Technical Field of the Invention

The present invention provides a urinary catheter which is configured to aid flushing of the urethra in use.

Background to the Invention

Urinary catheters for draining urine from the bladder may be indwelling or intermittent and are used to drain urine from a bladder. Intermittent catheters are typically used by patkients suffering from urinary incontinence or by disabled individuals several times a day to drain the bladder as required.

It is relatively common for users of intermittent catheters to develop urinary tract infections or other complications. In some cases, this is because intermittent catheters typically comprise a closed lumen which expels urine from the bladder without it contacting the urethra wall. As such there can be a persistent build-up of bacteria and debris (e.g., skins cells or excretions) which would otherwise be flushed out by the urine.

WO2012/85124 describes an intermittent urinary catheter comprising an elongate shaft with an insertion end, a handle connected to the elongate shaft at a distance from the insertion end, and a discharge end extending past the handle in a direction opposite the insertion end. The elongate shaft is provided with at least one discharge channel having an elongate opening extending along the elongate shaft. The discharge channel includes an opening against which a flow of urine can contact the urethra in use to aid with flushing of the urethra.

CN210992518U describes an indwelling catheter capable of flushing a urethra. The catheter includes a plurality of grooves formed along the length direction, and a plurality of small holes are formed at the bottom of each groove at intervals. During use, secretions in the urethra of a patkient enter the grooves and are discharged.

US 10668249 describes an intermittent catheter having a distal portion, a proximal portion, and a plurality of drainage eyes disposed at a junction between the distal portion and the proximal portion. The distal portion includes a tip, a plurality of elongated ribs, and a plurality of external flow paths. The proximal portion includes an internal lumen and a proximal end. The plurality of drainage eyes communicate with the plurality of external flow paths and the internal lumen. The present invention seeks to provide an improved catheter for flushing urethra in use.

Summary of the Invention

The present invention provides a catheter according to the appended claims. The present disclosure provides, in one broad aspect, a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and bladder, and an outlet end. The main body may further comprise an external flushing portion between the insertion end and the outlet end. The external flushing portion may define a fluid flow path from the insertion end to the outlet end. The fluid flow path may be open to the exterior of the main body.

Providing an external flushing portion defining a fluid flow path from the insertion end to the outlet end that is open to the exterior of the main body of the catheter allows a flow of urine to contact the urethra during use. The flow of urine may act to flush the urethra and help reduce the possibility of infection.

The main body may comprise a formation extending from an external surface of the main body. The formation may extend around the main body to form a ridge between the insertion end and the outlet end. The distance between the formation and the insertion end may be fixed and may correspond to a maximum desired insertion depth of the catheter into the urethra. The formation may be configured to abut the base of the urethra upon insertion of the catheter into the urethra up to the maximum desired insertion depth. The formation may be an annular ring.

In one broad aspect of the invention, there is provided a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and bladder and an outlet end, the elongate main body further comprising an annular ring extending from an external surface of the main body around the main body to form a ridge between the insertion end and the outlet end, wherein the distance between the annular ring and the insertion end is fixed and corresponds to a maximum desired insertion depth of the catheter into the urethra, and wherein the annular ring is configured to abut the base of the urethra upon insertion of the catheter into the urethra up to the maximum desired insertion depth.

Another broad aspect of the invention provides a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and bladder, an outlet end, and an external flushing portion between the insertion end and the outlet end, the external flushing portion defining a fluid flow path from the insertion end to the outlet end which is open to the exterior of the elongate main body, the elongate main body further comprising an annular ring extending from an external surface of the main body around the main body to form a ridge between the insertion end and the outlet end, wherein the distance between the annular ring and the insertion end is fixed and corresponds to a maximum desired insertion depth of the catheter into the urethra, and wherein the annular ring is configured to abut the base of the urethra upon insertion of the catheter into the urethra up to the maximum desired insertion depth.

In accordance with a first aspect of the invention, there is provided an intermittent urinary catheter comprising: an elongate main body having an insertion end for insertion into a urethra and bladder, an outlet end, and an external flushing portion between the insertion end and the outlet end, the external flushing portion defining a fluid flow path from the insertion end to the outlet end which is open to the exterior of the elongate main body, the elongate main body further comprising an annular ring extending from an external surface of the main body around the main body to form a ridge between the insertion end and the outlet end, wherein the distance between the annular ring and the insertion end is fixed and corresponds to a maximum desired insertion depth of the catheter into the urethra, and wherein the annular ring is configured to abut the base of the urethra upon insertion of the catheter into the urethra up to the maximum desired insertion depth.

Advantageously, the annular ring provides a visual and/or tactile feedback to the user to indicate when the catheter has reached or is close to reaching the maximum desired insertion depth and is appropriately positioned for the drainage of urine from the bladder. The annular ring may also provide a visual and/or physical indicator for the appropriate positioning of a funnel provided at the outlet end of the catheter.

Notably, the maximum desired insertion depth may not be the same as the maximum possible insertion depth. The maximum possible insertion depth is already a feature of catheters with funnels, as the funnel is typically much larger in diameter than the urethral opening, and hence the catheter cannot be inserted beyond the point at which the funnel abuts the urethral opening. However, when inserted to this depth (i.e., “all the way"), many catheters cannot fully drain the bladder, typically because eyelets at the insertion end are located too far into the bladder. By defining a maximum desired insertion depth, which is less than the maximum possible insertion depth, any eyelets or the like can be arranged closer to the intersection between the end of the urethra and the bladder, and the bladder can therefore be drained more fully.

The external flushing portion may comprise an external flow channel providing a fluid flow path from the insertion end to the outlet end. The external flushing portion may comprise a tubular wall defining an internal passageway therein and a plurality of apertures distributed along the length thereof to provide fluid communication between the internal passageway and exterior of the main body. The external flushing portion may comprise an open lattice structure to provide fluid communication between the external flushing portion and exterior of the main body.

The outlet end may have an outlet portion and the annular ring may extend from an external surface of the outlet portion. The outlet portion may define a drainage channel for the flow of fluid from the external flow channel through the outlet portion via a drainage aperture formed therebetween. The annular ring may be positioned relative to a junction between the external flushing portion and the outlet portion such that the drainage aperture is positioned, in use, within the urethra when the catheter is inserted into the urethra and the annular ring abuts the base of the urethra. For example, the annular ring may be positioned between 5mm and 15mm from the junction.

This is advantageous as it can avoid urine flowing out of the urethral opening along the external flow channels and thus being spilt, e.g., on a user’s hands, floor, etc. Rather, with the drainage aperture positioned within the urethra, urine will flow from the external flow channel into the drainage aperture and thus into the outlet portion, from where it can be directed out of the outlet portion into a suitable receptacle (e.g., a toilet).

The annular ring and outlet portion may be together configured to plug the urethral opening when the catheter is inserted into the urethra and the annular ring abuts the base of the urethra. The annular ring may be at least 1mm greater in diameter than the part of the main body intended to be inserted into the urethra. The annular ring may be integral to the main body. The annular ring may be immovable with respect to the main body. Accordingly, in one embodiment there is provided an intermittent urinary catheter comprising: an elongate main body having an insertion end for insertion into a urethra and bladder, an outlet end, and an external flushing portion between the insertion end and the outlet end, the external flushing portion defining a fluid flow path from the insertion end to the outlet end which is open to the exterior of the elongate main body, the elongate main body further comprising an annular ring extending from an external surface of the main body around the main body to form a ridge between the insertion end and the outlet end, wherein the distance between the annular ring and the insertion end is fixed and corresponds to a maximum desired insertion depth of the catheter into the urethra, and wherein the annular ring is configured to abut the base of the urethra upon insertion of the catheter into the urethra up to the maximum desired insertion depth, and wherein the annular ring is integral to the main body.

In another embodiment, there is provided an intermittent urinary catheter comprising: an elongate main body having an insertion end for insertion into a urethra and bladder, an outlet end, and an external flushing portion between the insertion end and the outlet end, the external flushing portion defining a fluid flow path from the insertion end to the outlet end which is open to the exterior of the elongate main body, the elongate main body further comprising an annular ring extending from an external surface of the main body around the main body to form a ridge between the insertion end and the outlet end, wherein the distance between the annular ring and the insertion end is fixed and corresponds to a maximum desired insertion depth of the catheter into the urethra, and wherein the annular ring is configured to abut the base of the urethra upon insertion of the catheter into the urethra up to the maximum desired insertion depth, and wherein the annular ring is immovable with respect to the main body.

A side of the annular ring facing the insertion end may comprise a convex surface extending outwardly from the main body and away from the insertion end. The annular ring may be symmetrical about a plane extending perpendicularly to the longitudinal axis of the main body.

The outermost diameter of the annular ring may be greater than the outermost diameter of the main body between the annular ring and the insertion end. The outermost diameter of the annular ring may be greater than the outermost diameter of the rest of the main body. The annular ring may have a convex outer surface. The outer surface of the annular ring may be continuously curved.

For a female catheter, the annular ring may be between 80 mm and 100 mm from the terminal end of the insertion end. For a male catheter, the annular ring may be between 330 mm and 390 mm from the terminal end of the insertion end. The annular ring may be between 10 mm and 20 mm from the terminal end of the outlet end. The annular ring may be between 5 mm and 15 mm from a junction between the external flushing portion and the outlet portion.

The external flow channel may be in fluid communication with the drainage channel via the drainage aperture formed at a junction between the external flushing portion and the outlet portion. The external flow channel may be longitudinally separated from the drainage channel (i.e., spaced apart from the drainage channel in the longitudinal direction such that there is a gap (i.e., open gap) between the external flow channel and the drainage channel). The outlet portion may be shaped at the junction to guide liquid from the external flow channel toward the drainage channel. The outlet portion may be angled at the junction to guide liquid from the external flow channel toward the drainage channel.

The number of external flow channels may be any suitable number for providing a described flow contact area and length. The catheter may comprise between one and six external flow channels. The catheter may comprise between two and five external flow channels. There may be a plurality of external flow channels and a plurality of corresponding drainage apertures. There may be four external flow channels and four corresponding drainage apertures. There may be an equal number of external flow channels and drainage apertures.

Each external flow channel may comprise a straight and/or helical portion. Each external flow channel may be aligned with a corresponding drainage aperture. Each drainage aperture may extend axially and/or radially.

The insertion end may have an insertion portion comprising an inner lumen in fluid communication with the or each external flow channel. The inner lumen and the, or each, external flow channel may be longitudinally separated (i.e., spaced apart in the longitudinal direction such that there is a gap (i.e., open gap) between the, or each, external flow channel and the inner lumen). The insertion portion may comprise one or more eyelets formed in an external surface thereof and extending through to the inner lumen of the insertion portion. The insertion portion may comprise two eyelets arranged on opposite sides respectively of the insertion portion. At least two eyelets may be longitudinally offset.

The distance between the annular ring and an eyelet of the one or more eyelets may correspond to the distance between the urethral opening and a desired location within the bladder of an intended user of the catheter. The distance between the annular ring and the eyelet may be measured between a proximal edge of the annular ring and a distal edge of the eyelet. The desired location within the bladder may be local to the opening between the bladder and the urethra. For a female catheter, the distance between the proximal edge of the annular ring and the distal edge of the eyelet may be between 70 mm and 80 mm. For a male catheter, the distance between the proximal edge of the annular ring and the distal edge of the eyelet may be between 320 mm and 350 mm. Advantageously, the distance may correspond to an optimised position of the eyelet relative to the opening between the bladder and the urethra when the annular ring abuts the urethral opening, thereby helping to ensure more complete emptying of the bladder, in use. For example, for a female catheter, where there are two eyelets that are longitudinally offset from each other, a first eyelet may be between 70 mm and 80 mm from the annular ring and the second eyelet may be between 80 mm and 90 mm from the annular ring.

The external flushing portion may comprise one or more walls each having an external surface arranged, in use, to contact the urethra wall and support the urethra in an open state. The, or each, wall may define the, or each, external flow channel. The, or each, wall may extend longitudinally. The, or each, wall may be straight or helical. The pitch of a helical wall may be constant. The, or each, wall may comprise a longitudinal axis. The cross-section of the, or each, wall transverse to the longitudinal axis of the main body may comprise a rounded profile. The rounded profile may comprise one or more radiuses of curvature.

The, or each, wall may extend radially from a central axis of the main body. The, or each, radially extending wall may comprise an outermost surface and respective opposing side walls. The combined area of the outer surface of the walls may be greater than the combined area of the open faces of the external flow channels. Alternatively, the combined area of the open faces of the external flow channels may be greater than the combined area of the outer surface of the walls. Preferably, the outer flow surface area created by the external flow channels is equal to or greater than the surface area of the inner lumen of the equivalent conventional catheter (i.e., a catheter comprising a tube defining an inner lumen along the length thereof for the outflow of urine) of the corresponding CH size.

The, or each, external flow channel may provide a fluid flow path to the outlet portion. The, or each, external flow channel may extend fully to the outlet portion. The, or each, external flow channel may extend continuously along the main body from the insertion end to the outlet portion.

The main body of the catheter may comprise an elongate member. The main body may be straight (i.e., in the absence of bending forces, at rest, the main body may be substantially straight). The main body may be rigid (i.e., substantially rigid, for example with a shore hardness of between A80 and A90), thereby aiding insertion and maintaining the shape of the external flow channels in use.

The radially outermost surface of the, or each, wall may define an outside diameter of the external flushing portion. The outside diameter may be constant along the external flushing portion and insertion portion of the catheter. Hence, the overall width of the external flushing portion and insertion portion of the catheter may be constant along the length thereof. The cross-sectional area of the, or each, flow channel may be constant along the length of the external flushing portion.

The catheter may be formed as a singular piece. Alternatively, the catheter may be formed from separate component pieces that are attached together.

The outlet portion may be shaped and configured for the attachment of a separate funnel to an end portion thereof. The outlet portion may be attached to a funnel. The outlet portion may be formed integrally with a funnel.

The annular ring may be positioned between the external flushing portion and the funnel. The annular ring may be spaced apart from the external flushing portion in the longitudinal direction. The annular ring may be spaced apart from the external funnel in the longitudinal direction. The catheter may be a male urinary catheter or a female urinary catheter. The catheter may be a permanent or intermittent catheter. In a preferred embodiment, the catheter is an intermittent female urinary catheter.

For a female catheter, the length of the catheter may be between 150mm and 180mm, preferably 160mm. For a male catheter, the length of the catheter may be between 360mm and 420mm, is preferably 405mm.

For a female catheter the length of the external flushing portion may be between 50 mm and 70 mm, preferably 60 mm. For a male catheter the length of the external flushing portion may be between 280 mm and 320 mm, preferably 300 mm.

The diameter of the insertion portion and the external flushing portion may be between 2 mm and 6 mm depending on the intended user’s size requirements.

The pitch of the helical external flow channels may be between 15 mm and 40 mm, preferably 30 mm.

The depth of the external flow channels may be between 0.5mm and 2mm, preferably 1mm.

The present disclosure provides, in a second aspect, a method of manufacturing a catheter according to any aspect described herein by injection moulding and/or 3D printing. The catheter may be manufactured in separate parts and joined together by welding, e.g., heat welding.

The present disclosure provides, in a third aspect, a method of catheterization using a catheter according to any aspect described herein. The method may comprise the steps of: (i) providing a catheter comprising an elongate main body having an insertion end, an external flushing portion and an outlet end, the main body further comprising an annular ring extending from an external surface of the main body around the main body to form a ridge between the insertion end and the outlet end, wherein the distance between the annular ring and the insertion end is fixed and corresponds to a maximum desired insertion depth of the catheter into the urethra (and/or plugs the urethra), and (ii) inserting the catheter into the bladder via the urethra until the annular ring abuts the base of the urethra and the external flushing portion is in fluid communication with the bladder so that urine can drain from the bladder through the urethra along the external flushing portion. The skilled person will appreciate that except where mutually exclusive, a feature described in relation to any one of the aspects, embodiments or examples described herein may be applied to any other aspect, embodiment, or example. Furthermore, except where mutually exclusive, any feature described herein may be applied to any aspect and/or combined with any other feature described herein.

Brief Description of the Drawings

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 shows a perspective view from the proximal end of a schematic representation of a catheter according to the present disclosure;

Figure 2 shows an alternative perspective view from the distal end of the catheter of Figure 1 ;

Figure 3 shows a first side view of the catheter of Figure 1;

Figure 4 shows a second side view of the catheter of Figure 1, the second side view rotated through 90 degrees from the first side view;

Figure 5 shows a cross-sectional view of the catheter of Figure 1;

Figure 6 shows an enlarged perspective view of the junction between the external flushing portion and the outlet portion of the catheter of Figure 1;

Figure 7 shows an alternative enlarged perspective view of the junction between the external flushing portion and the outlet portion of the catheter of Figure 1;

Figure 8 shows an alternative enlarged perspective view of the outlet portion at the junction with the external flushing portion of the catheter shown of Figure 1;

Figure 9 shows an enlarged perspective view of the insertion portion and part of the external flushing portion of the catheter of Figure 1; and,

Figure 10 shows a side view of the catheter of Figure 1 with a funnel attached at the outlet end.

Detailed Description of the Invention

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments and the inventive concept. However, those skilled in the art will understand that the present invention may be practiced without these specific details or with known equivalents of these specific details, that the present invention is not limited to the described embodiments, and that the present invention may be practiced in a variety of alternative embodiments. It will also be appreciated that well known methods, procedures, components, and systems may have not been described in detail.

In the following description, reference to longitudinal should be taken to be in relation to the longitudinal axis of the catheter, unless otherwise stated. Reference to the “transverse cross-section”, or simply “cross-section”, should be taken to be the cross-section which is transverse to the longitudinal axis of the main body, unless otherwise stated. References to distal and proximal made herein should be taken to be in relation to the insertion end of the catheter.

The catheters described herein are primarily intermittent female urinary catheters. However, it will be appreciated that the inventive concepts and features described herein may be applied to indwelling urinary catheters and may be applied to male or female catheters whether intermittent or indwelling.

Figures 1 and 2 show a urinary catheter 1 comprising an elongate main body 3 having an insertion end 5 for insertion of the catheter 1 into a urethra and an outlet end 7 forming an exit for the outflow of fluid e.g., urine, from the catheter 1. An insertion portion 9 for urging the catheter 1 along the urethra and into the bladder is formed at the insertion end 5, and an outlet portion 11 for the outflow of fluid, e.g., urine, from the catheter 1 is formed at the outlet end 7.

The main body 3 further comprises an external flushing portion 13 extending between the insertion portion 9 and the outlet portion 11. The external flushing portion 13 comprises a plurality of external flow channels 15 which provide a fluid flow path. The external flow channels 15 are provided in the external surface of the main body 3, are elongate and open faced in the radial direction so that, when inserted, the catheter 1 mates with the urethral wall (not shown) to enclose the flow channels 15. Hence, when inserted, the urethral wall is exposed to a flow of urine flowing along the external flow channels 15 of the external flushing portion 13.

The external flow channels 15 are separated by walls 17 which extend along the longitudinal axis 19 of the catheter 1 thereby forming one or more substantially straight walls 17 that are parallel with the longitudinal axis 19. The size and number of external flow channels 15 may vary according to the application and desired characteristics of the catheter 1. Typically, the size and number of the external flow channels 15 may be varied to alter the flow rate, velocity of the urine on the urethral wall, and the area of the urethral wall to be exposed to the urine. In the present embodiment, there are four external flow channels 15 divided by four walls 17.

The respective external flow channels 15 and walls 17 are substantially the same in shape and dimension and are equally distributed about the circumference of the main body 3. Accordingly, the external flushing portion 13 is symmetrical about a plane extending along the longitudinal axis 19 and each external flow channel 15 and each wall 17 has a diametrically opposed counterpart.

It can be seen from the cross-sectional view of Figure 5 and the perspective view of Figure 8, that the external flushing portion 13 comprises a solid central core or spine 21 extending along the central axis of the main body 3. The four walls 17 extend radially from the central spine 21 and each comprises an outermost surface 23 and opposing sidewalls 24. The outermost surface 23 of the walls 17 is convex and curves about the circumference of the main body 3. The outer diameter of the external flushing portion 13 is defined by the distance between the outermost surfaces of two diametrically opposed walls 17.

The radius of curvature of the outermost surface of a wall 17 is substantially the same as that of the external walls of the insertion portion 9 and the outlet portion 11 respectively such that the insertion portion 9, external flushing portion 13 and the outlet portion 11 share substantially the same outermost diameter at the respective junctions therebetween. Accordingly, the outermost diameter is approximately constant along the length of the catheter 1 intended for insertion into the urethra and the outermost surface of a wall 17 of the external flushing portion 6 is substantially aligned with the surface of the external wall of the outlet portion 5. Thus, there is no discernible ledge or step formed at the junction between the outer surfaces of the external flushing portion 6 and the outlet portion 5 in the longitudinal direction.

In the present example, the external flow channels 15 are defined by a base, being part of the spine 21, and the sidewalls 24 of adjacent walls 17 that are angled to form a flow channel with a V-shaped cross-section (which may be referred to as a wedge shape or tapered cross-section). It will be appreciated that other channel shapes may be adopted such as, for example, square, concave, or rectangular shaped crosssections.

In the present embodiment, as shown most clearly in Figures 5 and 9, the insertion portion 9 comprises a solid tubular wall 25 defining a central inlet lumen 27 extending longitudinally along the central axis of the main body 3. The inlet lumen 27 may be closed at the proximal end and open at the junction between the insertion portion 9 and the external flushing portion 13. One or more eyelets 29 are formed through the external wall 25 of the insertion portion 9 and into the inlet lumen 27. The open end of the inlet lumen 27 may be open to the external flushing portion 13 such that a fluid flow path for the flow of urine is formed from the or each eyelet 29 to one or more of the plurality of external flow channels 15 via the inlet lumen 27.

A space (i.e., empty space) 31, hereinafter the inlet space 31, is formed through the body of the external flushing portion 13 at a position local to the junction between the insertion portion 9 and the external flushing portion 13 such that a gap (i.e., open gap) is formed between the inlet lumen 27 and the external flow channels 15. The space 31 may be between 3mm and 15mm in length and preferably 7mm. The inlet space 31 may comprise two perpendicular, intersecting channels each extending entirely through the external flushing portion 13 and defined by the remaining portions of the external flushing portion 13. The remaining portions form four pillars 32 that are substantially equally distributed about the circumference of the main body 3. Thus, the inlet space 31 may have a cruciform cross-section transverse to the longitudinal axis of the main body. The result is that urine exiting the inlet lumen 27 into the external flushing portion 13 must traverse the inlet space 31 to enter the external flow channels 15. Advantageously, spacing the inlet lumen 27 and the external flow channels 15 apart in the longitudinal direction reduces the risk of the flow path therebetween becoming blocked by the wall of the urethra.

The insertion portion 9 may be configured to aid insertion and may comprise one more features or formations to this end. In the embodiment shown in Figure 1, the insertion portion 9 is provided with a rounded terminal end 33 but this is not a limitation and the terminal end may be provided with a bulb or cone shaped member or a noncircular cross-section to aid insertion of the catheter 1. With reference to Figures 3 to 8, the outlet portion 11 comprises a solid tubular wall 35 extending from the junction between the external flushing portion 13 and the outlet portion 11. The tubular wall 35 defines an outlet lumen 37 having an inlet 39 at the junction between the external flushing portion 13 and the outlet portion 11 and extends through to an outlet 41 provided in the end face 43 of the outlet portion 11 to form a nozzle for an exiting flow of urine from the catheter 1.

In the present example, as at the junction between the insertion portion 9 and the external flushing portion 13, a space (i.e., empty space) 45, hereinafter the outlet space 45, is formed through the body of the external flushing portion 13 at a position local to the junction between the external flushing portion 13 and the outlet portion 11. Likewise, the length of the space 45 may be between 3mm and 15mm, preferably 7mm. The outlet space 45 is formed by two intersecting channels extending perpendicularly to one another from one side of the external flushing portion 13 to the other to produce an outlet space 45 with a substantially cruciform cross-section in the transverse direction. The remaining portions of the external flushing portion 13 form four pillars 47 that are substantially equally distributed about the circumference of the main body 3 and configured to support the urethra in an open position. Thus, a plurality of drainage apertures 49 are formed at the base of each external flow channel 15 of the external flushing portion 13 and extend both radially and axially.

The outlet space 45 is aligned with the outlet lumen 37 such that a fluid flow path is formed from the external flow channels 15 through the drainage apertures 49 and outlet space 45 and into the outlet lumen 37, thereby allowing urine to exit the catheter 1 via the outlet 41. As shown in Figure 5, the upper face of the outlet portion 11 is angled toward the inlet 39 such that a ramp is formed from the drainage apertures 49 toward the outlet lumen 37, thereby guiding urine to flow from the external flow channels 15 into the outlet lumen 37.

The outlet portion 11 is shaped and configured for at least partial insertion into the urethra together with the external flushing portion 13 so that the drainage apertures 49 may be positioned entirely within the urethra and so that the inserted part of the outlet portion 11 may form a seal at the urethral opening. Thus, urine flowing along the external flow channels 15 between the external flushing portion 13 and the urethral wall may enter the outlet lumen 37 through the drainage apertures 49 without leaking from the urethral opening between the outlet portion 11 and urethral wall.

Whilst in the present embodiment a single common outlet lumen 37 is provided for drainage of urine from the external flow channels 15, it will be appreciated that the outlet portion 11 may take a different form and may comprise more than one outlet which may or may not be provided in the external end face 43 of the outlet portion 11. For example, the outlet portion 11 may comprise a plurality of separate, non-converging lumens or channels extending fully through the outlet portion 11 to a corresponding exit aperture. In such an example, each channel may be in fluid communication only with a corresponding external flow channel 15 such that multiple independent, nonconverging fluid flow paths are formed from the insertion end 5 through to the terminal end i.e., the endmost face 43 of the catheter 1. In doing so, urine may flow in multiple streams in a broadly axial direction along the external flushing portion 13, through the outlet portion 11 and into a funnel or receptacle such as a toilet bowl.

To facilitate the user in determining the appropriate amount to which the catheter 1 should be inserted into the urethra, the outlet portion 11 includes a formation 53 that provides an insertion depth guide, which in this embodiment is a formation in the form of an annular ring. The annular ring 53 extends fully around the circumference of the outlet portion 11 and comprises a convex outer surface 55 extending from the wall 35 of the outlet portion 11. In the present example, the annular ring 53 is integrally formed with the outlet wall 35 and shaped such that the proximal face 57 curves from the outlet wall 35 away from the insertion end 5. Furthermore, the shape of the convex outer surface 55 is substantially symmetrical about a plane 58 extending through the centre of the annular ring 53 in the transverse direction such that the proximal and distal faces have the same general shape and curvature.

The annular ring 53 is spaced apart from the end face 43 of the outlet portion 11 and positioned a distance from the terminal end 33 of the insertion end 5 of the catheter 1 that represents a maximum desired insertion depth 59 of the catheter 1 into the urethra and, ultimately, the bladder. For a female urinary catheter, the annular ring 53 is positioned on the outlet portion 11 between 80mm and 100mm, preferably 90 mm, from the tip 33 of the insertion portion 9. For a male urinary catheter, the annular ring 53 is positioned on the outlet portion 11 between 330mm and 390mm, preferably 360mm, from the tip 33 of the insertion portion 9.

The annular ring 53 is shaped and configured to form a relatively gentle ridge that is positioned, in use, to abut the base of the urethra when the catheter 1 has been inserted into the urethra up to the maximum desired insertion depth. When the catheter is positioned as such, the inserted part of the outlet portion 11 and the annular ring 53 together plug the urethral opening to limit the passage of urine from the urethral opening around the catheter 1 and, thereby, reduce the risk of leakage of urine between the catheter 1 and the urethral wall. To this end, the diameter of the annular ring 53 is greater than the outermost diameter of the main body 3 extending from the annular ring 53 to the tip 33 of the insertion portion 9 i.e., the parts of the catheter 1 intended to be inserted into the urethra. Furthermore, the diameter of the annular ring 53 is greater than the maximum natural diameter of the urethral opening of an intended patient so that, when the annular ring 53 abuts the base of the urethra in use, it restricts the catheter 1 from being inserted beyond the annular ring 53 and, hence, too far inside the urethra and bladder. Accordingly, the diameter of the annular ring 53 is 1mm greater than the diameter of the catheter 1 according to the chosen catheter CH size which may range, for example, from 2 mm (CH06) to 6mm (CH18). For example, for a catheter of size CH06 and, hence, 3 mm diameter, the diameter of the annular ring 53 is 4 mm and for a catheter of size CH14 and, hence, 4.67 mm diameter, the diameter of the annular ring is 5.67 mm. Advantageously, the annular ring 53 provides a non-intrusive, tactile and/or visual feedback to the user to determine when the catheter 1 has been appropriately positioned within the urethra and bladder.

The annular ring 53 is positioned on the outlet portion 11 between 5mm and 15 mm, preferably 10mm, from the junction between the outlet portion 11 and the external flushing portion 13 so that the drainage apertures 49 are positioned fully within the urethra when the catheter 1 is inserted into the urethra and the annular ring 53 abuts the base of the urethra. As described above, positioning the drainage apertures 49 fully within the urethra ensures a flow of urine into the outlet lumen 37 whilst minimising leakage of urine through the urethral opening between the catheter 1 and the urethral wall. Therefore, the annular ring 53 provides the further advantage of indicating to the user when the drainage apertures are appropriately positioned within the urethra. The annular ring 53 may also be arranged to form a physical and/or visual guide for a separate funnel attachment 61 that may be inserted over the wall 35 of the outlet portion 11 from the end face 43. The distance between the annular ring 53 and the end face 43 of the outlet portion 11 may therefore correspond to the maximum desired insertion position of the funnel. Accordingly, in the present example, the annular ring 53 is positioned approximately 10mm from the end face 43 of the catheter 1.

Referring to Figure 10 the funnel 61 may be attached to the outlet end 7 and provided to channel urine draining via the catheter 1 into a suitable receptacle such as a toilet or bed pan. The funnel 61 may define a conical shaped cavity which flares outwardly toward an outlet end 63 of the funnel 61. Accordingly, urine may flow from the external flushing portion 13 through the outlet lumen 37 and out from the catheter 1 via the cavity of the funnel 61. The annular ring 53 may be spaced apart in the longitudinal direction from the funnel 61 so that the annular ring 53, rather than the funnel 61 first abuts the base of the urethra when the catheter 1 is inserted into the urethra up to a maximum desired insertion depth. Advantageously, the annular ring 53 may be more precisely positioned relative to the insertion tip 33 than the funnel 61 during manufacture such that the distance of separation between the annular ring 53 and the insertion tip 33 can be more accurately controlled and repeated for bulk manufacture of the catheter 1.

In some embodiments, the catheter is formed of a material of the group comprising: polyvinyl chloride, polytetrafluoroethylene, polyolefins, latex, silicones, synthetic rubbers, polyurethanes, polyesters, polyacrylates, polyamides, thermoplastic elastomeric materials, styrene block copolymers, polyether block amide, thermoplastic vulcanizates, thermoplastic copolyesters, thermoplastic polyamides, and water disintegrable or enzymatically hydrolysable material, or combinations, blends or copolymers of any of the above materials.

In preferred embodiments, the catheter is formed of a material of the group comprising: polyolefins, polyesters, poly acrylates, polyamides, thermoplastic elastomeric material, polyether block amide, thermoplastic vulcanizates, thermoplastic copolyesters, thermoplastic polyamides, fluororubber, and water disintegrable or enzymatically hydrolysable material or combinations, blends or co-polymers of any of the above materials. In some embodiments, said water disintegrable or enzymatically hydrolysable material comprises a material of teh group comprising: polyvinyl alcohol, extrudable polyvinyl alcohol, poly aery lie acids, polylactic acid, polyesters, polyglycolide, polyglycolic acid, poly lactic-co-glycolic acid, polylactide, amines, polyacrylamides, poly(N-(2-Hydroxypropyl) methacrylamide), starch, modified starches or derivatives, amylopectin, pectin, xanthan, scleroglucan, dextrin, chitosans, chitins, agar, alginate, carrageenans, laminarin, saccharides, polysaccharides, sucrose, polyethylene oxide, polypropylene oxide, acrylics, polyacrylic acid blends, poly(methacrylic acid), polystyrene sulfonate, polyethylene sulfonate, lignin sulfonate, polymethacrylamides, copolymers of aminoalkyl-acrylamides and methacrylamides, melamine-formaldehyde copolymers, vinyl alcohol copolymers, cellulose ethers, poly-ethers, polyethylene oxide, blends of polyethylene- polypropylene glycol, carboxymethyl cellulose, guar gum, locust bean gum, hydroxypropyl cellulose, vinylpyrrolidone polymers and copolymers, polyvinyl pyrrolidone-ethylene-vinyl acetate, polyvinyl pyrrolidone- carboxymethyl cellulose, carboxymethyl cellulose shellac, copolymers of vinylpyrrolidone with vinyl acetate, hydroxyethyl cellulose, gelatin, poly-caprolactone, poly(p-dioxanone), or combinations, blends or co-polymers of any of the above materials. In some preferred embodiments, the catheter is formed of a polyolefin material, especially polyethylene and/or polypropylene. In some preferred embodiments, the catheter is formed of a thermoplastic elastomeric material. In some preferred embodiments the catheter may be made from a polyolefin based synthetic thermoplastic polyolefin elastomer (TPE) containing a hydrophilic additive. In some preferred embodiments the catheter may be made from a polymer mixture comprising a first polymer and a second polymer, wherein the first polymer is a thermoplastic or thermo-curing polymer, and the second polymer is an amphiphilic block copolymer possessing both hydrophilic and lipophilic properties. A possible suitable polymer mixture is described and disclosed in EP2493521A1.

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.