U.S. patent application number 10/204568 was filed with the patent office on 2003-08-14 for blood lancet with hygienic tip protection.
Invention is credited to Argauer, Herbert, Deck, Frank, Fritz, Michael, Immekus, Claudio, List, Hans, Weiss, Thomas.
Application Number | 20030153939 10/204568 |
Document ID | / |
Family ID | 7633569 |
Filed Date | 2003-08-14 |
United States Patent
Application |
20030153939 |
Kind Code |
A1 |
Fritz, Michael ; et
al. |
August 14, 2003 |
Blood lancet with hygienic tip protection
Abstract
The invention concerns lancets with a lancet needle, the tip of
the lancet needle being embedded in an elastic material.
Furthermore the invention concerns lancets where the tip of the
lancet needle is surrounded by a hollow body which partially
consists of an elastic material that can be pierced by the tip of
the lancet needle during the lancing process and which reseals the
tip of the lancet needle in the hollow body when it is retracted.
In addition the invention concerns a lancet magazine in which the
lancets are accommodated in individual chambers, each chamber
having an opening through which the tip of the lancet needle can
pass, which is sealed by an elastic material. Finally the invention
concerns the use of an elastic material as a component of a lancet
or a lancet magazine to maintain the sterility of at least the tip
of a lancet needle in the unused state and to hygienically protect
at least the tip of a lancet needle in the used state.
Inventors: |
Fritz, Michael; (Biblis,
DE) ; Argauer, Herbert; (Pirk, DE) ; List,
Hans; (Hesseneck-Kailbach, DE) ; Weiss, Thomas;
(Mannheim, DE) ; Deck, Frank; (Niederkirchen,
DE) ; Immekus, Claudio; (Mannheim, DE) |
Correspondence
Address: |
BOSE MCKINNEY & EVANS LLP
135 N PENNSYLVANIA ST
SUITE 2700
INDIANAPOLIS
IN
46204
US
|
Family ID: |
7633569 |
Appl. No.: |
10/204568 |
Filed: |
November 27, 2002 |
PCT Filed: |
February 28, 2001 |
PCT NO: |
PCT/EP01/02198 |
Current U.S.
Class: |
606/181 |
Current CPC
Class: |
A61B 5/15186 20130101;
A61B 5/150022 20130101; A61B 5/150633 20130101; A61B 5/15142
20130101; A61B 5/150572 20130101; A61B 5/150412 20130101; A61B
5/15171 20130101; A61B 5/15176 20130101; A61B 5/150503 20130101;
A61B 5/15151 20130101; A61B 5/15165 20130101 |
Class at
Publication: |
606/181 |
International
Class: |
A61B 017/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 4, 2000 |
DE |
10010694.3 |
Claims
1. Lancet containing a lancet needle with a tip and a lancet body
which completely surrounds at least the tip region of the lancet
needle, characterized in that the lancet body of the lancet is
composed of an elastic material at least in the tip region of the
lancet needle in which the tip of the lancet needle is
embedded.
2. Lancet containing a lancet needle with a tip and a hollow body
which surrounds at least the tip of the lancet needle,
characterized in that the tip region of the lancet needle can move
in the hollow body and the hollow body at least partially consists
of an elastic material which can be pierced by the tip of the
lancet needle during the lancing process and which optionally
reseals the tip of the lancet needle in the hollow body when it is
retracted.
3. Lancet as claimed in one of the claims 1 or 2, characterized in
that the elastic material is a thermoplastic elastomer.
4. Lancet as claimed in one of the claims 1 to 3, characterized in
that the elastic material is stabilized by a stiff material.
5. Set of lancets containing at least two lancets as claimed in one
of the claims 1 to 4 which are connected together.
6. Set of lancets as claimed in claim 5, characterized in that the
lancets are joined together by the elastic material.
7. Lancet magazine containing at least two lancets each comprising
a lancet needle with a tip which are each accommodated in
individual chambers of the lancet magazine that are independent of
one another, each chamber having at least one opening through which
the tip of the lancet needle can pass, characterized in that the
said opening of the chamber is sealed by an elastic material in
such a manner that the elastic material can be pierced by the tip
of the lancet needle during the lancing process and reseals after
the tip of the lancet needle has been retracted into the
chamber.
8. Lancet magazine as claimed in claim 7, characterized in that the
elastic material is a thermoplastic elastomer.
9. Use of an elastic material as a component of a lancet or of a
lancet magazine to maintain the sterility of at least the tip of a
lancet needle in the unused state.
10. Use as claimed in claim 9, where the elastic material is
additionally used to hygienically shield at least the tip of a
lancet needle in the used state.
11. Use as claimed in claim 9 or 10, characterized in that the
elastic material is a thermoplastic elastomer.
Description
[0001] The invention concerns a lancet comprising a lancet needle
with a tip and a lancet body which completely surrounds at least
the tip region of the lancet needle. In addition the invention
concerns a lancet comprising a lancet needle with a tip and a
hollow body which surrounds at least the tip of the lancet needle.
The invention also concerns a lancet magazine containing at least
two lancets which each contain a lancet needle with a tip and which
are each accommodated in individual chambers of the lancet magazine
that are independent of one another, each chamber having at least
one opening through which the tip of the lancet needle can emerge.
Finally the invention concerns the use of an elastic material as a
component of a lancet or lancet magazine.
[0002] The examination of blood samples in clinical diagnostics
enables an early and reliable detection of pathological states and
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 several
milliliters of blood are often collected for the analysis of a
person to be examined by venepuncture in hospitals and by
physicians in private practice in order to carry out many
laboratory tests, nowadays a few microliters of blood are usually
sufficient for individual analyses of only one parameter. Such
small amounts of blood do not require venepuncture. On the
contrary, it is sufficient to obtain blood by pushing a sterile
sharp lancet through the skin e.g. into the finger pad or earlobe
of the person to be examined in order to collect a few microliters
of blood for the analysis. This method is particularly suitable
when it is possible to carry out the analysis of the blood sample
immediately after blood collection.
[0003] Lancets and corresponding devices (so-called blood
collection instruments, blood lancet devices or, as they are
referred to in the following, lancing devices) which enable a
substantially pain-free and reproducible blood collection are
available especially in the so-called home-monitoring field i.e.
where medical laymen themselves carry out simple analyses of the
blood, especially for the regular blood withdrawal by diabetics
which has to be carried out several times daily to monitor the
blood glucose concentration. Furthermore the use of lancets with
lancing devices is intended to lower the psychological barrier to
piercing one's own body which is particularly important for
children that suffer from diabetes and depend on regular blood
glucose tests. Examples of lancets and lancing devices are the
commercially available devices (lancing devices) and lancets:
Glucolet.RTM. from the Bayer AG Company and Softclix.RTM. from
Roche Diagnostics GmbH. Such lancets and devices (lancing devices)
are for example the subject matter of WO-A 98/48695, EP-A 0 565970,
U.S. Pat. No. 4,442,836 or U.S. Pat. No. 5,554,166.
[0004] The lancets of the prior art usually have a metal lancet
needle with a tip which may be optionally sharpened. In many
embodiments a plastic lancet body made of a rigid
injection-mouldable material is injected onto the lancet needle to
facilitate the handling of the lancet and optionally for its
attachment in a lancing device. In the unused state the tip of the
lancet needle is surrounded by a protective sheath to ensure its
sterility. This sheath is usually composed of the same rigid
material as the actual lancet body and then usually forms a single
unit with this. The protective sheath can be separated from the
lancet body and removed from the tip of the lancet needle before
using the lancet. A predetermined breaking point is located between
the lancet body and protective sheath for this purpose. After using
the lancet, the tip of the lancet needle is unprotected and is thus
a potential source of injury to the user and possibly other
persons.
[0005] In order to avoid accidental injury on a used lancet needle,
it is usually recommended that the users insert the tip of the
lancet needle after use into the previously removed protective
sheath. However, experience shows that not all users follow this
advice and hence a large number of used lancets with unprotected
tips are discarded. U.S. Pat. No. 5,304,192 and WO-A 96/02189
propose lancets as a solution to this problem in which the tip of
the lancet needle can be pushed or pulled into the lancet body
after use. Since in these cases the lancet body is manufactured
from a non-elastic, substantially rigid or stiff material, the tip
of the lancet needle, although it is concealed in the lancet body,
is not completely hygienically protected because a channel remains
in the material of the lancet body via which the lancet tip is in
contact with the surroundings.
[0006] In the present commercially available systems the lancets
are usually provided in a loose form for use in lancing devices.
For each lancing process the user manually removes a lancet from a
pack, for example a cardboard box or a tube containing a plurality
of lancets which are usually in a disordered arrangement and
loosely packed. Subsequently the lancing device is prepared for
receiving the lancet by for example unscrewing or pulling off a
protective cap to expose the lancet holder of the lancing device.
The lancet holder is used to receive the lancets. It also guides
the lancet during the actual lancing process. The lancet removed
from the pack is manually inserted into the lancet holder of the
lancing device and fixed there. Then the protective sheath that
surrounds the lancet tip and protects the tip as well as the user
has to be manually removed from the lancet. Subsequently the
lancing device is sealed again with its protective cap. The
protective cap ensures that the lancet is no longer accessible from
outside. It usually has an opening through which the lancet tip can
pass during the actual lancing process. Finally the lancing device
is tensioned and is available for the lancing process to collect
blood.
[0007] The many manual operating steps required for conventional
lancet systems (lancet and lancing device) are felt to be
disadvantageous by the user and are particularly problematic when
perception is limited in a hypoglycaemic state. Moreover, the user
is not prevented from using a once inserted lancet several times
for lancing and collecting blood. This is risky for hygienic
reasons especially when the lancet system is used by more than one
person which for example may be the case in doctor's practices or
hospitals. On the other hand, the repeated use of lancets also
leads to increasing pain for the user since the lancets are
designed for single use and rapidly become blunt when used several
times. Furthermore with the lancing devices and lancets of the
prior art there is a risk that lancing devices will be used with
lancets that do not fit i.e. with lancets that are not suitable for
a particular type of lancing device and thus lead to sub-optimal
lancing results (reproducibility, lack of pain, amount of blood
collected) or that the lancets are inserted incorrectly into the
lancing devices. Furthermore a user can be accidentally injured
when the lancets and lancing devices are used improperly.
[0008] There have therefore be no lack of attempts to eliminate the
said disadvantages. Lancing devices are known from U.S. Pat. No.
5,514,152, U.S. Pat. No. 5,152,775, WO-A 98/14125, U.S. Pat. No.
3,030,959, U.S. Pat. No. 4,794,926 and U.S. Pat. No. 5,035,704
which store several lancets and can use these individually and in
succession for lancing processes. After the lancing process the
lancets can be removed individually from the device. However, these
systems with lancet storage do not solve the above-mentioned
problems of used lancets anymore than the systems which manually
have to be individually loaded with lancets.
[0009] In summary it can be ascertained that all designs of the
prior art for lancets and lancet systems i.e. lancing devices or
instruments in which lancets can be stored have the disadvantage
that it is not possible to ensure the sterility, i.e. the asepsis,
of the unused lancet needle and in particular its tip until
immediately before the lancing process, and a safe and hygienic
disposal of the once used lancet is completely left to the user.
This is a considerable problem especially for systems in which
unused lancets are stored together with used lancets i.e. in
particular for lancet magazines and corresponding lancing devices
which do not immediately eject a used lancet and instead store the
used lancets until the entire store of lancets has been used
up.
[0010] The object of the invention is to eliminate the
disadvantages of the prior art. In particular the object of the
present invention is to provide lancets in which at least the
lancet needle tip is kept sterile, i.e. aseptic, in the unused
state until immediately before use and can be stored hygienically
in the used state. Ideally this object should be achieved without
the user having to adopt separate measures for the hygienic
storage. Moreover, the user should be protected from accidental
injury by the lancet and in particular the used lancet.
[0011] The object is achieved by the subject matter of the
invention as characterized in the patent claims.
[0012] The invention concerns a lancet containing a lancet needle
with a tip and a lancet body which completely surrounds at least
the tip region of the lancet needle, wherein the lancet body of the
lancet according to the invention is composed of an elastic
material at least in the tip region of the lancet needle in which
the tip of the lancet needle is embedded.
[0013] The lancets according to the invention are designed for
single use and should therefore also be referred to as single-use
blood lancets or disposable blood lancets.
[0014] The lancet of the invention comprises a needle (lancet
needle) with a tip. The needle is usually several millimeters (mm)
to a few centimeters (cm) long and has an elongate shape. Needles
typically have a cylindrical shape since this needle shape is
particularly easy to manufacture; however, other needle shapes
having different designs are also possible. The tip region of the
needle comprises the needle tip which is inserted into the tissue
when the lancet is used as directed. Hence the tip of the lancet
needle is the part of the lancet which comes into contact with and
may injure the skin of the individual to be pierced and thus causes
a body fluid and in particular blood or interstitial liquid to flow
out.
[0015] The tip of the lancet needle can for example be rotationally
symmetrical as is generally the case for sewing needles. However,
it has proven to be advantageous to provide the needle tip with one
or several bevels. The edges formed in this manner which are
slanted relative to the longitudinal axis of the needle and
converge to form a tip, act as a sharp cutting edge in the piercing
process and make the piercing process less painful than is the case
with rotationally symmetrical needles.
[0016] The lancet needle of the lancet according to the invention
is manufactured from a material which is hard enough to withstand
mechanical stress without deformation during the piercing process,
during the processing steps or other stresses which may occur. In
addition the material must be such that no particles break off or
become detached during the piercing process. Finally it must be
possible to machine the needle in such a manner that the needle tip
is sufficiently pointed and the edges of the needle tip can
optionally be ground to a sufficient sharpness. Materials that are
very suitable for the lancet needle are above all metals and of
these especially high-grade steels. However, needles made of
ceramics or plastics are also conceivable. High-grade steel needles
are particularly preferred.
[0017] According to the invention at least the tip of the lancet
needle of the lancet according to the invention is surrounded by a
plastic body which is referred to as the lancet body in the
following. An important feature is that the lancet body is composed
of an elastic material in the tip region of the lancet needle. At
least the tip of the lancet needle is completely surrounded on all
sides by this elastic material i.e. it is embedded in it and thus
sealed from the surroundings. The elastic material of the lancet
body which in various embodiments 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. In 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 thus be able
to pierce the skin of the individual to be examined in order to
collect blood. Another important property is that the elastic
material closes around the tip of the lancet needle when the lancet
needle is optionally retracted into the lancet body. After the
lancing process the lancet needle can be returned in a preferred
embodiment to its initial position relative to the lancet body by
reversing the piercing movement and in this position the tip is
again completely enclosed on all sides by the elastic material of
the lancet body.
[0018] The elastic material of the lancet body which completely
encloses the tip of the lancet needle ensures the sterility of the
lancet needle tip before use and preferably until immediately
before use and optionally hygienically encloses the lancet needle
tip after use. Consequently the elastic material is impenetrable to
germs and prevents their entry or escape depending on whether the
lancet needle is unused or used. In addition the elastic material
represents a mechanical protection for the lancet needle tip and
thus also prevents unintentional injury on the lancet needle
tip.
[0019] Suitable elastic materials for the lancet body of the
present invention have proven to be rubber, caoutchouc, silicone,
elastomers and in particular thermoplastic elastomers. These have
properties that are important for the present invention: they are
soft, deformable, can be pierced by the lancet needle without
damaging the tip and they form a tight seal around the used lancet
needle tip. Furthermore they can be used for injection moulding
processes which enables the lancets to be mass-produced in large
numbers.
[0020] Thermoplastic elastomers which are also referred to as
elastoplasts or thermoplasts or thermoplastic rubbers combine in
the ideal case the handling properties of elastomers and the
processing characteristics of thermoplasts. Thermoplastic
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). Thermoplastic elastomers based
on styrene-ethylene-butylene-styrene polymers (SEBS polymers, e.g.
Evoprene.RTM. from Evode Plastics or Thermolast K from the
Gummiwerk Kraiburg GmbH) have for example proven to be particularly
suitable.
[0021] During the piercing process the lancet needle is moved
relative to the lancet body. During this movement the latter is
preferably fixed in its position by the lancing device or the
lancing instrument. The lancet needle can have a special shape to
enable it to be driven such as a needle head at the opposite end to
the tip or it can have another lancet body in addition to the
lancet body which surrounds the tip which is engaged by a drive
element of the lancing device. The shape of the needle or of the
additional lancet body can interact in a suitable manner with an
appropriate drive device in the lancing instrument (lancing
device).
[0022] In order to achieve the advantage that the lancet needle tip
is hygienically enclosed by the elastic material of the lancet body
before use and is also hygienically surrounded by the elastic
material after use, it is of course necessary to return the lancet
needle essentially to its original position relative to the lancet
body containing the elastic material after use i.e. after the
lancing process. This can be achieved by suitable interaction with
a suitably adapted lancing device. In this connection it is only
important that the lancet needle tip is again enclosed by the
elastic material of the lancet body after use which thus prevents
accidental injury on the needle tip.
[0023] In order to increase the stability of the elastic material,
it is possible to combine it with a stiff material such as a stiff
plastic material. In this case the outside of the elastic material
which does not come into contact with the lancet needle can for
example be stabilized with a layer of a stiff material such as a
stiff plastic. It is also possible to manufacture only the lancet
needle tip region of the lancet body from an elastic material and
to manufacture the remaining lancet body from conventional stiff
plastics. The elastic material and the stiff material can be glued
together or joined together in an injection moulding process for
example in a two-component injection moulding process. The stiff
material of the lancet body mechanically stabilizes the elastic
material during the lancing process and simplifies the fixing of
the elastic part of the lancet body by the lancing device during
the lancing process.
[0024] The invention additionally concerns a lancet containing a
lancet needle comprising a tip and a hollow body which surrounds at
least the tip of the lancet needle wherein the tip region of the
lancet needle of the lancet according to the invention can move in
the hollow body and the hollow body at least partially consists of
an elastic material which can be pierced by the tip of the lancet
needle during the lancing process and which optionally reseals the
tip of the lancet needle in the hollow body when it is
retracted.
[0025] Whereas in the case of the lancet described above according
to a first aspect of the invention the tip region of the lancet
needle is completely surrounded on all sides, and thus without any
remaining hollow space around the tip, by an elastic material which
embeds the lancet needle tip to ensure sterility before use and
hygienic shielding after use, in a second aspect of the invention
which is described now the tip of the lancet needle is surrounded
by a hollow body which is closed on all sides. The regions of this
hollow body which do not come into contact with the tip of the
lancet needle are advantageously manufactured from a stiff and
preferably injection mouldable material. An essential feature of
the invention is that the region of the hollow body which is
pierced by the lancet needle tip during the lancing process
consists of an elastic material.
[0026] 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 the attachment of the
lancet body can be realised as described above by suitable
constructional measures.
[0027] The elastic material which comprises a part of the hollow
lancet body is pierced by the lancet needle tip during the lancing
process and optionally reseals after the lancet needle tip has been
retracted again into the hollow body and thus seals the hollow
body. Hence the lancet needle tip is sealed in a sterile manner in
the hollow body until immediately before use and is hygienically
enclosed in it after use.
[0028] The lancet of this embodiment can, like the lancet of the
alternative embodiment described above, in addition to the lancet
body which encloses the tip of the lancet needle, have a further
lancet body which interacts with suitable elements of a lancing
device during the lancing process. In addition the lancet needle
can have a special shape, for example it can have a head at the end
opposite to the tip.
[0029] With regard to the properties of the elastic material and
the connection of the elastic material with the stiff material of
the lancet body, the same applies as already stated above for the
first embodiment of the invention.
[0030] An additional subject matter of the invention is a set of
lancets which contains at least two of the lancets according to the
invention that are connected together. This is the third subject
matter of the invention.
[0031] The lancets of the set of lancets according to the present
invention can be of such a type that the lancet needle tip is
completely surrounded or embedded on all sides by an elastic
material without any remaining hollow space around the tip, or of a
type where the lancet needle tip is enclosed in a hollow body. The
individual lancets, which in turn are each composed of at least a
lancet needle and a lancet body, are connected together in the set
of lancets according to the invention. The connection is
advantageously via the lancet body. Identical lancets are
preferably connected together.
[0032] The lancets in the set of lancets can either be connected by
thin bars or cross-pieces or be attached to a carrier tape made for
example of paper or plastic. The lancets are preferably connected
in such a manner that the individual lancet needles of the
individual lancets of the set of lancets are enclosed in a
continuous piece of the elastic material. In this case the elastic
material can be in the form of an elastic tape. The elastic tape as
a connecting means for several and preferably several identical
lancets is particularly suitable for lancets of the first subject
matter of the invention i.e. lancets in which the lancet needle tip
is completely embedded in the elastic material. However, an elastic
tape material can also be used as a connecting material for lancets
of the second subject matter of the invention i.e. lancets which
have a hollow body around the lancet needle tip.
[0033] Another subject matter of the invention is a lancet magazine
with chambers for storing lancets. The magazine according to the
invention contains at least two lancets which each contain a lancet
needle with a tip and which are each accommodated in individual
chambers of the lancet magazine which are independent of one
another. Each chamber has at least one opening through which the
tip of the lancet needle emerges. The lancet magazine of the
present invention is characterized in that the said opening of the
chamber is sealed by an elastic material. The elastic material is
pierced by the tip of the lancet needle during the lancing process
and optionally reseals after the tip of the lancet needle has been
retracted again into the chamber.
[0034] Like the set of lancets according to the third subject
matter of the invention, the lancet magazine (fourth subject matter
of the invention) is used for the common storage of unused lancets
(cassetting) and optionally also to store used lancets
(recassetting). In contrast to the set of lancets, the individual
lancets in the lancet magazine are not directly joined together but
are located in individual chambers of the magazine. Here they are
independent of one another. The chambers in the magazine are
disposed in an essentially regular geometric pattern where
neighbouring chambers have at least one and preferably two common
wall(s).
[0035] The individual chambers of the magazine have at least one
opening for the tip of the lancet needle. According to the
invention this opening is closed by an elastic material which has
the properties mentioned above in connection with the first subject
matter of the invention. The tip of the lancet needle can penetrate
through the elastic material during the lancing process. The
elastic material optionally reseals when the lancet needle tip is
retracted into the chamber of the lancet magazine. The chamber is
then again tightly sealed.
[0036] The chambers of the lancet magazine can be sealed by
suitable constructional measures in such a manner that the tip
region of the lancet needle is sterile before use and is optionally
hygienically shielded from the environment after use. For example
the lancet can have a lancet body which, by means of suitable
forming, interacts with the inner wall of the chamber of the lancet
magazine to form a seal. It is important for the invention only
that the opening of the chamber through which the lancet needle tip
passes during the lancing process is closed by the elastic
material.
[0037] The individual chambers can be arranged in any manner in the
lancet magazine. For example a plurality of lancet chambers can be
arranged next to one another resulting in an essentially cuboid or
bar-shaped magazine. The chambers may also be arranged
symmetrically around a central axis resulting in a lancet magazine
in the shape of a cylinder (like the cylinder of a revolver).
However, other arrangements are also conceivable and feasible.
[0038] Finally the invention concerns the use of an elastic
material as a component of a lancet or a lancet magazine where the
elastic material is used to maintain the sterility of at least the
tip of a lancet needle in the unused state. In a preferred
embodiment the elastic material can also be used to hygienically
shield at least the tip of a lancet in the used state.
[0039] The use of an elastic material according to the invention to
protect the tip of the lancet needle ensures the sterility of an
unused lancet needle tip and optionally hygienically screens the
used lancet needle tip.
[0040] The lancet needle tip can be sterilized in the unused state
by suitable measures such as gamma irradiation. Once sterilized the
lancet needle tips remains sterilized by means of the appropriate
lancet body or an appropriate lancet magazine which inter alia
consist of an elastic material. In contrast to the prior art where
up to now no elastic materials have been described for shielding
the lancet needle tips, the use of the elastic material according
to the present invention also allows a hygienic sheathing of the
used lancet needle tip. A channel which may be present for a short
time through which the lancet needle can pass for the purpose of
piercing is sealed again by the elastic material after the lancet
needle is retracted i.e. after the lancing process is completed.
Hence contaminants adhering to the lancet needle tip after the
lancing process and in particular germs and infectious material
cannot reach the surroundings. This is particularly advantageous
for disposable lancets which are individually disposed off after
use. However, this property is extremely important for sets of
lancets and lancet magazines in which used lancets are also stored
next to unused lancets which can then be disposed off as a
whole.
[0041] The invention has the following advantages:
[0042] In all embodiments the tip of the lancet needle is shielded
in a germ-tight manner in the unused state i.e. germs cannot
penetrate through to the lancet needle tip
[0043] until immediately before the lancet is used. After suitable
sterilization the lancet tips remain sterile for a long period.
[0044] In all embodiments the tip of the lancet needle can be
hygienically protected in the used state. An accidental
contamination of the environment (user, objects, other lancets) is
substantially prevented.
[0045] The user of the lancets according to the invention is
protected from accidental injury on a used lancet needle. The same
also applies to persons other than the actual user.
[0046] The lancets and sets of lancets according to the invention
can be manufactured cost-effectively in large numbers with
conventional injection moulding processes.
[0047] The lancets and sets of lancets according to the invention
can be considerably miniaturized and are therefore suitable for use
in compact, automated systems.
[0048] The invention is further elucidated by the following FIGS. 1
to 6.
[0049] The numbers in the figures denote:
[0050] 1 lancet needle
[0051] 2 tip of the lancet needle
[0052] 3 lancet body made of elastic material
[0053] 3' edge of the lancet body 3
[0054] 4 stabilizing layer
[0055] 5 lancet body made of rigid material
[0056] 5' projecting part of the lancet body
[0057] 6 seal made of elastic material
[0058] 7 lancet body
[0059] 8 chamber wall
[0060] 9 lancet body
[0061] 10 lancet
[0062] 11 set of lancets
[0063] 12 lancet (10) in chamber
[0064] FIG. 1 shows a schematic longitudinal section through a
preferred embodiment of a lancet according to the invention.
[0065] FIG. 2 shows a schematic longitudinal section through an
alternative, equally preferred embodiment of a lancet according to
the invention.
[0066] FIG. 3 shows a schematic longitudinal section through
another alternative of a preferred embodiment of the lancet
according to the invention.
[0067] FIG. 4 shows a schematic top-view of a preferred embodiment
of a set of lancets according to the invention.
[0068] FIG. 5 shows a schematic longitudinal section through a
chamber of a preferred lancet magazine according to the invention
including a lancet located therein.
[0069] FIG. 6 shows a further preferred embodiment of a lancet
according to the invention in a schematic sectional view.
[0070] The preferred embodiment of the lancet (10) according to the
invention shown in FIG. 1 contains a lancet needle (1) the tip
region (2) of which is surrounded by a lancet body (3) which is
manufactured from an elastic material. The tip (2) of the lancet
needle (1) is completely surrounded by the elastic material of the
lancet body (3). Outside the region of the tip (2) of the lancet
needle (1), the lancet body (3) has a recess such that the lancet
body (3) has an edge (3') at least on one side that can interact
with appropriate gripping or holding devices in a lancing device in
order to hold the lancet body (3). It is necessary to hold the
lancet body (3) because the lancet needle (1) has to be moved
relative to the lancet body (3) during the lancing process and must
be able to pass through it in the tip region (2) of the lancet
needle (1). FIG. 1a shows the lancet (10) at the end of the
forwards movement of the lancing process.
[0071] The recess in the lancet body (3) also serves to reduce the
frictional forces between the lancet needle (1) and lancet body (3)
during the lancing movement.
[0072] The cross-section of the lancet needle (1) and of the lancet
body (3) perpendicular to the longitudinal axis of the needle
preferably has a round shape. However, the cross-section can also
have any other shape, for example quadratic or rectangular. It is
also not necessary for the lancet needle (1) and the lancet body
(3) to have the same cross-sectional shape. For example the lancet
needle (1) can have an essentially round cross-section and the
lancet body (3) can have a rectangular cross-section.
[0073] FIG. 2 shows a schematic longitudinal section of another
equally preferred embodiment of a lancet (10) according to the
invention. The lancet (10) is composed of essentially the same
elements as the lancet (10) shown in FIG. 1. In contrast to the
lancet (10) shown in FIG. 1, a stabilizing layer (4) is applied to
one side of the lancet body (3) which is composed of an elastic
material. This stabilizing layer (4) can be glued onto the lancet
body (3). However, it is preferred that the stabilizing layer (4)
is joined together with the lancet body (3) in an injection
moulding process with the lancet needle (1).
[0074] The purpose of the stabilizing layer (4) is to prevent
deformation of the elastic lancet body (3) during the lancing
process. In particular it should prevent stretching of the lancet
body (3).
[0075] Another preferred embodiment of the lancet (10) according to
the invention is shown in FIG. 3 in a schematic longitudinal
section. The lancet body (3, 5) of the lancet (10) consists in this
case of two different components. The tip (2) of the lancet needle
(1) is enclosed by a lancet body (3) made of an elastic material.
The lancet needle (1) is joined to a lancet body (5) made of a
rigid material at a distance from the tip region (2) of the lancet
needle (1). The lancet body (5) made of rigid material is in turn
joined to the lancet body (3) made of elastic material. In order to
enlarge the joining surface between the elastic lancet body
material (3) and the rigid lancet body material (5), the rigid
lancet body material (5) can have projecting parts (5'). The rigid
and elastic material (3, 5) of the lancet body can in turn be
joined by gluing or two-component injection moulding.
[0076] Whereas in the case of the embodiments of FIGS. 1 and 2, the
lancet body (3) is held during the lancing process by direct action
on the elastic material of the lancet body (3), in the embodiment
of FIG. 3 the lancet body (5), which consists of a rigid material,
is held during the lancing process. In this case the lancet needle
(1) is moved along its longitudinal axis. During this process it
penetrates the surface of the elastic lancet body (3). After the
lancing process, the lancet needle (1) is retracted such that the
elastic lancet body (3) can again be positioned around the tip (2)
of the lancet needle (1). The lancet body (3, 5) is fixed in its
position during the lancing process.
[0077] FIG. 4 shows a schematic top-view of a set of lancets (11).
A plurality of lancet needles (1) with a tip (2) are embedded in
this embodiment of the set of lancets (11) in a single tape-like
lancet body (3) made of elastic material. The set of lancets (11)
is suitable for use in an automated system in which a plurality of
lancets is stored and can be used individually for lancing
processes.
[0078] A longitudinal section through the longitudinal axis of an
individual lancet of a set of lancets (11) would correspond
essentially to the lancet (10) shown in FIG. 1 or 2. The set of
lancets (11) can, like the lancet of FIG. 2, have a stabilizing
layer (4) (not shown in FIG. 4). This stabilizes the set of lancets
(11) as a whole and the individual lancets contained therein not
only during the lancing process but also strengthens them
mechanically which can for example be advantageous for the
automated handling of the set of lancets (11) in a mechanical
system for storing and using lancets.
[0079] Since the lancet body (3) of the set of lancets (11)
consists of an elastic material, it is possible to compactly
package the entire set of lancets (11) for example by rolling them
together spirally around the longitudinal axis of the first lancet
needle (2) in the set of lancets (11).
[0080] FIG. 5 shows a schematic longitudinal section through a
chamber of a lancet magazine which contains a lancet (10). The
individual chambers can be arranged in any desired manner in the
lancet magazine. For example the chambers can be arranged next to
or behind one another and thus form an essentially cuboid shaped
magazine or be radially arranged around a central axis and thus
form an essentially cylindrical or barrel-shaped magazine. The
lancet (10) is enclosed in the chamber by the chamber walls (8). In
the embodiment shown in FIG. 5 the lancet body (7) which surrounds
the lancet needle (1) and the chamber wall (8) have a matching
complementary shape such that the tip region (2) of the lancet
needle (1) is in a closed hollow space. In addition to the chamber
wall (8) and the lancet body, the hollow space is also closed by a
seal (6) made of elastic material. The seal (6) can be pierced
during the lancing process by the tip (2) of the lancet (10) and
reseals after the lancet (10) is retracted into the chamber of the
magazine like the septum of a glass ampoule which is for example
used to store vaccines. The seal (6) made of elastic material thus
ensures a hygienic storage and disposal of an already used lancet
(10).
[0081] The seal (6) of the lancet body (9) in the lancet (10) of
FIG. 6 has a similar septum function. This lancet (10) consists of
a lancet needle (1) with a tip (2) which is located in a closed
hollow space which is formed by the lancet body (9) which is
manufactured from a rigid material and the seal (6) made of elastic
material. During the lancing process the lancet needle (1) glides
along its longitudinal axis with its tip (2) facing forwards
whereas the lancet body (9) is held stationary by suitable means in
a lancing device. In this process the tip (2) of the lancet needle
(1) pierces the seal (6) made of elastic material. FIG. 6a shows
the lancet (10) at the end of the forwards movement of the lancing
process.
[0082] The elastic material properties of the seal (6) ensure that
the hollow space is resealed after retracting the lancet needle (1)
after the lancing process and in particular after retracting the
tip (2) of the lancet needle (1) into the hollow space of the
lancet body (9).
* * * * *