CA2494895A1

CA2494895A1 - Process for manufacturing an analytical device containing lancet and test element

Info

Publication number: CA2494895A1
Application number: CA002494895A
Authority: CA
Inventors: Hans-Juergen Kuhr; Michael Fritz; Thomas Weiss; Richard Forster
Original assignee: F. Hoffmann-La Roche Ag; Hans-Juergen Kuhr; Michael Fritz; Thomas Weiss; Richard Forster
Current assignee: F Hoffmann La Roche AG
Priority date: 2001-08-29
Filing date: 2002-08-27
Publication date: 2003-02-28
Also published as: US9215993B2; DE10142232B4; JP2005185852A; EP1466558A3; US20130239390A1; ATE406839T1; EP1287785A1; EP1466558B2; JP2003153885A; EP1287785B1; DE50212744D1; ES2276877T3; EP1466558A2; DK1466558T3; EP1466558B1; DK1287785T3; US8523784B2; DE50208937D1; US7396334B2; DE10142232A1

Abstract

The device (1) comprises a lancet needle (2) axially movable inside a housing. When the tip of the lancet (2) is retracted the small blood sample is collected in a gap in the bottom of the housing. The lid is made of a test strip (9) with a particular area positioned above the receptacle and to be used for the examination by the laboratory technician. The devices (1) are injection molded in a row (13) beside each other in a first step, covered by the test strip material (14) in a second step, and finally separated for individual use.

Description

PROCESS FOR MANUFACTURING AN ANALYTICAL DEVICE
H1ITH LANCET ArtD TEST ELEMENT
This is a divisional application of Canadian patent application No. 2,399,890.
The invention concerns a process for manufacturing an analytical device which contains a lancet and an analytical test element.
The examination of blood samples in clinical diagnostics enables the early and reliable recognition of pathological states as well as a specific: and well-founded monitoring of physical conditions. Medical blood diagnostics always requires the collection of a blood sample from the individual to be examined. Whereas in hospitals and in doctor's offices several millilitres of blood are usually collected by venepuncture from a person to be examined for analysis in order to carry out many laboratory tests, individual analyses which are directed towards one parameter nowadays often only require blood quantities ranging from a few microlit:res down to less than one microlitre. Such small quantities of blood do not require a laborious and painful v~nepuncture. Instead it is sufficient to push a sterile sharp lancet into a finger pad or earlobe of the perso:l to be examined to collect blood through the skin and thus to obtain a few microlitres of blood or less for analysis. This method is particularly suitable when it is possible to carry out the analysis of the blood sample immediately after blood collection.
Lancets and suitable instruments for them (so-called blood withdrawal instruments, blood lancet devices or-as they are referred to in the following-lancing aids) which enable blood collection that is as painfree and reproducible as possible are available especially for so-called home monitoring i.e. where medical laymen carry out simple analyses of the blood by themselves and are used in particular by diabetics to collect blood regularly and several times daily to monitor the blood glucose concentration. Furthermore the use of lancets with lancing aids is intended to reduce the psychological barrier associated with piercing one's own body which is particularly important for children that suffer from diabetes and need regular blood glucose tests. The commercially available instruments (lancing aids) and lancets Glucolet (R) from Bayer AG and Softclix(R) from Roche Diagnostics GmbH are mentioned as examples of lancets and lancing aids. Such lancets and instruments (lancing aids) are for examp__e the subject matter of WO-A
98/48695, EP-A 0 565 970, U.;3. Pat. No. 4,442,836 or U.S.
Pat. No. 5,554,166.
Personal blood sugar determination (so-called home monitoring) is today a world-wide method in diabetes monitoring. Blood sugar instruments of the prior art such as the Accu-Chek Sensor (f:rom Roche Diagnostics) are composed of a measuring instrument into which a test element (test strip, sensor) is inserted. The test strip is contacted with a drop of blood which has previously been collected from the finger pad by means of a lancing aid. The numerous system comf>onents (lancet, lancing aid, test strip and measuring inst=rument) need a lot of space and require a relatively complex handling. There are now also systems with a high degree of integration which are thus more simple to operate. 'these for example include the AccuCheck Compact (from Roche Diagnostics), the Glucometer Dex (from Bayer Diagnostics; and the Soft-Sense (from Medisense). In the two former systems the test strips are stored in the measuring instrument in magazines and are available for the measurement.
A next step in ininiaturizatian is for example to integrate several functions or functional elements into a single analytical device (disposable,). For example the operating process can be considerably simplified by a suitable combination of the lancing process and sensory analyte concentration detection on ~~ test strip. There are the following examples of this in the prior art:
EP-B 0 199 484 (Audio Bionics) describes an analytical device ("disposable"; abbre~riated dispo) containing an integrated lancet which is actuated by the instrument (see FIG. 9 for example). The lar..cet is retracted again after the puncture by means of a specific spring mounting ("spring-mounted lance means"). The dispo contains a so-called "wick means" through which the sample liquid is passed from the body surface to the analytical area which is an optically analysable te;3t field.
A method is described in L~.S. Pat. No. 6,143,164 (E.
Heller & Comp.) in which a body opening (for example a small puncture or incision through the skin) is made and subsequently body fluid is transported into a sensor and examined there for the presence of an analyte. For this purpose U.S. Pat. No. 6,143,164 discloses an analytical device in which a lancing de~,rice is attached to a sensor test strip. The sample liquid is transported from the body opening to the actual detection element of the sensor for example again by means oi: a wick or a capillary gap/channel.
WO 99/26539 (Mercury Diagnost__cs), U.S. Pat. No. 5,951,492 (Mercury Diagnostics) and U.:.. Pat. No. 6,056,701 (Amira n I - I

Medical) describe, inter alia, collection devices for body fluids comprising an elongate handle; a test field being attached to its head region.
U.S. Pat. No. 6,032,059 (Abbott) and U.S. Pat. No.
6,014,577 (Abbott) describe a disposable containing a needle which is used to pier<:e the skin. Body fluid which is previously sucked into the needle by capillary action is analysed by a sensor integrated into the needle.
U.S. Pat. No. 5,801,057 (Smart et al.) describes a disposable made of silicon containing an integrated hollow needle. A collection chamber for aspirated body fluid is located at one end of this hollow needle. The concentration of a blood component can be determined in the body fluid by a suitable reaction chemistry.
U.S. Pat. No. 5,035,704 (L,~mbert et al.) discloses a system for collecting blood containing a magazine for disposables. It is possible to integrate a lancet element into the dispos . A blood drop is transferred to the test field by direct skin contact and can be increased by applying a vacuum.
U.S. Pat. No. 6,132,449 (Agilent Technologies) discloses an integrated dispo with ~~ puncturing and measuring function. The puncturing element is activated perpendicular to the dispo pli~ne whereby it passes through the dispo. The wound opening is in direct contact with several capillary structures which transport the emerging blood into a separate analytical part of the dispo.
A key problem in collecting blood using a so-called "integrated disposable" (in which the lancet and test element are connected together or form a single unit) is i ~ il I- I

the fact that, after puncture:, the capillary blood usually does not automatically emerge from the wound. This adverse effect is increased by directly contacting a disposable with the wound opening. AftE~r a puncture the blood drop must be actively conveyed to the skin surface by for example mechanically opening the wound and/or applying gentle pressure to the tissue around the wound area (for example by simple "finger milking"). Application of a vacuum can assist this process.
Experiments in the laboratory have shown that it is advantageous to keep the wound open during the period of blood collection. However, this fact results in a complicated movement process of the dispo since a very rapid p~.ercing motion and a slow blood withdrawal movement can only be achieved with a waiting time in the system.
Only a few of the dispo designs proposed in the prior art are suitable for this.
A rigid protruding lancet tip has a tendency to cause unintentional injury when collecting the blood drop. Hence a lancing device which moves relative to the disposable is preferable. However, this requirement in combination with the dispos known in the prior art leads to a complicated and thus expensive dispo design.
A further difficulty with known dispos is to ensure the sterility of the lancet for she period until it is used.
In the prior art it is known that the tip can be protected by a cap which is manually removed before use. However, such a cap impairs the automation of blood sugar measurements. Previously desc=:ibed concepts which would in principle enable an automated blood sugar determination with an integrated disposable: have the disadvantage that there is a latent risk of contaminating the lancet needle tip. Components of the test field (chemicals, biological components, adhesives etc.) can migrate within the dispo via the air or over the surfaces. Thus a sterilization of the needle tip carried oL.t initially is in no way sufficient without further protective measures to meet the requirements for a sterile medical product.
The lancets of the prior art usually have a metal lancet needle with a tip which can he optionally ground. In order to facilitate the handling of the lancet and optionally to attach it in a lancing device, a plastic lancet body made of a rigid, injection-mou=.dable material is usually injected onto the lancet needle in many embodiments. In the unused state the tip of the lancet needle is surrounded by a protective=_ covering to ensure its sterility. This is usually composed of the same rigid material as the actual lance~~ body and usually forms one unit with this body. The protective covering can be separated from the lancet body before using the lancet and removed from the tip of t)ze lancet needle. For this purpose there is usually a weakened point between the lancet body and protective ~~over. After the lancet has been used, the tip of the lan~~et needle is unprotected and is hence a potential source of injury to the user and possibly to other persons.
The object of the present invention was therefore to eliminate the disadvantages of the prior art and in particular the disadvantages mentioned above. In particular the object of the present invention was to provide a process for manufa~~turing an analytical device (synonymous with "disposable", abbreviated: "dispo") which does not have the disadvantages of the prior art. In particular the dispo according to the invention should ensure the sterility of the :.ancets until they have been _ 7 _ used while simultaneously integrating the lancet and test element (test strip, sensor). Another object of the present invention is to provide a process for manufacturing an analytical device containing lancets in which at least the lancet neE~dle tip is kept sterile, i.e.
germ-free, in the unused state until immediately before use and which can be stored hygienically in the used state . This obj ect should be ideally achieved without the user having to employ separ~~te measures for the hygienic storage of the analytical devices being manufactured according to the invention. Moreover the user should be protected from accidental injury by the lancet and in particular by the used la:zcet. Finally it should be preferably possible to simply transfer the sample from the site of blood collection to the site of blood examination.
A first subject matter of the invention is a process for manufacturing an analytical device which contains a lancet. The main components of the lancet are a lancet needle with a tip and a .Lancet body that completely surrounds the lancet needle ~.t least in the region of the tip. The lancet needle can be moved relative to the lancet body. The lancet body is composed of a soft and deformable material at least in the region of the tip of the lancet needle in which the tip of the lancet needle is embedded.
The analytical device additionally contains an analytical test element which is permanently attached to the lancet body.
Another subject matter of the invention is a process for manufacturing a further analytical device which contains a lancet . The lancet in this case comprises a lancet needle with a tip and a lancet bod~~ which is in the form of a hollow body in the region of the tip of the lancet needle and which surrounds the tip of the lancet needle. In this U I I

g _ case the lancet needle is ,also movable relative to the lancet body. The hollow body is composed at least partially of a soft and deformable material which can be pierced by the tip of the lancet needle during the lancing process and after retraction optionally reseals the tip of the lancet needle in the hollow body. The analytical device additionally contain. an analytical test element which is permanently connec~~ed to the lancet body. The process for manufacturing an analytical device of the invention contains the steps of sterilization of the tip of a lancet needle, and afterwards connecting lancet body and test element forming an analytical device.
Finally the invention concerns a process for manufacturing such analytical devices.
The object of the invention is preferably composed of a process for manufacturing a miniaturized dispo which combines the three functions of puncturing, blood transfer from the wound generated by the puncturing to the test element and sensor in one element.
The main body of the analyt=_cal device according to the invention is composed of ~. rigid plastic body whose external shape is preferably adapted for the purpose of holding it in an instrument. A lancet needle is embedded in this plastic in such a manner that its tip preferably does not protrude beyond the front edge of the main body.
The main body can therefore also be referred to as the lancet body. In the preferred embodiment the main body has ridges which are used to fix the needle in the main body and to guide it during the lancing movement. However, most of the needle is preferably not attached to the main body in order to reduce the frictional force during the lancing movement. The contact surfaces between the needle and _ g _ lancet body are preferably kept to a minimum and suitably pretreated, for example siliconized.
The lancets according to the invention are preferably designed to be used once and can therefore be referred to as single-use blood lancets or disposable blood lancets.
The lancet of the invention comprises a needle (lancet needle) with a tip. The needle is usually several millimetres (mm) to a few centimetres (cm) in length and has an elongate shape. Needles are typically cylindrical since this needle shape is particularly easy to manufacture; however, othe:_ needle shapes are also possible. The tip region of the needle comprises the needle tip which is inserted into the tissue when the lancet is used correctly. Consequently the tip of the lancet needle is that part of: the lancet which comes into contact with the skin of the individual to be pricked which optionally injures the skin and thus causes a body fluid and in particular blond or interstitial fluid to flow out.
The tip of the lancet needle can for example be rotationally symmetrical which is generally the case for pins. However, it has also proven to be advantageous to provide the needle tip with one or several ground surfaces. The resulting edges which make an angle with the longitudinal axis of the needle and converge in a tip act as a sharp cutting edge during lancing and make the puncturing process less painful than is the case with rotationally symmetrical needles.
The lancet needle of the lancet according to the invention is manufactured from a matE~rial which is sufficiently rigid to withstand mechanical strain during the lancing process, the processing steps or other strains which may - LD -occur without deformation. The material must also be such that no particles break off or become detached during the lancing process. Finally the needle material must also be sufficiently machinable to enable the needle tip to be sufficiently pointed and th~= edges of the needle to be ground adequately sharply. Very suitable materials for the lancet needle are above all rletals and in particular high-grade steels. However, needles can also conceivably be made of silicon, ceramics cr plastics. High-grade steel needles are particularly preferred.
In one embodiment of the invention at least the tip of the lancet needle of the lancet recording to the invention is surrounded by the lancet bode. The lancet body is composed of a soft and deformable material in the region of the tip of the lancet needle, the material being preferably an elastic material. At least the tip of the lancet needle is completely surrounded on all sides by this elastic material i.e. it is embeddec. in it and thus sealed from the environment . The elastic material of the lancet body, which in the various embodirlents can completely or only partially form the lancet body, is characterized in that it is soft, deformable and can be pierced by the tip of the lancet needle without damaging the tip. During the lancing process the lancet needle is moved along its longitudinal axis relative to the lancet body and its tip emerges from the lancet body in order to pierce the skin of the individual to be examined for blood collection. A
further important and preferred property according to the invention is that the soft and deformable material optionally again makes a tight seal around the tip of the lancet needle when the lancet needle is retracted into the lancet body. After the lancing process the lancet needle is moved in a preferred embodiment into its initial position relative to the lancet body by reversing the - .L1 -movement of the lancing process and in this position the tip is again completely er..closed on all sides by the material of the lancet body.
The material of the lancet body which completely encloses the tip of the lancet needle ensures the sterility of the lancet needle tip before use, preferably until immediately before use and optionally ensures a hygienic enclosure of the lancet needle tip after use. The term "hygienic enclosure" means that biolo<~ical material (tissue, body fluid) which may adhere to the needle after the puncture is essentially encapsulated by the soft and deformable material. This prevents esp<~cially germs and infectious material from reaching the environment or at least greatly reduces this risk. Consequently the material is impervious to germs and thus prevents their penetration or escape depending on whether the lancet needle is unused or used.
In addition the material represents a mechanical protection for the lancet needle tip and thus also prevents accidental injury on the lancet needle tip.
Rubber, coautchouc, silicone, elastomers and in particular thermoplastic elastomers have proven to be suitable as the material for the lancet bod-~ of the present invention.
These have properties that a:re important for the present invention: they are soft, deformable, can be pierced by the lancet needle without damaging the tip and make a tight seal around the used l~.ncet needle tip. Furthermore they can be used for inject:_on moulding processes which allows a mass production of lancets in large numbers.
Thermoplastic elastomers which are also called elastoplasts or thermoplasts or thermoplastic coautchoucs ideally combine the handling properties of elastomers and the processing properties of thermoplasts. Thermoplastic i i v . I I

- :. 2 -elastomers are for example styrene oligoblock copolymers (so-called TPE-S), thermoplastic polyolefins (TPE-O), thermoplastic polyurethanes (TPE-U), thermoplastic copolyesters (TPE-E) and thermoplastic copolyamides (TPE-A). In particular thermoplastic elastomers based on styrene-ethylene-butylene-styrene-polymers (SEBS polymers, e.g. Evoprene (R) from Evode :?lastics or Thermolast K from "Gummiwerk Kraiburg GmbH) h~.ve for example proven to be particularly suitable.
l0 During the lancing process the lancet needle is moved relative to the lancet body. The latter is preferably held in its position by the lancing aid or lancing instrument during this process. The lancet needle can be specially shaped for the purposes of the drive mechanism and for example have a needle head at: the end opposite to the tip or have another lancet body in addition to the lancet body which encloses the tip and can be engaged by a drive element of the lancing aid. The shape of the needle or of the additional lancet body can interact in a suitable manner with a corresponding drive device in the lancing instrument (lancing aid). Such means can generally be referred to as a thickening o~' the needle.
In order to achieve the advantage that the lancet needle tip is enclosed in a sterile manner before use by the material of the lancet body a:~d is hygienically surrounded by the material after use, it is of course necessary that the lancet needle is moved back after use, i.e. after the lancing process, essentially into its original position relative to the lancet body containing the material. This can be achieved by suitable interaction with a correspondingly adapted lanci:zg aid. It is only important that, after use, the lancet needle tip is again enclosed i i - :L 3 -by the material of the lan~~et body which thus prevents accidental injury on the neec.le tip.
In order to increase the stability of the material it is possible to combine it with a stiff material, for example a stiff plastic material. For example the outside of the material which does not come into contact with the tip of the lancet needle can be stabilized with a layer of a stiff material, for example a stiff plastic. It is also possible to manufacture the :lancet body from the soft and deformable material only in the region of the lancet needle tip and to manufacture the remaining lancet body from conventional stiff pla~~tics. In this case the soft and deformable material and the stiff material can be glued together or joined together by an injection moulding process, for example a two component injection moulding process. The stiff material of the lancet body ensures the mechanical stability of the material during the lancing process and facilitates the immobilization of the soft and deformable part of the lan<:et body during the lancing process by the lancing aid. The stiff material can also be a part of the test element, for example a capillary gap test element as described in 1a0 99/29429.
In a further embodiment of: the invention the lancet contains a lancet needle with a tip and a hollow body which surrounds at least the tip of the lancet needle, the lancet needle being movable ~n~ithin the hollow body in the region of its tip and the hollow body being at least partially composed of a soft and deformable material that can be pierced by the tip of the lancet needle during the lancing process and which o~~tionally reseals the tip of the lancet needle in the hollow body when it is retracted.

i i - ._4 -Whereas with the lancet described further above according to the first embodiment, the region of the tip of the lancet needle is completely surrounded on all sides by a soft and deformable material and thus without any remaining hollow space around the tip to ensure sterility before use and hygienic shielding after use, in the second embodiment described above th.e tip of the lancet needle is surrounded by the hollow body which is closed on all sides. The areas of this hcllow body which do not come into contact with the la:zcet needle are preferably manufactured from a stiff material and preferably an injection mouldable material.
During the lancing process the lancet needle is moved relative to the hollow body which represents the lancet body. The holder and drive for the lancet needle and attachment of the lancet bod~~ can be achieved by suitable constructional measures in the lancing aid as described above.
The soft and deformable material which comprises a part of the hollow lancet body is pierced by the lancet needle tip during the lancing process rind optionally reseals after the lancet needle tip is retracted into the hollow body and thus seals the hollow body. Hence the lancet needle tip is thus aseptically pealed in the hollow body immediately before use and i~ hygienically enclosed in it after use.
The lancet of this embodiment can, like the lancet of the alternative inventive embodiment described above, also have an additional lancet body in addition to the lancet body which encloses the tip of the lancet needle which interacts with suitable elements of a lancing device during the lancing process. In addition the lancet needle - ::5 -can have a special shape, far example have a head at the end opposite to the tip.
With regard to the properties of the soft and deformable material and the joining of this material with the stiff material of the lancet body the same applies as that already mentioned above with reference to the first embodiment.
The blood transfer from the wound/puncturing site of the lancet to the measuring site is achieved according to the invention by two basically different methods: On the one hand the operator of the analytical device can manually transfer the blood drop obtained after the lancing process onto the corresponding test element. However, the blood transfer is preferably achieved "automatically" without any assistance by the user of. the dispos according to the invention. For this purpose the dispo can have means for sample liquid transport. These means are preferably capillary active, for examplE~ in the form of~a gap or a channel in a rigid main body or absorbent matrix materials. It is also possible to combine these two basic methods for example in t:zat the blood is firstly transported through a capillary channel, taken up by an absorbent matrix material ;end dispensed onto a test element.
Fleeces, papers, wicks or fabrics have proven to be particularly suitable as absorbent materials in the sense of this invention.
In a preferred embodiment thE. main body (lancet body) of the analytical device contain. the means for sample liquid transport. This may be an absorbent wick recessed into the lancet body or preferably a formed capillary gap which is i i i - :L6 -located directly next to th~~ needle and has an inlet in the proximity of the needle outlet. As a result the dispo does not have to be laterally moved for blood collection (or only slightly). The geometry of the inlet opening is designed such that the blood drop that forms can collect there as easily as possible and has for example a funnel or notch shape. The capillar~~ action then ensures that the required amount of blood, which can be considerably below 1 microlitre, is aspirated. By this means the blood reaches the test field and reacts there with the test chemistry to generate an an<<lysable electrical signal or colour change. The capillary gap can be moulded into the plastic during the injection moulding or be subsequently introduced into the plastic body for example by embossing or milling.
In another preferred variant the means for sample liquid transport (e.g. a capillary chap or a wick) is not moulded into the plastic which forms the lancet body but is produced by the specific structure of the test element.
For example the test element can have a structure similar to WO 99/29429 or EP-A 0 359 x331.
The methods known in the ~>rior art are used for the sensory detection of the an~~lyte in particular of blood glucose. Photometric and electrochemical methods are preferred.
The analytical test element of the inventive analytical device can be composed of a detection film which is directly joined to the lancets body. Such detection films are known in diverse embodiments from the prior art. For example such a detection film is described in WO 99/29429.
Furthermore, as already mentioned above, a complete conventional test element can be joined to the main i i i - 7.7 -body/lancet body of the device according to the invention.
Such test elements are also known to a person skilled in the art.
The test element can be join~:d to the lancet body in many different ways. These include but are not limited to, glueing, welding, clippin~~, attachment via velcro fastening or magnets, sewing, screwing and such like. The test element is preferably clued to the lancet body for example by means of hot-melts adhesive or by means of a double-coated adhesive tape.
In general the operation of the disposables according to the invention can be describe~3 as follows:
1. The dispo is inserted into the holding device of a (blood sugar) measuring instr»ment and is attached there.
2. The drive mechanism of the lancing unit is tensioned and coupled to tree needle thickening of the dispo.
3. When the lancing process is actuated, the needle is moved forwards and in this process emerges at high speed from the soft plastic. The entire lancing process only takes a few milliseconds.

4. After the skin has been punctured the needle is retracted again into the soft. plastic (initial position).
The drive is optionally disengaged.

5. After a suitable drop of blood has formed, the entire collection device i:a moved forward until the suction opening (e. g. capillary) contacts the drop.
Alternatively the blood drop can be manually applied to ~~ i i the appropriate sample ap~~lication zone of the test element.

6. In the variants of the disposable which have means for sample liquid transport, the suction action of these means transports the blood in the dispo to a site where a signal is generated by means of a photometric or electrochemical reaction which depends on the concentration of the blood component.
A disposable according to the invention can in principle be manufactured by the following simple steps:
(1) Injection moulding the main body including embedding the lancet needle loptionally with generation of the "needle head" i.e. a thickening that can be engaged by a lancing instrument) (2) sheathing the needy tip with soft plastic (3) sterilizing the "crude disposables" (which are essentially composed of the lancet optionally together with a capillary channel in the lancet body) for example by means of gamma radiation (4) test assembly i.e. connecting the test element with the main body.
Preferably the "crude dispos" as well as the test elements can be present as a tape matE~rial which is separated into the individual dispos after the test assembly for example by cutting or punching. Irrespective of whether the disposables according to the invention are manufactured as rolls or tape material in a continuous process or batch-wise or individually, it is important that the lancet and - :L9 -test element are not joined together until after the lancet needle has been steri:_ized. A sterilization of the-disposables after final assembly could result in damage to sensitive chemical or bioloc3ical substances in the test field. This can be avoided b~~ the process according to the invention.
Finally a subject matter of ~~he invention is the use of a soft and deformable material as a component of a lancet of an analytical device where the material maintains the sterility of at least the t:_p of a lancet needle in the unused state. In a preferrec. embodiment the material can also be used to hygienically shield at least the tip of the lancet needle in the used state.
The use according to the invention of a soft and deformable material to shield the tip of the lancet needle ensures the sterility of an unused lancet needle tip and optionally hygienically shields the used lancet needle tip.
The lancet needle tip can he sterilized in the unused state by suitable measures such as for example gamma radiation. Once sterilized the lancet needle tips remain sterilized by the correspondi:zg lancet body which includes a soft and deformable material. In contrast to the prior art where no such materials for shielding lancet needle tips have been described, the use of the material according to the invention also enables the hygienic screening or shielding of the used lancet needle tip. The use of the material allows resealing of a channel which may be present for a brief time through which the lancet needle can pass for the purposes of lancing after the lancet needle has been retracted i.e. after completion of the lancing process. Hence contaminants, in particular _ ~>~ _ germs and infectious material which may adhere to the lancet needle tip after the lancing process cannot reach the environment or only to ~ limited extent. This is of particular advantage for disposable lancets which are individually disposed of after use. This property is, however, of outstanding importance for sets of lancets and lancet magazines in which us<sd lancets are stored next to unused lancets which can then be disposed of as a whole.
The invention has the following advantages:
- The tip of the lancet needle is shielded germ-tight in the unused state in all embodiments i.e. germs cannot reach the lancet needle tip until immediately before using the lancet. After suitable sterilization the lancet tips remain sterile for a long period.
- The sterility of the lancet needle is also ensured in the subsequent manufacturing steps such as the joining of lancet and test element. In this process the sensitive needle tip is protected from mechanical influence (bending etc . ) .
- In all embodiments the i:ip of the lancet needle can be hygienically screened in the used state. An accidental contamination of the surrour..dings (user, objects, other lancets) is substantially excluded.
- The user of disposables according to the invention is protected from accidental injury on a used lancet needle.
The same of course also applies to other persons than the actual user.

li I. i _ ,01 _ - The disposables accord~_ng to the invention can be manufactured cost-effective~_y in large numbers using conventional injection moulding processes.
- The disposables according to the invention can be miniaturized to a substantial degree and are therefore suitable for use in compact automated systems.
- All previously known variants of test strips and sensors can be used as analytical test elements.
The invention is further E=lucidated by the following figures:
FIG. 1 shows schematically a first preferred embodiment of the analytical device according to the invention in several views.
FIG. 2 shows schematically a second preferred embodiment of the analytical device according to the invention in several views.
FIG. 3 shows schematically a third preferred embodiment of the analytical device acco:_ding to the invention in several views.
FIG. 4 shows schematically a fourth preferred embodiment of the analytical device acc=ording to the invention in several views.
FIG. 5 shows schematically a j=fifth preferred embodiment of the analytical device according to the invention in several views.

i i - ~2 -FIG. 6 shows schematically ~~he manufacture of analytical devices according to FIG. 2 from tape material.
Although only test elements that can be evaluated optically are shown in each of the individual figures, this should not be limiting to the subject matter of the present invention. Rather it is obvious to a person skilled in the art that the detection reaction of the test element can be monitored by any method. In addition to optical methods (such as reflection photometry, absorption measurement or fluorescence measurement) in particular electrochemical methods are preferred (such as potentiometry, amperometry, voltametry, coulometry for example).
The figures and letters in th~= figures denote:
1, analytical device (di:~posable, dispo) 2. lancet 3. lancet needle 4. lancet body 5. plastic part of the 1«ncet body 6. part of the lancet bocLy made of a soft and deformable material 7. capillary gap 8. thickening of the needle end 9, test element _ ~; 3 _ 10. test field 11. sealing foil 12. thickening in the mi3dle of the needle 13. lancet tape/belt 14. test element tape/be.lt FIG. 1 shows schematically a preferred embodiment of the analytical device in several 3etail figures (lA-1E).
FIG. lA firstly shows the lancet (2). It contains a lancet needle (3) which is embedded in a lancet body (4). The lancet body (4) is composed of a hard plastic part (5) and a part made of a soft and deformable material (6). A
capillary gap (7) is worked into the hard plastic part (5) of the lancet body (4) and is used to transport the sample liquid.
A thickening (8) is attached ~o the rear end of the lancet needle (3) and enables the lancet needle to be easily gripped in the lancing aid or in the lancing instrument.
FIG. 1B shows the final analytical device (1). A strip-shaped test element (9) which contains a test field (10) is attached to the hard pla:~tic part (5) of the lancet body (4) . The test field is accessible for sample liquid through the capillary gap (7).
FIG. 1C shows a perspective ~riew of the underside of the analytical device (1). In this view it is clear that the hard plastic part (5) of the lancet body (4) only touches and holds the lancet needle (3) in the area of two bars.

11 I . I

- ::4 -Furthermore the dashed lines indicate how the tip of the lancet needle (3) is embedded in the material (6) of the lancet body.
FIG. 1D shows a longitudinal section through the analytical device (1).
FIG. lE shows a front view of the analytical device (1).
The drawings (2A-2E) of FI~i. 2 show another preferred embodiment of the analytic,~l device according to the invention.
In FIG. 2A the lancet (2) of the analytical device (1) is first shown in perspective from above. The lancet (2) is composed of a lancet needle (3) which is embedded in a lancet body (4). This is composed of a hard plastic part (5) and a part made of the soft and deformable material (6) . In addition a thickening (8) is attached to the rear end of the lancet A needle (3) which is used to grip the lancet needle (3} by a lancing instrument.
In contrast to FIG. 1 the analytical device in FIG. 2 does not have a capillary gap in the lancet body (4) but as part of the test element (9).
FIG. 2B shows the final assembled analytical device (1} in which a test element (9) is attached to the lancet body (4) . This test element contains a capillar~r gap (7) which makes the test field (10) accE~ssible to a blood sample.
FIG. 2C shows a perspective view of the analytical device (1) according to FIG. 2B from below. As in FIG. 1C, FIG.
2C makes it clear that the lancet needle (3) is only connected to the hard plastic part (5) of the lancet body (4) by bars. The needle tip of the lancet needle (3) is II I I

:>, 5 _ completely embedded in the material (6) of the lancet body.
FIG. 2D represents a longitudinal section through the analytical device (1) of FIG. 2B. FIG. 2E shows a corresponding front view of the analytical device (1) of FIG. 2B. FIGS. 2D and 2E make it clear that the capillary gap (7) is port of the test element (9).
FIG. 3 shows another preferred embodiment of the analytical device (1) of the invention in several detailed drawings (3A-3E).
The embodiment of FIG. 3 contains a capillary gap (7) as part of the hard plastic part (5) of the lancet body (4) similar to the embodiment of FIG. 1. Only the position of the capillary gap (7) and the position of the test element (9) differ from the embodiment of FIG. 1. Whereas in the embodiment of FIG. 1 the te:~t element (9) and capillary gap (7) are arranged on one of the large boundary surfaces of the lancet body (4), these elements are arranged laterally on one of the narrow boundary surfaces of the lancet body (4) in the embodiment of FIG. 3. Otherwise the function and structure of the embodiment of FIG. 3 essentially corresponds to t:zat described in FIG. 1. In this connection FIGS. 3A to :3E correspond to FIGS. lA to lE.
Another preferred embodiment of the analytical device (1) according to the invention is shown in several detailed drawings (FIGS. 4A-4F) in FIG. 4. Whereas in the embodiments according to FIG, 1 to FIG. 3 the capillary gap (7) was either part of the hard plastic part (5) of the lancet body (4) or part caf the test element (9), the capillary gap (7) in the embodiment of FIG. 4 is partially ~i I" i - .26 -disposed in the material (6) of the lancet body (4) and partially in the test element (9) . As shown in particular in FIG. 4D the capillary gap (7) can be divided into three partial regions (7, 7A and 7B) . These are in contact with one another in such a manner that sample liquid transport is possible.
As in the embodiments of FIGS. 1 to 3, the embodiment of FIG. 4 is composed of a lancE~t (2) which contains a lancet needle (3) which is partiall:~ surrounded by a lancet body (4). In this case the lancet body (4) is composed of a hard plastic part (5) and a soft and deformable material (6) which in particular surrounds the lancet needle tip (cf. FIG. 4A) . A thickening (8) is attached to the lancet needle at the rear end of t:he lancet body (3) which in turn is designed to enable a lancing device to grip the needle (3 ) .
As shown in FIGS. 4B and 4~~, a test element (9) which contains a test f field ( 10 ) i:~ attached to the lancet body (4). As already described the test field (10) is accessible to the sample liquid via a system of capillary channels (7, 7A, 7B).
The outlet opening of the lancet needle (3) is closed by a sealing foil (11) in this embodiment. When the lancet is used the sealing foil (11) can either be pierced by the lancet needle (3) or the sealing foil (11) is removed manually before use.
FIG. 4E shows a front view of the outlet opening of the lancet of the analytical device (1).
FIG. 4F shows an enlarged view of the detail labelled X in the front view of FIG. 4E. Th=_s view shows especially that ~ i i - i: 7 -four capillary channels (7) which enable sample transport to the test element (9) are present in the material (6) of the lancet body (4).
A thickening (8) is provided in the rear of the lancet needle (3) in embodiments of FIGS. 1 to 4 which is of major importance for the lancing movement. This thickening (8) is designed such that it can be coupled to a lancing drive. In this case the drive carries out the forwards.and backwards movement of the needle (3). Alternatively a drive coupling is also conceivable in which a plunger carries out the forward movement. It is then moved back by a spring which is pressed together during the forward movement and then subsequently relaxes. The thickening (8) on the needle (3) is important for this as one of the contact points for the spring. This spring can either be a component of the disposable or a component of the instrument or of a cassette or a magazine. The thickening (8) can for example be an attachable plastic or metal part. The needle (3) can a:.so be mechanically deformed (squeezing, bending) to produce a thickening (8).
Another embodiment of the invention is shown in several detailed drawings (5A-5D) of FIG. 5. In this embodiment the thickening (11) of the la:ZCet needle (3) is not at the rear end of the lancet needle (3), but rather in the region of the middle of th~s needle. In this case the thickening is located inside the lancet body (4). In this case an appropriate drive mechanism can only act laterally on the disposable. An advantage of this solution is that disposables are particularly compact and robust.
Otherwise the analytical device (1) corresponds essentially to the embodiment of FIG. 2.

_ : 8 _ Of course it is also possible to combine an embodiment of FIG. 1 i.e. an embodiment in which the capillary gap (7) is part of the lancet body (4) with a thickening (12) in the middle of the needle.
FIG. 5A shows a view of th~~ analytical device (1) from below. FIG. 5B shows a sectional view through the longitudinal axis of the analytical device (1). FIG. 5C
shows a perspective view of the underside of the analytical device (1) in which the lancet needle (3) is in a position in which it is before or after the lancing process. The tip of the lancet needle is embedded in the material (6) of the lancet body. In FIG. 5D-which for the sake of clarity is shown without a test element (9) and the material (6)-the lancet (2) is in the position in which the lancet needle (3) ._s present during the lancing process. The lancet needle tip protrudes from the contours of the lancet body (4) .
FIG. 6 is a greatly simplifie3 schematic representation of how analytical devices (1) according to FIG. 2 are manufactured from tape material. In area A lancets (12) which are assembled to form ~~ tape or belt (13) and test elements (9) are assembled t~~ form a tape or belt (14).
Two tapes are combined in area B and the test element tape (14) is glued to the lancet ~~ape (13). Finally in area C
the combined tapes are cut into individual analytical devices (1) for example by cutting off the terminal device (1) .

Claims

1. Process for manufacturing an analytical device containing i) a lancet with a lancet needle which contains a tip for puncturing the skin generating a wound and with a lancet bode which surrounds the lancet needle at least in the area of the tip, and ii) an analytical test element, with a test field in which a test reagent reacts with a body fluid generating a measurable electrical signal or a colour change and the analytical test element being connected to the lancet body whereas the process for manufacturing contains the steps of a) sterilization of the tip of the lancet needle, and afterwards b) connecting lancet body and test element forming the analytical device.

2. Process for manufacturing an analytical device as claimed in claim 1 wherein the lancet is characterized in that the lancet needle being movable relative to the lancet body.

3. Process for manufacturing an analytical device as claimed in claim 1 or 2, wherein the lancet is characterized in that the lancet body being composed at least in the area of the tip of the lancet needle of a soft and deformable material in which the tip of the lancet needle is embedded.

4. Process for manufacturing an analytical device as claimed in claim 3, wherein the soft and deformable material is elastic.

5. Process for manufacturing an analytical device as claimed in claim 1, 2 or 3, wherein the sterilization of the tip of the lancet needle is done by means of gamma radiation.