivel axis, whereby the moveable holder device is moved translationally. A swivel movement in this respect can be initiated advantageously by means of a leg spring. 
     If also the spring element is mounted on a swivel axis of a control curved track element, the construction of the present pricking device can be further simplified. 
     Preferably the curved track is formed oval, whereby an acceleration and speed profile with regard to the holder device of the pricking means can be further influenced. In particular the holder device can be accelerated substantially better in straighter sections of an oval curved track, so that as a result in particular a faster forward movement of the pricking aid or holder device can be achieved. This is presumably because in the straighter areas of the oval curved track, there is less friction between the holder device and the guide areas of the curved track. 
     A further advantageous embodiment provides that the curved track has a side guiding element within which the holder device is at least partly arranged and guided. If the curved track has a side guiding element, for example in the form of a groove, the holder device can be guided particularly reliably along the curved track. 
     The holder device can engage particularly simply in the curved track, in particular in the guiding element, if the holder device has a curve follower. Such a curve follower can very easily be produced by means of a guide peg which engages in the guiding element. Preferably the guide peg is formed by the holder device itself. For example a curve follower is moulded on the holder device in an injection moulding method. Evidently the curve follower can also be connected with the holder device in another way. 
     If the curve follower of the holder device can always only move in one peripheral direction along the curved track both on the translational forward movement of the holder device and on the translational return movement of the holder device, only by means of the present holder device can an essentially circular drive motion be transferred directly into a linear output movement. 
     Such a transfer of movement can be achieved very well if a curve follower of the holder device is arranged inside a profile of a curved track such that the curve follower is mounted mobile inside the profile only in a single peripheral direction along the curved track. Also the movement kinematics of the pricking means on a pricking device can be executed advantageously. 
     In particular a good trigger safety of the present pricking device can be guaranteed if the curve follower of the holder device is arranged in a starting position inside the curved track, and the curved track with regard to the starting position has a inlet area for the curve follower and an outlet area for the curve follower, wherein the inlet area and outlet area are different. The operating reliability of the pricking device can be further improved if the curve follower is in a starting position such that when the pricking device is in a state ready for operation, on triggering of the pricking device the curve follower can move out of the start position over the outlet area, and after the pricking means has performed a pricking movement, it can return via the inlet area to the starting position. 
     Further advantages, objectives and properties of the present invention are explained in the description below with reference to the enclosed drawing which shows as an example a pricking device for taking a blood sample with a pricking means which can be operated repeatedly. 
    
    
     
       The drawing shows: 
         FIG. 1  diagrammatically a first cross-section view of a pricking device for taking a blood sample in a state ready for operation in which a curve follower of a holder device is arranged in a starting position inside a curved track of a control curved track element; 
         FIG. 2  diagrammatically a further cross-section view of the pricking device in the state ready for operation of  FIG. 1 ; 
         FIG. 3  diagrammatically a perspective cross-section view of the pricking device in the state ready for operation of  FIGS. 1 and 2 ; 
         FIG. 4  diagrammatically a cross-section view of the pricking device in a pricking position of a pricking means of the pricking device; 
         FIG. 5  diagrammatically a further cross-section view of the pricking device in the pricking position in  FIG. 4 ; 
         FIG. 6  diagrammatically a cross-section view of the pricking device in a rest position after performing a pricking movement and in an untensioned state; 
         FIG. 7  diagrammatically a cross-section view of a pricking device during a pricking process with spring drive again tensioned, and 
         FIG. 8  diagrammatically a perspective view of the housing of the pricking device from  FIGS. 1 to 7 . 
     
    
    
     The pricking device  1  shown in  FIGS. 1 to 8  for taking blood samples has a flat housing  2  (see in particular  FIG. 8 ) on the underside  3  of which a treatment opening  4  is provided through which for treatment a pricking means  5  can be accelerated briefly out of a housing interior  7  of the pricking device  1  in a pricking movement  6  (see  FIGS. 4 and 5 ). The pricking device  1  is a pricking device  1  which can be operated repeatedly, which after successful pricking, allows the pricking means  5  to be retracted again into the housing  2  immediately and then the pricking device  1  can be pre-tensioned again in order to be operated a second time. 
     The pricking means  5  in the form of a pricking needle  8 , after successfully piercing the upper skin layer of a patient, is retracted again immediately into the flat housing  2  so there is no further risk of injury from the tip  9  of the pricking needle  8 . 
     The pricking means  5  is held by a suitable moveable holder device  10 , often called a lancet holder, wherein the moveable holder device  10  can be moved forward and back translationally by means of a linear guide  11  along a fictitious pricking axis which is embodied by the pricking needle  8 . 
     So that the pricking means  5  can ideally always perform an almost identical pricking movement  6 , the pricking device  1  has further means  12  for driving the moveable holder device  10 . 
     These drive means  12  in this embodiment example comprise in particular a control curved track element  13  and a spring element  14  in the form of a leg spring  15 . The spring element  14  is here clamped with a first leg  16  in a housing holder  17  and with a second leg  18  in a holder  19  of the control curved track element  13  so that it can be tensioned. 
     The drive means  12  furthermore have a curved track  20  in which the moveable holder device  10  engages directly. The curved track  20  is here allocated to the control curved track element  13 . So that the holder device  10  can follow the curved track  20  reliably when the control curved track element  13  is swivelled about a swivel axis  21 , the holder device  10  forms a curve follower  22  which is arranged in a guiding element  23  of the curved track  20 . The curved track  20  in itself is formed as an oval endless curved track  24  on the control curved track element  13  so that the curve follower  22  can also follow the curved track  20  endlessly in just one direction. 
     In order to be able to move the control curved track element  13  manually such that the spring element  14  can be pre-tensioned with a sufficiently great spring force, on the top  25  of the flat housing  2  is provided a manually activatable button  26  which can be pressed into the flat housing  2  along arrow direction  27 . During such activation the curved track element  13  can be moved, the spring element  14  pre-tensioned and the entire pricking device  1  transferred to a tensioned state ready for operation as shown in  FIG. 1 . During the tensioning process a button element bar  28  of the manually activatable button element  26  can press against a projection  29  of the control curved track element  13 , whereby the control curved track element  13  is swivelled about the swivel axis  21 . As a result the spring element  14  is tensioned. The button element  26  can then be moved back to its starting position (see  FIG. 1 ) by means of a coil spring  30 . 
     In order to be able to trigger the pricking device  1 , the pricking device  1  has a suitable trigger device  31  which comprises a pusher  32  (see for examples  FIGS. 2 and 3 ) with a locking arm  33 . The locking arm  33  can suitably correspond with the moveable holder device  10  so that the moveable holder device  10  is locked with the locking arm  33 , in particular when the spring element  14  is pre-tensioned. As a result a pricking movement  6  can be prevented as long as the pusher  32  of the trigger device  31  is not activated and the trigger device  31  is not triggered. 
     According to the depictions in  FIGS. 1 to 3 , the pricking device  1  is in a tensioned state ready for operation in which the curve follower  22  inside the guiding element  23  is in a starting position  34  on the curved track  20 . The geometries and interplay of the control curved track element  13 , curved track  20 , the swivel ability  35  of the control curved track element  13  and hence the curved track  20 , the holder device  10  and the curve follower  22  are selected such that the curve follower  22  can move only in one peripheral direction  36  along the curved track  20 . In particular as a result it can be guaranteed that the holding device  10  with the pricking means  5  cannot reverberate after the actual pricking movement  6 , so it is ensured that per activation of the pricking device  1 , the pricking means  5  can only reach through the treatment opening  4  a single time. 
     To trigger the pricking device  1  ready for operation, the pusher  32  is activated manually whereby the locking arm  33  releases the control curved track element  13 . The holder device  10  can then perform a translational forward movement  37  (see  FIG. 4 ) in the sense of the pricking movement  6 , initiating the translational forward movement  37  and associated possible pressurisation of the pricking means  5  by the spring force or a spring movement  38  of the expanding leg spring  15  or the spring movement  38  of the second leg  18  of the spring leg  15 . The spring movement  38  swivels the control curved track element  13  about the swivel axis  21 . The control curved track element  13  is thus guided additionally in a guide  39  along an arc section  40 . 
     Due to the swivel movement of the control track element  13 , the curve follower  22  follows the curved track  20  along peripheral direction  36  and the holding device  10  with pricking means  5  can perform the pricking movement  6 . According to the depictions in  FIGS. 4 and 5 , the pricking device  1  is shown in a pricking state in which the holder device  10  is deflected to a maximum in its translation forward movement  37 . The curve follower  22  is here in a position closest to the treatment opening  4 . 
     Advantageously on a translational return movement  41  of the holder device  10 , at the same time the curve follower  22  is guided in the continued forward peripheral direction  36 , as shown in particular in the view in  FIG. 4 . This immediate translational return movement  41  is also made possible by the still expanding leg spring  15 . Consequently there is never an essentially reversed movement of the curve follower  22  within the curved track  20  of the control curved track element  13 . Rather the curve follower  22  always moves further in the clockwise direction along the curved track  20  until the pricking device  1  reaches a rest state in an untensioned state, as shown in the view in  FIG. 6 . 
     Now the pricking device  1  can be re-tensioned for a further pricking movement  6  in that the manually activatable button element  26  is pushed in direction of arrow  27 , whereby the spring element  14  can be re-tensioned i.e. compressed with a tension movement  42 . In this tensioning process the curve follower  22  moves further along the curved track  20  in the peripheral direction  36  until the curve follower  22  has moved back to its starting position  34 , the spring element  14  is pre-tensioned and the pricking device  1  is again ready for use as shown in the view in  FIG. 7 . Here too an inlet area  43  for the curve follower  22  on the curved track  20  and an outlet area  44  for the curve follower  22  on the curved track  22  are marked. The curve follower  22  runs through the outlet area  44  only when the pricking device  1  is triggered, when the curve follower  22  leaves its starting position. Curve follower  22  only runs through the inlet area  43  when the pricking device  1  or spring element  14  is tensioned and the curve follower  22  is moved into the starting position  34 . To this extent the inlet area  43  and outlet area  44  are different areas of the curved track  20 . 
     Advantageously the holder device  10  with the present pricking device  1  engages directly in the curved track  20  so that a rotational movement of swivel movement of the control curved track element  13  can be converted directly with very little loss into a translational pricking movement  6  of the holding device  10 . 
     Advantageously a substantially oval curved track is used here with regard to the control curved track element  13  in order to allow maximum acceleration of the curve follower  22  and hence the pricking means  5  in the forward and subsequently in the reverse direction in the straighter sections of the substantially oval curved track  20 . This ideally allows a further reduction of the puncture pain. 
     The curved track  20  essentially serves as a guide curve for the holding device  10  and its triggering. Thus the pricking means  5  can only pierce the skin once and not—as in previous spring-guided systems—lead to reverberation and thus secondary pricking or repeated piercing of the skin. Also the entire structure of the present pricking device  1  advantageously has a particularly flat design as all essentially moveable components can be formed flat and are low in number. In particular only one curve follower  22  is required, which is also arranged in a guiding element  23  and thus requires no additional construction height inside the pricking device  1 . 
     All features disclosed in the application documents are claimed as essential to the invention as they where novel individually or in combination in relation to the prior art. 
     List of References 
     
         
           1 . Pricking device 
           2 . Housing 
           3 . Underside 
           4 . Treatment opening 
           5 . Pricking means 
           6 . Pricking movement 
           7 . Housing interior 
           8 . Pricking needle 
           9 . Pricking needle tip 
           10 . Moveable holder device 
           11 . Linear guide 
           12 . Drive means 
           13 . Control curved track element 
           14 . Spring element 
           15 . Leg spring 
           16 . First leg 
           17 . Housing holder 
           18 . Second leg 
           19 . Holder of control curved track element 
           20 . Curved track 
           21 . Swivel axis 
           22 . Curve follower 
           23 . Guiding element 
           24 . Endless curved track 
           25 . Top side 
           26 . Manually activatable button element 
           27 . Arrow direction 
           28 . Button element bar 
           29 . Projection 
           30 . Coil spring 
           31 . Trigger device 
           32 . Trigger 
           33 . Locking arm 
           34 . Starting position 
           35 . Swivel capacity 
           36 . Peripheral direction 
           37 . Translational forward movement 
           38 . Spring movement 
           39 . Guide 
           40 . Arc section 
           41 . Translational return movement 
           42 . Tension movement 
           43 . Inlet area 
           44 . Outlet area