DE102006061262B3 - Piercing device for taking blood from part of body e.g. finger, for diagnosing e.g. diabetes, has overload protection that is formed by drive spring and spring support for preventing overloading of drive spring using overload protection - Google Patents

Abstract

The device has a housing with an opening for attachment to a part of a body, and a rotor unit (9) with a drive spring (10) supported between a drive unit i.e. drive rotor (18), and a clamping unit i.e. clamping rotor (8), such that the spring is supported at the clamping unit in a clamped condition and at the drive unit with a spring support (25). An overload protection is formed by the drive spring and the spring support for preventing overloading of the drive spring with the help of the overload protection.

Description

The The invention relates to a puncturing device for taking blood for Diagnostic purposes with a housing with an opening for attachment to a body part and with a rotor unit comprising a drive element, a tensioning element and a drive spring, wherein the drive spring between the elements is mounted so that they are at least in the tense Condition on the one hand on the clamping element and on the other hand on the drive element each with a spring support supported.

Around for diagnostic Purpose a small amount of blood from a body part, such as the Finger, to be taken, are lancets for creating a wound into the corresponding body part stung. For this purpose, punches are used. By means of a Lancet drive of the lancing device The lancet is mechanically pricked into the skin. As drive element the puncturing movement is a spring. Punches and lancets are common Matched components of a lancing system. In simple devices is in an oblong casing arranged compression spring attached directly attached to the lancet are.

such simple punches bump on little acceptance and can the high requirements do not meet, if regular monitoring certain analytical values of the blood is required as this for example Diabetics are the ones who are supposed to control their blood sugar levels frequently. Only then is it possible an adjustment of insulin injections to the blood sugar level to meet needs. The one for this used devices, the on a big one Accept acceptance should presuppose that the puncture with the least possible pain connected is. This goal is achieved, for example, by that lancing equipment are used, in which the fastest possible puncture takes place and the lancet after reaching a predetermined lancing depth again withdrawn against the puncture direction.

Such puncturing devices feature usually over a rotor drive in which a tensioning rotor biases a spiral spring. The relief of the tension spring triggers the lancing process, wherein the rotational movement of the coil spring in a translational movement of the lancet in the direction of puncture and after reaching the reversal point against the puncture direction is implemented.

Such systems are known in the art and are used for example in the EP 1 504 718 A2 described. In this system, a tension rotor is rotated by a coil spring is wound. By actuating a trigger mechanism, the preloaded coil spring relaxes so that the lancet performs a puncture movement along a puncture path. The puncturing movement is controlled by a path control, wherein the puncturing movement is defined by the formation of a control cam.

Of the Tension rotor and the drive spring form together with a drive rotor a rotor unit. The drive rotor acts on the lancet in such a way that via a Coupling mechanism the movement of the drive rotor in the puncture movement the lancet is implemented. Such a rotor unit is in lancing devices but also used to move other functional elements. For example it is known to move a reference element by means of the rotor unit, which is used to adjust the lancing depth of the lancet. For punches, which also comprise an analysis unit in addition to the lancing unit Rotor units used to the analysis unit after the puncture in the body part the housing opening of the lancing device to move so that the blood exiting the wound is absorbed can be.

The Rotor units is always in common that their faulty operation or the incorrect operation of the tensioning rotor to overstress the drive spring to lead can. This may cause damage the drive spring or the rotor unit result. When the power spring is designed as a spiral spring, the clamping by the maximum possible twist angle limited the spiral spring. If the maximum angle of rotation is reached, so moving on is not possible without any damage on the device enter.

Out The prior art thus results in the problem of proposing a puncturing device, in which a spanning a clamping mechanism can be easily prevented. The clamping mechanism should over it also inexpensive and be robust.

Is solved the present problem by an inventive lancing device with the Features of claim 1.

The puncturing device according to the invention for taking blood from a body part for diagnostic purposes has a housing with an opening for engagement with a body part and a lancet, which is movable in the housing along a predetermined Einichweges. A rotor unit of the puncturing device comprises a drive element, a tensioning element and a drive spring. The drive spring is mounted between the two elements such that it is supported at least in the tensioned state on the one hand to the clamping element and on the other hand to the drive element, each with a spring support. The lancing device has an overload protection, the is formed by means of the drive spring and at least one of the spring supports between the drive spring and one of the elements. As a result, an overload of the drive spring is prevented.

The Drive element and the clamping element are components of the rotor unit. These functional elements can each be multi-part, so consist of several components. she are not understood as an item. The two are preferred Elements rotors, so that the drive element as a drive rotor and the tensioning element is designed as a tensioning rotor of the rotor unit are.

The The puncher according to the invention has the Advantage on that overstretching the spring by repeatedly pressing the tensioning element or the tensioning rotor is prevented, since the overload protection triggers. Advantageous is the overload protection as realized a kind of slip clutch. The spring support between the drive spring and the tensioning rotor or the drive rotor can by traction, by a strong concern or friction between the spring and the elements, by adhesion or by a positive fit, For example, hooking into a trained eyelet are generated. Further the person skilled in known compounds that occur when crossing solve an occurring force, can be used between the drive spring and the rotors.

at the lancing devices known in the prior art can by repeated Actuate the tension rotor are spanned the drive spring, so that damage occur. The repeated actuation leads the clamping rotor to a multiple tensioning of the drive spring, before these in her stored energy transfers to the drive rotor, in turn, the movement a functional element of the puncturing device drives, such as a lancing depth reference element or integrated in the lancing device Analysis unit.

Of the overload protection according to the invention, the drive spring and at least one spring support between the drive spring and one of the rotors, so the drive rotor or the tensioning rotor, reliably prevents over-tensioning and thus overloading the power spring, the overload protection triggers. It is of particular advantage that the overload protection only from two Elements, namely the drive spring and one of the rotors is formed. There are not any additional elements necessary to exclude an overload on the spring. damage the spring and / or other parts of the rotor unit are reliably excluded. This will be the overall reliability of the lancing device elevated. The training of overload protection by means of the drive spring and at least one of the spring supports has a high robustness and is against tolerances of the supports and the spring very insensitive.

Preferably, the rotor unit is used for driving the lancet of the puncturing device. The drive rotor is preferably coupled to the lancet via a coupling mechanism such that during relaxation of the drive spring, the lancet is moved at a high speed in a predetermined puncture path until the lancet, upon reaching a reversal point of movement with its tip, forms a wound in the opening of the lancing device adjacent body part generated. The driven by the drive spring drive rotor is rotatable about an axis, so that the rotational movement of the drive rotor is converted by the coupling mechanism in the puncturing movement of the lancet. This type of coupling between lancet and drive rotor is for example in the EP 1504718 A2 described. The additional formation of an overload protection in the lancing device means that incorrect applications are precluded by repeated tensioning of the tensioning rotor before the puncture of the lancet. However, the lancing operation is not affected by the overload protection. Also, the user is not affected by the operation, so that he perceives no difference to the previously used lancing devices.

• a) Der Überlastschutz wird durch eine Federabstützung zwischen der Antriebsfeder und dem Antriebsrotor gebildet. In dieser bevorzugten Ausführungsform ist die Federabstützung derart gebildet, dass bei Überschreiten eines vorbestimmten Wertes einer von dem Spannrotor auf die Antriebsfeder ausgeübten Spannkraft die Antriebsfeder eine Drehbewegung in Wirkrichtung der Spannkraft relativ zu dem Antriebsrotor ausführt. Es kommt somit zu einem Durchrutschen der Antriebsfeder relativ zu dem Antriebsrotor, wobei sich die Antriebsfeder bevorzugt um 360° dreht, da sie unter Vorspannung steht und nach der 360°-Umdrehung von der Federabstützung wieder gefangen wird.
• b) Die Federabstützung wird zwischen der Antriebsfeder und dem Spannrotor gebildet. In dieser ebenfalls bevorzugten Ausführungsform ist die Federabstützung der Antriebsfeder an dem Spannrotor so ausgebildet, dass bei Überschreiten eines vorbestimmten Wertes einer von dem Spannrotor auf die Antriebsfeder ausgeübten Spannkraft die Antriebsfeder eine Drehbewegung entgegen der Wirkrichtung der Spannkraft relativ zu dem Spannrotor ausführt. Somit ergibt sich also ein Durchrutschen des Spannrotors gegenüber der Antriebsfeder. Die Antriebsfeder verharrt in ihrem Zustand, während der Spannrotor weiterbewegt wird.
• c) Im Gegensatz zu den unter a) und b) skizzierten Federabstützungen an einem Rotor ist auch eine aufwendigere Ausführungsform möglich, bei der eine Federabstützung der Antriebsfeder sowohl an dem Spannrotor wie auch an dem Antriebsrotor stattfindet. Bei dieser Ausführungsform kann durch eine angepasste Ausbildung der beiden Federabstützungen auf besondere Gegebenheiten der Rotoreinheit bzw. der von dem Antriebsrotor angetriebenen Funktionselemente Rechnung getragen werden. Beispielsweise kann beim Antrieb einer Analyseeinheit im Stechgerät abhängig von ihrer Position die eine oder andere Federabstützung als Überlastschutz wirken.

The overload protection of the puncturing device is formed by means of the drive spring and at least one of the spring supports between the drive spring and one of the rotors. This results in three possible embodiments:

• a) The overload protection is formed by a spring support between the drive spring and the drive rotor. In this preferred embodiment, the spring support is formed such that when a predetermined value of a force exerted by the tensioning rotor on the drive spring tension force is exceeded, the drive spring performs a rotational movement in the effective direction of the clamping force relative to the drive rotor. It thus comes to a slippage of the drive spring relative to the drive rotor, wherein the drive spring preferably rotates through 360 °, since it is under bias and is caught by the 360 ° rotation of the spring support again.
• b) The spring support is formed between the drive spring and the tensioning rotor. In this likewise preferred embodiment, the spring support of the drive spring is formed on the tensioning rotor so that when a predetermined value of a tensioning rotor exerted on the drive spring tension force is exceeded, the drive spring performs a rotational movement counter to the effective direction of the clamping force relative to the tensioning rotor. Thus results So slipping of the clamping rotor relative to the drive spring. The drive spring remains in its state while the tension rotor is moved on.
• c) In contrast to the sketched under a) and b) spring supports on a rotor and a more complex embodiment is possible in which a spring support of the drive spring takes place both on the tensioning rotor as well as on the drive rotor. In this embodiment, due to an adapted design of the two spring supports, special circumstances of the rotor unit or of the functional elements driven by the drive rotor can be taken into account. For example, when driving an analysis unit in the lancing device depending on their position, one or the other spring support act as overload protection.

In a further preferred embodiment the drive spring is a spiral spring, with which also the under a) realized to c) described advantageous embodiments of the spring support can be. The above supports are independent of whether the tensioning rotor at the inner end of the coil spring and the Drive rotor at the outer end supported or the other way around.

The The invention will be described in the following with reference to the figures embodiments explained in more detail. The Particularities shown there may be individually or in combination used to preferred embodiments of the invention create. The illustrated embodiments however, they are not limiting by the claims It shows:

1 a partially cutaway perspective view of a puncturing device according to the invention;

2 a perspective view of a rotor unit of the in the puncturing device according to 1 used lancet drive;

3 a sectional view through the rotor unit according to 2 with a coil spring;

4 a detailed view of the outer end of the coil spring of the rotor unit;

5 the spiral spring out 3 in uninstalled, relaxed state as a top view and

6 a detailed drawing of a bending portion of the coil spring.

The puncturing device shown in the figures 1 includes an elongated housing 2 with a cap 3 at one end. The cap 3 has an opening 4 on which a body part is applied, in which a wound is to be produced. One in the case 2 movable lancet is from a lancet drive shown here only partially 5 at high speed in Einstechrichtung on the opening 4 to move until the tip of the lancet in the at the opening 4 adjacent body part punctures. 1 shows the puncturing device, in which a rotor unit 9 Part of the lancet drive 5 is.

The 1 to 6 illustrate the design features of the rotor unit 9 of the lancet drive 5 , With the lancet drive 5 acts a clamping device 6 together, the rotor unit 9 tensioned so that the energy stored therein on the lancet drive 5 can be transferred to move the lancet in the puncture direction. During the clamping phase of the lancing device 1 is the on a tension knob 7 applied force by means of the clamping device 6 on the rotor unit 9 transferring a tensioning rotor 8th , a power spring 10 and a drive rotor 18 includes. The tension rotor 8th and the drive rotor 18 are rotatable about a common axis perpendicular to the puncture direction and perpendicular to the longitudinal axis of the housing 2 runs. During tensioning drives the clamping device 6 the tensioning rotor 8th on, whose clamping force on the drive spring 10 is transmitted. During the propulsion phase of the lancing of the lancet, the drive spring relaxes 10 and thereby drives the drive rotor 18 whose rotational movement is in turn converted into the translational puncturing movement of the lancet.

For tensioning the lancet drive 5 becomes the translationally moving tension knob 7 and with him a power transmission part 11 towards the opening 4 too moved. A rack 12 is part of the power transmission part 11 and moves in with the tensioning rotor 8th coaxial pinion 13 , The pinion 13 is with the tensioning rotor 8th over a freewheel 31 connected such that both parts are coupled together during the clamping movement. During the return of the power transmission part 11 and the tension knob 7 against the puncture direction under the action of a return spring 14 are the pinion 13 and the tensioning rotor 8th on the other hand decoupled. The freewheel 31 is in this embodiment by means of two elastic tongues 15 realized with the pinion 13 are connected.

By rotation of the clamping rotor 8th becomes the drive spring 10 curious, as a spiral spring 16 is trained. The spiral spring 16 is in a rotor housing 17 the rotor unit 9 stored, whose wall 21 the spiral spring 16 enclose. The rotor housing 17 is either on the tensioning rotor 8th or on a drive rotor 18 educated. In a preferred embodiment, therefore, one of the both rotors 8th . 18 a trough-shaped depression 19 on, which is designed such that the drive spring 10 is stored therein. The drive spring 10 is doing by the circumferential wall 21 the trough-shaped depression 19 enclosed. The trough-shaped depression 19 is part of the rotor housing 17 ,

In 3 is such a rotor unit 9 shown in which the rotor housing 17 a component of the drive rotor 18 is. The trough-shaped depression 19 makes a recording 20 into which the spiral spring 16 is inserted in such a way that it from the wall 21 the depression 19 is enclosed circumferentially.

Preferably, the outer end extends 26 the spiral spring 16 when installed inside the trough-shaped depression 19 along the outside of the coil spring such that a bending section 24 the spiral spring 16 at one in the trough-shaped depression 19 trained and inwardly directed cam 22 is applied. The cam 22 is as a projection in the wall 21 the depression 19 educated. The cam 22 protrudes radially inwards and points to the center of the rotor housing 17 out. To the cam 22 closes a bulge 23 on, which is the interior of the recess 19 increased. Here is the wall thickness of the wall 21 is in the area of the bulge 23 reduced.

In the bulge 23 a part of the bending section protrudes 24 the spiral spring 16 into it. Another part of the bending section 24 is located on the cam 22 on, leaving a spring support 25 between the drive spring 10 and the drive rotor 18 is formed.

From the outer end 26 the spiral spring 16 up to the bending section 24 a brake section extends 27 , In the embodiment shown, the bending section 24 from the brake section 27 includes.

When tensioning the coil spring 16 engages the tensioning rotor 8th , of which only a part is shown, to the inner end 28 the spiral spring 16 at. By turning the clamping rotor 8th counterclockwise becomes the inner end 28 the spiral spring 16 twisted so that it is stretched. Is preferably a predetermined angle of rotation of the coil spring 16 or alternatively a predefined value of the tension rotor 8th on the coil spring 16 Exceeded applied clamping force, so exceeds the on the coil spring 16 applied force the holding force of the spring support 25 , The bending section 24 is elastically deformed and slips on the cam 22 in the direction of clockwise, which corresponds to the effective direction of the clamping force. The from the cam 22 and the bending section 24 formed slip clutch triggers and slips through.

Preferably, therefore, the spring support 25 the drive spring 10 on the drive rotor 18 such that, when a predetermined value is exceeded, one of the tensioning rotor 8th on the drive spring 10 applied clamping force the drive spring 10 a rotational movement in the effective direction of the clamping force relative to the drive rotor 18 performs. The slip clutch formed thereby prevents damage to the drive spring 10 , the drive rotor 18 or the tension rotor 8th or the clamping device 6 , On the normal lancing operation of the lancing device 1 However, the slip clutch has no influence.

When the slip clutch triggers, the bending section will slip 24 and the brake section 27 at the cam 22 past and then along the wall 21 of the rotor housing. The sliding friction between the brake section 27 and the wall 21 Brakes the rotational movement of the drive spring 10 in the depression 19 of the drive rotor 18 from. After a 360 ° turn of the drive spring 10 the bending section arrives 24 in the bulge 23 of the rotor housing 17 and expands upon reaching the bulge 23 in the radial direction of the rotor housing 17 until he finally got to the nock 22 comes to a standstill, causing the rotational movement of the drive spring 10 is ended. From the 360 ° revolution of the drive spring 10 in the effective direction of the clamping force results in a reduction of the spiral spring 16 acting clamping force. Only on further rotation of the tensioning rotor 8th and thus at a further tensioning of the drive spring 10 the predetermined value of the clamping force can be exceeded again, so that the slip clutch triggers again and the drive spring 10 slip past the cam.

The braking effect of the drive spring 10 when slipping through the length of the brake section 27 influenced. Another influencing factor is the outer spring end 26 the spiral spring 16 , This is preferably slightly bent inward in the last millimeters, particularly preferably in the last 1.5 mm. During the rotation of the drive spring 10 thereby lies the spring end 26 not on the wall 21 of the rotor housing 17 at. This avoids an increased friction of the drive spring 10 or its outer end 26 on the wall 21 is generated, which could lead to a deceleration of the rotational movement of the spring to a standstill. The outer end 26 is in 4 shown in detail. The bent outer end 26 the spiral spring 16 additionally has an advantageous effect on the noise, which is thereby reduced.

5 shows that as a spiral spring 16 trained drive spring 10 as delivered, when relaxed and not in the rotor housing 17 the rotor unit 9 is installed. The outer turn 32 the spiral spring 16 differs markedly from the other turns and points clearly to the outside. It is directed outwards so that a sufficiently high contact pressure of the spring against the wall 21 of the rotor housing 17 after installation arises. The outer turn 32 presses the bending section 24 consequently to the hump-like cam 22 of the drive rotor 18 so that a desired spring support 25 between the drive spring 10 and the drive rotor 18 arises.

The bending section 24 preferably comprises a first outwardly bent portion 29 and a second inwardly bent portion 30 , He is so trained that the outer end 26 the spiral spring 16 in the relaxed state towards the center of the drive spring 10 is aligned. The length of the brake section 27 and the formation of the outer coil 32 the spiral spring 16 are such that the outer end 26 to the inner end 28 comes up to a small gap.

The formation of the bending section 24 who in 6 is shown in detail, is one of the main factors influencing the spring support 25 and the slip clutch of the rotor unit 9 , The one between the outer winding 32 the spiral spring 16 and the first section 29 formed angle α is preferably in a range between 140 ° and 160 °, with an angle of 150 ° is particularly preferred. This angle α has a high influence on the so-called release angle, the rotation angle at which triggers the clutch and the drive spring 10 opposite the drive rotor 18 is twisted in the effective direction of the clamping force. The trigger angle reflects the predetermined value of the clamping force whose achievement causes the release of the spring support. The release angle of the coil spring shown in the embodiment 16 is 660 ° with a tolerance range of +/- 140 °. The rotor unit 9 holding this spiral spring 16 with an angle α of 150 °, works very reliably and is insensitive to tolerances and other manufacturing variations.

1

lancing device

2

casing

3

cap

4

opening

5

Lancet drive

6

tensioning device

7

tension knob

8th

tensioning rotor

9

rotor unit

10

driving spring

11

Power train

12

rack

13

pinion

14

Return spring

15

tongue

16

spiral spring

17

rotor housing

18

drive rotor

19

deepening

20

admission

21

wall

22

cam

23

bulge

24

bending section

25

spring support

26

outer end

27

braking section

28

inner The End

29

first outward directed section

30

second inward section

31

freewheel

32

outer turn

Claims (10)

Puncture device ( 1 ) for taking blood from a body part for diagnostic purposes, having a housing ( 2 ) with an opening ( 4 ) for abutment with a body part, a rotor unit having a drive element, a tensioning element and a drive spring ( 10 ), wherein the drive spring ( 10 ) is mounted between the elements such that they at least in the tensioned state on the one hand on the clamping element and on the other hand on the drive element, each with a spring support ( 25 ), characterized in that the puncturing device ( 1 ) one by means of the drive spring ( 10 ) and at least one of the spring supports ( 25 ) has formed overload protection, by which an overload of the drive spring ( 10 ) is prevented. Latching device according to claim 1, characterized in that the drive element is a drive rotor ( 18 ) and the tensioning element a tensioning rotor ( 8th ). Latching device according to claim 2, characterized in that the drive rotor ( 18 ) via a coupling mechanism in such a way with a in the housing ( 2 ) is coupled along a predetermined insertion path movable lancet, that the lancet during the relaxation of the drive spring ( 10 ) is moved at a high speed in the predetermined puncture path until reaching a reversal point of the movement at which the tip of the lancet has a wound in the at the opening ( 4 ) created adjacent body part, wherein the rotatable about an axis drive rotor ( 18 ) of the drive spring ( 10 ) is moved so that the rotational movement of the drive rotor ( 18 ) is converted by the coupling mechanism into the puncturing movement of the lancet. Lancing device according to claim 2 or 3, characterized in that the spring support of the drive spring ( 10 ) on the drive rotor ( 18 ) is designed such that when a predetermined value is exceeded, one of the tensioning rotor ( 8th ) on the drive spring ( 10 ) applied tension force the drive spring ( 10 ) a rotational movement in the effective direction of the clamping force relative to the drive rotor ( 18 ). Lancing device according to claim 2 or 3, characterized in that the spring support of the drive spring ( 10 ) on the tensioning rotor ( 8th ) is designed such that when a predetermined value is exceeded, one of the tensioning rotor ( 8th ) on the drive spring ( 10 ) applied spring force the drive spring ( 10 ) a rotational movement counter to the effective direction of the clamping force relative to the tensioning rotor ( 8th ). Lancing device according to claim 4 or 5, characterized in that the drive spring ( 10 ) as a spiral spring ( 16 ) is formed and a brake section ( 27 ) such that the rotational movement of the drive spring ( 10 ) is slowed down when a predetermined value of the applied tension force is exceeded relative to the one rotor. Latching device according to one of the preceding claims, characterized in that the drive spring ( 10 ) as a spiral spring ( 16 ) is formed, which in the region of one of its ends a bending section ( 24 ) such that one end of the drive spring ( 10 ) in the relaxed, unassembled state of the drive spring ( 10 ) towards its center. Lancing device according to claim 7, characterized in that one of the rotors with a trough-shaped depression ( 19 ) is designed such that the drive spring ( 10 ) is mounted therein, wherein the drive spring ( 10 ) of a circumferential wall of the trough-shaped depression ( 19 ) is enclosed. Lancing device according to claim 8, characterized in that the outer end of the spiral spring ( 16 ) in the installed state within the trough-shaped depression ( 19 ) along the outside of the coil spring ( 16 ) such that the bending section ( 24 ) of the spiral spring ( 16 ) at one in the trough-shaped depression ( 19 ) formed and inwardly directed cam ( 22 ) is present. Lancing device according to one of claims 7 to 9, characterized in that the bending section ( 24 ) comprises a first outwardly bent portion and a second inwardly bent portion.