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 aid 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 make catheter having a wire mesh support structure which allows urine to contact the urethra.

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 a first aspect, a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outflow end. A plurality of external flow channels may be provided in an external surface of the main body. The catheter may be an intermittent urinary catheter.

Providing external flow channels on an external surface of 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 external flow channels may be defined by a plurality of walls which extend along the length of the main body. The plurality of walls may extend longitudinally and circumferentially. The plurality of walls may be helical. The pitch of the helical walls may be constant. 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. The outermost surface may comprise a first radius. A transition between the outermost surface and the respective sidewalls may comprise a second radius. The external flow channels may be formed between the plurality of walls. The external flow channel may be formed by a third radius. The first radius may be larger than the second and third radius. The second radius may be smaller than the first and second radius.

The radially extending walls may be joined by a fillet of constant radius, thereby providing a rounded external flow channel.

The rounded helical walls may provide the main body with a twisted or corkscrew appearance comprising a plurality of helical members and helical channels or flutes extending therebetween. The twisted configuration may be referred to a barley twist or twisted rope configuration. The helical walls may be generally rounded with the separation between the rounded helical walls defining the flow channels.

The external flow channels may be defined by a plurality of rounded helical walls which extend along the length of the main body, the separation between the rounded helical walls defining the flow channels. The rounded helical walls may be convex.

Providing rounded helical walls allows the cross-sectional area of the flow channels to be as wide as possible whilst also providing sufficient contact with the urethra wall such that the catheter does not move in use.

The external flow channels may provide a fluid flow path from the insertion end to the outflow end. The flow channels may extend fully to a terminal end of the catheter at the outflow end. The external flow channels may comprise a helical portion at the outflow end.

Providing an external flow channel which extends to the terminal end of the catheter removes the need to have the flow channels being diverted internally thereby making the manufacture of the catheters more straightforward and also ensuring the full extent of the urethra is contacted by a flow of urine.

Providing helical portions at the outflow and of the catheter allows urine to aid with coalescing the flow of urine as it leaves the outflow end. In some embodiments, the helical portions provided at the outflow end are configured to coalesce a flow of urine as it leaves the outflow end.

The external flow channels may extend continuously along the full length of the main body from a terminal end of the catheter at the insertion end to the terminal end of the catheter at the outflow end. Providing the channels along the full length of the catheter allows the entire length of the urethra to receive a flow of urine during use, thereby maximising the benefit of the contacting flow. Further, providing the flow channels along the entire length allows the axial position of the catheter within the urethra to vary whilst still ensuring there is flow contact only the full length of the urethra.

In some embodiments, the external flow channels may comprise one or more straight portions and/or one or more helical portions. A helical portion may be provided at the outflow end to allow the urine flow to coalesce. In some embodiments, the external flow channels on the main body may be helical. Providing helical flow channels on the main body may provide for superior flushing of the urethra. This is because, firstly, the flow path for a helical channel is longer and so the flushing benefit is greater. Secondly, as the flow path extends circumferentially and axially, it is more likely that the entirety of the urethra will receive a flow of urine, either by urine passing axially between helical channels, or as the catheter is withdrawn. As such, the helical portion may extend continuously along the full length of the main body from the insertion end to the outflow end.

The pitch of the helical channels may or may not be constant along the length of the catheter. The cross-sectional area of the flow channels may or may not be constant along the length of the catheter.

The main body of the catheter may comprise an elongate member. The main body may be straight. The main body may be rigid, thereby aiding insertion and also maintaining the shape of the external flow channels in use.

The radially outermost surface of the plurality of walls, e.g., the helical 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 external surface of the plurality of walls and the external flow channels may be continuously curved. The external surface of the main body may be continuously curved along the full length thereof. The continuous curvature may be in all dimensions (rather than being curved merely by virtue of being a helix). Hence, the plurality of walls and external flow channels may be transversely curved and longitudinally curved. A line of the external surface which extends along a longitudinal plane of the main body may be continuously curve. The line may be sinusoidal or comprise a periodic arrangement of fixed radius sections in which the outermost surface comprises a first longitudinal radius, the flow channel comprises a second longitudinal radius and the transition between the first and second longitudinal radiuses comprises a third radius. The first longitudinal radius may be larger than the second and third longitudinal radius. The second longitudinal radius may be smaller than the first and third longitudinal radiuses.

The number of external flow channels may be any suitable 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 flow channels. The catheter may comprise four external flow channels. The external surface may be configured to contact the urethra along the full length thereof.

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

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

The diameter of the catheter may be between 2mm and 6mm depending on the intended user’s requirements.

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

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

The main body may be solid. Solid is to be understood as meaning not hollow. The entire main body may be solid, not hollow. Alternatively, only a portion of the main body may be solid. For example, where a portion of the main body comprises the plurality of external flow channels, the entire portion comprising the plurality of external flow channels may be solid. In this case other portions of the main body may be hollow. A solid body is easier to manufacture, for example by extrusion or injection moulding than a hollow one.

The catheter may comprise a hollow insertion portion at the insertion end and define an inner lumen in fluid communication with the external flow channels. 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 inner lumen may be separated from the external flow channels in the longitudinal direction such that a gap is formed between the external flow channels and the inner lumen.

The catheter may comprise a hollow outlet portion at the outflow end and define a drainage channel extending through the outlet portion. Each external flow channel may be in fluid communication with the drainage channel via a corresponding drainage aperture. Each external flow channel may terminate in a drainage aperture. Each external flow channel may be separated from the drainage channel in the longitudinal direction such that a gap is formed between the external flow channels and the drainage channel.

The external flow channels may be arranged such that upon insertion of the catheter into the urethra, the external flow channels provide the only fluid flow paths for urine from the bladder along the urethra.

The catheter may further comprise a formation extending from an external surface of the main body in the form of an annular ring forming a ridge between the insertion end and the outflow end and arranged, in use, to abut the base of the urethra upon insertion of the catheter into the urethra, 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.

The present disclosure provides, in a second aspect, a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outflow end, a plurality of external flow channels in an external surface of the main body, the flow channels providing a fluid flow path from the insertion end to the outflow end, wherein the external flow channels are defined by a plurality of rounded helical walls which extend along the length of the main body, the separation between the rounded helical walls defining the flow channels.

The present disclosure provides, in a third aspect, a catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outflow end; a plurality of external flow channels provided in an external surface of the main body, the flow channels providing a fluid flow path from the insertion end to the outflow end, wherein the flow channels extend fully to a terminal end of the catheter at the outflow end and comprise a helical portion at the outflow end.

The present disclosure provides, in a fourth aspect, a method of manufacturing a catheter according to any aspect described herein by extrusion and/or injection moulding and/or 3D printing.

The present disclosure provides, in a fifth 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 for insertion into a urethra and an outflow end, a plurality of external flow channels in an external surface of the main body, the external flow channels providing a fluid flow path from the insertion end to the outflow end, wherein the external flow channels are defined by a plurality of rounded helical walls, the separation between the rounded helical walls defining the flow channels, and (ii) inserting the catheter into the bladder via the urethra until the external flow channels are in fluid communication with the bladder so that urine can drain from the bladder through the urethra along the external flow channels of the catheter.

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 schematic representation of a catheter according to the present disclosure;

Figure 2 shows an end view of the outflow end of the catheter of Figure 1; Figure 3 shows a side view of the insertion end of the catheter of Figure 1; Figure 4 shows a longitudinal section of the catheter of Figure 1, detailing the continuous curvature of the flow channel profile;

Figure 5 shows an enlarged view of the longitudinal section shown in Figure 4 Figure 6 shows a first side view of a schematic representation of an alternative embodiment of a catheter according to the present disclosure;

Figure 7 shows a second side view of the catheter shown in Figure 6, the second side view circumferentially offset from the first side view by 90 degrees;

Figure 8 shows a cross-sectional side view of the catheter shown in Figure 6, with helical walls extending along the opposite side shown in broken lines.

Figure 9 shows a side view of an outflow end of an alternative embodiment of a catheter according to the present disclosure;

Figure 10 shows a cross sectional view of the outflow end shown in Figure 9; Figure 11 shows a perspective view of part of the outflow end shown in Figures 6 or 9, with an optional depth insertion guide extending therefrom;

Figure 12 shows a perspective view from the distal end of the outflow end shown in Figures 9 and 10 with an optional depth insertion guide extending therefrom;

Figure 13 shows a perspective view of a funnel portion that may be integrally formed at the outflow end of a catheter according to the present disclosure;

Figure 14 shows an end view from the distal end of the funnel portion shown in Figure 13;

Figure 15 shows a cross-sectional side view of the funnel portion shown in Figure 13;

Figure 16 shows a perspective view of an insertion end of an alternative embodiment of a catheter according to the present disclosure; and,

Figure 17 shows a cross-sectional view of the insertion end shown in Figure 16. 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 male or female intermittent urinary catheters. Figure 1 shows a urinary catheter 1 comprising an elongate main body 2 having an insertion end 3 for insertion into a urethra and an outflow end 4 which is located externally of the user’s body and provides an exit point for a flow of urine, when in use.

The main body 2 may comprise a plurality of external flow channels 5 which provide a fluid flow path. The external channels 5 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 mates with the urethra wall to enclose the flow channels 5 and form the only fluid flow paths for the flow of urine along the corresponding section of the urethra. Hence, when inserted, the urethral wall is exposed to a flow of urine flowing along the external flow channels 5.

The main body 2 may comprise one or more walls 6 which extend along the body 2 and define the external flow channels 5 therebetween. A radially outer surface of the walls 6 define the outer diameter of the main body 2.

In the case of Figure 1, the walls 6 extend along and around the longitudinal axis 7 of the catheter 1 thereby forming helical walls. The separation between axially adjacent walls 6 (or axially adjacent turns of the same helical wall when there is only one wall) defining the external flow channel.

The size and number of external flow channels 5 may vary according to the application and desired characteristics of the catheter 1. Typically, the size and number of the flow channels 5 may be varied to alter the flow rate, velocity of the urine on the urethra wall, the area of urethra wall which is exposed etc.

The provision of helical walls 6 is preferable in some embodiments as it may provide a longer flow path for the urine to pass along which slows the speed of the urine and allows more of the surface area to be flushed more effectively. Further, providing a helical channel allows the urethral wall to be better supported whilst exposing a greater surface area. Further still, providing helical walls 6 which extend circumferentially around the catheter can provide a wiping action against the urethra wall when withdrawing the catheter 1, thereby helping flush the urethra wall.

As can be seen in Figure 1, the external flow channels 5 may extend to the terminal ends 3t, 4t of the insertion end 3 and outflow end 4. In doing so, the urine which passes along the channels 5 may continue to flow in a broadly axial direction from the outflow end 4 into a receptacle such as a toilet bowl. Figure 2 shows the outflow end 4 of the main body 2 viewed end-on and shows the open end of the channels 5 in the axial direction. Hence, the terminal end 4t, i.e., the endmost face of the catheter 1, may comprise the open ends of the flow channels 5.

The cross-sectional area of the open ends of the flow channels 5 may be the same as the flow channel 5 along the length of the main body 2. However, in some embodiments, the open ends may comprise a flared portion such that the end of a flow channel 5 expands towards the open end. In other embodiments, the channels 5 may narrow to provide a smaller open end cross-sectional flow area. Adjusting the size of the opening at the terminal end 4t of the catheter 1 may help to control the velocity of the exiting flow, thereby allowing more control to aid the formation of a single stream.

When viewed end on as shown in Figure 2, it can be seen that the main body 2 may comprise an outer external diameter 8 defined by the outermost surface of the helical walls 9 and an inner external diameter 10, defined by the radially innermost surface of the channel 5.

It can be seen from the view in Figure 2, that the main body 2 may comprise a solid central core 13 with a plurality of walls 6 extending radially from the core 13. Each of walls 6 may comprise an outermost surface 9 and opposing sidewalls which extend inwardly to define the sides of the flow channels 5. Circumferentially adjacent walls 6 are joined by a curved region to provide a base 11 of the flow channel. In the example shown, the base of the flow channel 5 is provided by a filleted region which extends between the neighbouring radially extending walls. Although the bottom surface 11 of the channels 5 are shown as having a constant radius of curvature between the side walls, this is not a limitation and other shapes may be possible.

The transition 12 between the channel 5 and the outermost surface 9 is generally continuously curved to provide a smooth and relatively gradual transition between the channel 5 and the outer surface 9.

Generally, the outermost surface 9 may comprise a radius of curvature Rl. The base 11 of the flow channel 5 may comprise a radius of curvature R2. The transition between the base 11 of the flow channel 5 and the outermost surface may be defined by a radius R3. Rl may be greater than R2 and R3. R3 may be smaller than Rl and R2.

Figure 3 shows the insertion end 3 of the catheter 1. The terminal end 3t of the catheter at the insertion end 3 is generally rounded such that it can be inserted more readily and comfortably without causing distress and/or damage to the urethra wall of a user. In some embodiments, the insertion end may include a formation to aid insertion, such as a bulb or cone, in which the end of the catheter 1 is broader than the main body 2 or otherwise specifically shaped to aid insertion.

The external flow channels 5 may extend towards the insertion end 3 and terminate at or local to the terminal end 3t of the insertion end 3. Providing the channels 5 local to the insertion end 3 means a flow channel 5 can be created as soon as the catheter 1 enters the bladder, thereby making the catheter 1 less sensitive to axial position in use.

The external flow channels 5 are shown as extending along the full length of the catheter 1 in Figure 1. Hence, the flow channels 5 can be considered to be extending from the terminal end 3t of the insertion end 3 to the terminal end 4t of the outflow end 4. However, although this may provide advantages in terms of positioning and outflow performance, it is also the case that in some instances the flow channels 5 may not extend to the extreme ends of the main body 2. Further, although the flow channels 5 are shown as being exclusively helical with a constant pitch, this may not be the case and the flow channels 5 may comprise helixes of varying pitch along the length and possible sections in which the flow channels 5 are straight.

In some embodiments, the catheter 1 may be provided with helical flow channels 5 at the outflow end 4 extending to the terminal end 4t. Providing helical flow channels 5 at the outflow end 4 of the catheter 1, as shown in Figure 2, may be advantageous for helping to control the stream of urine leaving the catheter tip, however, in some embodiments, the flow channels 5 may not be helical and may be configured to join each other upstream of the tip to provide one or more combined flow channel 4 exits at the end.

Although Figure 1 shows the terminal end 4t of the outflow end 4 as having a flat end surface normal to the longitudinal axis 7, it will be appreciated that the end may be rounded in a similar way to the insertion end 3, or in some other way. Providing similar ends at either end of the main body 2 may allow the catheter to be used in either orientation.

Figure 4 shows a longitudinal cross-section of the main body 2 of the catheter 1 and reveals the profile of the external surface of the walls 6 and flow channels 5. As can be seen, the line 14 of the external profile which lies along the longitudinal section comprises a flow channel portion 15, a helical wall portion 16, and a transition 17 between the flow channel portion 15 and the outermost surface of the helical wall portion 16. The flow channel portion 15 and transition 17 is provided by a continuously curving surface. Also, the outermost surface of the helical wall is continuously curving but may include flat region at an apex of the wall 16. In the embodiment shown, the radius of curvature of the outermost portion 16 of the helical wall is greater than that of the flow channel portion 15 to provide the outermost portion 16 with a flatter surface to reside against the wall of the urethra in use. The continuously curving transition 15 and curving outermost portion 16 allows the catheter 1 to gain sufficient purchase on the wall of the urethra to ensure it remains in situ during use, whilst maximising the contact area of the flow channel 5.

The radiuses of curvature of the longitudinal profile are shown more clearly in Figure 5 in which the outermost surface 9 of the wall 6 comprises a radius R4, the flow channel 5 comprises radius R5, and the transition between the flow channel 5 and outermost surface 9 of the wall 6 has a single radius R6. R4 may be greater than R5 and R6. R6 may be smaller than R4 and R5. It will be appreciated that the various portions of the walls described herein may include different radiuses or varying radiuses of curvature. In some embodiments, the curvature of the channel 5 and wall 6 may be defined by one or more radiuses or a function such as a half sine wave or similar.

The curvature of the flow channel 5 may be chosen to provide a minimum cross- sectional area for the flow area.

The respective widths of the helical wall 6 and the external flow channel 5 is approximately the same in the embodiments shown in Figure 1. However, this need not be the case and the spacing width of the wall 6 may be increased or decreased in relation to the width of the channels 5, as required. It will be appreciated that a catheter 1 with wider walls will provide more support for the urethra compared to a catheter with relatively wider channels.

Figures 6 to 8 show an alternative embodiment of a urinary catheter which is in many respects the same as that of figures 1-5 and therefore only the differences are described, and like reference numerals (incremented by 100) are used for like features. In the present example, extending inboard from the terminal end 104t of the outflow end 104 is a substantially cylindrical, solid outlet portion 118 which may be shaped and configured for at least partial insertion into the urethra i.e., with a diameter less than the diameter of the urethra of the intended user. Accordingly, the outlet portion 118 may share the same outermost diameter as the portion of the main body comprising helical channels 105, hereinafter the external flushing portion 119. In the present example, the external flushing portion 119 has a solid central core and a diameter of between 2mm and 6mm depending on the anatomy of the intended user, and the pitch is 30mm to achieve a minimum desired urine flow rate when in use.

Whilst urine may be directed to flow over the solid wall of the outlet portion 118 when exiting the catheter, Figures 9 and 10 show a possible alternative arrangement in which the outlet portion 118 comprises a tubular wall defining an outlet lumen 120 extending longitudinally along the central axis of the outlet portion 118 from a junction between the outlet portion 118 and the external flushing portion 119 to the lower face 121 of the outlet portion 118 and, hence, the terminal end 104t of the outflow end 104. With this arrangement a drainage aperture 122 is formed at the base of each external flow channel 105 local to the junction between the outlet portion 118 and the external flushing portion 119 to provide a fluid flow path from the external flow channel 105 to the outlet lumen 120. The drainage apertures 122 extend radially and axially through the main body such that they each meet at a common space (i.e., empty space) at the central axis of the main body 102. Accordingly, the external flow channels 105 are separated from the outlet lumen 120 in the longitudinal direction to form a gap (i.e., empty gap) therebetween which may serve to minimise the likelihood of the flow paths being blocked by the urethral wall when in use.

As mentioned, the outlet portion 118 may be shaped and configured for at least partial insertion into the urethra together with the external flushing portion 119. This may be especially desirable where drainage apertures 122 are provided and are to be positioned within the urethra in use to allow urine to drain therethrough and into the outlet lumen 120 before exiting the urethra, thereby reducing potential leakage of urine between the catheter 101 and urethral opening.

As shown in Figures 11 and 12, to assist a user of the catheter 101 in correctly positioning the catheter 101 within the urethra, an insertion depth guide 123 may be integrally formed with the outlet portion 118 and arranged to extend radially from the outer surface thereof. In this embodiment the insertion depth guide 123 is a formation in the form of a ring, e.g., an annular ring. The annular ring 123 may have a convex outer surface extending from the outlet wall and fully around the circumference of the outlet portion 118. The annular ring 123 is shaped such that the proximal face 124 curves from the wall of the outlet portion 118 away from the insertion end 103. The annular ring 123 is spaced apart from the end face 121 of the outlet portion 118 and positioned a distance from the terminal end or tip 103t of the insertion end 103 of the catheter 101 that represents a maximum desired insertion depth of the catheter 101 into the urethra and, ultimately, the bladder. 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.

Accordingly, the annular ring 123 is shaped and configured to form a relatively gentle ridge that is positioned, in use, to abut the base of the urethra and provide a nonintrusive, tactile and/or visual feedback to the user to indicate when the external flushing portion 119 is in fluid communication with the bladder and, if present, the drainage apertures 122 are appropriately positioned within the urethra.

The annular ring 123 may also be arranged to form an insertion guide or abutment for a separate funnel attachment (not shown) that may be inserted over the wall of the outlet portion 118 from the end face 121 thereof. The distance between the annular ring 123 and the end face 121 of the outlet portion 118 may therefore be equivalent to the maximum desired insertion distance for the funnel attachment along the outlet portion 118 and thereby assist a user in correctly positioning a funnel for the outflow of urine from the catheter 101 without leakage.

In some embodiments, it will be appreciated that a funnel may be incorporated into, and integrally formed with, the outlet portion. Referring to Figures 13 to 15, an alternative catheter 201 comprises an external flushing portion 219 having the same general form as that described above in which the length of the external flushing portion 219 comprising external flow channels 205 has a solid core. In this alternative embodiment, the outlet portion 218 comprises a funnel portion 224 forming a conical cavity 225 which expands toward an outlet at the end face of the funnel portion 224 for the outflow of urine from the catheter 201.

The outlet portion 218 comprises a substantially tubular wall portion with a diameter greater than that of the external flushing portion 219. The proximal end of the outlet portion 218 comprises an annular face 226 encircling the external flushing portion 218 and extending to an internal recessed portion 227 with a tapered inner wall 228. The recessed portion 227 is shaped to capture urine flowing between the external flushing portion 119 and the urethral wall and direct the urine toward the lower face of the recessed portion 227. Four drainage apertures 222 are formed at the base of the corresponding external flow channels 205 and into the conical cavity 225 of the funnel portion 224.

The external flushing portion 219 is shaped and configured to be inserted into the urethra until the annular face 226 of the outlet portion 218 abuts the base of the urethra and encircles the urethra to capture urine flowing therefrom and direct it to the drainage apertures 222. Accordingly, in the present embodiment, the outlet portion 218 is not shaped and configured to be partially inserted into the urethra and there is no requirement for a depth insertion guide extending from the outer wall of the outlet portion 218. A flange 229 extends from the outlet portion 218 and is provided to allow handling and positioning of the catheter 201 when being inserted into and removed from the urethra.

In a further alternative catheter, as shown in Figures 16 and 17, the catheter 301 may comprise an insertion portion 330 at the insertion end 303 which is shaped and configured to extend into the bladder when the catheter 301 is inserted into the urethra. The insertion portion 330 may extend from the proximal end of the external flushing portion 319 to the terminal end 3O3t of the insertion end 303. The insertion portion 330 may be configured to aid insertion and may comprise one more features or formations to this end. In the embodiment shown in Figures 16 and 17, the insertion portion 330 is provided with a rounded terminal end 3O3t but this is not a limitation, and the terminal end may be provided with a bulb or cone shaped member to aid insertion of the catheter 301 into the urethra and bladder.

The insertion portion 330 comprises a tubular wall 332 defining an inner lumen

333 which is closed at the terminal end 3O3t of the catheter 301 and open to the external flushing portion 319 via an outlet formed at a junction between the insertion portion 330 and the external flushing portion 319. A pair of stadium shaped eyelets 334 are formed through the wall 330 of the insertion portion 330 on opposite sides respectively and extend into the inner lumen 333. The eyelets 334 are longitudinally offset such that one eyelet is closer to the terminal end 3O3t of the catheter 301 and the other eyelet is closer to the external flushing portion 319. Accordingly, a fluid flow path is formed from the insertion end 303 to the external flushing portion 319 via the eyelets 334 and inner lumen 333 so that urine may drain from the bladder through the insertion end 303 and into the external flushing portion 319. As in the above-described embodiments, the length of the external flushing portion 319 comprising external flow channels 305 has a solid core such that, when the catheter 301 is inserted into the urethra and bladder, urine is directed to drain from the bladder and out from the urethra only via the external flow channels 305.

It will be appreciated that the number, shape, and position of the eyelets 334 need not be limited as described above and that more, or less, eyelets 334 may be provided in different positions along the insertion portion 330. For example, the eyelets 334 could be rectangular, oval, square or circular and/or may be diametrically opposed at substantially the same longitudinal position. There could be just one eyelet 334 or more than two eyelets 334 arranged at various locations about and/or along the wall of the insertion portion 330.

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 the 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 following numbered clauses set out certain definitions of the invention:

1. An intermittent urinary catheter comprising: an elongate main body having an insertion end for insertion into a urethra and an outflow end; a plurality of external flow channels in an external surface of the main body, the flow channels providing a fluid flow path from the insertion end to the outflow end, wherein the external flow channels are defined by a plurality of rounded helical walls which extend along the length of the main body, the separation between the rounded helical walls defining the flow channels. The catheter of clause 1, wherein the external surface is continuously curved along the full length of the main body from a terminal end of the catheter at the insertion end to a terminal end of the catheter at the outflow end. The catheter of clauses 1 or 2, wherein a line of the external surface which extends along a longitudinal plane of the main body continuously curves. The catheter of clause 3 wherein the line is sinusoidal. The catheter of any preceding clause, comprising four external flow channels. The catheter of any preceding clause, wherein the external surface is configured to contact the urethra along the full length thereof. The catheter of any preceding clause, wherein the flow channels extend to and define the outflow end. The catheter of any preceding clause, wherein the external flow channels are configured to coalesce a flow of urine as it leaves the outflow end. The catheter of any preceding clause, wherein the external flow channels extend along the full length of the main body from a terminal end of the catheter at the insertion end to a terminal end of the catheter at the outflow end. The catheter of any preceding clause, wherein the main body is rigid. The catheter of any preceding clause, wherein the main body is straight. The catheter of any preceding clause, wherein the main body comprises a uniform diameter from the insertion end to the outflow end. The catheter of any preceding clause, wherein the catheter is an intermittent female catheter. The catheter of any preceding clause, wherein a length of the catheter is between 150mm and 420mm. The catheter of any preceding clause, wherein a width of the catheter is between 2mm and 6mm. The catheter of any preceding clause, wherein the pitch of the helical portion of comprises a pitch of between 15mm and 40mm. The catheter of any preceding clause, wherein the pitch of the helical portion is 30mm. The catheter of any preceding clause, further comprising an insertion portion at the insertion end and defining an inner lumen in fluid communication with the external flow channels, and wherein the insertion portion comprises one or more eyelets formed in an external surface thereof and extending through to the inner lumen of the insertion portion. The catheter of clause 18, wherein the inner lumen is separated from the external flow channels in the longitudinal direction such that a gap is formed between the external flow channels and the inner lumen. The catheter of any preceding clause, further comprising an outlet portion at the outflow end, the outlet portion comprising a drainage channel extending through the outlet portion. The catheter of clause 20, wherein each external flow channel is in fluid communication with the drainage channel via a corresponding drainage aperture. The catheter of clause 20 or clause 21, wherein each external flow channel terminates in a drainage aperture. The catheter of any one of clauses 20 to 22, wherein each external flow channel is separated from the drainage channel in the longitudinal direction such that a gap is formed between the external flow channels and the drainage channel. The catheter of any preceding clause, wherein the part of the main body comprising the plurality of external flow channels has a solid core. The catheter of any preceding clause, further comprising a formation extending from an external surface of the main body in the form of an annular ring forming a ridge between the insertion end and the outflow end and arranged, in use, to abut the base of the urethra upon insertion of the catheter into the urethra, 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. 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.