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.

CN206239873 describes an indwelling male catheter having a wire mesh support structure which allows urine to contact the urethra.

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 the urethra in use.

Summary of the Invention

The present invention provides a catheter according to the appended claims.

The present disclosure provides, in a first aspect, a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outlet end having an exit from which fluid may exit the catheter. The insertion end may comprise an insertion portion. The outlet end may comprise an outlet portion for the outflow of fluid from the catheter via the exit.

The elongate main body may further have an external flushing portion between the insertion portion and the outlet portion. The external flushing portion may comprise a plurality of open external flow channels provided in an external surface of the main body. The external flow channels may provide a fluid flow path from the insertion portion to the outlet portion.

Providing external flow channels on an external surface 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 outlet portion may comprise a plurality of discrete non-converging drainage channels extending entirely from a junction between the outlet portion and the external flushing portion to the exit of the outlet end. Each drainage channel of the plurality of drainage channels may be in fluid communication with a corresponding external flow channel of the plurality of external flow channels via a corresponding drainage aperture formed at the junction between the outlet portion and the external flushing portion.

Accordingly, one embodiment of the invention provides a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outlet end having an exit from which fluid may exit the catheter, the insertion end comprising an insertion portion and the outlet end comprising an outlet portion for the outflow of fluid from the catheter via the exit, the elongate main body further having an external flushing portion between the insertion portion and the outlet portion, the external flushing portion comprising a plurality of open external flow channels provided in an external surface of the main body, the external flow channels providing a fluid flow path from the insertion portion to the outlet portion, wherein the outlet portion comprises a plurality of discrete non-converging drainage channels extending entirely from a junction between the outlet portion and the external flushing portion to the exit of the outlet end, wherein each drainage channel of the plurality of drainage channels is in fluid communication with a corresponding external flow channel of the plurality of external flow channels via a corresponding drainage aperture formed at the junction between the outlet portion and the external flushing portion.

The insertion portion may comprise a tubular wall defining an inner lumen having an open end at a junction between the insertion portion and the external flushing portion such that the inner lumen and the external flow channels are in fluid communication. The insertion portion may further comprise one or more eyelets formed through the tubular wall and into the inner lumen to define one or more fluid flow paths through the, or each, eyelet to the external flushing portion via the inner lumen. A gap may be formed between the external flow channels and the open end of the inner lumen such that the external flow channels are separated from the open end of the inner lumen in the longitudinal direction.

Accordingly another embodiment of the invention provides a catheter comprising an elongate main body having an insertion end for insertion into a urethra and an outlet end having an exit from which fluid may exit the catheter, the insertion end comprising an insertion portion and the outlet end comprising an outlet portion for the outflow of fluid from the catheter via the exit, the elongate main body further having an external flushing portion between the insertion portion and the outlet portion, the external flushing portion comprising a plurality of open external flow channels provided in an external surface of the main body, the external flow channels providing a fluid flow path from the insertion portion to the outlet portion, and wherein the insertion portion comprises a tubular wall defining an inner lumen having an open end at a junction between the insertion portion and the external flushing portion such that the inner lumen and the external flow channels are in fluid communication, wherein the insertion portion further comprises one or more eyelets formed through the tubular wall and into the inner lumen to define one or more fluid flow paths through the, or each, eyelet to the external flushing portion via the inner lumen, and wherein a gap is formed between the external flow channels and the open end of the inner lumen such that the external flow channels are separated from the open end of the inner lumen in the longitudinal direction.

A preferred embodiment of the invention provides a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outlet end having an exit from which fluid may exit the catheter, the insertion end comprising an insertion portion and the outlet end comprising an outlet portion for the outflow of fluid from the catheter via the exit, the elongate main body further having an external flushing portion between the insertion portion and the outlet portion, the external flushing portion comprising a plurality of open external flow channels provided in an external surface of the main body, the external flow channels providing a fluid flow path from the insertion portion to the outlet portion, wherein the outlet portion comprises a plurality of discrete non-converging drainage channels extending entirely from a junction between the outlet portion and the external flushing portion to the exit of the outlet end, wherein each drainage channel of the plurality of drainage channels is in fluid communication with a corresponding external flow channel of the plurality of external flow channels via a corresponding drainage aperture formed at the junction between the outlet portion and the external flushing portion, and wherein the insertion portion comprises a tubular wall defining an inner lumen having an open end at a junction between the insertion portion and the external flushing portion such that the inner lumen and the external flow channels are in fluid communication, wherein the insertion portion further comprises one or more eyelets formed through the tubular wall and into the inner lumen to define one or more fluid flow paths through the, or each, eyelet to the external flushing portion via the inner lumen, and wherein a gap is formed between the external flow channels and the open end of the inner lumen such that the external flow channels are separated from the open end of the inner lumen in the longitudinal direction.

Each external flow channel may comprise straight portions. The gap may be provided by an open space. At least part of the open space may extend diametrically through the catheter. At least part of the open space may extend diametrically through the catheter from a terminal end of one external flow channel of the plurality of external flow channels to the terminal end of another external flow channel of the plurality of external flow channels. The open space may extend between the terminal ends of each of the plurality of external flow channels. At least part of the open space may have a rectangular cross-section in the longitudinal direction. Additionally, or alternatively, at least part of the open space may have a square and/or circular and/or oval and/or stadium shaped cross-section in the longitudinal direction. The width of part of the open space may increase in the transverse direction away from the central axis of the main body. Thus, part of the open space may have a trapezoidal cross-section in the transverse direction. Where there are four external flow channels circumferentially evenly distributed about the main body to form two pairs of diametrically opposed external flow channels, the open space may comprise a first through channel extending between the terminal ends of the external flow channels of the first pair, and a second through channel extending between the terminal ends of the external flow channels of the second pair. The first and second through channels may extend substantially perpendicular to one another. The first and second through channels may intersect at the central axis of the catheter. Thus, the open space may have a substantially cruciform cross section in the transverse direction.

The open end of the inner lumen may be separated from the external flow channels in the longitudinal direction by between 3mm and 15mm, preferably 7mm.

The outlet portion may comprise a solid central core and the drainage channels may be evenly distributed about the core. The external flushing portion may comprise a solid central core and the external flow channels may be evenly distributed about the core. The part of the external flushing portion comprising the external flow channels may have a solid cross-section. The part of the external flushing portion comprising the external flow channels may be entirely solid. Each external flow channel of the plurality of external flow channels may be aligned with a corresponding drainage channel.

The shape of a base portion of an external flow channel of the plurality of external flow channels may have the same shape as a base portion of a corresponding drainage channel of the plurality of drainage channels.

The base of the external flow channels, drainage apertures and drainage channels may have the same profile. There may be an equal number of external flow channels and drainage channels. Each external flow channel and corresponding drainage channel may form a continuous fluid flow path in the axial direction from the insertion portion to the exit of the outlet end. The number of drainage apertures may correspond to the number of external flow channels and drainage channels.

The exit of the outlet end may comprise a plurality of outlets, each outlet formed at the terminal end of a corresponding drainage channel of the plurality of drainage channels. The exit of the outlet end may be formed in an end face of the outlet portion.

The drainage apertures may extend axially and/or radially. The external flow channels may extend along the entire length of the external flushing portion.

The catheter may comprise a plurality of walls each having an external surface arranged, in use, to contact the urethral wall and support the urethra in an open state. The plurality of walls may define the plurality of external flow channels and the crosssection of the plurality of walls transverse to the longitudinal axis may have a continuously curved profile.

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 two and six external flow channels. The catheter may comprise between three and five external flow channels. There may be four external flow channels and four corresponding drainage channels. There may be four drainage apertures.

The external flushing portion may be longer than the outlet portion and/or 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 outlet portion of the catheter may be shaped and configured for at least partial insertion into the urethra such that the plurality of drainage apertures are positioned fully within the urethra and a seal is formed at the urethral opening between the outlet portion and the urethral wall, in use. The outlet portion may be cylindrical. The outermost diameter of the part of the outlet portion intended for partial insertion into the urethra may be less than the diameter of the urethra.

The catheter may further comprise a formation extending from an external surface of the main body and arranged, in use, to abut the base of the urethra upon insertion of the catheter into the urethra. The formation may be a ring, e.g., an annular ring. The formation, e.g., annular ring, may have a convex surface. A proximal face of the formation, e.g., annular ring, may curve from the outlet portion away from the insertion end. The distance between the formation and the insertion end may be fixed and correspond to a maximum desired insertion depth of the catheter into the urethra. The formation may form a ridge extending around the main body.

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 plurality of walls may extend longitudinally. The plurality of walls may be straight. The plurality of walls may comprise a longitudinal axis. The cross-section of the plurality of walls 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 plurality of walls may extend radially from a central axis of the main body. The radially extending walls may comprise an outermost surface and respective opposing side walls. Providing rounded walls allows the cross-sectional area of the flow channels to be as wide as possible whilst also providing sufficient contact with the urethral wall such that the catheter does not move in use and provides improved comfort to the user.

The external flow channels may provide a fluid flow path from the insertion portion to the outlet portion. The flow channels may extend fully to the outlet portion. The external flow channels may extend continuously along the main body from the insertion portion 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 plurality of walls may define an outside diameter of the catheter. The outside diameter may be constant along the length of the catheter. Hence, the overall width of the catheter may be constant along the length thereof. The cross-sectional area of the flow channels may be constant along the length of the catheter.

The insertion portion, outlet portion and the external flushing portion may be formed as a singular piece. The insertion portion, outlet portion and the external flushing portion may be formed as separate component pieces that are attached together.

The cross-section of the external flushing portion transverse to the longitudinal axis of the main body may comprise a continuously curved outermost surface.

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

The catheter may be a male urinary catheter or a female urinary catheter. The catheter may be a permanent or intermittent urinary catheter. In a preferred embodiment, the catheter is an intermittent female urinary catheter.

The cross-sectional area of the external flow channels may be between 14mm ^A 2 and 22mm ^A 2, preferably 17.5mm ^A 2. The width of the external flow channels may be between 1 mm and 2 mm, preferably 1.25 mm.

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, preferably 400mm.

The length of the insertion portion may be between 20mm and 40mm, preferably 30mm. The length of the outlet portion may be between 10mm and 30mm, preferably 20mm.

The external flushing portion may comprise between 20% and 80% of the length of the catheter. 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 catheter may be between 2 mm and 6 mm depending on the intended user’s size requirements.

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 extrusion and/or injection moulding and/or 3D printing. The method may comprise the steps of extruding an insertion portion of the catheter, extruding an external flushing portion of the catheter, extruding an outlet portion of the catheter, and attaching the insertion portion, the external flushing portion, and the outlet portion together. The portions may be attached by welding, for example heat friction welding. The method may comprise the step of extruding the external flushing portion having a plurality of open-faced external flow channels formed in an external surface of the external flushing portion and extending the full length of the external flushing portion. The method may comprise the step of extruding the outlet portion with a tubular wall and having a plurality of drainage channels extending from an upper face of the outlet portion to a lower face thereof. The method may comprise the step of extruding the insertion portion having a rounded tip at the insertion end and/or an inner lumen with one or more eyelets extending through a wall of the insertion portion into the inner lumen. The method may comprise the step of removing part of the catheter between the insertion portion and the external flushing portion to create a gap between the external flow channels and the insertion portion in the longitudinal direction.

The method may comprise the step of attaching the external flushing portion to the outlet portion such that each external flow channel is aligned with a corresponding drainage channel and such that each external flow channel is in fluid communication with a corresponding drainage channel via a drainage aperture formed therebetween.

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 insertion portion, an external flushing portion and an outlet portion, the external flushing portion comprising a plurality of open-faced external flow channels extending from the insertion portion to the outlet portion, the outlet portion comprising one or more drainage channels for the outflow of fluid from the catheter, wherein the external flow channels are each in fluid communication with a drainage channel of the outlet portion via a corresponding drainage aperture formed therebetween, and (ii) inserting the catheter into the bladder via the urethra until at least one external flow channel of the catheter is in fluid communication with the bladder so that urine can drain from the bladder through the urethra along one or more, or each, external flow channel of the catheter. The outlet portion may be partially inserted into the urethra such that the drainage apertures are fully located inside the urethra. Where the insertion portion comprises an inner lumen and one or more eyelets defining a fluid flow path through the insertion portion to the external flow channels, the method may comprise the step of inserting the catheter into the urethra until one or more eyelets is located within the bladder for the drainage of urine from the bladder through the insertion portion. Where the catheter comprises an insertion depth guide extending from the outlet portion of the catheter, the method may comprise the step of inserting the catheter into the urethra until the insertion depth guide abuts the base of the urethra.

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 of a schematic representation of a catheter according to the present disclosure;

Figure 2 shows a first side view of the catheter of Figure 1;

Figure 3 shows a second side view of the catheter of Figure 1, the second side view circumferentially offset by 90 degrees from the first side view;

Figure 4 shows a cross sectional side view of the catheter of Figure 1;

Figure 5 shows an enlarged, compressed, perspective view of the catheter of Figure 1 viewed from the distal end;

Figure 6 shows an enlarged, compressed, perspective view of the catheter of Figure 1 viewed from the proximal end;

Figure 7 shows an enlarged perspective view of a cross-section of the external flushing portion of the catheter of Figure 1; Figure 8 shows an enlarged perspective view of the outlet portion shown in Figure 1 with an optional insertion depth guide extending therefrom;

Figure 9 shows an enlarged perspective view of a schematic representation of an alternative embodiment of a catheter according to the present disclosure;

Figure 10 shows a side view of the catheter shown in Figure 9;

Figure 11 shows an enlarged perspective view of the insertion end of the catheter of Figure 9 from the proximal end;

Figure 12 shows a cross-sectional view through the outlet portion of the catheter of Figure 9 taken through the line A- A shown in Figure 15;

Figure 13 shows a cross-sectional side view of the catheter shown in Figure 9 taken through the line B-B shown in Figure 14;

Figure 14 shows a side view of the catheter shown in Figure 9; and,

Figure 15 shows a side view of the catheter shown in Figure 9, which is circumferentially offset from the side view of Figure 14 by 90 degrees.

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 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.

Figure 1 shows a urinary catheter 1 comprising an elongate main body 2 having an insertion end 3 for insertion of the catheter 1 into a urethra and an outlet end 4 having an exit from which fluid (e.g., urine) exits the catheter 1. The insertion end 3 comprises an insertion portion 5 for the inflow of fluid, e.g., urine, and the outlet end 4 comprises an outlet portion 6 for the outflow of fluid, e.g., urine, from the catheter 1 via the exit.

The main body 2 comprises an external flushing portion 7 extending between the insertion portion 5 and the outlet portion 6. The external flushing portion 7 comprises a plurality of external flow channels 8 which provide a fluid flow path. The external flow channels 8 are provided in the external surface of the main body 2, 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 8. Hence, when inserted, the urethral wall is exposed to a flow of urine flowing along the external flow channels 8 of the external flushing portion 7.

The external flow channels 8 are defined by walls 9 which extend along the longitudinal axis 10 of the catheter 1 thereby forming one or more substantially straight walls 9 that are parallel with the longitudinal axis 10. The size and number of external flow channels 8 may vary according to the application and desired characteristics of the catheter 1. Typically, the size and number of the external flow channels 8 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 8 and, correspondingly, four walls 9.

With reference to Figure 7 the respective external flow channels 8 and walls 9 are substantially the same in shape and dimension and are equally distributed about the circumference of the main body 2 such that external flushing portion 7 has a substantially cruciform cross section. Accordingly, the external flushing portion 7 is symmetrical about a plane extending along the longitudinal axis 10 and each external flow channel 8 and each wall 9 has a diametrically opposed counterpart.

The external flushing portion 7 comprises a solid central core 11 extending along the length thereof. The four solid walls 9 extend radially from the central core 11 and each comprises an outermost surface 12 having a convex surface that curves about the circumference of the main body 2. The outer diameter of the external flushing portion 7 is defined by the distance between the outermost surfaces 12 of two diametrically opposed walls 9. The radius of curvature of the outermost surface 12 of a wall 9 is substantially equivalent to that of the insertion portion 5 and the outlet portion 6 such that the external flushing portion 7, the insertion portion 5 and the outlet portion 6 share substantially the same outermost diameter. Consequently, the outermost diameter is approximately constant along the entire length of the catheter 1 and the outermost surface 12 of a wall 9 of the external flushing portion 7 is substantially aligned with the outermost surface of the insertion portion 5 and outlet portion 6 such that no discernible ledge or step is formed at an interface therebetween in the longitudinal direction.

The opposing sidewalls of two adjacent walls 9 curve inwardly and toward one another to meet to form a continuously curved base portion 13 of the external flow channel 8. The curved base portion 13 of the external flow channel 8 is connected to the outermost surface 12 of each flanking wall 9 by a corresponding rounded transition 14. The rounded transition 14 and curved outermost surface 12 allows the catheter 1 to gain sufficient purchase on the wall of the urethra to ensure it remains in situ during use, whilst providing a relatively large open-faced area of the flow channel 8 for adequate flushing contact of urine with the urethra wall. 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.

Although the external flow channels 8 are described as comprising a curved base portion 13 extending to the outermost surface 12 of the longitudinal walls 9 via the rounded transitions 14, it will be appreciated that other channel shapes are possible and may provide adequate flushing of the urethra. For example, the external flow channels 8 may comprise a base and sidewalls that are angled to form a flow channel 8 with a V-shaped cross-section (which may be referred to as a wedge shape or tapered cross-section) or a square or rectangular shaped cross-section.

As can be seen in Figures 1 to 4, the external flushing portion 7 extends fully between the insertion portion 5 and the outlet portion 6. In the present embodiment, the insertion portion 5 comprises a solid, cylindrical body having a solid outer wall 27 and extends from the proximal end of the external flushing portion 7 to the insertion tip 16 of the catheter 1. The insertion portion 5 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 5 is provided with a rounded insertion terminal end 16 but this is not a limitation and the terminal end may be provided with a bulb or cone shaped member or a non-circular cross-section to aid insertion of the catheter 1.

The external flow channels 8 are shaped and configured to receive a flow of urine from the user’s bladder in use and channel the urine towards the outlet portion 6. Accordingly, the proximal ends of the external flow channels 8 are angled at the transition between the external flushing portion 7 and the insertion portion 5 to form a ramp 17 from the outer surface of the insertion portion 5 to the corresponding external flow channel 8. The ramped transitions 17 serve to guide urine from the bladder into the external flow channels 8 and thereby encourage the drainage of urine from the bladder via the external flushing portion 7.

Referring to Figures 5 and 6, the outlet portion 6 is substantially cylindrical with a solid outer wall 15 and defines a plurality of drainage channels 18 which are substantially equally distributed circumferentially about a solid, central core 19. Each drainage channel 18 extends fully from a junction between the external flushing portion

7 and the outlet portion 5 to the end face 20 of the outlet portion 6 and, hence, the terminal outlet end of the catheter 1. The drainage channels 18 are each independent of one another, do not converge and extend longitudinally through the outlet portion 6 to form substantially straight channels 18. Each drainage channel 18 terminates with an outlet 21 in the end face 20 of the outlet portion 5. The outlets 21 together define an exit for the outflow of urine from the catheter 1.

The drainage channels 18 are equivalent in number to the external flow channels

8 and are aligned such that each external flow channel 8 is in fluid communication with a corresponding drainage channel 18 via a drainage aperture 23 formed at the interface between the external flow channel 8 and the corresponding drainage channel 18. Each drainage channel 18 comprises a curved base portion which extends either side toward the outer wall of the outlet portion 6. A rounded transition having the same radius of curvature as the rounded transition of the external flow channels 8 is formed on either side of the curved base portion such that the shape and cross-section of a drainage channel 18 is substantially the same as that of an external flow channel 8. The corresponding drainage apertures 23 are similarly shaped such that a plurality of substantially straight, continuous, and uniform flow channels are formed along the main body 2 from the junction between the insertion portion 5 and the external flushing portion 7 fully to the end face 20 of the outlet portion 6. Accordingly, urine may drain from the bladder via multiple non-converging axial flow paths which exit from the outlets 21 in multiple streams at the end of the catheter 1.

Providing a plurality of independent, non-converging flow paths from the insertion portion 5 fully to the terminal outlet end of the outlet portion 6 can produce a more natural flushing effect of the urethra. With the above-described embodiment, it is possible to achieve flow rates along the flow channels that are comparable to those of a conventional catheter with internal, rather than external, flow channels. For example, one embodiment having a diameter of 6 mm (i.e., catheter size CH18) can achieve flow rates of approximately 1,290 ml/min.

Referring to Figure 8, the outlet portion 6 may optionally include a formation 30 that provides an insertion depth guide which, in this embodiment, is a formation in the form of an annular ring. The annular ring 30 may have a convex outer surface extending from the outlet wall 15 and fully around the circumference of the outlet portion 6. The annular ring 30 may be integrally formed with the outlet portion 6 and shaped such that the proximal face 32 curves from the wall of the outlet portion 6 away from the insertion end 3. The annular ring 30 is spaced apart from the end face 20 of the outlet portion 6 and positioned a distance from the insertion tip 16 of the catheter 1 that represents a maximum desired insertion depth 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 100mm, from the tip 33 of the insertion portion 9 and for a male urinary catheter, the annular ring 53 is positioned on the outlet portion 11 between 330 mm and 390 mm, preferably 360 mm from the tip 33 of the insertion portion 9.

Accordingly, the annular ring 30 is shaped and configured to form a gentle ridge that is positioned, in use, to abut the base of the urethra and provide a non-intrusive, tactile and/or visual feedback to the user to indicate when the drainage apertures 23 are appropriately positioned within the urethra and the catheter 1 has reached or is approaching its maximum desired insertion depth.

The annular ring 30 may also be arranged to form an abutment for a separate funnel attachment (not shown) that may be inserted over the wall 15 of the outlet portion 6 from the end face 20 thereof. The distance between the annular ring 30 and end face 20 of the outlet portion 6 may therefore be equivalent to the maximum desired insertion distance for the funnel attachment over the wall 15 of the outlet portion 6 and assist a user in correctly positioning a funnel for the outflow of urine from the catheter 1 without leakage.

It will be appreciated that the insertion portion need not be entirely solid and could comprise one or more external and/or internal channels or other means for directing urine toward the external flushing portion. For example, Figures 9 to 15 show an alternative embodiment which is in many respects the same as that of figures 1-8 and like reference numerals (incremented by 100) are used for like features. In this embodiment, the catheter 101 comprises an elongate main body 102 having an insertion portion 105 at the insertion end 103, an outlet portion 106 at the outlet end 104, and an external flushing portion 107 extending between the insertion portion 105 and the outlet portion 106.

The external flushing portion 107 comprises a solid, central core 111 extending along the central axis of the main body 102 and a plurality of substantially straight, longitudinal walls 109 extending radially therefrom. The walls 109 and base of the central core 111 together define a plurality of substantially straight, elongate external flow channels 108 which define a fluid flow path from the insertion portion 105 to the outlet portion 106. In the present example, there are four walls 109 and, correspondingly, four external flow channels 108. As in the first described embodiment, the walls 109 and flow channels 108 are substantially equally distributed circumferentially about the main body 102 such that each wall 109 and each flow channel 108 has a diametrically opposed counterpart. Thus, the distance between two diametrically opposed walls 109 defines the outermost diameter of the external flushing section 107.

The outlet portion 106 is substantially cylindrical and extends from a distal end of the external flushing portion 107 to the terminal outlet end of the catheter 101. The outlet portion 106 has a solid core section 119 and defines a plurality of separate, nonconverging drainage channels 118 extending from the proximal end of the outlet portion 106 through to the terminal end of the catheter 101 at the lower face 120 of the outlet portion 106. In the present example, the number of drainage channels 118 is equal to the number of external flow channels 108 and, thus, there are four drainage channels 118. The drainage channels 118 are substantially equally distributed circumferentially about the main body 102 and arranged such that each external flow channel 108 is aligned, and in fluid communication, with a corresponding drainage channel 118 via a corresponding drainage aperture. Accordingly, multiple, separate, non-converging axial fluid flow paths are defined by the external flow channels 108 and drainage channels 118 that extend from the proximal end of the external flushing portion 107 entirely through to the lower face 120 of the outlet portion 106 (i.e., the terminal outlet end of the catheter 101).

The insertion portion 105 comprises a cylindrical, solid wall 127 defining a central inner lumen 135 extending longitudinally through the insertion portion 105 along the central axis thereof. The inner lumen 135 is closed at the insertion end 116 and open at the junction between the insertion portion 105 and the external flushing portion 107. One or more eyelets 125 are formed through the external wall 127 of the insertion portion 105 and into the inner lumen 135. The open end of the inner lumen 135 is open to the external flushing portion 107 such that a fluid flow path for the flow of urine is formed from the or each eyelet 125 to one or more of the plurality of external flow channels 108 via the inner lumen 135.

In the present embodiment, a space 129 (i.e., an empty space) is formed through the central core 111 of the external flushing portion 107 at a position local to the junction between the insertion portion 105 and the external flushing portion 107 such that a gap (i.e., an open gap) is formed between the open end of the inner lumen 135 and the external flow channels 108. The empty space 129 may be defined by two perpendicular, intersecting through channels each extending entirely through the core 111 of the body of the external flushing portion 107 from one side to the other. Thus, the empty space 129 may have a substantially cruciform cross-section transverse to the longitudinal axis of the main body. In the present example, the through channels may have a substantially rectangular cross section in the longitudinal direction. However, it will be appreciated that other channel shapes are possible, and the through channels may have a square, circular, oval, or stadium shaped cross-section depending on the shape of material removed from the core 111 in forming the space 129.

The empty space 129 is formed to extend between the terminal ends of the external flow channels 108 at the junction between the external flushing portion 107 and the insertion portion 105. The result is that urine exiting the inner lumen 135 must traverse the empty space 129 to enter the external flow channels 108. Advantageously, providing the empty space 129 between the inner lumen and the external flow channels 108 reduces the risk of the flow path therebetween becoming blocked by the wall of the urethra. Accordingly, the longitudinal gap formed by the space 129 between the flow channels 108 and the open end of the inner lumen 135 is preferably between 3mm and 15mm, e.g., 7mm, and the width of the space 129 is approximately equal to that of an external flow channel 108. Accordingly, the risk of a surface of the urethra blocking the flow path at the junction between the external flushing portion 107 and the insertion portion 105 is reduced.

As in the first described embodiment, the outlet portion 106 of the catheter 101 may additionally comprise an optional depth insertion guide (not shown) in the form of an annular ring which is shaped and configured to abut the base of the urethra in use, and which is positioned a fixed distance from the insertion tip 116 that represents the maximum desired insertion depth of the catheter 101.

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.