U.S. patent application number 11/905349 was filed with the patent office on 2008-01-31 for method of producing a catheter and a catheter.
This patent application is currently assigned to COLOPLAST A/S. Invention is credited to Lars Bogelund Jensen, Allan Tanghoj.
Application Number | 20080027414 11/905349 |
Document ID | / |
Family ID | 43971015 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080027414 |
Kind Code |
A1 |
Tanghoj; Allan ; et
al. |
January 31, 2008 |
Method of producing a catheter and a catheter
Abstract
A method of producing a medical catheter having a catheter body
part and a catheter tip in one integrated part by injection
moulding and a catheter produced by the method. A multicomponent
moulding technique for producing a catheter, e.g. a catheter made
from two materials with different characteristics, is preferred.
Such a catheter may be used for urinary catheterisation and for
similar purposes of draining a bodily fluid.
Inventors: |
Tanghoj; Allan; (Kokkedal,
DK) ; Jensen; Lars Bogelund; (Rodovre, DK) |
Correspondence
Address: |
JACOBSON HOLMAN PLLC
400 SEVENTH STREET N.W.
SUITE 600
WASHINGTON
DC
20004
US
|
Assignee: |
COLOPLAST A/S
|
Family ID: |
43971015 |
Appl. No.: |
11/905349 |
Filed: |
September 28, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10482230 |
Apr 15, 2004 |
|
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|
PCT/DK02/00451 |
Jun 28, 2002 |
|
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11905349 |
Sep 28, 2007 |
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Current U.S.
Class: |
604/523 ;
264/245 |
Current CPC
Class: |
A61M 39/22 20130101;
A61M 25/0111 20130101; A61M 25/002 20130101; A61F 5/4405 20130101;
A61M 25/007 20130101; A61M 25/0015 20130101; A61M 25/0043 20130101;
A61M 2025/0046 20130101; A61M 25/0017 20130101; A61M 25/0068
20130101; B29C 45/16 20130101; A61M 2039/222 20130101; B29K
2995/0092 20130101; A61M 25/0009 20130101; B29C 45/1676 20130101;
A61M 25/01 20130101; A61F 5/44 20130101; B29L 2031/7542
20130101 |
Class at
Publication: |
604/523 ;
264/245 |
International
Class: |
A61M 25/16 20060101
A61M025/16; A61M 27/00 20060101 A61M027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 29, 2001 |
DK |
PA 2001 01041 |
Sep 24, 2001 |
DK |
PA 2001 01386 |
Dec 13, 2001 |
DK |
PA 2001 01869 |
Dec 13, 2001 |
DK |
PA 2001 01870 |
Apr 17, 2002 |
DK |
PA 2002 00569 |
Apr 17, 2002 |
DK |
PA 2002 00570 |
Jun 13, 2002 |
DK |
PA 2002 00895 |
Claims
1. A method for producing a catheter with parts having different
characteristics, said method comprising the steps of: injecting at
least two different fluid catheter materials into a mould formed to
define an insertable catheter tip and body; and subsequently
solidifying the materials in said mold.
2. The method according to claim 1, wherein the step of injecting
includes injecting the catheter materials into the mould in more
than one injection cycle.
3. The method according to claim 1, wherein the step of injecting
includes injecting two fluid catheter materials having different
characteristics relating to the softness of the materials after
solidification.
4. The method according to claim 1, wherein the step of injecting
includes injecting two fluid catheter materials having different
characteristics relating to the colours of the materials.
5. The method according to claim 1, wherein the step of injecting
includes injecting two fluid catheter materials having different
characteristics relating to the strengths of the materials.
6. The method according to claim 1, wherein the step of injecting
includes injecting two fluid catheter materials having different
characteristics relating to the slipperiness of the materials after
solidification.
7. The method according to claim 1, wherein the step of injecting
includes injecting two fluid catheter materials having different
characteristics relating to the ability of the solidified materials
to absorb liquid substances.
8. An injection moulded catheter made by injecting at least two
different fluid catheter materials into a mould formed to define an
insertable catheter tip and body and subsequently solidifying the
materials in said mould.
9. The catheter according to claim 8, wherein the catheter body has
a first radial size, and wherein the tip has an intermediate part
with a second radial size, the second radial size being larger than
the first radial size.
10. The catheter according to claim 9, comprising at least one
opening between the intermediate part of the tip and the body for
draining body fluid from a body cavity into the catheter.
11. The catheter according to claim 9, wherein the tip has a narrow
part with a third radial size which is smaller than the second
radial size, the catheter comprising at least one opening between
the narrow part and the intermediate part for draining body fluid
from a body cavity into the catheter.
12. The catheter according to claim 8, wherein at least one of the
materials is a hydrophilic polymer material.
13. A method for producing a catheter with parts having different
characteristics, said method comprising the steps of: injecting a
first catheter material into a mould formed to define an insertable
catheter tip and body; injecting a second catheter material having
different characteristics into said mould; and subsequently
solidifying the materials in said mold.
14. The method according to claim 13, wherein said steps of
injecting are performed at an injection pressure in a range of
about 500 bar to about 1500 bar.
15. The method according to claim 13, further comprising forming a
connector part simultaneously with at least one of said injecting
steps.
16. The method according to claim 13, further comprising coating
the mould with a hydrophilic material prior to said steps of
injecting.
17. The method according to claim 13, further comprising combining
the injecting steps with blow moulding.
18. The method according to claim 13, wherein a structure for
attaching the catheter to a peripheral article is formed
simultaneously with at least one of said injecting steps.
19. The method according to claim 15, wherein said connector part
is formed simultaneously with a proximal insertion section of said
catheter.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of copending application
Ser. No. 10/482,230, filed Apr. 15, 2004, which is a
nationalization of PCT/DK02/00451, filed Jun. 28, 2002 and
published in English, and hereby claims the priority thereof to
which it is entitled.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method of producing a
medical catheter. In particular, the invention relates to a method
wherein a catheter is produced by solidifying a fluid catheter
material in a mould.
[0004] 2. Background of the Invention
[0005] In general, medical catheters are used for draining bodily
fluids such as blood and urine. A catheter for medical use is
typically provided with a tubular oblong catheter body part made
from a piece of flexible medical hose with an internal conduit,
e.g. a PVC or PU hose having a substantially circular outer and
inner cross-sectional shape. In an insertable end thereof, the
catheter forms one or more openings through which fluid can drain
from a bodily cavity and into the tubular body. In order to ease
the insertion and to avoid injuring the bodily tissue when the
catheter is inserted into a body opening and guided through a
bodily canal, e.g. the urethra or a blood vessel, the insertable
end is normally provided with a smoothly rounded tip. In the case
of most catheters, the tip is formed by heating and melting an end
part of the medical hose until its conduit seals. Even though the
existing catheters are formed with a tip providing an acceptably
safe and comfortable insertion, it is a desire to further shape a
larger and more curved tip of the inserted part of the catheter
since this may allow for an easier and safer insertion. However,
the present technique of forming the tip of a medial hose does not
support in making such a tip. As an alternative, some catheters are
made from a medical hose with a glued-on catheter tip. This
solution allows for a catheter with a larger and more curved tip,
but the additional process step of providing a tip part and gluing
the part to the medical hose implies additional production costs.
Moreover, there is potential risk that the tip falls off during the
catheterisation and thus remains inside the body cavity, e.g. in
the bladder. For economical and for safety reasons, the on-glued
catheter tip is therefore undesired.
[0006] When the tip has been formed, a number of draining holes are
normally drilled or punched radially into the hose in the vicinity
of the tip. In order to avoid that the holes damage the bodily
tissue during the insertion of the catheter, the edges of the holes
must be smoothly rounded. Accordingly, the process of making the
holes is time-consuming and expensive.
[0007] At its opposite end, the oblong catheter body is formed with
an opening allowing the fluid to drain out of the catheter and into
an appropriate place of disposal. In this opposite end, most
catheters are provided with a connector part. The connector part
allows the catheter to be connected e.g. to a bag for collecting
the fluid. The connector part is normally formed by adhesively
bonding a funnel-shaped member to the medical hose. Once again, the
additional process of gluing a separate member onto the hose is
cost-inefficient and implies a larger percentage of defect
products.
DESCRIPTION OF THE INVENTION
[0008] It is an object of the present invention to overcome the
above described problems by providing a method of producing a
catheter, said method comprising the steps of:
[0009] injecting a fluid catheter material into a mould formed to
define an insertable catheter tip and a catheter body in one part,
and subsequently
[0010] solidifying the material therein.
[0011] The injection may take place in a regular machine for
injection moulding. Depending upon the size and length of the
catheter, the injection pressure may be in the range of 500-1500
bar, such as 750-1250 bar such as in the size of 1000 bar.
[0012] The injection moulding process is in particular suitable for
relatively short catheters, i.e. catheters which are in the range
of 50-90 mm., such as in the range of 55-85 mm., such as in the
range of 60-80 mm. such as with a length in the size of 70 mm.
which length has been found to be a suitable insertable length for
most female individuals. For male individuals, catheter sections
may preferably be provided in a length in the range of 180-250 mm.,
such as in the range of 190-240 mm., such as in the range of
200-230 mm. such as in the size of 220 mm.
[0013] The catheter may further comprise connection means for
connecting the proximal insertion section to a further catheter
section or to a urinary collection bag. The connector part may be
made from the same material as the proximal insertion section,
whereby, at the step of forming the proximal insertion section, the
proximal insertion section and the connector part may be formed
substantially simultaneously. Alternatively, the connector part may
be made from a material different from the material of the proximal
insertion section, whereby the connector part and the proximal
insertion section are formed in distinct process steps, for example
in a multi-component injection moulding process.
[0014] The mould could be formed to define the body part as an
oblong hollow, tubular part with an internal conduit of a size
allowing bodily fluid to be drained through the catheter body. As
an alternative, the body part could be provided in the form of an
oblong solid kernel with one or more vanes extending radially from
the kernel and along the entire length thereof. The vanes thus
define a number of draining passages for draining urine between the
kernel and a bodily draining passage, e.g. the urethra.
[0015] In order to allow the bodily fluid, e.g. urine from the
bladder, to enter the hollow, tubular body part of the catheter,
the mould could be formed to define at least one draining hole in
the vicinity of the tip.
[0016] A connector part may be provided for connecting the catheter
to a hose for extending the length of the catheter or for
connecting the catheter to disposal means, e.g. to a urinary
collection bag. The connector section could preferably be made in
one part with the catheter body and the tip. The connector part may
be made from the same material as the proximal insertion section
and preferably substantially simultaneous therewith, e.g. during
the same injection step. Alternatively, the connector part may be
made from a material different from the material of the proximal
insertion section. The connector part and the proximal insertion
section are thus formed in distinct process steps, for example in a
multi-component injection moulding process. The connector part may
also be arranged as a separate component in the injection mould
before the injection of the catheter material so that the connector
part is moulded into engagement with the catheter body part during
the injection moulding of the body part of the catheter. In a
similar manner, a catheter tip may be arranged as a separate
component in the mould and, during the injection moulding of the
body part of the catheter, be moulded into the catheter. In a
similar manner, additional components may be arranged in the mould
prior to the injection moulding of the catheter body. As an
example, one or more ring-shaped coloured members may be arranged
for the purpose of visualizing a certain length of the catheter,
e.g. for visualizing the intended insertable length. As another
example, one or more objects made of a material, which improves the
visualisation of the catheter in an x-ray or ultra-sound image may
be arranged in the mould prior to the injection moulding of the
catheter body.
[0017] In order to allow a user of the catheter to get a better
grip, the catheter may be provided with means for attaching the
catheter to peripheral articles such as a hand-grip for firmly
gripping the catheter. The means for attaching the catheter to
peripheral articles could be an out or inwardly extending bulge. As
a further option, the catheter could be formed in one piece with
means for handling the catheter during the insertion, e.g. a handle
part which supports for a firm hand grip. As an example, the
catheter could be provided in a diameter allowing for insertion
into the urethra and with a catheter section not adapted for
insertion and provided in a much larger diameter allowing a firm
hand grip in the catheter.
[0018] Depending upon the type of catheterisation, the bodily fluid
is typically drained either into a place of disposal e.g. into a
toilet or into a reservoir or container for collecting the fluid.
Accordingly, the mould could be formed to further define a
reservoir for collecting the bodily fluids. The reservoir could be
a plastic bag moulded in one piece with the catheter, e.g. by a
combined injection and blow moulding process.
[0019] In order to fixate the catheter in the bodily passage, the
catheter could be provided with a balloon in the vicinity of the
inserted tip. The balloon could be moulded into one piece with the
catheter.
[0020] Sometimes, it is desired that different parts of the
catheter is provided with different characteristics. As an example,
it may be desired for a urinary catheter that the insertable part
is relatively soft and flexible so that the catheter can pass
through the curved passage of the urethra. On the other hand, those
parts of the catheter which is not adapted for insertion into the
urethra may preferably be relatively less flexible, thus allowing
an easier grip and allowing the inserted part of the catheter to be
manipulated via the not inserted art.
[0021] Similarly, it may often be desired that the outer surface of
the catheter is provided in a low-frictional material supporting an
easier and more comfortable insertion of the catheter into the
urinary canal. Accordingly, it may be desired to provide a surface
layer of the catheter in a low-friction material such as FEP, PTFE
or in a hydrophilic material such as polyvinylidone while the
remaining part of the catheter is provided in a stronger and more
durable material such as a thermoplastic elastomeric material,
other thermoplastic materials, curable elastomeric materials,
polyamide resins or elastomers or any mixture thereof, i.e. the
group may comprise materials like, PVC, PU, PE, latex, and/or
Kraton.TM.. As an example, the mould may be coated with a
hydrophilic material prior to the injection of a thermoplastic
elastomeric material into the mould. As an alternative, series of
injections of one or more types of thermoplastic elastomeric
materials into the mould may take place. As an example, a
hydrophilic material or a similar low frictional material such as
siloxane, FEP etc. may firstly be injected to form an outer layer
of the catheter. Subsequently, one or more types of materials, e.g.
materials with different characteristics, are injected in one or
more injection cycles in order to form the rest of the
catheter.
[0022] As an advantage of the injection moulding process, the
surface of the catheter may easily be provided with a surface
roughness defining anchoring points for adhering a low frictional
material to the surface of the catheter, e.g. anchoring points for
bonding a FEP or PTFE (Teflon.TM.) coating to the surface.
[0023] When injecting the material in more than one injection
cycle, a catheter either comprising multiple layers or laminates or
more individual sections in the length, is formed. Due to the
laminated structure, the laminated structure may be more durable
towards mechanical stress. Due to the individual sections in the
length, a first part of the catheter, e.g. the part of the catheter
which is intended to be inserted into the urethra or similar body
canal, may be made in a softer material than the remaining catheter
or it may be made in another colour or with another slipperiness,
i.e. more slippery than the parts not intended to be inserted.
[0024] The different characteristics may relate to the softness of
the material after solidification, the colour of the material, the
strength of the material, the slipperiness of the material after
solidification or to the ability of the solidified material to
absorb liquid substances.
[0025] As an example, the part of the catheter which is adapted for
insertion into the body canal, may be coloured in a colour
different from the colour of the other parts of the catheter. In
that way, the user can easily avoid touching the insertable part of
the catheter.
[0026] In order to reduce the resistance against insertion into the
body canal, the radial size of the tip may be larger than the
radial size of the rest of the catheter. As an example, the tip may
be formed into an onion-shaped or bulbous knob or the tip may be
formed with a conical shape. Preferably, the tip is provided with a
first end part, fronting the body canal opening during the
insertion and provided with a narrow radial size. From this end
part, the tip widens out in an intermediate part until the radial
size exceeds the radial size of the catheter body part. Between the
intermediate part of the tip and the catheter body part, the radial
size slopes down in a second end part until the radial size of the
catheter body part.
[0027] Inlet openings for draining bodily fluid from a body cavity
and into the catheter may be provided either in the first end part,
in the intermediate part or in the second end part or in more than
one part or even en all of the parts. As an example, the tip may be
formed in with a plurality of small holes in the tip.
[0028] According to a second aspect, the present invention relates
to a catheter formed by the above described method and comprising
the above described features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Preferred embodiments of the invention will now be described
in details with reference to the drawing in which:
[0030] FIG. 1 shows an injection-moulded catheter with a tip and a
connector,
[0031] FIG. 2 shows a bulbous catheter tip,
[0032] FIG. 3 shows a conical catheter tip,
[0033] FIG. 4 shows a spherical catheter tip,
[0034] FIG. 5 shows a catheter with a reservoir for collecting
bodily fluids, and
[0035] FIG. 6 shows a catheter in the form of an oblong solid
kernel with a plurality of vanes extending radially from the kernel
and along the entire length thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Further scope of applicability of the present invention will
become apparent from the detailed description given hereinafter.
However, it should be understood that the detailed description and
specific examples, while indicating preferred embodiments of the
invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the
invention will become apparent to those skilled in the art from
this detailed description.
[0037] Referring to FIG. 1, the invention relates to a method of
producing a catheter 1 by injecting a fluid catheter material into
a mould formed to define an insertable catheter tip 3 and a
catheter body 4 and subsequently solidifying the material therein.
As shown, a catheter connector section 7 may be formed in one part
with the catheter body. Furthermore, means 8 for attaching the
catheter to peripheral articles for easing the handling of the
catheter could be formed in one part with the catheter body during
the moulding process.
[0038] In the insertable end, i.e. in the vicinity of the tip, a
draining hole 2 allows bodily fluids to flow from a body cavity and
into an internal conduit of the catheter. The internal conduit
transports the fluid to the connector part where the fluid can be
disposed into a bag or into a place of disposal.
[0039] The catheter of FIG. 1, is on its insertable part provided
with a friction reducing material 5 and on its non-insertable part
with a highly frictional material 6. The friction reducing material
supports in a safe and easy insertion of the catheter into a body
canal such as the urethra and the highly frictional material
supports an easier grip in the non-inserted part and thus supports
for easier manipulation of the catheter. The characteristics of the
materials 5 and 6, respectively, could also relate to different
colours indicating to the user which part of the catheter is
intended to be inserted. The characteristics could also relate to
different resiliency of the insertable part versus the
non-insertable part e.g. allowing the inserted part easily to
follow a curved body canal, e.g. for passing through the urethra
around the prostate.
[0040] FIGS. 2, 3 and 4 shows three different alternative tip
shapes, i.e. a bulbous tip 10 of FIG. 2, a conical tip 20 of FIG. 3
and a spherical tip 25 of FIG. 4. The tip is provided in the
inserted end of the catheter body 11 in one part with the body and
during the moulding process. The tip is formed with a first end
part 12 with a radial size which is smaller than the radial size of
the catheter body, an intermediate part 13 with a radial size which
is larger than the radial size of the catheter and a second end
part 14 wherein the size slopes down to the radial size of the
catheter. In order to allow bodily fluids to drain into an internal
conduit of the catheter, draining holes are provided in one or more
of the parts of the tip. In FIGS. 2 and 3, draining holes 15 are
provided in the first end part and draining holes 17 are provided
in the second end part. The tip is internally moulded with a
conduit 16 for guiding the fluid to the body part of the catheter.
As shown in FIG. 4, a draining hole or holes may be provided in the
tip, so that the opening point in the axial direction of the
catheter body. In that case it is important that edges of the hole
or holes are smoothly rounded in order not to injure the body
canal.
[0041] FIG. 5 shows a catheter 30 and a reservoir 31 formed by
moulding in one part for collecting the bodily fluids, e.g. blood
or urine. The reservoir could be formed during the injection
moulding process by combining the injection moulding process with
blow moulding. During this process, pressurized gas is used for
expanding the reservoir part of the catheter product into a plastic
bag or plastic bottle shaped item. The reservoir may, during the
moulding process, be provided with filling level indication marks
33 and may internally be provided with a hydrophilic material for
the conversion of a liquid substance into a substantially solid or
gel-like substance.
[0042] FIG. 6 shows catheter in the form of a solid kernel 36 with
a plurality of radially extending vanes 37. The vanes form a number
of draining passages for draining urine between the kernel and a
bodily draining passage, e.g. the urethra.
[0043] The invention being thus described, it will be apparent that
the same may be varied in many ways. Such variations are not to be
regarded as a departure from the spirit and scope of the invention,
and all such modifications as would be recognized by one skilled in
the art are intended to be included within the scope of the
following claims.
* * * * *