WO2025196453A1

WO2025196453A1 - Laser welding of catheter assembly components

Info

Publication number: WO2025196453A1
Application number: PCT/GB2025/050606
Authority: WO
Inventors: Alexander Savitski; Tom BOLTON; Aliaksandr PIASHEVICH; Marian NOVAK
Original assignee: Convatec Ltd
Current assignee: Convatec Ltd
Priority date: 2024-03-22
Filing date: 2025-03-21
Publication date: 2025-09-25
Anticipated expiration: 2026-09-22

Abstract

A method of manufacturing a catheter assembly comprises providing a catheter (1) and a drainage element (5,6), arranging the drainage element (5,6) such that fluid may flow along the catheter (1) to the drainage element (5,6), and directing a laser beam onto the drainage element (5,6) to form a laser weld. The laser weld is formed between the catheter (1) and drainage element (5,6), or between first and second drainage elements (5,6). The drainage element (5) may comprise a plurality of projections (21) extending from a tube. The projections and tube may together define the external profile of the drainage element. The drainage element (5) may comprise a weld zone (A) that is larger than a spacing between adjacent projections and which has a similar internal and external profile to enable laser welding of the drainage element (5) to the catheter (1).

Description

Laser welding of catheter assembly components

Technical Field of the Invention

The present invention relates to methods of manufacturing catheter assemblies using laser welding. The invention also relates to components of catheter assemblies, such as drainage elements for a catheter like a funnel, that are optimised for laser welding. In particular, the invention relates to intermittent urinary catheter assemblies. to the Invention

Many people suffer from urinary problems that can make it difficult to pass urine. Intermittent catheter assemblies can provide a convenient and portable solution to this problem as a user is able to self-catheterise to relieve themselves as required. This reduces the effect of their urinary condition on their life and allows thm to enjoy a relatively normal lifestyle.

Known urinary catheter assemblies comprise funnels to direct the flow of liquid out of the catheter in use. For example, the funnel may be used to direct liquid from the catheter into a toilet bowl or other suitable receptacle. This can make the catheter assembly easier and more hygienic to use as the user is less likely to spill urine or have it contact their hands or clothing. Where a catheter assembly is used in this way without collecting the urine, it is known as a “open” catheter assembly.

Alternatively, the catheter assembly may be a “closed” catheter assembly and comprise a fluid collection bag, or other suitable receptacle, fluidly connected to the catheter to collect urine that flows along the catheter. In closed catheter assemblies, a connector is typically provided to connect the urine bag to the catheter, for example the connector could be attached directly to the catheter or it could be a separate device in fluid communication with the catheter via attachment to a funnel.

To ensure a catheter assembly is easy, hygienic and comfortable to use, it is important that the different components are securely attached to one another and without any significant risk of leakage of fluid between components. Existing methods for manufacture of catheter assemblies have employed an adhesive to adhere different components together, or alternatively have used solvents to bond the generally plastic catheter components together. While adhesive and solvent bonding can provide secure and hermitic attachment of components, there is a need to provide alternative means of attaching catheter components together, for example, use of an adhesive or solvent necessitates liquid/gel handling during manufacture which can be problematic and difficult to automate. In addition, the adhesive or solvent is itself an additional consumable that needs to be purchased and stored which adds complexity to the manufacture process, and can increase the environmental cost of the process due to the hazardous nature of the consumable and/or additional energy usage of the process.

It is an object of embodiments of th present invention to at least partially overcome or alleviate the above problems and/or to provide an improved method of manufacturing a catheter assembly and an improved catheter assembly.

Summary of the Invention

In broad terms, the invention concerns a method of manufacturing a catheter assembly comprising providing at least two catheter assembly components and directing a laser beam onto two of the at least two catheter assembly components to form a laser weld therebetween.

A catheter assembly component may be a catheter. The method may comprise providing a catheter. The catheter may comprise a proximal end for insertion into the body. The catheter may comprise a distal end.

A catheter assembly component may be a drainage element. The drainage element may comprise any one or more features of the catheter assembly component as described above and herein. The method may comprise providing one or more drainage elements. The method may comprise providing a first and a second drainage element. The first drainage element may be arranged to receive fluid flowing along the catheter.

The method may comprise arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element.

The method may comprise directing a laser beam onto the first and second drainage elements to form a laser weld therebetween. Thus, in some aspects, the invention provides a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween.

Thus, laser welding is advantageously used to securely attach two or more catheter components together, such as drainage elements, without the need for any additional materials like adhesives or solvents.

The first drainage element may be provided by the distal end of the catheter. The second drainage element may be a funnel. The first drainage element may be a funnel connectable to the distal end of the catheter. The second drainage element may be a connector. Thus, the method facilitates flexible attachment of different catheter assembly components to provide both open and closed assemblies.

In a first aspect of the invention, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector.

Advantageously, laser welding provides a convenient and novel method of attaching different drainage elements of a catheter assembly together. This technique enables secure welds to be formed between the different components of the catheter assembly without additional raw materials and with high accuracy and repeatability. Additionally, it removes the need for careful placement of liquids between the components during manufacture as the components can be simply placed next to each other and then welded with the laser. Laser welding is also suitable for creating fluid- tight hermetic seals between components which is particularly important in the field of catheter assemblies.

The catheter may be a urinary catheter. The catheter may be a male urinary catheter (i.e. a catheter for catheterisation of men). The catheter may be a female urinary catheter (i.e. a catheter for catheterisation of women). The catheter may be an intermittent catheter. In one embodiment, the catheter is an intermittent urinary catheter. The catheter may be tubular. The distal end of the catheter may be tubular.

One of the first or second drainage elements may be an outer element. The other of the first or second drainage elements may be an inner element. For example, the first drainage element may be the outer element and the second drainage element may be the inner element, or vice versa. Preferably, where a drainage element is a funnel, it is the outer element. Thus, the funnel may be designed to fit around the other drainage elements and ensure a secure and efficient laser weld therebetween, for example as described below in relation to the third aspect of the invention.

The method may comprise directing the laser beam onto the inner element via the outer element. Thus, the laser beam may be incident on the outer element and then the inner element. The method may comprise directing the laser beam through the entire thickness of the outer element and then onto the inner element. This allows the method to be performed non-invasively as the laser beam penetrates through the drainage elements to create the laser weld.

The first and/or second drainage elements may comprise a non-reflective coating. The outer element may comprise a non-reflective coating on an outer surface. The laser may be directed onto the outer surface of the outer element. The interface between the first and second drainage elements may be non-reflecting. The refractive indices of the first and second drainage elements may be similar, or preferably, substantially the same. Thus, the welding process is more efficient as reflections are minimised. The method may comprise absorbing part of the laser beam into the outer element, preferably to cause melting of the outer element during formation of the laser weld. The method may comprise heating the outer element via absorption of the laser beam by the outer element. Thus, the laser is absorbed by the outer element to the extent that it melts which facilitates formation of a strong weld. The method may comprise melting a majority of the thickness of the outer element during formation of the laser weld. The method may comprise melting the entire thickness of the outer element during formation of the laser weld. Thus, more of the outer element is able to contribute to the weld further enhancing the weld strength.

The method may comprise absorbing no more than 50%, no more than 40%, no more than 30% of the laser beam by the outer element. The method may comprise absorbing at least 10%, at least 20%, or at least 30% of the laser beam by the outer element. The method may comprise absorbing 10-40%, or 20-30% of the laser beam by the outer element. Thus, a significant portion of the beam is available for absorption by the inner element.

The method may comprise absorbing part of the laser beam into the inner element. The method may comprise heating the inner element via absorption of the laser beam by the inner element. The method may comprise delivering sufficient energy to the inner element via laser absorption to heat, but preferably not melt the inner element. The method may comprise softening the inner element. Thus, the laser beam is absorbed by the inner element to heat and soften it but not necessarily to melt it. This ensures that the structural stability of the inner element remains and enables it to maintain the typical tubular construction of the relevant drainage element without it collapsing and blocking. As both elements are heated, the method may involve increasing weld pressure by thermal expansion of the elements.

The method may comprise using the laser beam to heat the outer element to a higher temperature than the inner element. The method may comprise melting the inner element via heat conduction from the outer element. The method may comprise melting a surface (e.g. an outer surface) of the inner element in contact with the outer element, preferably by heat conduction from the outer element. A surface (e.g. an inner surface) of the inner element distal from the outer element is preferably not melted during formation of the laser weld. Thus, the outer element may advantageously heat the inner element and enable a more localised weld to form without compromising the structural properties of the drainage elements. Advantageously, melting of the inner element may be driven by a combination of laser absorption and heat conduction from the outer element. This is preferably compared to just laser absorption as this could compromise the drainage element structure if its entire thickness is melted. It is also preferably compared to just heat conduction as it reduces temperature differences in the material during welding.

The outer element may comprise an inner surface and an outer surface. The inner element may comprise an inner surface and an outer surface. The method may comprise arranging the inner surface of the outer element in contact with the outer surface of the inner element. The inner surface of the outer element may match the outer surface of the inner element in regions where the laser weld is formed. In regions where the laser weld is formed and before welding, a gap between the inner and outer elements may be no more than 0.4 mm, no more than 0.3 mm, or no more than 0.2 mm, or no more than 0.1 mm. Before welding, the inner and outer elements in regions where the laser weld is formed may be in intimate contact. Before welding, the inner and outer elements may be held together by an interference fit. The intimate contact and/or interference fit ensure the laser weld can be formed effectively.

A thickness of an element may be defined between the inner and outer surfaces. The thickness of the outer element may be no more than 5 mm, no more than 4 mm or no more than 3 mm. The thickness of the outer element may be at least 0.5 mm, or at least 1 mm. Preferably the thickness of the outer element is 0.8 to 0.9 mm. The thickness of the inner element may be no more than 2 mm, no more than 1 mm or no more than 0.5 mm. The thickness of the inner element may be at least 0.1 mm, or at least 0.2 mm or at least 0.5 mm. The thickness of the inner element is preferably 0.5 to 1 mm. The thickness of the drainage elements may be substantially constant across the laser weld. Thus, the weld is more effectively formed due to an appropriate and preferably constant wall thickness.

The method may comprise (at least partially) melting the first and/or second drainage elements during formation of the laser weld. Preferably, both the first and second drainage elements are partially melted during formation of the laser weld. The method may comprise melting a melt zone of the first and/or second drainage elements. The melt zone may encompass parts of the first and second drainage elements. The method may comprise placing an inner surface of the outer element in contact with a outer surface of the inner element. The method may comprise partially melting the inner surface of the outer element. The melt zone may comprise the outer surface of the inner element. The method may comprise partially melting the outer surface of the inner element. The melt zone may extend at least 50%, or at least 80%, or at least 90% through the thickness of the outer element. The melt zone may comprise an outer surface of the outer element. The melt zone may span substantially all of the thickness of the outer element. The melt zone may not comprise a surface (e.g. an inner surface) of the inner element distal from the outer element. The melt zone may extend no more than 50%, or no more than 40%, or no more than 30% through the thickness of the inner element. The melt zone may extend at least 5%, or at least 10%, or at least 20% through the thickness of the inner element. The method may comprise allowing the first and/or second drainage elements to solidify to form the laser weld. Thus, strong and permanent bonds between the first and/or second drainage elements are formed via the laser welding process without compromising the structure of the inner element.

The method may comprise placing an external fixture against the outer surface of the outer element. The method may comprise controlling the shape of the outer surface using the external fixture. The external fixture may be substantially transparent to the laser beam. The external fixture may be formed from glass, quartz or a fluoropolymer. Thus, the aesthetic appearance of the outer surface can be controlled and improved if required.

The laser weld may be configured to provide a fluid-tight seal, for example between the first and second drainage elements. The laser weld may be configured to prevent separation of the first and second drainage elements from one another. The first and second drainage elements may be secured together without application of an adhesive, for example in a region of overlap between the first and second drainage elements. Thus, the laser weld both ensures that gases and liquids cannot pass out of the catheter assembly unintentionally which prevents unpleasant smells and leaks of liquid. In addition, the laser weld provides structural integrity of the catheter assembly by preventing the first and second drainage elements from separating from one another without the need for adhesives.

The drainage elements may be tubular. The drainage elements may comprise an axis along their tubular shape. The drainage elements may be configured to fit within one another co-axially. The method may comprise arranging the drainage elements coaxially. The method may comprise pressing the inner and outer elements against one another, preferably during formation of the laser weld. The outer surface of the inner element may not fit within the inner surface of the outer element without deformation of the inner and/or outer element. The method may comprise deforming the inner and /or outer element to fit the inner element within the outer element. A diameter or width of the inner element (or outer element) may be reduced (or increased) by at least 1% or at least 2% or at least 3% when the inner and outer elements are arranged together. A diameter or width of the inner element (or outer element) may be reduced (or increased) by no more than 10% or no more than 8% or no more than 6% when the inner and outer elements are arranged together. Preferably, a diameter or width of the inner element (or outer element) may be reduced (or increased) by 3% to 8% when the inner and outer elements are arranged together. These changes may be due to compression of the inner element and/or stretching of the outer element. The inner surface of the outer element may be tapered. The inner element may be formed of a resilient material. The inner/outer element may bear against the outer/inner element. Thus, the elements are deformed and thereby presses against one another which enables a close fit and ideal conditions for forming a laser weld.

The method may comprise forming a weld that extends around the perimeter of the drainage elements when viewed down their axis. Preferably, the laser weld may extend all the way around the perimeter of the drainage elements when viewed down their axis. Thus, a fluid-tight seal may be formed using the laser weld. The laser weld may provide a fluid-tight seal between the drainage elements.

The laser weld may be any suitable shape or size, but is preferably a continuous loop. A weld area at the interface between the first and second drainage elements may be defined by the total area of the interface between the drainage elements which comprises a laser weld. The weld area may extend no more than 10 mm, no more than 8 mm or no more than 6 mm along the axis of the drainage element. The weld area may extend at least 2 mm, at least 3 mm or at least 4 mm along the axis of the drainage element. The weld area may extend at least the thickness of the drainage element along the axis of the drainage element. The weld area may extend at least twice the thickness of the drainage element along the axis of the drainage element. The thickness may be measured as an average across the weld area. The weld area may comprise a plurality of independent laser welds. The weld area may define a weld zone. Thus, the laser weld more securely retains the drainage elements together.

The method may comprise forming a laser weld spaced from an edge of the first and second drainage elements. The laser weld may be spaced by at least 1 mm, at least 2 mm or at least 5 mm. Thus, the edges of the drainage elements are not melted which helps maintain their structure and shape.

The method may comprise forming two or more laser welds between the first and second drainage elements. Each of the two or more laser welds may have any one or more of the optional features of the weld mentioned above and may be formed according to the method described herein and any one or more of the optional features of that method. Each of the two or more laser welds may be different or may be formed differently. Each of the two or more laser welds may be independent. Thus, the drainage elements may be more securely held together via multiple welds.

The method may comprise forming a laser weld configured to resist separation of the drainage elements. The laser weld may resist movement of the drainage elements with respect to each other. The laser weld may comprise a weld strength defining a force which it can resist. The weld strength may be at least 10 N, at least 15 N, at least 20 N, at least 40 N or at least 60 N. The weld strength may be no more than 200 N, no more than 100 N or no more than 80 N. The weld strength is preferably 60 N or more. Optionally, the weld strength is 60 N to 200 N, or 60 N to 150 N, or 60 N to 100 N, or 60 N to 80 N. The laser weld may resist axial separation, and optionally axial movement, of the drainage elements. Axial movement/separation may be movement/separation in a direction along an axis of the drainage elements. The weld strength may therefore be a tensile strength. Thus, the tensile strength of the weld is high enough to ensure the structural integrity of the catheter assembly in use, but also is not excessively strong such that the overall functionality and manufacturing complexity are negatively affected.

The drainage elements (e.g. first and second drainage elements) may be arranged to volumetrically absorb the laser beam. Volumetric absorption of the laser beam may account for the majority of, or preferably substantially all of, the heat generated during welding. Surface absorption, or interfacial absorption, may account for a minority, or preferably substantially none of, the heat generated during welding. Thus, the laser beam is absorbed volumetrically which helps provide even homogeneous heating of the drainage elements without specific additives to drive absorption processes.

The drainage elements may each comprise a thermoplastics material. The thermoplastics material may volumetrically absorb the laser beam, preferably to cause heating, and optionally melting, of the material. The outer element may comprise a material that has a higher absorption co-efficient than the inner element. Thus, the outer element may be preferentially heated compared to the inner element.

In the method, the laser weld may be formed primarily as a result of volumetric absorption of the laser beam. The laser beam and first and second drainage elements may be configured such that during formation of the laser weld volumetric absorption in the first and/or second drainage element generates more heat than interfacial absorption at an interface of the first and second drainage elements. Many suitable configurations, such as use of thermoplastic materials and selection of specific laser wavelengths are described herein. This enables more effective welding as more material of the drainage elements engage in the welding process.

The thermoplastic material may comprise a material that is suitable for laser welding. The thermoplastics material may comprise polyethylene (high density (HDPE) and low density (LDPE)), ethylene-vinyl acetate (EVA), ethylene methyl acrylate (EMA), thermoplastic elastomer (TPE) or the like. The first and second drainage elements may be formed of the same material, or alternatively, may be formed of different materials. Where the first and second drainage elements are formed of different materials, they are preferably formed of materials which can form a laser weld therebetween when melted. The catheter may be formed of TPE. The funnel may be formed of LDPE or EVA. The connector may be formed of LDPE or EVA. The catheter may be formed of a different material to the funnel and/or connector. The funnel and connector may be formed of the same material. Preferably, both drainage elements are formed of a material comprising polyethylene. Thus, the drainage elements may be formed of a wide variety of materials.

The melt zone may be free from additives configured to absorb visible light. There may be no such additives between the drainage elements, and/or in either the drainage elements. Thus, the laser is selected such that the visible colour of the drainage elements does not need to be altered through the addition of additives, such as carbon black, which may make the product unacceptable from a quality I user appeal perspective.

The laser used to form the laser weld may have a wavelength outside visible light. The method may comprise using non-visible light to form the weld. The laser may be a microwave laser. The laser may have a wavelength of over 1 ,000 nm. The laser may have a wavelength of over 1.1 microns, preferably over 1.2 microns. The laser may have a wavelength of over 1.4 microns. The laser may have a wavelength of over 1.6 microns. The laser may have a wavelength of over 1.8 microns. The laser may have a wavelength of over 1.9 microns. The laser may have a wavelength of no more than 3 microns. The laser may have a wavelength of no more than 2.5 microns. The laser may have a wavelength of no more than 2.3 microns. The laser may have a wavelength of no more than 2.2 microns. The laser may have a wavelength of no more than 2.1 microns. The laser may have a wavelength of 1.2 to 2.2 microns. The laser may have a wavelength of 1.6 to 2.2 microns. The laser may have a wavelength of about 2 microns, preferably about 2.0 microns and most preferably 1,940 nm. Thus, the laser wavelength can be selected such that it is easily volumetrically absorbed by the thermoplastics materials to ensure efficient heating through the thickness of the base plate. A wavelength in the range over 1.1 microns is preferred as this is outside the selective heating window of about 0.8 to 1.1 microns. In this selective heating window thermoplastic materials exhibit very low volumetric absorption and require additives in order to absorb sufficient energy to melt. A laser wavelength in the range of 1.2 to 2.2 microns is preferred due to the moderate volumetric absorption properties of thermoplastic materials at these wavelengths. A laser wavelength in the range of 1.6 to 2.2 microns is more preferred as it provides further improved absorption in thermoplastics compared to below 1.6 microns. Around 2 microns and specifically 1940 nm is most preferred due to the wide commercial availability of cheap laser sources at these wavelengths.

Of course, in alternative embodiments, different wavelengths may be chosen. In such situations one or both drainage elements may comprise additives to facilitate laser welding. Preferably, the inner element may comprise additives configured to absorb the laser and generate heat. The additives may comprise carbon black. In such embodiments, the inner element may be heated more than the outer element. The inner element may be melted by absorption of the laser beam by the additives. The outer element may be melted by heat conduction from the inner element.

The laser may be a continuous wave laser. The laser power density incident on the outer element during welding may be at least 20 Wmm'², 40 Wmm'², 60 Wmm'², or 80 Wmm^-2. The laser power density incident on the outer element during welding may be no more than 80 Wmm^-2, 60 Wmm^-2, 40 Wmm^-2, or 20 Wmm^-2. Preferably the laser power density is 60-65 Wmm^-2. The beam width may be at least 2 mm. Thus, the laser weld can be efficiently formed without burning the material.

The method may comprise forming the first and/or second drainage elements. The method may comprise injection moulding the first and/or second drainage elements. The funnel may be formed by injection moulding. The connector may be formed by injection moulding.

The method may comprise forming a laser weld between the catheter and funnel. The method may comprise forming a laser weld between the funnel and connector. The method may comprise forming a first laser weld between the catheter and funnel, and forming a second laser weld between the funnel and connector. Thus, laser welding can be used to attach multiple catheter assembly components together if required. The method may comprise providing a sleeve. The method may comprise arranging the catheter inside the sleeve. The method may comprise attaching the funnel and/or connector to one end of the sleeve. The sleeve may be configured to enclose at least part of the catheter from the proximal end to the distal end. The sleeve may be configured to enclose the majority of the catheter from the proximal end to the distal end. The sleeve may be configured to enclose substantially all of the catheter from the proximal end to the distal end. The sleeve may be formed of a flexible plastics material. Thus, the catheter is protected and easier to handle.

The catheter assembly may comprise a fluid collection bag. The method may comprise providing a fluid collection bag. The method may comprise arranging the fluid collection bag in fluid communication with the catheter. The fluid collection bag may comprise an inlet to allow fluid to enter the bag. The fluid collection bag may be directly connected to the funnel. The funnel may provide the inlet. Thus, the assembly may be arranged for fluid to flow from the catheter, through the funnel and directly into the fluid collection bag. The funnel may therefore function as a connector if required.

The fluid collection bag may be directly connected to the connector. The connector may provide the inlet. Thus, the assembly may be arranged for fluid to flow from the catheter, through the funnel, through the connector and then into the fluid collection bag.

The fluid collection bag may be any suitable shape or size, for example rectangular, circular, elliptical, cuboid, spherical, etc. The fluid collection bag may comprise a front panel and a rear panel. The fluid collection bag may comprise a peripheral bond joining the periphery of the front panel and rear panel to form the fluid collection bag. The peripheral bond may define a base, two lateral edges and an upper edge of the fluid collection bag. The two lateral edges may comprise a right lateral edge and a left lateral edge. The right lateral edge and left lateral edge may be defined as the right and left sides of the bag when viewing the bag with the rear panel behind the front panel, the base at the bottom of the bag and the upper edge at the top of the bag. The bag may have a width between the left lateral edge and right lateral edge of at least 10, 12, 15 or 20 cm. The bag may have a width no more than 25, 20, or 15 cm. Preferably, the width is between 10 and 20 cm, most preferably between 12 and 15 cm. The base may define a bottom of the bag. The upper edge may define a top of the bag. The height of the bag from the base to the upper edge may be at least 25, 30, 35 or 40 cm. The height of the bag may be no more than 45, 40, 35 or 30 cm. The height may be between 25 and 40 cm, 30 and 35 cm, or most preferably 33 and 35 cm. The bag may be configured to hold at least 500, 700, or 1000 ml of fluid, and may hold no more than 1000 ml, for example, it may hold at least 700 ml of fluid.

The fluid collection bag and/or sleeve may comprise a flexible plastics material. For example, polypropylene (PP), polyethylene terephthalate (PET), low density polyethylene (LDPE), metalized polyester (MET PET), orientated polypropylene (OPP), or polyvinyl chloride (PVC). Thus, in some embodiments, the method may comprise attaching the fluid collection bag and/or sleeve to another catheter assembly component by laser welding.

The peripheral bond may provide a water-tight seal. Preferably, the peripheral bond provides a sterile seal. The peripheral bond may comprise any one or more of: a weld; mechanical seal; heat seal; pressure seal; adhesive; solvent bond; ultraviolet bond; ultrasonic weld; laser weld; impulse weld; or friction weld. This ensures that the catheter is maintained within a sterile environment prior to use and also that once the catheter has been used any fluid contained within the bag does not leak out unintentionally.

According to a broad aspect of the invention, there is provided a catheter assembly manufactured by a method comprising the steps of: providing at least two catheter assembly components; and, directing a laser beam onto two of the at least two catheter assembly components to form a laser weld therebetween.

According to a second aspect of the invention, there is provided a catheter assembly manufactured according to the method of the first aspect of the invention above.

Thus in a broad aspect, the invention also provides for a catheter assembly comprising a catheter and first and second drainage elements, wherein the first and second drainage elements are arranged such that fluid may flow along the catheter to the first drainage element and then to the second drainage element, and the first and second drainage elements are attached to one another by a laser weld. Such a catheter assembly can of course include any one or more of the features of the methods, catheter assemblies, catheter assembly components and drainage elements described herein.

In broad terms, the invention also relates to a catheter assembly component that is optimised for laser welding. The catheter assembly component may comprise a weld zone to facilitate formation of a laser weld between it and another catheter component.

The catheter assembly component may have an internal profile. The catheter assembly component may have an external profile. In the weld zone, the external and internal profiles of the catheter assembly component may be similar to one another. The catheter assembly component may comprise a plurality of projections. The projections may define the external profile. The catheter assembly component may comprise a tube. The tube may define the internal profile. The tube may define the external profile, preferably together with the projections. The catheter assembly component may be a drainage element for a catheter.

In one aspect, there is provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone to facilitate formation of a laser weld between the drainage element and catheter.

The plurality of projections may be arranged with a spacing between the centres of adjacent projections in a first direction. The weld zone may span at least the spacing in the first direction.

According to a third aspect of the present invention, there is provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element are similar to one another in the weld zone to facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction.

Advantageously, the drainage element in the weld zone thereby has a roughly constant thickness. This helps the formation of a weld because as the drainage element melts during welding, there is less likely to be large changes in shape or disfiguration of the surface of the drainage element. This helps ensure the weld is strong and less visible once formed.

By including protrusions, the weld zone may be recessed with respect to the tips of the projections. This helps ensure that the weld is less visible to the user and also that the external profile can be adapted to ensure the drainage element is easy to handle for the user. Due to the projections, the drainage element is also suitable for manufacture by injection moulding without significant risk of sink marks.

As mentioned above, the weld zone spans at least the spacing of projections in the first direction. In other words, the weld zone extends over at least the spacing in the first direction. The spacing is therefore not measured/defined across the weld zone. Where the weld zone is provided between two projections, those two projections are not adjacent. So, the weld zone provides a region suitable for welding that has a size in the first direction at least as large as the spacing. Thus, the weld zone is generally provided on one side of at least two spaced projections.

The drainage element may comprise two adjacent projections spaced in the first direction then the weld zone extending from the two adjacent projections. The drainage element may therefore comprise two adjacent projections on one side of the weld zone. The drainage element may comprise two adjacent projections on the other side of the weld zone. For example, along the first direction, the drainage element may comprise two adjacent projections with a spacing therebetween, then the weld zone, then another two adjacent projections with a spacing therebetween, and the weld zone spans at least the spacing of either of the two adjacent projections in the first direction. This arrangement may be provided for each weld zone where the drainage element comprises multiple weld zones. This can help ensure the weld is less visible to the user as the weld zone is recessed between the projections, while also making the drainage element easier to handle.

The drainage element may be open ended. The drainage element may comprise an inlet end. The inlet end may be configured to be coupled to the catheter. The drainage element may comprise an outlet end. The drainage element may have a length measured between the inlet and outlet ends. The outlet end may be configured to allow liquid to pass out of the drainage element in use. The drainage element may comprise an outlet portion. The outlet portion may be configured to direct the flow of liquid out of the drainage element. The outlet end may be provided in the outlet portion. The outlet portion may be generally tubular. The outlet portion may be tapered. The outlet portion may have a substantially constant wall thickness. The outlet portion may be frustoconical.

The drainage element may comprise a locator. The locator may be configured to identify the orientation of the catheter. The locator may be positioned to correspond to a curve in the catheter. The locator may be provided where the catheter is a coude catheter. The locator may be positioned upwards in use. The locator may comprise a locator rib. The locator rib may extend along at least part of the length of the drainage element. The locator may comprise a locator marking. Thus, the locator assists the user in using the catheter and aligning it with their bladder once inside the body.

The drainage element may comprise an inlet portion. The inlet end may be provided in the inlet portion. The outlet portion may be joined to the inlet portion. The outlet portion may be narrowest at the point it meets the inlet portion. The inlet portion may be narrowest at the point it meets the outlet portion. The outlet portion may cover at least 40%, at least 50%, at least 60%, at least 70% or at least 80% the length of the drainage element. The outlet portion may cover no more than 80%, no more than 70%, no more than 60%, or no more than 50% the length of the drainage element. Preferably the outlet portion covers 60-70% the length of the drainage element. Preferably the outlet portion is longer than the inlet portion.

The inlet portion may be configured to receive the catheter. The inlet portion may be configured to provide a liquid path from the inside of the catheter into the drainage element. The inlet portion may be configured to engage the catheter. The inlet portion may be configured to receive the distal end of the catheter. Thus, the catheter may be securely attached to the drainage element.

A plurality of gaps may be provided between the plurality of projections. The spacing between adjacent projections may be substantially constant in regions outside a weld zone. The inlet portion may comprise a handling zone. The handling zone may comprise at least two of the plurality of projections. In the handling zone, the tips of the projections may together define a handling surface. In the handling zone, the external profile and internal profile may be different. The handling surface may extend across the gaps. Thus, the tips of the projections enable a handling surface to be defined and its feel and shape controlled using the size of the projections to ensure the drainage element is easy to use. Advantageously, when gripping the drainage element, the drainage element is more easy to grip because the alternate gaps and protrusions provide a undulating surface. However, the appearance and feel of the drainage element remains enhanced due to the handling surface being defined by the tips of the protrusions.

The weld zone and handling zone may not be overlapping. In the handling zone, the spacing between adjacent projections may be at least 0.5 mm, at least 1 mm, or at least 2 mm. In the handling zone, the spacing between adjacent projections may be no more than 5 mm, 3 mm or 2 mm. Preferably, in the handling zone, the spacing between adjacent projections is about 2 mm. The spacing between projections may be at least the thickness of the drainage element. The spacing between projections may be no more than twice the thickness of the drainage element. The thickness may be measured at a midpoint between the projections. The spacing may be substantially constant across three or more projections. The spacing may be substantially constant within a handling zone. This helps provide a more ergonomic feel to the handling zone.

The internal profile of the drainage element may comprise a stepped region. A region of the handling surface corresponding to the stepped region may be smooth. The external profile/handling surface may therefore be substantially different from the internal profile. This allows additional design freedom to optimise the internal and external profiles, and handling surface, for their different functions. While a stepped region is given as an example, the internal profile may alternatively be chamfered, tapered or have a different irregular shape, and a corresponding part of the handling surface be smoothed or otherwise have a different shape as defined by the tips of the protrusions.

In addition, due to the projections, the drainage element is able to be manufactured cheaply and easily using injection moulding and without suffering from sink mark artefacts associated with injection moulding of objects with varying wall thickness. The projections also reduce the total material required reducing weight and cost. This also provides a more pleasant experience for the user when manipulating the drainage element while the internal profile is stepped. Due to the provided design freedom to alter the internal profile independently of the handling surface, the same drainage element to be used for different types/sizes of catheter. This means manufacturing is cheaper and simpler as less types of drainage element need to be produced for all the different types/sizes of catheter.

The first direction may be substantially parallel to the axis of the catheter when received in the inlet portion. The weld zone may be at least 50%, at least 75% or at least 100% larger than the spacing in the first direction. The weld zone may be no more than 5 times, 4 times or 3 times larger than the spacing in the first direction. Preferably, the weld zone is about double the spacing in the first direction, for example spanning about 4 mm in the first direction. The weld zone may extend over a distance of at least the thickness of the drainage element, at least twice the thickness of the drainage element, or at least three times the thickness of the drainage element. The weld zone may extend over a distance of no more than four times the thickness of the drainage element, no more than three times the thickness of the drainage element, or no more than twice the thickness of the drainage element. The thickness may be measured as an average across the weld zone. This ensures that the weld zone can provide a widened band around the drainage element.

The tube may have a substantially constant wall thickness. The projections may have a wall thickness that is substantially the same as the wall thickness of the tube. The wall thickness of the tube may be at least 0.5 mm, at least 0.7 mm, or at least 1 mm. The wall thickness of the projections may be no more than 1.5 mm, no more than 1 mm, no more than 0.7 mm. The wall thickness of the projections may be at least 0.5 mm, at least 0.7 mm, or at least 1 mm. The wall thickness of the tube may be no more than 1.5 mm, no more than 1 mm, no more than 0.7 mm. Thus, the wall thicknesses are the same which means that the drainage element can be effectively manufactured with injection moulding and without sink mark artefacts.

The projections may have a radial length defined as the distance the projections extend from the internal tube in a radial direction. The radial length may change along the length of the drainage element. Changes in the radial length may counter changes in the internal profile. The radial length may be at least 1 mm, at least 1.5 mm, at least 2mm. The radial length may be no more than 3 mm, no more than 2 mm or no more than 1.5 mm. Thus, the length of the projections can be easily adjusted to ensure the correct handling surface for the drainage element irrespective of the internal profile.

The inlet portion may comprise one or more catheter receiving zones. The inlet portion may comprise two or more catheter receiving zones, preferably only two catheter receiving zones. Each catheter receiving zone may be configured to receive a different catheter. For example, a different size, shape and/or type of catheter. The catheter receiving zones may be arranged in series. The catheter receiving zones may be arranged substantially co-axially. This can allow the same specification of drainage element to be used with different catheters in a production line, which simplifies the manufacture process for a range of catheters.

The stepped region may comprise at least two steps in the internal profile. The internal profile of the inlet portion may comprise a step between adjacent catheter receiving zones. The step may provide a stop or flange at one end of a catheter receiving zone. This helps ensure that a catheter is not over inserted into the inlet portion.

The inlet portion may comprise two or more weld zones. The two or more weld zones may be spaced from one another. The two or more weld zones may be spaced from one another along an axis of the tube. The two or more weld zones may correspond to regions of the tube with different diameters. A weld zone may be provided for each catheter receiving zone. Thus, irrespective of the catheter used, it may be securely welded into place. A weld zone may be split into spaced weld zone parts such that a single weld may be formed spanning the weld zone parts. The thickness of each weld zone part may be substantially constant. The internal profile may be substantially constant across the weld zone. The internal profile may be substantially constant in regions spanning adjacent weld zone parts. Adjacent weld zone parts may be spaced by no more than 2 mm, no more than 1.5 mm or no more than 1 mm to facilitate formation of a weld spanning both weld zone parts. A single projection may be provided between adjacent weld zone parts. The single projection may have a height of no more than 5 mm, no more than 4 mm or no more than 3 mm, or no more than 2 mm. The single projection may have a height of no more than three times the thickness of the drainage element (or combined thickness of the drainage elements), no more than two times the thickness of the drainage element (or combined thickness of the drainage elements), or no more than the thickness of the drainage element (or combined thickness of the drainage elements). The drainage element thickness may be measured adjacent to the projection. The projection may have a thickness as defined by the projection wall thickness above. The single projection may have a thickness of no more than two times the thickness of the drainage element (or combined thickness of the drainage elements), or no more than the thickness of the drainage element (or combined thickness of the drainage elements). Of course, conversely the weld zone parts may be separated by a recession. The recession may have similar properties to the projection above. The recession may have a depth of no more than the thickness of the drainage element, or no more than half the thickness of the drainage element. In the weld zone, or a weld zone part, the internal and external profiles may be shaped such that the thickness of the drainage element increases by no more than 200%, or no more than 150%, or no more than 100%, or no more than 50%, or no more than 25% over a distance equivalent to the thickness of the drainage element. Thus, this ensures that the external and internal profiles remain similar enough to facilitate laser welding even where there are small differences in the profiles.

The absolute thickness of the drainage element in the weld zone may be as defined for the outer element above. This helps ensure the thickness is suitable for welding. A weld zone may extend from each step. A weld zone may not extend across a step, or a stepped region, of the internal profile. Thus, the catheter is securely welded into place close to the step. This is typically the region where the catheter is most closely fitted within the inlet portion and so helps ensure an effective laser weld.

The tube may comprise a flange. The flange may be provided at one end of the inlet portion. The flange may be configured to prevent over insertion of the catheter into the drainage element. The flange may provide a step in the internal profile of the drainage element. The weld zone may extend along the inlet portion from the flange. Thus, as with the step, the catheter is more securely welded into place via location of the weld zone at/next to the flange.

The weld zone may be spaced from the inlet end. By spacing the weld zone from the inlet end, the weld is protected from higher shearing and transverse forces that are present on the catheter at the inlet end as these can be borne by the tube itself around the inlet end. This helps ensure the weld need only provide significant resistance against axial movement of the catheter along the inlet portion.

The internal profile may be tapered adjacent to the inlet end. The internal profile may be converging from the inlet end towards the outlet portion. The internal profile may taper inwards from the inlet end to the catheter receiving zone or catheter receiving zones. The inlet end may have an internal diameter of at least 3 mm, at least 4 mm, at least 5 mm, at least 6 mm or at least 7 mm. The inlet end may have an internal diameter of no more than 8 mm, no more than 7 mm, no more than 6 mm, no more than 5 mm. Preferably, the inlet end has an internal diameter of about 6 mm or about 5 mm. The catheter receiving zone proximal to the inlet end may have a diameter that is about 0.5 to 1.5 mm smaller than the inlet end, for example 0.7 mm smaller. Thus, when fitting a catheter to the funnel, the taper helps guide the catheter into the catheter receiving zone or zones to be retained by the funnel.

The internal profile may preferably only be defined by the tube. The internal profile may tapered in each catheter receiving zone. The internal profile may be tapered to deform the catheter when it is received in the catheter receiving zone. The internal profile may be tapered across a weld zone. This ensures the catheter is effectively wedged into each weld zone. The internal profile may have a width measured across it perpendicular to the axis of the drainage element. The internal profile may reduce by no more than 5%, or no more than 4% across a weld zone. The internal profile may reduce by at least 1%, or at least 2% across a weld zone. The internal profile may reduce by about 2% to 3% across a weld zone. The external profile may also reduce with the internal profile. This helps provide adequate deformation of the catheter to ensure a tight fit and efficient welding without damaging the catheter or blocking it.

The thickness of the drainage element may be substantially constant across a majority of the weld zone, for example at least 50%, at least 60%, at least 70%, at least 80% or at least 90% of the area of the weld zone. Preferably, the thickness of the drainage element is constant across the entire weld zone. This enables more efficient welding as the laser beam settings do not need to be changed to account for varying thicknesses, and also more consistent thicknesses ensures a higher quality weld.

In the weld zone, the internal and external profiles may match one another. This may provide a constant tube thickness across the weld zone. Where the thickness of the tube is constant, the internal profile is also preferably constant. The external profile of the tube in the weld zone may be defined by only the tube. The weld zone, or weld zone part, may be substantially free of the projections. This helps to ensure that the laser weld can be efficiently formed across the entire weld zone, large fluctuations in thickness could cause issues like material transport, deformation and uneven final weld strength once the drainage elements are melted and then solidified.

The weld zone may extend around at least 50%, at least 75%, or at least 95% of the perimeter of the drainage element in a plane perpendicular to its axis. The weld zone may extend around substantially the entire perimeter of the drainage element in a plane perpendicular to its axis. Thus, the weld can then inhibit passage of fluids unintentionally leaking out of the drainage element.

The plurality of projections may comprise one or more ribs. Each rib may be elongate and extend around and/or along the drainage element. Each rib may have a length measured along the rib as it extends around and/or along the drainage element. Each rib may have a thickness defined perpendicular to its length. The thickness of each rib may be substantially the same as the wall thickness of the tube. Each rib may have a thickness of between 0.5 to 3 mm, or preferably between 0.5 to 1.5 mm. The thickness of each rib may be tapered. The thickness of each rib may be smallest at its tip. The tip may have a thickness of 0.5 to 1 mm. The ribs thus provide a stronger structure to the protrusions while helping to ensure even injection moulding and making it easier to remove the drainage element from the mould once formed.

The one or more ribs may comprise two or more ribs. At least two of the two or more ribs may be intersecting ribs. The intersecting ribs may intersect one another at substantially perpendicular angles. Thus, the ribs are able to provide structural support to one another and also facilitate the creation of a more easily gripped drainage element that can provide good gripping action in multiple directions.

The one or more ribs may comprise one or more circumferential ribs extending around a circumference of the drainage element. The circumferential ribs may extend at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 100% of the way around the circumference of the drainage element. The circumferential ribs may be evenly spaced along the length of the drainage element. The drainage element may comprise at least five, or at least six circumferential ribs. The drainage element may comprise no more than ten, or no more than eight circumferential ribs. Thus, the circumferential ribs help to ensure the drainage element is easy to grip and apply a force along the length of the drainage element to move the catheter into and out of the body.

A circumferential rib may be provided around the inlet end. The circumferential rib around the inlet end may provide an inlet flange. An outer diameter of the inlet flange may be at least 8 mm, at least 10 mm, or at least 12 mm. An outer diameter of the inlet flange may be no more than 15 mm, no more than 12 mm or no more than 10 mm. Preferably, the outer diameter of the inlet flange is about 10 mm. The sleeve may be attached to the rib providing the inlet flange. Thus a flange is provided around the inlet end to help ensure the drainage element is easier to use and manufacture as part of a catheter assembly.

Where the drainage element comprises two or more weld zones, at least one projection may be provided between adjacent weld zones. Preferably, a handling zone comprising at least two projections is provided between adjacent weld zones. In one embodiment, the drainage element may comprise two weld zones and two handling zones. A handling zone (e.g. first handling zone) may extend from the inlet end. A first weld zone may extend from the inlet handling zone. A second weld zone may be provided between the first weld zone and the outlet portion. A handling zone (e.g. second handling zone) may be provided between the first and second weld zones. The first handling zone may be longer than the second handling zone. The first handling zone may comprise more projections than the second handling zone. The first handling zone may comprise at least twice as many projections as the second handling zone. The spacing of the projections in the first and second handling zones may be substantially the same. Thus, the drainage element is optimally arranged to receive two different catheters while maintaining ergonomic handling surfaces.

A circumferential rib may be provided between adjacent weld zones. At least two circumferential ribs may be provided between adjacent weld zones. A handling zone may comprise at least two circumferential ribs. Each handling zone may comprise at least two circumferential ribs. This ensure the drainage element is easier and more comfortable to hold, while facilitating the provision of different weld zones.

The one or more ribs may comprise one or more axial ribs extending along the length of the drainage element. The radial length of an axial rib may change along the length of the drainage element. The one or more axial ribs may be evenly spaced around the circumference of the drainage element. An axial rib may intersect at least two other ribs, preferably at least two circumferential ribs. An axial rib may extend along the majority of the length of the drainage element covered by the protrusions. An axial rib preferably extends along the entire length of the drainage element that is covered by the protrusions. An axial rib may extend from the inlet end. Each axial rib may be substantially the same length. An axial rib may extend across each handling zone. The weld zone may be free of axial ribs. Thus, the axial ribs provide structural support to the circumferential ribs.

The one or more ribs may comprise at least four ribs. The at least four ribs may comprise at least four axial ribs. Each axial rib may comprise any one or more features of a rib or axial rib as described herein. The drainage element may comprise two or more weld zone parts arranged at the same point along a length of the drainage element. The two or more weld zone parts may be separated by a single axial rib. The drainage element may comprise four weld zone parts, adjacent weld zone parts may be separated by a single axial rib. The axial rib may have a height of no more than 200% the thickness of the drainage element in the weld zone. The axial rib may have a width of no more twice the thickness of the drainage element in the weld zone. The adjacent weld zone parts may thus be spaced to facilitate formation of a laser weld between adjacent weld zone parts.

The drainage element may be a funnel. The drainage element/funnel may comprise a weld zone provided on its outlet portion. The drainage element/funnel may be configured to receive a connector into its outlet portion. The drainage element/funnel may comprise a weld zone for formation of a laser weld to a connector. The locator rib may be provided between the weld zone for the connector and the weld zone for the catheter. The drainage element/funnel may have three weld zones. Each weld zone may be provided for welding the drainage element/funnel to a different catheter assembly component, e.g. a different type/size of catheter or connector. Each weld zone may have any one or more of the features described above, for example, the weld zone for the connector may have an internal profile that tapers as described in relation to the catheter receiving zones above. Thus, the funnel may be welded to the catheter at one end, and optionally, a connector at its other end. This means that a single open catheter assembly may be manufactured, and then optionally also used in the production of a closed catheter assembly by welding to a connector when required. This simplifies manufacturing, reducing economic and environmental costs.

The funnel may comprise a skirt. The skirt may be a part of the outlet portion. The skirt may be provided at the outlet end. The skirt may comprise a widened section of the outlet portion. The skirt may be about 0.5 mm, about 1mm or about 1.5mm wider than the rest of the outlet portion. The skirt may span at least 5%, at least 10%, or at least 15% of the length of the outlet portion. The skirt may span no more than 20%, no more than 15% or no more than 10% of the length of the outlet portion. The skirt preferably spans about 10% of the length of the outlet portion. The skirt may be configured to engage the wetting mechanism. Thus, the skirt provides a structure that can better engage the wetting mechanism. The funnel may comprise a plurality of locating protrusions. The locating protrusions may be configured to engage a catheter assembly component, such as a wetting mechanism. The locating protrusions are preferably provided in pairs. The pairs of locating protrusions may be spaced around the circumference of the funnel. The locating protrusions may be located approximately 10-30% along the length of the funnel from the outlet end.

The locator rib may be provided between the skirt and the inlet portion. The locator rib may be provided between the locating protrusions and the inlet portion. A weld zone may be provided on the outlet portion. A weld zone may be provided between the locator rib and the outlet end. A weld zone may be provided between the locating protrusions and the inlet portion. A weld zone may be provided between the locating protrusions and the locating rib. Thus the weld zone may be provided in a substantially flat/constant thickness region of the outlet portion.

The drainage element may be a connector. The connector may be integrally formed with, or operably connected to, a fluid collection bag. The connector may comprise an inlet portion. The inlet portion may be receivable by the outlet portion of the funnel. The inlet portion may have a shape corresponding to the internal profile of the funnel. The connector may comprise an outlet portion. The connector may comprise a stop. The stop may be configured to prevent over insertion of the connector into the funnel.

In a broad aspect, there is provided a catheter assembly comprising a catheter and a drainage element, wherein the drainage element comprises an inlet portion configured to receive the catheter and a weld zone, wherein the catheter is provided in the inlet portion and the drainage element and catheter are attached to one another via a laser weld in the weld zone.

In a broad aspect, there is provided a catheter assembly comprising a catheter, a drainage element, wherein the drainage element comprises an inlet portion attached to the catheter and a weld zone, wherein the assembly further comprises a connector provided in an outlet portion of the drainage element and arranged to receive fluid from the catheter via the drainage element, and the drainage element and connector are attached to one another via a laser weld in the weld zone. According to a fourth aspect of the present invention, there is provided a catheter assembly comprising a catheter and the drainage element of the third aspect, wherein the catheter is provided in the inlet portion and the drainage element and catheter are attached to one another via a laser weld in the weld zone.

The drainage element may be a funnel. The catheter assembly may comprise a connector. The connector and funnel may be attached to one another via a laser weld.

According to a fifth aspect of the present invention there is provided a method of using a drainage element to drain a catheter. The drainage element may be the drainage element of the third aspect above. The method may comprise attaching the drainage element to the catheter via a laser weld, for example as described in relation to the first aspect above. The method may comprise allowing fluid to flow out of the catheter through the drainage element. The method may comprise directing fluid into a receptacle. The method may comprise attaching a second drainage element to the drainage element, for example via a laser weld as described in relation to the first aspect above. The method may comprise using a catheter assembly of the fourth aspect. The method may comprise inserting a catheter into the body until fluid flows through the catheter.

The methods, catheter assemblies, catheter assembly components and drainage elements described herein in general/broad terms and in relation to the first to fifth aspects above may of course include any one or more features of one another, optional or otherwise. For example, in one example there may be provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element are similar to one another in the weld zone to facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction according to the third aspect wherein the drainage element comprises a non-reflective coating as described in relation to the third aspect.

In another example, there is provided a catheter assembly comprising a catheter and a drainage element, wherein the drainage element comprises an inlet portion configured to receive the catheter and a weld zone, wherein the catheter is provided in the inlet portion and the drainage element and catheter are attached to one another via a laser weld in the weld zone, wherein the drainage element comprises a handling zone comprising at least two circumferential ribs, wherein the handling zone and weld zone are not overlapping.

Some specific and preferred embodiments of the invention are set out below. Each of these apply generally to the other embodiments and therefore may include any one or more of the features of the first to fourth aspects above or one another interchangeably.

In one preferred embodiment, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing an intermittent urinary catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or, the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector.

In another preferred embodiment, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or, the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector, wherein the method comprises melting a majority of a thickness of the outer element during formation of the laser weld, and preferably wherein the method comprises melting the entire thickness of the outer element during formation of the laser weld.

In another preferred embodiment, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or, the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector, wherein the method comprises using the laser beam to heat the outer element to a higher temperature than the inner element.

In another preferred embodiment, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or, the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector, wherein the first and/or second drainage elements comprise a thermoplastics material which volumetrically absorbs the laser beam to cause melting of the first and/or second drainage element and preferably wherein the laser beam and first and second drainage elements are configured such that during formation of the laser weld volumetric absorption in the first and/or second drainage element generates more heat than interfacial absorption at an interface of the first and second drainage elements.

In another preferred embodiment, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or, the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector, wherein the laser beam has a wavelength of over 1.1 microns and no more than 3 microns, preferably wherein the laser beam has a wavelength of about 2 microns.

In another preferred embodiment, there is provided a method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector, and optionally wherein the method comprises forming a first laser weld between the funnel and the catheter and preferably also forming a second laser weld between the funnel and the connector. In another preferred embodiment, there is provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element are similar to one another in the weld zone to facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction, wherein the inlet portion comprises two or more catheter receiving zones each configured to receive a different catheter and two or more weld zones, wherein a weld zone is provided for each catheter receiving zone.

In another preferred embodiment, there is provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element are similar to one another in the weld zone to facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction, wherein the tube comprises a flange provided at one end of the inlet portion, the flange configured to prevent over-insertion of the catheter into the drainage element, and the weld zone extends along the inlet portion from the flange.

In another preferred embodiment, there is provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element match one another in the weld zone to provide a constant tube thickness across the weld zone and facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction.

In another preferred embodiment, there is provided a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element are similar to one another in the weld zone to facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction, wherein the inlet portion comprises a handling zone comprising at least two of the plurality of projections and in the handling zone the external profile is different from the internal profile.

In another preferred embodiment, there is provided catheter assembly comprising a catheter and a drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element match one another in the weld zone to provide a constant tube thickness across the weld zone and facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction, wherein the catheter is inserted into the inlet portion and a laser weld is provided between the drainage element and the catheter. Preferably, in this embodiment the catheter is an intermittent urinary catheter.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 is a perspective view of a catheter, funnel and connector of a first embodiment of a catheter assembly;

Figure 2 is a cross-section of the funnel of Figure 1 before welding to the catheter and connector;

Figure 3 is a cross-section of the catheter, funnel and connector of Figure 1 after welding and with a sleeve;

Figure 4a-4c are cross-sections of detail A in Figure 3 at different stages of the laser welding manufacture process for the catheter assembly of Figure 1;

Figure 5 is a flow diagram showing the laser welding manufacture process for the catheter assembly of Figure 1 ;

Figure 6 is a perspective view of a catheter, funnel and connector of a second embodiment of a catheter assembly; and

Figure 7 is a cross section of the assembly of Figure 6.

Referring to Figures 1 to 4c, a first embodiment of a catheter assembly 100 comprises catheter assembly components of: a catheter 1 with a proximal end (not shown) for insertion into the body and a distal end 3; a sleeve 4; a funnel 5 and a connector 6. The sleeve 4 encloses the catheter 1 from the proximal end to the distal end 3 which assists in protecting and handling the catheter 1 during use.

The funnel 5 is tubular and is positioned at the distal end 3 of the catheter 1 and attached to both the catheter 1 and sleeve 4. The connector 6 is configured to connect the funnel 5 to a fluid collection bag (not shown), such that fluid may flow from the catheter 1 into the bag, as described further below. The catheter assembly 100 is thereby a closed catheter assembly, however, in some embodiments, the connector 6 and bag are simply not provided and the assembly is then an open catheter assembly.

In this embodiment, the sleeve 4 comprises a liquid impermeable flexible plastics material, for example a thermoplastic polyurethane (TPU) or low-density polyethylene (LDPE). The catheter 1 is formed from a thermoplastic elastomer (TPE).

The funnel 5 and connector 6 are relatively rigid compared to the catheter 1 and sleeve 4 and in this embodiment each comprises a flexible plastics material, for example low-density polyethylene (LDPE). The funnel 5 is configured to receive liquid from the distal end 3 of the catheter 1 and then direct the flow of liquid out of the funnel 5, for example into the connector 6 as described further below. The distal end 3, funnel 5 and connector 6 thereby each provide a drainage element for the catheter.

In this embodiment, the funnel 5 is generally tubular and is formed by a tube 7 extending between an inlet end 8 and an outlet end 9. The funnel 5 comprises an inlet portion 10 extending from the inlet end 8 and an outlet portion 11 extending from the outlet end 9, the inlet portion 10 and the outlet portion 11 meeting at the narrowest point along the tube 7. The inlet portion 10 is configured to receive the distal end 3 of the catheter 1 and provide a liquid path from inside the catheter 1 into the funnel 5. The outlet portion 11 is configured to direct the flow of liquid out of the funnel 5.

In this embodiment, the outlet portion 11 is longer than the inlet portion 10, and the outlet portion 11 covers about 60-70% of the length of the funnel 5.

In this embodiment, the tube 7 has a substantially constant wall thickness of about 0.8-0.9 mm. In the outlet portion 11, the tube 7 defines both the internal and external profile of the funnel 5 and is tapered with a frustoconical shape that diverges from the inlet portion 10 towards the outlet end 9. The outlet portion 11 is widest at the outlet end 9 with an external diameter of about 12 mm and an internal diameter of about 8-9 mm.

On the outside of the outlet portion 11, there is provided a locator in the form of a locator rib 12 which extends axially along the length of the funnel 5 and outlet portion 11. The locator rib 12 is positioned centrally with respect to the length of the outlet portion 11 and is configured to align with a curve in the catheter 1 so that the user can correctly position it within the body, for example, when using a coude catheter.

In this embodiment, where the inlet portion 10 meets the outlet portion 11, the tube 7 is about 3-5 mm wider on the outlet portion 11 side. Consequently, a flange 13 is provided to connect the inlet portion 10 to the outlet portion 11 to facilitate the stepchange in the internal profile of the funnel 5.

In this embodiment, the funnel 5 is configured to receive and retain more than one type and/or size of catheter. In particular, the funnel 5 is configured to be able to receive and retain two different sizes of catheter 1. The funnel 5 thereby comprises two catheter receiving zones (CRZ): a first CRZ 14 and a second CRZ 15. Each CRZ is configured to receive and retain a certain type/size of catheter.

In this embodiment, the internal profile of the inlet portion 10 is defined by the tube 7 and changes in the internal profile along the length of the inlet portion 10/funnel 5 provide the first and second CRZs 14, 15. The two CRZs are provided in series and coaxially with the tube 7 extending from the inlet end 8 to the first CRZ 14, then the second CRZ 15 and finally to the outlet portion 11.

In this embodiment, the internal profile of the funnel 5 narrows from the inlet end 8 towards the outlet portion 11. The internal profile tapers down from a diameter of about 6 mm at the inlet end 8 by about 2 mm to the first CRZ 14. The internal profile is then gently tapers across the first CRZ 14 to deliver an overall 2% reduction in diameter of the inlet portion across the first CRZ 14. The internal profile then steps down to the second CRZ 15, which has a diameter about 1 mm less than the first CRZ 14. The internal profile is also gently tapered in across the second CRZ 15 to also deliver a 2 % reduction in diameter before stepping down again before meeting the outlet portion 11.

As described above, at the end of each CRZ distal from the inlet end 8, a catheter stop is provided in the form of a catheter flange 16. The catheter flange 16 provides a step in the internal profile of the funnel 5 and helps prevent over insertion of a catheter into a respective CRZ 14, 15. The inlet portion 10 therefore comprises a stepped region of the internal profile of the funnel 5. In this embodiment, the catheter 1 is tubular and is sized to fit into the second CRZ 15 and therefore, the distal end 3 of the catheter 1 can be moved past the first CRZ 14 to be received into the second CRZ 14 such that liquid can pass from the catheter 1, through the distal end 3 and into the funnel 5 as described further below.

In this embodiment, the inlet portion 10 of the funnel 5 comprises first and second weld zones 17, 18 in which the internal and external profile of the funnel is substantially the same to facilitate formation of a laser weld 27 between the funnel 5 and catheter 1. Each weld zone 17, 18 corresponds to arespective CRZ 14, 15 and each weld zone extends from the catheter flange 16 of each CRZ 14, 15 towards the inlet end 8. Each weld zone extends around the tubular funnel 5 so as to provide a fluid-tight seal between the funnel and catheter once a weld is formed, in addition, each weld zone extends along an axis of the tube 7 approximately 4 mm from each flange. The weld zones 17, 18 thereby provide a welding area that is suitable for retaining the catheter 1 in the funnel 5 with sufficient strength for normal use. Of course, the exact size, shape and configuration of the weld zones can be changed depending on an embodiment’s requirements. For example, the weld zone may not extend all the way round the circumference of the tube where a fluid-tight seal is not required or is provided by alternative means.

In this embodiment, the funnel 5 comprises first and second handling zones 19,

20 defined by a plurality of protrusions in the form of circumferential ribs 21. The ribs

21 each extend outward from the tube 7 and comprise a tip distal from the tube 7, the tips of the ribs 21 together define handling surfaces of the funnel 5 in the inlet portion 10, as indicated by the broken lines in Figure 2. This allows the handling surface of the funnel 5 to be different from its internal profile, which is restricted due to the need to provide the first and second CRZ 14, 15. In addition, gaps 22 are provided between adjacent ribs 21. This allows the funnel 5 to be constructed with less material than a filled design, while also avoiding sink mark artefacts that can occur in injection moulded items of varying thickness. The ribs 21 and gaps 22 also provide a more easily gripped external surface, making the funnel easier to handle.

In this embodiment, the ribs 21 are tapered slightly with the tips being the narrowest part of each rib 21. The ribs 21 are approximately 1.5 mm across at their base and 0.5 mm to 1 mm at the tip. This makes them easier to manufacture by injection moulding. In addition, the tip of each rib 21 is substantially planar, this helps them to define a smoother and more comfortable to hold handling surface for the funnel 5 without sharp edges.

In this embodiment, a circumferential rib 21 is provided at the inlet end 8 and provides an inlet flange 23 to form the inlet end 8. The inlet flange 23 having an external diameter of about 10 mm in this embodiment. The first handling zone 19 extends from the inlet end 8 and comprises four circumferential ribs 21 starting with the one at the inlet end 8 defining the inlet flange 23 and then being evenly spaced across the inlet portion 10 to the first weld zone 17. The second weld zone 18 extends along the inlet portion 10 from the outlet portion 11 and the second handling zone 20 is provided between the first and second weld zones 17, 18. The second handling zone 20 comprises two ribs 21 with the same spacing as the ribs 21 of the first handling zone 19. The spacing of the ribs 21 being defined as the distance between the centres of adjacent ribs 21 in a first direction that is parallel to the axis of the tube 7, the spacing in this embodiment being about 2 mm. In this embodiment, each weld zone 17, 18 spans about twice the spacing of the ribs 21 in the first direction, this ensures a strong and simple weld can be formed to retain the catheter 1 in the funnel 5. The weld thereby extends about 3-4 mm along the axis of the tubular funnel 5 and once formed provides a tensile strength of 60-80 N to prevent axial separation/movement of the funnel 5 and catheter 1.

In this embodiment, four axial ribs 24 are provided which extend from the inlet flange 23 to the outlet portion 11. The axial ribs 24 therefore also define the handling surfaces of the funnel 5 along the inlet portion 10. Each axial rib 24 intersects all of the circumferential ribs 21, this helps the ribs 21, 24 to support one another and prevent damage to them during use. The four axial ribs 24 are spaced evenly around the circumference of the funnel 5. As shown in Figure 1, the ribs 21, 24 thereby divide the weld zones 17, 18 into four parts 17a, 18a, which can each also be thought of as a weld zone. In relation to the second weld zone 18, and the associated second weld zone parts 18a, the axial ribs 24 have a height of about 1 mm. Additionally, adjacent weld zone parts 18a are separated by a gap of about 1.5 mm, therefore, the shape of the external and internal profiles in the second weld zone 18 is still similar enough to facilitate formation of a laser weld around the complete circumference of the catheter 3. In addition, as the weld zone parts 18a have a substantially constant tube thickness, and cover at least 5% of the weld zone 18 area, this also helps ensure the internal and external profiles are similar enough across the second weld zone 18 as a whole to facilitate formation of a laser weld across the entire zone 18.

In contrast, the axial ribs 24 when extending across the first weld zone 17 are higher, e.g. at least 3 mm, and a similar width. This creates a difference in the external and internal profiles between adjacent weld zone parts 17a that inhibits formation of a continuous weld extending between adjacent weld zone parts 17a. For example, the rib introduces a change in thickness of the funnel by more than 200% over a very short distance which is not suitable for welding (e.g. about 2-3 mm height). Of course, each weld zone part 17a is still individually suitable for welding as the thickness is constant in these regions and so a catheter 1 may be welded into the first CRZ 14, however, a fluid-tight seal as provided in the second CRZ 15 may be more difficult/impossible to achieve. Of course, in other embodiments, the external profile may not exactly match the internal profile across any of the weld zone, but due to the external profile still remaining similar, such as the thickness not increasing by more than 100% over a distance equivalent to the thickness, a laser weld is facilitated. For example, the external profile may slowly increase/decrease, or may have surface roughness, undulations, or projections on a short length scale that is effectively averaged out/removed once the material is melted during welding.

In this embodiment, the handling surfaces 19, 20 of the inlet portion 10 are shaped to provide a premium look through smoothly changing features that avoid unnecessary step changes in size. The handling surfaces are therefore smooth across the stepped region of the internal profile in the inlet portion 10.

The second handling surface 20 of the inlet portion 10 is shaped to match the external profile of the outlet portion 11. Consequently, the ribs 21, 24 have a radial length adjacent to the flange 13, measured as the radial distance from the tip of the rib 21, 24 to the tube 7, that is substantially the same as the size of the flange 13. The length of the ribs 21, 24 then increases towards the inlet end 8 such that the second handling surface 20 is diverging which provides a shape that is more easily gripped by the user and is better suited to applying a force along the axis of the catheter 1 for insertion/removal of the catheter from the body.

In this embodiment, the ribs 21, 24 of the first handling surface 19 are shaped to provide a constant external profile over the remainder of the inlet portion 10 to the inlet end 8. The ribs 21, 24 therefore decrease in radial length slightly as they approach the inlet end 8 due to the tapering of the tube 7 which is largest at the inlet end 8. This constant region can be more suited to engaging the sleeve 4, such as where it is fitted over a part of the funnel 5.

In this embodiment, the funnel comprises a skirt 25 at the outlet end 9. The skirt 25 comprises a widened portion of the outlet portion 11 that is about 1 mm wider diameter than the rest of the outlet portion 11. The skirt 25 spans about 10% of the length of the funnel 5 from the outlet end 9.

In this embodiment, the funnel comprises a plurality of locating protrusions in the form of six pairs of locating protrusions 26. The protrusions in each pair 26 are arranged adjacent to one another along the length of the funnel 5. The pairs 26 are all positioned at the same point along the length of the funnel, about 20% of the length of the funnel from the outlet end 9. The pairs 26 are evenly spaced around the circumference of the funnel 5. Each locating protrusion is hemispherical and extends outward from the surface of the funnel by about 0.6 mm. The locating protrusions therefore extend out past the external profile of outlet end 9 and skirt 26. In other embodiments, the locating protrusions are configured to retain a wetting mechanism or other catheter assembly component on the end of the funnel 5 by interference/push-fit.

In this embodiment, the catheter 1 is tubular and arranged for liquid to flow down its centre and out of the distal end 3. The catheter 1 is a C12 size (4 mm diameter) and the second CRZ 15 of the funnel 5 is sized such that the catheter 1 may be inserted into it. The second CRZ 15 tapers slightly, reducing in diameter by about 2% such that the catheter 1 is compressed/deformed when fully inserted into the second CRZ 15. A first laser weld 27 is provided between the distal end 3 of the catheter 1 and the funnel 5 in a position corresponding to the second weld zone 18. The laser weld 27 is primarily spaced slightly from the tip of the distal end 3 of the catheter 1, and extends along the distal end 3 of the catheter 1 from the tip, this helps maintain the shape of the catheter

I during manufacture. The catheter 1 is thereby secured in the funnel 5 and the process of forming the laser weld 27 is described further below.

In a different embodiment, the same funnel 5 could be used but with a C14 size catheter, this would fit in the same manner into the first CRZ 14 instead with a laser weld provided in a position corresponding to the first weld zone 17.

In this embodiment, the connector 6 is tubular and comprises an inlet portion 28 that is sized to fit within the outlet portion 11 of the funnel 5. In this embodiment, the external profile of the connector 6 matches the internal profile of the funnel in the outlet portion 11 such that a tight fit is provided between them. This facilitates formation of a second laser weld 29 between the funnel 5 and the connector 6. The second laser weld 29 is spaced from the end of the inlet portion 28 of the connector 6 by about 5 mm which helps maintain the shape of the connector 6 during manufacture as described below. In this embodiment, a third weld zone 30 is thereby provided by the outlet portion 11 of the funnel 5. The third weld zone 30 comprises a band of the outlet portion

I I in which the external and internal profiles are substantially the same, for example, it does not correspond to the position of the locator rib 12 or locating protrusions 26 which would impede welding. In this embodiment, the third weld zone 29 is provided at a point along the funnel 5 between the locator rib 12 and locating protrusions 26.

In this embodiment, the connector 6 also comprises an outlet portion 31 configured to connect to a fluid collection bag and facilitate transfer of fluid from the funnel to the bag. The outlet portion 31 comprises a circumferential stop 32 that extends outward at the point the outlet portion 31 of the connector 6 meets the inlet portion 28. This acts to prevent over insertion of the connector 6 into the funnel 5.

Thus, as shown in Figure 3, the catheter assembly 100 provides a liquid path from the catheter 1, through the distal end 3 of the catheter 1 into the funnel 5, and then out of the funnel 5 through the connector 6, see broken arrows denoted “LP” in Figure 3.

To manufacture the catheter assembly 100, the catheter 1 is provided and the funnel 5 and connector 6 are injection moulded. Due to the tapered inlet and outlet portions 10, 11 and tapered ribs 21, 24, the funnel 5 is advantageously suitable for injection moulding. The distal end 3 of the catheter 1 is then inserted into the inlet portion 10 of the funnel 5 and laser welded into place, similarly, the connector 6 is inserted into the outlet portion 11 and laser welded into place.

In general, the laser welding process is applicable to various catheter assembly components, such as first and second drainage elements like the distal end of the catheter and funnel, or the funnel and the connector. The process of laser welding is the same for both the catheter and connector, and so only the welding process for the catheter is described in detail.

Referring to Figures 4a, 4b, 4c and 5, the laser welding process begins with step SI, at step SI, the distal end 3 of the catheter 1 is inserted into the inlet portion 10 until it is abutting the catheter flange 16 of the second CRZ 15. In these examples, the funnel is thereby an outer element because it is on the outside and is exposed directly to the laser beam, and the catheter (or connector) is an inner element which receives the laser beam via the outer element, as described below. The outer element comprises an outer surface 33 on an outside of the funnel and an opposite inner surface 34 facing the inner element. The inner element comprises an outer surface 35 facing the outer element and an opposite inner surface 36.

In this position, as shown in Figure 4a, the distal end 3 is compressed and deformed as it is slightly larger than the internal profile of the second CRZ 15. This leads to a 3% to 8% reduction in the diameter of the catheter 1 as it is inserted into the funnel 5. Consequently, once fully inserted, the outer surface 35 of the catheter 1 presses outward against the inner surface 34 of the funnel 5 due to the resiliently deformable nature of the catheter 1. This is important for laser welding because it generates pressure and reduces the likelihood of any gaps between the two components to help form a strong weld.

In this embodiment, at step S2, a laser beam L is directed onto the outer surface 33 of the outer element (funnel 5). The laser beam is incident at an angle of close to 90 degrees to the outer surface 33, which is roughly parallel to the inner surface 34 due to the nature of the internal and external profiles of the weld zone. Preferably, the outer surface and inner surface 33, 34 both comprise a non-reflective coating to reduce reflections and maximise transfer of the laser beam L into the funnel 5 and catheter 1.

In this embodiment, the laser beam L has a wavelength of about 2 microns, or 1940 nm, which, due to the thermoplastic material used to construct the funnel 5 and catheter 1, is volumetrically absorbed by both components to cause heating of the components. In this example, about 20-30% of the laser beam is absorbed by the funnel 5 leaving a significant portion available for absorption by the catheter 1.

At step S2, both the funnel 5 and catheter 1 are heated via direct absorption of the laser beam L by each respective component. As they are heated, they will thermally expand which increases welding pressure.

At step S3, and as shown in Figure 4b, the energy absorbed from the laser beam L eventually heats the components sufficiently to cause melting of the funnel and catheter in a region defined by a melt zone 37. In this embodiment, the melt zone 7 spans the entire thickness of the funnel 5 between its outer and inner surfaces 33, 34, this melting is driven almost entirely by volumetric absorption of the laser beam by the funnel 5. In contrast, the melt zone 37 only spans part of the thickness of the catheter 1 and does not extend to its inner surface 36, for example it may only span up to 50% of the thickness of the catheter 1. The melting of the catheter 1 is thereby a combination of direct volumetric absorption of the laser by the catheter 1 to heat and soften the entire catheter 1 but also heat conduction from the funnel 5 to supply additional heat locally at the outer surface of the catheter. This is important as it ensures the catheter 1 maintains its inner surface structure and reduces the likelihood of structural failure of the catheter during welding which might lead to blockages or other damage.

Therefore, as described above, the laser beam L, funnel 5 and catheter 1 are configured such that volumetric absorption generates more heat during welding than other processes such as interfacial absorption.

At step S4, the laser beam L is deactivated and the components are allowed to cool and solidify. At step S5 and as shown in Figure 4c, the components have completely solidified and due to their complementary nature, a laser weld 27 has formed between them in the region of the melt zone 37.

In this embodiment, the laser beam L has a power density of 60-65 Wmm'² at a wavelength of 2,000 nm with a beam width of about 1.5-3 mm. In step S3, the laser beam L is scanned across the surface of the funnel 5 to continuously melt and weld the funnel to the catheter 1. In other embodiments, more advanced laser welding techniques could also be used such as that described in US2020/0246916A1.

In some embodiments, an external fixture, such as a glass transfer plate is brought into contact with the outer surface 33 of the outer element. This enables the shape of the surface to be controlled by the external fixture to provide a certain aesthetic appearance to the funnel 5.

The process can then be repeated to attach the connector 6 to the funnel 5 and form the second laser weld 29. In the laser welding processes, the material and absorption co-efficient of the inner and outer elements are selected to be compatible with one another for laser welding and such that the inner element melts via a combination of direct volumetric absorption of the laser beam and heat conduction from the outer element. This is most simply achieved by selecting the same material for the inner and outer elements, like the funnel 5 and connector 6 of this embodiment, but it is also possible to use two different but complementary materials, such as the funnel 5 and catheter 1 of this embodiment. For example, both the funnel 5 and catheter 1 comprise polyethylene and so may be welded together using the described method.

Once the connector 6, funnel 5 and catheter 1 are welded together, the sleeve 4 is provided around the catheter and is attached to the funnel 5. For example, it may be adhered to the inlet flange 23 via an adhesive. Alternatively, laser welding may be used.

In use, the user may lubricate the catheter 1 through any suitable known means, for example, they may release a wetting fluid into the sleeve 4 to wet the catheter 1. The sleeve 4 is then moved to expose the proximal end which the user then inserts into the body until fluid begins to flow along the catheter 1. The fluid then passes along the liquid path (LP) shown in Figure 3, through the distal end 3, into the funnel 5 and on into the connector 6 and any attached fluid collection bag.

In a second embodiment of the catheter assembly 100’ as shown in Figures 6 and 7, the components are similar to those described above in relation to the first embodiment. However, the funnel 5’ only has a single handling zone 19’ and the axial ribs 24’ only extend across the single handling zone 19’. The external profile of the funnel 5’ in the first and second weld zones 17’, 18’ is therefore free of ribs and substantially flat all the way around the circumference of the funnel 5’, and the thickness of each weld zone 17, 18’ is constant. This provides a funnel 5’ that is more suited for formation of a fluid-tight weld between the funnel 5’ and the catheter 1’, because the internal and external profiles match one another all the way round the circumference. As shown, in this embodiment, the funnel 5’ is narrower at the second weld zone 18’ than at the first weld zone 17’.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims. For example, in other embodiments where a closed catheter assembly is required, the funnel may be directly connected to a fluid collection bag without the need for a separate connector. In such embodiments, the funnel is effectively just a connector, or alternatively, the funnel may not be present and the connector may comprise features, such as one or more CRZs, to make it suitable for being welded directly to the catheter.

Claims

1. A method of manufacturing a catheter assembly comprising the steps of: providing a catheter comprising a proximal end for insertion into the body and a distal end; providing first and second drainage elements, wherein the first drainage element is arranged to receive fluid flowing along the catheter; arranging the first and second drainage elements such that fluid may flow along the catheter to the first drainage element and then to the second drainage element; and, directing a laser beam onto the first and second drainage elements to form a laser weld therebetween, wherein either: the first drainage element is provided by the distal end of the catheter and the second drainage element is a funnel; or, the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector.

2. A method according to claim 1 wherein the catheter is an intermittent urinary catheter.

3. A method according to claim 1 or claim 2 wherein one of the first or second drainage elements is an outer element and the other is an inner element, and the method comprises directing the laser beam onto the inner element via the outer element.

4. A method according to claim 3 wherein the method comprises absorbing part of the laser beam into the outer element to cause melting of the outer element during formation of the laser weld.

5. A method according to claim 4 wherein the method comprises melting a majority of a thickness of the outer element during formation of the laser weld.

6. A method according to any one of claims 3 to 5 wherein the method comprises using the laser beam to heat the outer element to a higher temperature than the inner element.

7. A method according to any one of claims 3 to 6 wherein the method comprises melting the inner element via heat conduction from the outer element.

8. A method according to any one of claims 3 to 7 wherein a surface of the inner element distal from the outer element is not melted during formation of the laser weld.

9. A method according to any preceding claim wherein the first and/or second drainage elements comprise a thermoplastics material which volumetrically absorbs the laser beam to cause melting of the first and/or second drainage element.

10. A method as claimed in claim 9 wherein the laser beam and first and second drainage elements are configured such that during formation of the laser weld volumetric absorption in the first and/or second drainage element generates more heat than interfacial absorption at an interface of the first and second drainage elements.

11. A method according to any preceding claim wherein the laser beam has a wavelength of over 1.1 microns and no more than 3 microns.

12. A method according to claim 11 wherein the laser beam has a wavelength of about 2 microns.

13. A method according to any preceding claim wherein the first drainage element is a funnel connectable to the distal end of the catheter and the second drainage element is a connector, and the method comprises forming a first laser weld between the funnel and the catheter and forming a second laser weld between the funnel and the connector.

14. A catheter assembly manufactured according to the method of any preceding claim.

15. A drainage element for a catheter, the drainage element comprising a tube defining an internal profile of the drainage element and a plurality of projections extending outward from the tube, wherein: the tube and projections together define an external profile of the drainage element; the drainage element comprises an inlet portion configured to receive the catheter; the inlet portion comprises a weld zone; the external and internal profiles of the drainage element are similar to one another in the weld zone to facilitate formation of a laser weld between the drainage element and catheter; the plurality of projections are arranged with a spacing between the centres of adjacent projections in a first direction; and the weld zone spans at least the spacing in the first direction.

16. A drainage element according to claim 15 wherein the inlet portion comprises two or more catheter receiving zones each configured to receive a different catheter and two or more weld zones, wherein a weld zone is provided for each catheter receiving zone.

17. A drainage element according to claim 16 wherein the internal profile of the inlet portion comprises a step between adjacent catheter receiving zones.

18. A drainage element according to claim 17 wherein a weld zone extends from each step.

19. A drainage element according to any one of claims 15 to 18 wherein the tube comprises a flange provided at one end of the inlet portion, the flange configured to prevent over-insertion of the catheter into the drainage element, and the weld zone extends along the inlet portion from the flange.

20. A drainage element according to any one of claims 15 to 19 comprising an inlet end at an end of the tube corresponding to an end of the inlet portion, and the weld zone is spaced from the inlet end.

21. A drainage element according to any one of claims 15 to 20 wherein in the weld zone the internal and external profiles match one another to provide a constant tube thickness across the weld zone.

22. A drainage element according to any one of claims 15 to 21 wherein the inlet portion comprises a handling zone comprising at least two of the plurality of projections and in the handling zone the external profile is different from the internal profile.

23. A drainage element according to any one of claims 15 to 22 further comprising an outlet portion configured to receive a connector, the outlet portion comprising a weld zone.

24. A catheter assembly comprising a catheter and the drainage element of any one of claims 15 to 23, wherein the catheter is inserted into the inlet portion and a laser weld is provided between the drainage element and the catheter.

25. A catheter assembly according to claim 24 wherein the laser weld provides a fluid-tight between the drainage element and the catheter.

26. A method according to any of claims 1 to 14 further comprising providing the drainage element of any of claims 15 to 23, arranging the catheter in the inlet portion, and directing the laser beam onto the weld zone to form a laser weld between the drainage element and catheter.