Urethral catheter

Abstract

To provide an intermittent hydrophilicity urethral catheter.SOLUTION: An intermittent hydrophilicity urethral catheter includes a tubular part. The tubular part is created by a base material and has a tubular wall defining an inner surface facing in the direction of the drainage duct and an outer surface on the opposite side facing the direction away from the drainage duct. At least an insertion possible part of the outer surface is covered with a hydrophilic material layer configured to change from a non-swelling state to a swollen state by contacting a swelling medium. The hydrophilic material defines a hydrophilicity surface with a coating thickness on the outer surface. The catheter is provided with a plurality of liquid discharge openings extending between an exit opening on the inner surface and an inlet opening on the outer surface. The outer surface encircles the opening on the outer surface, and a projection extending upward the hydrophilic material when the hydrophilic material is in the non-swollen state is formed.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to an intermittent hydrophilic urinary catheter, a method of using such a catheter, and a method of manufacturing such a catheter.

[0002] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated herein and constitute a part of this specification. The drawings illustrate the embodiments and serve to explain the principles of the embodiments together with the description. Many other embodiments and the intended advantages of the embodiments will be readily recognized as the same become better understood by reference to the following detailed description. The elements of the drawings are not necessarily drawn to scale relative to each other. Like reference numerals designate corresponding like parts.

Brief Description of the Drawings

[0003]

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Mode for Carrying Out the Invention

[0004] Embodiments of the present disclosure provide an intermittent hydrophilic urethral catheter defining a drainage conduit that extends longitudinally from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit. The catheter comprises a tubular portion made of a base material and having a tubular wall defining an inner surface facing towards the drainage conduit and an opposite outer surface facing away from the drainage conduit. At least the insertable portion of the outer surface is covered by a layer of hydrophilic material configured to swell upon contact with a swelling medium. The hydrophilic material defines a hydrophilic surface of the catheter with a coating thickness on the outer surface. The catheter comprises a plurality of drainage openings, each drainage opening being defined by a drainage opening wall extending between an internal opening in the inner surface and an external opening in the outer surface. The drainage openings are produced by laser ablation of the hydrophilic material and the base material such that the drainage opening walls are not covered by the hydrophilic material.

[0005] Since the drainage openings of the embodiments are produced by laser ablation in the base material covered with the hydrophilic material, the base material is removed together with the hydrophilic material at the drainage openings. Thus, no residue of the hydrophilic material remains on the drainage opening walls. In other words, there is no hydrophilic material on the drainage opening walls. This has the effect that the drainage openings can have very small dimensions and cannot be blocked by the swollen hydrophilic material.

[0006] Embodiments of the present disclosure provide an intermittent urethral catheter defining a drainage conduit that extends along a central axis from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit. The catheter comprises a plurality of drainage openings, each drainage opening extending along a centerline from an internal opening into the drainage conduit to an external opening in the outer surface, and at least two drainage openings having centerlines that intersect at an intersection outside the drainage conduit.

[0007] These embodiments have the effect that the fluid flow from a single point within the bladder can flow linearly into the drainage conduit through two or more drainage openings. This may provide improved flow characteristics and also reduce the risk of blockage.

[0008] Embodiments of the present disclosure provide an intermittent urethral catheter defining a drainage conduit extending along a central axis from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a plurality of drainage openings, each drainage opening extending along a corresponding centerline from an inner surface facing the drainage conduit to an outer surface facing away from the drainage conduit, the drainage openings being formed in pairs, and one pair of drainage openings being configured to include a first drainage opening and a second drainage opening both having the same centerline.

[0009] The drainage openings are arranged on both sides of the central axis. This has the effect of increasing the likelihood of providing a freer flow of urine into the drainage conduit, such that when the first drainage opening of a pair of drainage openings is biased against the wall of the urethra, the second drainage opening does not contact the opposite side of the urethra.

[0010] Embodiments of the present disclosure provide an intermittent hydrophilic urethral catheter defining a drainage conduit extending longitudinally from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a tubular portion made of a base material and having a tubular wall defining an inner surface facing the drainage conduit and an outer surface facing away from the drainage conduit, at least an insertable portion of the outer surface being covered by a layer of hydrophilic material configured to swell upon contact with a swelling medium, the hydrophilic material defining a hydrophilic surface of the catheter by a coating thickness on the outer surface, the catheter comprising a plurality of drainage openings extending between an internal opening on the inner surface and an external opening on the outer surface, and the outer surface forming a protrusion surrounding the external opening on the outer surface and extending above the hydrophilic material when the hydrophilic material is in a non-swollen state.

[0011] The protrusions typically extend radially.

[0012] In these embodiments, since the hydrophilic material must pass through the protrusions, there is an effect that the risk of the hydrophilic material being displaced to a position covering the drainage opening is further limited.

[0013] During insertion of the urethral catheter, the tissue of the urethra may be crushed and enter into the drainage opening. Providing protrusions around the drainage opening can have the effect that the tissue is lifted and passes through the drainage opening during movement of the catheter within the urethra. Therefore, the risk of abrasion can be reduced when the catheter slides along the tissue during insertion and removal of the catheter.

[0014] The dimensions of the protrusions and the thickness of the layer of hydrophilic material can be selected such that the hydrophilic material extends above the protrusions when swollen. Since the hydrophilic material extends above the protrusions when swollen, the tissue is protected by the hydrophilic material during insertion and removal of the catheter, and the risk of abrasion by the protrusions is reduced.

[0015] Embodiments of the present disclosure have the effect of providing an intermittent urethral catheter that significantly reduces the risk of affecting the bladder wall and urethral tissue during intermittent catheterization. Further, repositioning of the catheter is not required, and the catheterization procedure for emptying the bladder becomes easier, and thus the possibility of emptying the bladder to a sufficient level for each catheterization is higher.

[0016] During intermittent catheterization and bladder voiding, the bladder contracts and ultimately the bladder wall approaches the catheter. Due to the pressure difference between the bladder and the external environment, urine outflow through the catheter from the bladder is brought about. If all drainage openings in an intermittent urethral catheter are suddenly occluded by bladder wall tissue, a negative pressure pulse is generated in the catheter when the flowing water column of urine in the catheter suddenly stops. This negative pressure pulse can cause tissue to be suddenly sucked towards the drainage opening and, if the negative pressure is maintained, can even be sucked into the inner lumen of the catheter. This phenomenon is referred to as clogging in the context of the present disclosure. This suction can affect the bladder wall tissue. The magnitude of the negative pressure is determined, inter alia, by the abruptness of the occlusion of the drainage opening and the flow rate. If the catheter is a prior art intermittent catheter, such as one generally provided with two drainage openings, one of the drainage openings may become clogged by bladder wall tissue, thereby potentially resulting in only a limited negative pressure pulse. However, when the second and final drainage opening also becomes clogged by bladder wall tissue, the flow of urine through the catheter suddenly stops and a significant negative pressure pulse is generated in the catheter. This causes tissue adjacent to the drainage opening to be sucked into the lumen of the catheter through the drainage opening. The generation of this negative pressure pulse that sucks bladder tissue into the drainage opening may be perceived by the catheter user as a pinching in the bladder.

[0017] In contrast to these drawbacks of generally available catheters, the present disclosure provides an intermittent urethral catheter that uses a plurality of drainage openings, and the plurality of drainage openings prevent the possibility of sudden closure of all the drainage openings substantially simultaneously, thereby eliminating the generation of a negative pressure pulse that sucks bladder wall tissue toward and into the drainage openings. The plurality of drainage openings described herein ensure that, during urination, when contact occurs between the bladder wall and the catheter, any possible occlusion of the drainage openings occurs only gradually. Further, when the drainage openings are of a small size, the present disclosure provides the additional advantage that, when the last of all the drainage openings is occluded by the bladder wall tissue when complete drainage (no residual urine in the bladder) has been achieved, the trickle of urine passing through the last occluded drainage opening is reduced to a level at which only a very small negative pressure pulse is generated by the sudden closure of that last opening.

[0018] During use of prior art intermittent catheters, perhaps as described above, due to the inflow causing the bladder wall tissue to be sucked toward the drainage openings, there is a possibility of occlusion of the drainage openings by the bladder wall tissue. As demonstrated in the tests described below and shown in the figures with respect to prior art catheters, a significant amount of bladder wall tissue can enter the inner lumen of the catheter and be trapped at the drainage openings by the suction of the bladder tissue. This is thought to be because, due to the negative pressure pulse, the drainage openings become blocked as described above, and when the drainage openings are blocked, the pressure difference between the bladder wall and the pressure inside the inner lumen causes the bladder wall to gradually deform and enter the drainage openings. If the flow of urine is significantly or completely reduced due to occlusion of the drainage openings, the user may attempt to move the catheter up and down or rotate the catheter in order to reposition the drainage openings to restore the flow. The user may also pull out the catheter believing that the bladder is empty because the flow of urine has stopped. The risk of affecting the bladder wall tissue by movement of the catheter can be reduced by preventing the capture of bladder wall tissue at the drainage openings.

[0019] As described above, contact between the bladder wall and the drainage opening of a prior art catheter can cause the bladder wall tissue to occlude the drainage opening, thereby potentially reducing or completely stopping the flow of urine. Excessive occlusion of the drainage opening of an intermittent catheter can cause the user to believe that the bladder is empty because the flow has stopped or significantly decreased, and as a result, the user may remove the catheter. If the catheter user terminates the urination procedure prematurely for this reason, residual urine may remain in the bladder. The intermittent catheter with multiple small drainage openings according to the present disclosure prevents early occlusion of the drainage openings, thereby ensuring a reliable flow of urine until the bladder is empty. Accordingly, the intermittent catheter disclosed herein with multiple drainage openings ensures that the catheter user does not mistakenly believe that the bladder is empty and thereby prematurely end the urination procedure, resulting in residual urine remaining in the bladder.

[0020] Hereinafter, whenever reference is made to the proximal end of an element of the present disclosure, that reference is to the end adapted to be inserted. Whenever reference is made to the distal end of an element, that reference is to the end opposite the insertion end. In other words, the proximal end is the end closest to the user when the catheter is inserted, and the distal end is the opposite end, i.e., the end farthest from the user when the catheter is inserted.

[0021] The longitudinal direction is the direction from the distal end to the proximal end. The transverse direction corresponds to the direction across the catheter and is perpendicular to the longitudinal direction.

[0022] The intermittent urethral catheter according to the present disclosure comprises a main tubular portion extending from a tip portion at a proximal insertion end to a distal outlet end with respect to its proximal end. The tubular portion can be cylindrical or conical. In an embodiment, the tubular portion has an elliptical cross-section. The tubular portion is configured to provide a flow of urine through the intermittent catheter from a drainage portion to the distal end. A closed end portion including a closure tip is positioned at the proximal end of the catheter and provided as a rounded closed end of a tube constituting the main tubular portion of the catheter. The drainage portion of the tubular portion will typically be in the proximal portion of the tubular portion. In an embodiment, the drainage portion includes a plurality of drainage openings that enable a flow of urine between the outside of the catheter and the inner lumen of the tubular portion. In an embodiment, the drainage portion is longer than a typical flow zone in a catheter according to the prior art, the flow zone being defined as the length from the distal edge of the distal eyelet to the proximal edge of the proximal eyelet. In an embodiment, the intermittent catheter comprises a connector at the distal end. In one embodiment, the connector constitutes a flared end of the catheter such that the diameter of the connector increases with respect to the tubular portion. In an embodiment, the intermittent catheter comprises a handle at the distal end, the handle having a length that enables a user to manipulate the catheter.

[0023] Typically, intermittent urethral catheters range in size from 8FR to 18FR. FR (or French size or Charrière (Ch)) is a standard gauge for catheters that approximately corresponds to the outer circumference in mm. More precisely, the outer diameter of the catheter in mm corresponds to the value obtained by dividing the FR by 3. Thus, 8FR corresponds to a catheter having an outer diameter of 2.7 mm and 18FR corresponds to a catheter having an outer diameter of 6 mm.

[0024] The hydrophilic coating can be provided only on the insertable portion of the catheter. The hydrophilic surface coating is of a type that reduces friction in the surface area of the catheter that is intended to be inserted into the lower urinary tract of the user corresponding to the insertable portion of the catheter when hydrated or expanded using a swelling medium.

[0025] Intermittent hydrophilic catheters, unlike indwelling catheters, are not suitable for indwelling use because their hydrophilic surface coatings tend to adhere to the inside of the urethral mucosa when left in the body for periods exceeding 5 to 20 minutes. This is because the hydrophilic coating changes from a very smooth state when fully wet (95% moisture content) to an adhesive state when the hydration level of the coating is reduced (less than 75% moisture content).

[0026] The catheter can have a closed tip at the proximal insertion end, and the catheter can have a plurality of drainage openings that are distributed, in particular, over a portion of the catheter located near the closed tip, such as a portion that constitutes half or one-third of the total length of the catheter measured from the proximal end to the distal end.

[0027] The drainage openings described herein may be referred to in the art as eyelets or eyes. The drainage openings have a perimeter of a closed loop and can be circular, oval, square, triangular, and any other closed loop shape. This closed loop shape defines the outer opening of the drainage opening. The inner opening of the drainage opening also has a perimeter of a closed loop and typically, but not necessarily, has the same shape as the outer opening of the drainage opening.

[0028] The catheter can have at least 12 drainage openings, and the drainage openings can be arranged in one or more groups, for example, in a straight line extending longitudinally. The drainage openings can also be arranged in groups such that the density of the drainage openings between the groups is different.

[0029] Each drainage opening can be defined by a wall extending from an internal opening on the inner surface facing the drainage conduit to an external opening on the outer surface facing away from the drainage conduit. Thus, the drainage opening wall can have a height corresponding to the distance between the inner and outer surfaces of the tubular portion of the catheter. The drainage opening wall can, in particular, extend continuously between the inner and outer surfaces. The internal opening can also be understood as an outlet opening, and the external opening can also be understood as an inlet opening.

[0030] The tubular wall of the tube has a uniform wall thickness, thereby providing a uniform length of the drainage opening.

[0031] The tubular portion has a uniform outer surface, thereby enabling uniform adhesion with the hydrophilic material. Furthermore, the displacement of the hydrophilic material and thus the risk of occlusion of the drainage opening are minimized.

[0032] Embodiments relate to a catheter provided with a closure tip at the proximal insertion end. The closure tip can be formed as a Nelaton tip, a Flex tip, or generally as a type of tip known for urethral catheters.

[0033] In the context of the present disclosure, the body cavity refers to the urethra.

[0034] The catheter can define a non-drainage portion distal to the tip and a drainage portion distal to the non-drainage portion, and the drainage portion is provided with a plurality of drainage openings. The non-drainage portion can constitute, for example, less than 3 cm, or 2 cm, or less than 1 cm, and the drainage portion can constitute less than 20 cm, or less than 15 cm, or less than 10 cm.

[0035] The inflow of urine through the plurality of drainage openings is determined, as explained above, by the sum of the cross-sectional areas of all the drainage openings (total inflow area) and the pressure gradient between the drainage openings and the outlet from the catheter at the distal end. The sum of the cross-sectional areas of the plurality of drainage openings (total inflow area) must be large enough to allow proper inflow of urine; otherwise, emptying the bladder would take a very long time and would thus be inconvenient for intermittent catheter users. Each drainage opening provides a certain resistance to the inflow of urine, which is determined, inter alia, by the cross-sectional area of the drainage opening and the thickness of the catheter material at the drainage opening, i.e., the spread of the drainage opening wall from the inner opening to the outer opening.

[0036] Embodiments relate to the sum of the cross-sectional areas of the plurality of drainage openings being larger than the cross-sectional area of the drainage conduit of the catheter immediately distal to the drainage openings. Immediately distal to the drainage openings means within 5 mm in the longitudinal distal direction from the most distal drainage opening.

[0037] Embodiments relate to the tubular portion defining a convex outer surface, where the total inflow area of the drainage openings on the convex outer surface of the tubular portion is larger than the cross-sectional area of the drainage conduit of the catheter in a cross-section perpendicular to the longitudinal direction of the tubular portion at a position distal to the drainage openings.

[0038] In one embodiment, the sum of the cross-sectional areas of the plurality of drainage openings (total inflow area) is larger than twice the cross-sectional area of the inner lumen of the catheter immediately distal to the drainage openings. The total inflow area of the drainage openings is provided on the convex outer surface of the tubular portion. By providing such a large total inflow area, it is ensured that the resistance to flow at the drainage openings does not prevent filling of the drainage conduit of the catheter. Thus, the inflow into the drainage conduit through the drainage openings does not restrict the flow through the intermittent catheter.

[0039] Further embodiments relate to the sum of the cross-sectional areas of the plurality of drainage openings (total inflow area) being at least three times larger than the cross-sectional area of the drainage conduit of the catheter.

[0040] Embodiments relating to the total inflow area on the convex outer surface of the tubular portion being at least equal to or greater than the cross-sectional area of the drainage conduit of the tubular portion can relate to a catheter having a cylindrical tubular portion. In this case, the cross-sectional area of the drainage conduit is constant throughout the length of the catheter. However, these embodiments can also relate to a catheter having a conical tubular portion. In this case, the cross-sectional area increases along the length. In this case, the total inflow area should be compared to the cross-sectional area of the drainage conduit within 5 mm in the distal direction of, i.e., immediately distal to, the most distal drainage opening.

[0041] Embodiments relate to the number of drainage openings being greater than the number required to fill the drainage conduit immediately distal to the drainage openings. It should be understood that depending on the size of the individual drainage openings, a certain number of drainage openings are required to provide a total inflow area corresponding to the cross-sectional area of the drainage conduit distal to the drainage openings. This number of drainage openings is referred to in the present disclosure as the first predetermined number of drainage openings. Thus, embodiments relate to the number of drainage openings being greater than the first predetermined number of drainage openings.

[0042] Embodiments relate to an intermittent urethral catheter provided with a plurality of drainage openings configured to provide a total inflow area that exceeds the cross-sectional area of the drainage conduit of the catheter immediately distal to the most distal drainage opening of the drainage openings described above.

[0043] If the total inflow area exceeds the cross-sectional area of the drainage conduit of the catheter, or if the number of drainage openings is greater than the number required to fill the drainage conduit, it is ensured that at least one drainage opening is always available to provide inflow. This is because the inflow is less than what the drainage openings can drain, and thus at least one drainage opening can provide further inflow if another of the drainage openings is simultaneously blocked by bladder tissue. This means that the flow through the catheter is continuous until the bladder is empty. Thereby, the risk of leaving residual urine in the bladder is substantially reduced.

[0044] In the context of the present disclosure, pressure means differential pressure and not absolute pressure. This means that pressure is always shown as the pressure difference between the measurement point and the ambient pressure.

[0045] In one embodiment, the maximum dimension of each individual drainage opening on the convex outer surface of the tubular portion is less than 1 mm. The maximum dimension means the diameter in the case of a circular drainage opening, the major axis in the case of an elliptical opening, the diagonal in the case of a triangular or square opening, etc. In other words, the maximum dimension means the maximum of the dimensions crossing the opening between two oppositely located points on the outer periphery of the opening on the convex outer surface of the tubular portion. In related embodiments, each of the drainage openings has a cross-sectional area of less than 0.8 mm 2 In this way, the negative pressure generated when measured under 10 cm H2O can be made 50 mBar or less, and thus the impact on the bladder wall tissue is ensured to be significantly reduced compared to prior art catheters having a small number (such as two) of large drainage openings.

[0046]

[0047] In one embodiment, the maximum dimension of any one individual drainage opening on the convex outer surface of the tubular portion is less than 0.7 mm. In related embodiments, each of the individual drainage openings has a cross-sectional area of 0.4 mm 2 ​It has a cross-sectional area of less than this. This ensures that the negative pressure can be 40 mBar or less when measured under 10 cm H2O.

[0048] In one embodiment, the maximum dimension of any one individual drainage opening on the convex outer surface of the tubular portion is less than 0.5 mm. In related embodiments, each of the individual drainage openings is 0.2 mm 2 has a cross-sectional area of less than this.

[0049] In one embodiment, the number of drainage openings exceeds 20.

[0050] Thereby, the probability that all the drainage openings are blocked at once is significantly reduced.

[0051] In embodiments, the number of drainage openings can be made significantly large, for example, exceeding 200 or even about 260 drainage openings. This number can also be something close to 200, such as about 100, 120 or 150, or 180, etc.

[0052] An embodiment relates to an intermittent urinary catheter, where the catheter is CH10, each drainage opening has a maximum dimension of approximately 0.4 mm on the convex outer surface of the tubular portion, and the number of drainage openings is more than 32. Such a catheter provides proper inflow into the lumen of the catheter such that each drainage opening contributes to drainage, while at least one drainage opening remains open at all times. Approximately 0.4 mm means 0.35 - 0.45 mm.

[0053] Another embodiment relates to an intermittent urinary catheter, where the catheter is CH12, each drainage opening has a maximum dimension of approximately 0.7 mm on the convex outer surface of the tubular portion, and the number of drainage openings is more than 15. Approximately 0.7 mm means 0.65 - 0.75 mm.

[0054] The embodiment relates to an intermittent urinary catheter according to any of the preceding claims, wherein each drainage opening of the drainage openings extends transversely to the longitudinal direction of the catheter. Extending transversely means that the central axis of the drainage opening is substantially perpendicular to the longitudinal axis of the catheter and within 20 degrees in any direction.

[0055] In one embodiment, the drainage portion has a length of 4 cm in the longitudinal direction of the intermittent catheter. Thereby, the bladder can be drained appropriately. The drainage portion is positioned distally of the closed tip portion, and thus, when the closed tip portion is less than 2 cm in the longitudinal direction, the drainage portion is within the proximal 6 cm of the catheter. This is the common insertion length of the intermittent catheter into the bladder, and thus, by positioning the drainage region inside the bladder, the large cross-sectional area of the plurality of drainage openings is inside the bladder, and thus, good and rapid drainage of the bladder becomes possible. An approximately 4 cm drainage portion can be useful for both male and female catheters. Approximately 4 cm means 35 mm to 45 mm, such as 40 mm, 37 mm or 42 mm.

[0056] In one embodiment, the drainage portion has a length of 10 cm in the longitudinal direction of the intermittent catheter. Thereby, since there is a drainage opening positioned in the lower part of the bladder at the bladder neck, the safety for emptying the bladder is improved. Typically, the intermittent catheter is inserted into the bladder at 5 - 6 cm, and thus, in these embodiments, the drainage portion extends within a part of the urethra and is inside the bladder. A catheter having a drainage portion of 10 cm or more is particularly useful for male catheters. Other embodiments relate to the drainage portion having a length of approximately 8 cm, which means 75 mm to 85 mm, such as 77 mm, 80 mm or 82 mm.

[0057] In one embodiment, the drainage portion has a length of 15 cm in the longitudinal direction of the intermittent catheter. This improves the safety for emptying the bladder. This is particularly beneficial for users who tend to insert their own intermittent catheter too far into the bladder, probably because such users have no sensation during catheter insertion.

[0058] An embodiment relates to the drainage portion having a length of approximately 2 cm, meaning 15 - 25 mm. Such a short drainage portion is particularly useful for female catheters where the urethra is extremely short. With the short drainage portion, when some of the drainage openings are located outside the urethra, the risk of urine flowing out from the drainage openings is reduced.

[0059] In one embodiment, the drainage openings are positioned so as to be scattered along the longitudinal direction and over the circumference of the catheter.

[0060] In one embodiment, the drainage openings are positioned in four longitudinal rows with 90 - degree intervals over the circumference.

[0061] In one embodiment, the drainage openings are positioned in six longitudinal rows with 60 - degree intervals over the circumference.

[0062] In one embodiment, the drainage openings are positioned in eight longitudinal rows with 45 - degree intervals over the circumference.

[0063] In one embodiment, the drainage openings are positioned in two longitudinal rows with 180 - degree intervals over the circumference.

[0064] In one embodiment, the drainage openings are positioned in two pairs of parallel rows with 180 - degree intervals over the circumference.

[0065] In one embodiment, the drainage openings are scattered in a helical pattern over the circumference.

[0066] Increasing the number of directions enables more appropriate inflow and reduces the risk of the bladder tissue contacting and occluding all drainage openings.

[0067] In one embodiment, the distal portion of the catheter is a Nelaton tip, and the proximal end is simply closed, providing a hemispherical closed end.

[0068] The distal portion can be integrally molded with the main tubular portion either as a one-piece molding or a two-piece molding, or the distal portion can be prepared as a separate element and then attached to the main tubular portion, for example, by welding or adhesion.

[0069] In one embodiment, the distal portion is a flex tip. In this type of embodiment, the tip of the urethral catheter includes a drainage portion with a drainage opening for introducing urine into the internal lumen of the catheter from the distal end of the distal portion, an intermediate portion where the outer diameter of the catheter is reduced relative to the diameter of the rest of the catheter, and a proximal portion having a spherical portion with a diameter close to or exceeding the diameter of the tubular portion of the catheter. The spherical portion can also have a diameter slightly smaller than the diameter of the tubular portion of the catheter. The spherical portion can be nearly spherical in shape or slightly elongated, such as in the shape of an olive or a droplet. This type of distal portion can be useful for male users to guide the catheter around the bend of the urethra in the prostate.

[0070] The base material can be a polyurethane material (PU) or a polyolefin such as polyvinyl chloride (PVC) or polyethylene (PE). Other materials can be silicone materials, latex materials, styrene block copolymers, TPS (TPE-s) (thermoplastic elastomer materials), thermoplastic vulcanizates, TPV, thermoplastic copolymers, TPC (TPE-E), thermoplastic polyamides, TPA (TPE-A). The base material can also be understood as the basic material. The hydrophilic material can be polyvinylpyrrolidone (PVP) and copolymers.

[0071] The drain openings can be formed in pairs, and one pair of drain openings can include a first drain opening and a second drain opening that both have the same center line.

[0072] Embodiments relate to the drain openings of the pair being positioned at an oblique angle with respect to the longitudinal axis. Embodiments relate to the drain openings of the pair being positioned at an angle of 80 degrees to 87 degrees, such as an angle of 85 degrees to 87 degrees, with respect to the longitudinal axis.

[0073] The drain openings can be shaped such that the wall of the first drain opening converges from the outer opening towards the inner opening, and the wall of the second drain opening diverges from the outer opening towards the inner opening.

[0074] As used herein, converging means that the distance between the wall portions on both sides of the center line decreases in the direction from the outer surface to the inner surface. In other words, the outer opening has a larger area than the inner opening. Diverging means that the distance between the wall portions on both sides of the center line increases in the direction from the outer surface to the inner surface. In other words, the outer opening has a smaller area than the inner opening.

[0075] When the drain opening is circular, the drain opening wall can have the shape of a frustum of a cone. In this specification, it is stated that the shape is frustum-like to indicate that it is not essential for the cross-section of the drain opening to be circular.

[0076] The converging and diverging walls of the drain openings provide different flow characteristics through the first and second drain openings, increasing the likelihood that one of the two drain openings will be open when the other is blocked. Due to the predetermined characteristic shape of the diverging and converging walls, in one of the drain openings of the pair, the outer opening on the outer surface is larger than the inner opening on the inner surface, and in the other of the pair of drain openings, the opposite is true. Thus, occlusion of the tissue in contact with the relatively large opening does not prevent flow through the relatively small opening, and vice versa.

[0077] The first drainage opening and the second drainage opening can have different dimensions. That is, the dimensions of the first drainage opening in a cross-section transverse to the center line can be different from the dimensions of the second drainage opening, particularly when comparing the dimensions in a cross-section having the same distance to the inner surface and the outer surface.

[0078] The coating thickness decreases towards each inlet opening on the outer surface, thereby reducing the risk of blocking the flow through the inlet opening when the hydrophilic material swells. This means that the coating is thicker in the region between the drainage openings than in the region close to the drainage openings. Being close to the drainage openings means within a range of 0.5 mm from the edge of the drainage opening.

[0079] The tubular portion has a uniform outer surface, thereby enabling uniform adhesion to the hydrophilic material and further avoiding the displacement of the hydrophilic material and thus the possibility of blocking the drainage opening.

[0080] The present disclosure provides a manufacturing method. As an example, by using a CO2 laser, laser ablation can be brought about.

[0081] The present disclosure provides a method for manufacturing a hydrophilic urinary catheter. The method includes, for example, providing a tube by extruding a base material through a die that defines a tubular shape having an inner surface facing towards the drainage conduit and an opposite outer surface facing away from the drainage conduit, coating the outer surface with a hydrophilic material so as to define a hydrophilic surface, and providing a plurality of drainage openings from the outer surface to the inner surface by laser ablation of the hydrophilic material and the base material, wherein the drainage opening walls extending between the inner surface and the outer surface are not coated. Thereby, the laser ablation is used not only to establish the drainage openings but also to remove the hydrophilic material, thereby reducing the risk of blocking the drainage openings by the hydrophilic material.

[0082] The present disclosure further provides a method of manufacturing a hydrophilic urethral catheter. According to this method, a tube is provided by extruding a base material through a die defining a tubular shape having an inner surface facing towards the drainage conduit and an outer surface on the opposite side facing away from the drainage conduit. The outer surface is coated with a hydrophilic material so as to define a hydrophilic surface, and then, i.e., after coating of the outer surface, a plurality of drainage openings are provided from the outer surface to the inner surface by laser ablation of the hydrophilic material and the base material, and the drainage opening walls extending between the inner surface and the outer surface are not coated.

[0083] By this process, the hydrophilic material at the drainage openings is avoided without increasing the manufacturing complexity, and thus the method provides an easy way to manufacture a catheter that may have improved quality and not increased manufacturing costs.

[0084] Embodiments relate to a method of manufacturing an intermittent urethral catheter, the method comprising providing a tube made from a base material and defining a tubular shape having an inner surface facing towards an internal drainage conduit and an outer surface on the opposite side facing away from the internal drainage conduit, and providing a plurality of drainage openings extending between an internal opening on the inner surface and an external opening on the outer surface by laser ablation of the base material, the laser ablation being performed with laser light emitted from a light emitter point external to the drainage conduit at an emission angle such that a first emission angle is provided to a first group of the drainage openings and a second emission angle is provided to a second group of the drainage openings.

[0085] The method can enable efficient manufacturing such that a plurality of drainage openings are made by laser ablation from the same origin, for example from a single emission point.

[0086] The drainage openings can be provided in pairs of one drainage opening from the first group of the drainage openings and one drainage opening from the second group of the drainage openings, and the light emitter point moves relative to the tubular portion between each pair of the drainage openings.

[0087] When providing the drainage opening, the distance from the light-emitting body point to the outer surface can be maintained constant.

[0088] The drainage opening can be provided by ablation while the pressure inside the drainage conduit changes with respect to the pressure outside the drainage conduit.

[0089] An embodiment relates to a method of manufacturing a hydrophilic urethral catheter. The method includes providing a tube that is made from a base material and defines a drainage conduit that extends along a central axis from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit, and providing a plurality of drainage openings that extend between an internal opening on an inner surface facing the drainage conduit and an external opening on an outer surface facing away from the drainage conduit. The drainage openings are created by laser ablation of the base material, and the laser ablation is performed to form a pair of drainage openings including a first drainage opening and a second drainage opening, which is provided by simultaneous ablation of the base material along a common center line on both sides of the central axis.

[0090] The laser light can be emitted, in particular, from a light-emitting body point outside the drainage conduit through an internal drainage conduit. The light-emitting body point can be at a distance from the outer surface that corresponds to at least 10 times the distance from the outer surface to the central axis, or at least 15 or 20 times the distance from the outer surface to the central axis.

[0091] The drainage opening can be provided by ablation while the pressure inside the drainage conduit changes with respect to the pressure outside the drainage conduit.

[0092] The laser light can be emitted in at least two subsequent pulses, for example, 3, 4, 5, 6 or more subsequent pulses. The pulses can be emitted, in particular, at a frequency greater than 1 Hz, for example, greater than 2, 3, 4, 5, 6 or even a higher number of Hz.

[0093] The method can include a step of determining a pore size for at least one of the first drainage opening and the second drainage opening. Thus, laser ablation can be carried out with the number of shots determined by the pore size. In one embodiment, a limiting diameter is defined, and the number of shots increases until the limiting diameter of at least one of the first drainage opening and the second drainage opening is reached. In one embodiment, the limiting diameter is defined for both the first drainage opening and the second drainage opening, and the number of shots increases until both drainage openings have the required size.

[0094] As used herein, the term "continuous" is defined as the surface extending continuously without sharp angled corners or edges defining a radius of curvature less than 3 millimeters or similar distinct geometric variations.

[0095] As used herein, the term "uniform outer surface" is defined as the outer surface having the same surface irregularities, color and / or roughness or slipperiness in addition to the surface being continuous.

[0096] As used herein, the term "intermittent" is defined as the catheter not being for indwelling use and not having a balloon or other means for fixation within the bladder.

[0097] As used herein, the term "hydrophilic" is defined as the material swelling to an extent such that the resulting hydrogel reduces surface friction and facilitates easier insertion of the proximal end into the body cavity of the user.

Examples

[0098] The first test was conducted to compare the level of pressure pulses between a catheter according to the prior art and a catheter having a small drainage opening with a maximum dimension of less than 1.2 mm. The purpose of these first tests was to simulate a situation where one drainage opening is blocked by bladder tissue and the second (last) drainage opening is suddenly blocked. A catheter with one small drainage opening (maximum dimension less than 1.2 mm) was used and compared with a standard prior art catheter provided with two standard-sized drainage openings. In the latter case, one of the drainage openings was blocked with a piece of tape before the test. In all tests, the catheter was submerged in a water tank and drainage was initiated. The test configuration is shown in FIGS. 32 - 34 and is described below. The pressure pulse in the inner lumen of the catheter was determined at the moment when the second drainage opening was blocked. This corresponds to the situation during catheter drainage where the first of the two drainage openings in a prior art catheter is blocked by bladder tissue or urethral tissue and the suction through the catheter (caused by the flowing liquid) suddenly also causes the tissue blockage of the second of the two drainage openings.

[0099] The equipment used in the test is listed below. · A water tank with holes and O - rings · 25 L of water · A catheter with one open drainage opening. If the catheter was provided with two drainage openings, one of the drainage openings was blocked during the test. · A waterproof pressure sensor attached to a needle · A 5×5 cm porcine bladder piece · Latex gloves.

[0100] The test was conducted according to the following test protocol. · Prepare a water tank containing a seal adapted to provide a liquid - tight seal around the circumference of the catheter · Insert the catheter tip into the tank through the liquid - tight seal until one open drainage opening is fully inside the water tank · Cause water to start flowing out through the catheter · Ensure that there are no air bubbles in the catheter by gently tapping. · Insert the sensor needle into the catheter lumen at approximately 1 cm from one open drainage opening. · Ensure that there are no air bubbles in the catheter or the needle. This is important because even small air bubbles can obscure the pressure readings. · When there are no air bubbles in the catheter or the needle, adjust the position of the catheter in water to a dipping depth of 10 cm, which means that one open drainage opening is approximately 10 cm below the water surface. · Position the outer part of the catheter outside the water tank so that the height difference between one open drainage opening and the catheter connector is approximately 15 - 20 cm. · Wear latex gloves and remove the porcine bladder tissue. · Sink the tissue in water. · Start taking pressure readings and ensure that the sensor bellows is subtracted, i.e., set the sensor to zero. · Slowly guide the porcine bladder tissue towards one open drainage opening. · When the porcine bladder tissue reaches one open drainage opening, large (negative) pressure fluctuations occur in the inner lumen of the catheter. · Record the magnitude of this pressure fluctuation.

[0101] The recorded pressure fluctuations correspond to the pressure pulses in the catheter lumen. This is noted as the (negative) peak in the pressure curve (see the examples in Figures 26 - 28).

[0102] Some test results are shown in Table 1 below.

[0103]

Table 1

[0104] As can be seen from the above table, when the maximum dimension of the drainage opening is less than 1 mm (ID 1.1 to 1.5), the suction pressure is significantly reduced compared to a prior art catheter having a drainage opening with a maximum dimension of 3.9 mm (ID 1.6). All embodiments of the catheter according to the present disclosure as ID 1.1 to 1.5 in Table 1 have a suction pressure of less than 50 mBar (less than 44 mBar), while the prior art catheter of ID 1.6 having a drainage opening with a maximum dimension of 3.9 mm has a suction pressure of 200 mBar. Therefore, the threshold value of the suction pressure inside the lumen of the intermittent catheter according to the present disclosure can be set to 50 mBar when tested under 10 cm H2O as described above in Example 1.

[0105] The test results are also shown in FIGS. 26, 29A, and 29B.

[0106] The pressure inside a normally functioning bladder can reach about 400 to 500 mBar (40 to 50 cm H2O) before emptying.

[0107] The second and third tests were performed in the same manner, with the only difference being that the catheter was submerged under 50 cm H2O as opposed to 10 cm H2O. Furthermore, both male and female catheters were tested. The male catheter was tested with a height difference of 25 cm between the drainage opening and the outlet (connector), and the female catheter was tested with a height difference of 6 cm between the drainage opening and the outlet (connector).

[0108] The results are shown in Tables 2 and 3 below.

[0109]

Table 2

[0110]

Table 3

[0111] The results are also shown in FIGS. 27, 28, 30 and 31. IDs 1.7 to 1.14 were tested on male catheters and 1.15 to 1.22 were tested on female catheters.

[0112] The catheters tested as IDs 1.7 to 1.13 and 1.15 to 1.21 were polyurethane catheters of the type sold by Coloplast A / S under the trade name "SpeediCath®", and the prior art catheters tested (IDs 1.14 and 1.22) were PVC grade catheters sold by Hollister Inc under the trade name "VaPro®". All types of catheters were of size CH12. In the SpeediCath® catheters (IDs 1.7 to 1.13 and 1.15 to 1.22), only one drainage opening was created by laser cutting, and in the catheters of IDs 1.14 and 1.22, as described above, one of the two existing drainage openings was blocked prior to the test.

[0113] Preferably, the suction pressure at all times is less than the pressure reached inside a normally functioning bladder. In particular, a suction pressure approximately half that of prior art catheters is an improvement. Accordingly, embodiments relate to an intermittent urethral catheter having a drainage opening, modified such that the immersion depth is 50 cm and the height difference between the drainage opening and the outlet is 25 cm, and configured to provide a pressure pulse below a threshold of 350 mBar when tested as described in Example 1. Further embodiments relate to an intermittent urethral catheter having a drainage opening, modified such that the immersion depth is 50 cm and the height difference between the drainage opening and the outlet is 6 cm, and configured to provide a pressure pulse below a threshold of 300 mBar when tested as described in Example 1. Related embodiments relate to an intermittent urethral catheter having a drainage opening and configured to provide a pressure pulse below a threshold of 200 mBar. Related embodiments relate to an intermittent urethral catheter having a drainage opening and configured to provide a pressure pulse below a threshold of 100 mBar.

[0114] Another test was conducted to evaluate the number of drainage openings required to provide an optimal flow rate through the intermittent catheter according to the present disclosure. In this test, 108 prototype catheters were fabricated and the flow rate through each catheter was determined. The 108 catheters were of three CH sizes, namely CH10, CH12, and CH16. The catheters were provided with drainage openings of three sizes, namely 0.4 mm diameter, 0.6 mm diameter, and 0.8 mm diameter. The number of drainage openings was varied from 15 to 240, similar to the positioning of the drainage openings in the columns varied in 3 - 6 columns.

[0115] The results are shown in Figure 35 along with Table 4 below.

[0116]

Table 4

[0117] This result indicates that when the total cross-sectional area of the drainage openings (total inflow area) reaches the level of the cross-sectional area of the inner lumen of the catheter, the flow rate through the catheter does not increase any further. In other words, when the total inflow area reaches the level of the cross-sectional area of the inner lumen, the flow converges.

[0118] Detailed Description of the Drawings The features of the embodiments described in this application and various exemplary embodiments can be combined with each other ( "mix and match") unless otherwise specified.

[0119] Figures 1 to 4 show various problems of catheters according to the prior art. Figure 1 shows a part of a prior art catheter 100 having two drainage openings 101, 102 inserted into the bladder 10. During catheterization, one of the drainage openings 101 may be blocked by the bladder wall tissue as shown, and thereafter, all drainage of urine from the bladder occurs through the second drainage opening 102. This situation causes a high suction effect through the second drainage opening 102, which may cause the bladder wall tissue to contact this second drainage opening 102 as described above. Figure 2 shows a part of a prior art catheter 100 located within the bladder 10. This figure shows a situation where the prior art catheter is too high within the bladder 10, that is, located above the bladder neck 11, and thus the bladder 10 does not completely empty during catheterization. Residual urine in the bladder may cause urinary tract infections. Figure 3 shows how the prior art catheter 100 has to be moved up and down in an attempt to reduce the retention of residual urine. However, this up and down movement of the catheter may lead to the situation shown in Figure 4, that is, the urethral tissue 21 from the bladder 10 or the upper urethra 20 enters into the drainage opening and gets abraded during the up and down movement of the catheter.

[0120] Figure 5 shows the intermittent urethral catheter 1 described in this specification. The urethral catheter forms a drainage conduit that extends longitudinally from a proximal insertion end to a distal outlet end. The catheter is provided with a tip 2 at the proximal end. In Figure 5, the tip is shown as a Nelaton tip, but other tips can be applied. The tip 2 facilitates insertion into the bladder.

[0121] The urethral catheter is further provided with a connector 3 at the distal end. The connector is configured to discharge urine from the drainage conduit, for example, into an extension tube, into a collection bag, or into a toilet bowl.

[0122] A drainage opening 5 is positioned in the drainage portion 4. In this embodiment, the drainage openings 5 are positioned in four rows that are positioned in pairs with a 180-degree interval. In this figure, only two rows on one side of the intermittent urethral catheter are visible.

[0123] The catheter is for intermittent catheterization and does not include an inflatable balloon or similar means for long-term fixation within the bladder.

[0124] Figures 6 and 7 show the intermittent urethral catheter 1 described in this specification positioned with the drainage portion extending into the bladder 10. In this embodiment, the tip 2 is a flex tip. In Figure 6, the drainage openings 5 are scattered and positioned across the surface of the catheter. Figure 6 shows how urine inflow at multiple positions is made possible by a plurality of drainage openings. Furthermore, having this many drainage openings reduces the likelihood that bladder tissue will be suctioned into a single drainage opening during catheterization as described above. Figure 7 shows how the bladder 10 can be completely emptied by having this many drainage openings 5. This is because the likelihood that all of the drainage openings will be blocked is very low, and thus urine continues to flow out until the bladder 10 is completely empty. Furthermore, the drainage portion 4 is long, and thus the presence of the drainage openings 5 at the bladder neck 11 is made possible, whereby the bladder 10 is reliably emptied.

[0125] Figure 8 shows a portion of one embodiment of the intermittent urethral catheter 1 described herein positioned in the upper portion of the urethra 20. This figure shows how the tissue 21 of the urethra enters through the drainage opening 5, thereby reducing the risk of affecting the urethral tissue 20.

[0126] Figures 9A and 9B show that even when the catheter is inserted such that the tip 2 is at the top of the bladder (Figure 9B), the most distal drainage opening 5 of the drainage openings 5 is still positioned below the bladder neck, i.e., within the urethra, such that the drainage portion 4 of the urethral catheter described herein can be lengthened.

[0127] Figure 10 shows an enlarged cross-sectional view of a portion of the catheter along the longitudinal axis indicated by the central axis CA. In this figure, the catheter 1 includes a tubular portion 1a, the tubular portion 1a being made of a base material and defining an inner surface 6 facing the drainage conduit 7 and an outer surface 8 on the opposite side facing away from the drainage conduit, and it is schematically shown that the outer surface extends continuously from the proximal insertion end to the distal outlet.

[0128] The portion of the outer surface contemplated to be inserted into the body is covered by a layer 1b of hydrophilic material that forms the hydrophilic surface 9 of the catheter. The coating thickness Y defines the radial spread of the coating at the outer surface 8.

[0129] Figure 11 shows a further enlarged view of the drainage opening 5. Each drainage opening 5 is defined by a drainage opening wall 5a that extends between an internal opening 5b on the inner surface and an external opening 5c on the outer surface. In the illustrated embodiment, the external opening 5c is larger than the internal opening such that the drainage opening wall tapers from the outer surface to the inner surface.

[0130] The drainage opening is formed by laser ablation after the hydrophilic material has been deposited on the outer surface. As a result, both the hydrophilic material and the base material are melted away, and thus the walls of the drainage opening are not covered by the hydrophilic material.

[0131] FIG. 12 shows a further enlarged view of FIG. 11, indicating that the thickness of the hydrophilic material layer 9 decreases towards each inlet opening 5c on the outer surface 8, thereby forming a bevel 9a of the coating layer.

[0132] FIG. 13 shows an embodiment of a catheter with protrusions 410. The protrusions 410 surround the inlet opening 5c on the outer surface and extend beyond the hydrophilic surface 411 of the layer 9 when the hydrophilic material constituting the layer 9 is not swollen.

[0133] FIG. 14 shows the embodiment of FIG. 13 when the hydrophilic material is swollen. In this state, the hydrophilic material extends beyond the protrusions 410.

[0134] FIG. 15 shows the drainage part of the catheter as viewed from above. In this figure, it is shown that the drainage openings 5 are arranged in groups R1, R2, and R3. The first group R1 includes a plurality of drainage openings that are arranged along the first row and have non-circular external openings 8a. Group 3 also has non-circular openings. The group R2 includes a plurality of drainage openings that have circular external openings 8a.

[0135] FIG. 16A shows a side view of an embodiment of an intermittent urethral catheter 1 having drainage openings positioned in three groups 4a, 4b, and 4c. In the first group 4a, the drainage openings are positioned in a high-density configuration. In the second group 4b, the drainage openings are positioned in a low-density configuration. In the third group 4c, the drainage openings are positioned even further apart.

[0136] Figure 16B shows a side view of an embodiment of an intermittent urethral catheter having a drainage portion 4, with the drainage openings 5 positioned in three rows. In this figure, two rows are visible, while the third row is positioned on the rear side of the catheter and is thus shown by a phantom line.

[0137] Figure 17 shows an enlarged schematic cross - section of a portion of the catheter along the central axis CA. In this figure, the catheter 1 forms a tubular wall 1b that defines an inner surface 6 facing towards the drainage conduit 7 and an opposite outer surface 8 facing away from the drainage conduit, and it is shown that the outer surface extends continuously from the proximal insertion end to the distal outlet. Both the proximal insertion end and the distal outlet are outside the boundaries of Figure 17.

[0138] The catheter comprises a drainage portion intended to be inserted into the body. The drainage portion comprises a plurality of drainage openings 5. Each drainage opening extends along a corresponding center line CL from an internal opening 6a into the drainage conduit 7 to an external opening 8a on the outer surface 8. The center lines of the drainage openings intersect at an intersection point P outside the drainage conduit 7.

[0139] Figure 18 shows a perspective view of a portion of the drainage portion shown in Figure 15. In this figure, it is shown that the center lines CL of all the drainage openings intersect at the intersection point P.

[0140] Figure 19 shows a cross - sectional view taken across the central axis along section AA in Figure 15.

[0141] The drainage openings form a first group R1, a second group R2, and a third group R3 referred to and shown with respect to Figure 15. Each center line of the first group of drainage openings intersects at least one center line of the second group of drainage openings at an intersection point P outside the drainage conduit 7 and well above the outer surface 8.

[0142] In an alternative embodiment, a cross-sectional view of the type shown in FIG. 19 is considered for each drainage opening in one of the groups R1, R2 or R3. In this alternative embodiment, the midline for one group, i.e., the centerline for R1, for R2, or for R3, is parallel to the centerline of the same group of drainage openings in other cross-sectional views, while the centerline of one group of drainage openings still intersects at least one centerline of the other group of drainage openings at the intersection point P outside the drainage conduit 7.

[0143] FIG. 20 shows an enlarged schematic cross-section of a part of the catheter along the central axis CA. In this figure, it is shown that the catheter 1 forms a tubular wall 1b that defines an inner surface 6 facing towards the drainage conduit 7 and an opposite outer surface 8 facing away from the drainage conduit. The outer surface extends from the proximal insertion end to the distal outlet. Both the proximal insertion end and the distal outlet are outside the boundaries of FIG. 20.

[0144] The catheter comprises a drainage portion intended to be inserted into the body. The drainage portion comprises a plurality of drainage openings 5. Each drainage opening extends along a corresponding centerline CL from an internal opening 6a into the drainage conduit 7 to an external opening 8a on the outer surface 8.

[0145] Each drainage opening extends along a corresponding centerline from the inner surface facing towards the drainage conduit to the outer surface facing away from the drainage conduit, and the drainage openings are formed in pairs, with one pair of drainage openings including a first drainage opening 5' and a second drainage opening 5'' that both have the same centerline. Each pair of drainage openings includes one drainage opening 5' on one side of the central axis and another drainage opening 5'' on the opposite side of the central axis.

[0146] In the embodiment shown in FIG. 20, the centerlines CL of the drainage openings intersect at the intersection point P outside the drainage conduit 7.

[0147] In the embodiment shown in FIG. 20, the drainage opening is shown to taper in the upper half, which means that the inlet opening 8a is larger than the outlet opening 6a, while the drainage opening in the lower half of the figure is shown to flare out, which means that the outlet opening 6a is larger than the inlet opening 8a.

[0148] FIG. 21 shows an alternative embodiment in which the center lines are parallel. In the illustrated embodiment, the drainage opening has a vertical drainage opening wall, although it is also contemplated that the drainage opening walls can be tapered and flared respectively as shown in FIG. 20.

[0149] FIG. 22 shows a cross-sectional view taken transverse to the central axis along section line AA in FIG. 15. Each center line extends through two drainage openings 5' and 5''. At least the central pair of drainage openings are on opposite sides of the central axis CA.

[0150] The first group of drainage openings intersects at least one center line of the second group of drainage openings at an intersection P that is external to the drainage conduit 7 and well above the outer surface 8. In an alternative embodiment, the center lines are parallel as shown in FIG. 21.

[0151] FIG. 23 shows an enlarged schematic cross-section of a portion of the catheter along the central axis CA. In this figure, it is shown that the catheter 1 forms a tubular wall 1b that defines an inner surface 6 facing towards the drainage conduit 7 and an opposite outer surface 8 facing away from the drainage conduit. The outer surface extends from the proximal insertion end to the distal outlet. Both the proximal insertion end and the distal outlet are outside the boundaries of FIG. 23.

[0152] The catheter comprises a first drainage zone that is contemplated to be inserted into the body. The first drainage zone comprises a plurality of drainage openings 5. Each drainage opening extends along a corresponding center line CL from an internal opening 6a into the drainage conduit 7 to an external opening 8a at the outer surface 8.

[0153] Each drainage opening extends along the corresponding center line from the inner surface facing the drainage conduit towards the outer surface facing away from the drainage conduit, and the drainage openings are formed such that all the drainage openings are displaced relative to each other so that no drainage opening is located along the center line of another drainage opening.

[0154] In the view of FIG. 23, the catheter comprises a first group of drainage openings 5' and a second group of drainage openings 5''. The two groups are on both sides of the central axis CA and are offset in the direction of the central axis CA so that no drainage opening is on the center line of another drainage opening.

[0155] In the embodiment shown in FIG. 23, the center lines of the drainage openings intersect at an intersection point P outside the drainage conduit 7.

[0156] FIG. 24 shows an alternative embodiment in which the center lines are parallel.

[0157] FIG. 25 is similar to the view of FIG. 22 but shows a cross-sectional view based on the catheter portion as shown in FIG. 24. Each center line extends through only one drainage opening 5' or 5'' and never through two drainage openings.

[0158] The drainage opening 5' intersects at the intersection point P outside the drainage conduit 7.

[0159] Common to all of the above-described embodiments shown in FIGS. 5 to 25 is that the drainage openings can be effectively produced by laser ablation, for example, by a laser arranged at point P.

[0160] Figure 26 schematically shows the pressure pulses that occur in an intermittent catheter while emptying the bladder. This figure shows the pressure difference as a function of time between a series of blockages of the drainage opening in the catheter. The pressure pulse occurs as a sharp drop in pressure over a very short period (on the order of 100 milliseconds or less), which is shown as the peaks on the curve in the figure. As explained above, the pressure pulse occurs due to the tissue blocking the drainage opening, causing the flow of urine through the catheter to suddenly stop.

[0161] Figures 26 to 31 show the results obtained by testing various catheters using the test configuration in Figures 32 to 34. Figure 26 shows the results from testing a male catheter at a drainage height of 15 - 20 cm and a water level of 10 cm H2O. Starting from the left in Figure 26, this graph shows the pressure pulses obtained inside a prior art catheter of size CH16 with two standard drainage openings having a maximum dimension of 5.6 mm. Prior to the test, one of the drainage openings was blocked. From Figure 26, it can be seen that the pressure pulse exceeds 200 mBar. Moving to the right in the figure, the next graph shows the pressure pulses obtained inside a prior art catheter of size CH12 with two drainage openings having a maximum dimension of 3.9 mm. Such a catheter provides a pressure pulse of approximately 200 mBar. The third graph from the left shows the pressure pulses obtained with a prior art catheter of CH10 with a drainage opening having a maximum dimension of 3.4 mm. Here, the pressure pulse exceeds 100 mBar. The fourth graph from the left shows the pressure pulses obtained with an intermittent urethral catheter described herein having one open drainage opening with a maximum dimension of 1 mm. This graph shows that the pressure pulse only reaches about 40 mBar. The graph furthest to the right shows the pressure pulse for an intermittent urethral catheter described herein having one open drainage opening with a maximum dimension of approximately 0.4 mm. Here, the pressure pulse is substantially non - existent, i.e., there are almost no peaks on the curve.

[0162] Figure 27 shows the results from testing a male catheter at a drainage height of 25 cm and a water level of 50 cm H2O. Starting from the left in Figure 27, the graph shows the pressure pulses obtained with a catheter having one single open drainage opening, and the single drainage opening increases from left to right in the figure. These results are also reported in Table 2 below. For a drainage opening with a maximum dimension of 4 mm, the pressure pulse (under these test conditions) reaches 652 mBar, while looking from the left, the pressure pulse (under these test conditions) can be seen to be approximately 15 mBar lower when the drainage opening is 0.19 mm. With a drainage opening smaller than approximately 0.4 mm, a level below 100 mBar is obtained, with a drainage opening smaller than approximately 0.6 mm, a level below 200 mBar is obtained, and with a drainage opening smaller than approximately 1.00 mm, a level below 350 mBar is obtained.

[0163] Figure 28 shows the results from testing a female catheter at a drainage height of 6 cm and a water level of 50 cm H2O. Starting from the left in Figure 28, the graph shows the pressure pulses obtained in a catheter having one single open drainage opening, and the single drainage opening increases from left to right in the figure. These results are also reported in Table 3 above. For a drainage opening with a maximum dimension of 4 mm, the pressure pulse (under these test conditions) reaches 639 mBar, while from the left, the pressure pulse (under these test conditions) can be seen to be approximately 12 mBar lower when the drainage opening is 0.19 mm. With a drainage opening smaller than approximately 0.5 mm, a level below 100 mBar is obtained, with a drainage opening smaller than approximately 0.7 mm, a level below 200 mBar is obtained, and with a drainage opening smaller than approximately 1.00 mm, a level below 350 mBar is obtained.

[0164] Figures 29A and 29B show the test results for tests conducted according to the test configuration in Figure 32. Figure 29B shows, on a larger scale, the correlation between how much the bladder wall or urethral tissue enters the inner lumen through the drainage opening, the size of the drainage opening, and the measured pressure pulse. From the results of the tests, it is understood that a pressure level of less than 40 mBar reduces the risk that the bladder wall or urethral tissue enters the inner lumen through the small drainage opening of the intermittent catheter and reduces the risk of impact on the tissue. In embodiments of the present disclosure, an intermittent urethral catheter is achieved in which there is no or very little tissue entering the inner lumen through the small drainage opening when the pressure pulse is less than 40 mBar. When the drainage opening has a maximum dimension of less than 0.7 mm, a pressure pulse of less than 40 mBar is obtained. Accordingly, embodiments relate to an intermittent urethral catheter configured to provide a pressure pulse of less than 40 mBar. Related embodiments are intermittent urethral catheters having a drainage opening with a maximum dimension of less than 0.7 mm.

[0165] Figures 30 and 31 show the test results for tests conducted according to the test configuration in Figures 33 and 34. The results in Figure 30 are for testing a male catheter as shown in Figure 33, and the results in Figure 31 are for testing a female catheter as shown in Figure 34. The difference is that for the male catheter, the difference in height between the level of the drainage opening and the outlet of the catheter is 25 cm, while for the female catheter, the difference in height is 6 cm.

[0166] Figures 30 and 31 show the results of testing drainage openings with a maximum dimension of 1 mm or less. The curves show that for male catheters, when drainage openings less than 1 mm are used, the pressure is less than 350 mBar. For female catheters, the pressure pulse is less than 300 mBar. When a 0.8 mm drainage opening is used, the pressure pulse for male catheters is approximately 260 mbar and for female catheters is approximately 210 mBar. When a 0.4 mm drainage opening is used, the pressure pulse for male catheters is approximately 90 mBar and for female catheters is approximately 75 mBar.

[0167] Embodiment Non-limiting examples of embodiments of intermittent hydrophilic urethral catheters, methods of using such catheters, and methods of manufacturing are described below.

[0168] 1. An intermittent hydrophilic urethral catheter defining a drainage conduit that extends longitudinally from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a tube, the tube being made of a base material and having a tubular wall defining an inner surface facing the drainage conduit and an opposite outer surface facing away from the drainage conduit, at least the insertable portion of the outer surface being covered by a layer of hydrophilic material configured to change from a non-swollen state to a swollen state upon contact with a swelling medium, the hydrophilic material defining a hydrophilic surface of the catheter with a coating thickness on the outer surface, the catheter comprising a plurality of drainage openings, each drainage opening being defined by a drainage opening wall extending between an outlet opening on the inner surface and an inlet opening on the outer surface, the drainage opening wall not being covered by the hydrophilic material.

[0169] 2. The catheter according to embodiment 1, wherein the drainage openings are created by laser ablation of the hydrophilic material and the base material, thereby ensuring that the drainage opening walls are not covered by the hydrophilic material.

[0170] 3. The catheter according to embodiment 1 or 2, wherein the drainage opening wall has a height corresponding to the distance between the inner surface and the outer surface.

[0171] 4. The catheter according to any of the preceding embodiments, wherein the outer surface extends continuously from the proximal insertion end to the distal outlet end.

[0172] 5. The catheter according to any of the preceding embodiments, wherein the coating thickness decreases towards each inlet opening on the outer surface.

[0173] 6. The catheter according to any of the preceding embodiments, wherein the tubular wall of the tube has a uniform wall thickness.

[0174] 7. The catheter according to any of the preceding embodiments, wherein the tube has a uniform outer surface.

[0175] 8. The catheter according to any of the preceding embodiments, comprising a protrusion that surrounds the inlet opening on the outer surface and extends above the hydrophilic surface when the hydrophilic material is in a non-swollen state.

[0176] 9. The catheter according to embodiment 8, wherein the hydrophilic material extends above the protrusion when in a swollen state.

[0177] 10. The catheter according to any of the preceding embodiments, wherein the drainage opening has a cross-sectional area of less than 0.4 mm 2 30.

[0178] 11. The catheter according to any of the preceding embodiments, wherein the proximal insertion end forms a closure tip.

[0179] 12. The catheter according to embodiment 11, defining a non-drainage portion on the distal side of the tip and a drainage portion on the distal side of the non-drainage portion, and having a plurality of drainage openings provided in the drainage portion.

[0180] 13. A catheter according to any of the preceding embodiments, wherein the sum of the cross-sectional areas of the drainage openings is larger than the cross-sectional area of the drainage conduit.

[0181] 14. A method of manufacturing a hydrophilic urethral catheter, the method comprising: providing a tube made of a base material that defines a tubular shape having an inner surface facing the drainage conduit and an outer surface facing in a direction away from the drainage conduit; coating the outer surface with a hydrophilic material so as to define a hydrophilic surface; and providing a plurality of drainage openings from the outer surface to the inner surface by laser ablation of the hydrophilic material and the base material, wherein the drainage opening walls extending between the inner surface and the outer surface are not coated.

[0182] 15. The method according to embodiment 13, wherein the tube is prepared by extruding the base material through a die.

[0183] 16. A method of reducing the local suction peak pressure at the drainage openings within the bladder as a result of occlusion of the drainage openings, by using an intermittent urethral catheter according to any of embodiments 1 to 12.

[0184] 17. An intermittent urethral catheter defining a drainage conduit that extends along a central axis from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a plurality of drainage openings, each drainage opening extending along a corresponding centerline from an internal opening to the drainage conduit to an external opening on the outer surface, and at least two drainage openings having centerlines that intersect at an intersection outside the drainage conduit.

[0185] 18. The catheter according to embodiment 17, wherein the centerlines of the drainage openings intersect at the intersection.

[0186] 19. The catheter according to embodiment 17, comprising a first group of drainage openings and a second group of drainage openings, wherein the center lines of the first group of drainage openings are parallel, the center lines of the second group of openings are parallel, and each center line of the first group of drainage openings intersects at least one center line of the second group of drainage openings at an intersection point.

[0187] 20. The catheter according to any one of embodiments 17 to 19, wherein the intersecting center lines extend at an angle of 1 to 4 degrees from the intersection point.

[0188] 21. The catheter according to any one of embodiments 17 to 20, wherein the intersection point is at a distance from the outer surface corresponding to at least 10 times the distance from the outer surface to the central axis.

[0189] 22. The catheter according to any one of embodiments 17 to 21, wherein the first group of external openings is non-circular and the second group of external openings is circular.

[0190] 23. The catheter according to embodiment 22, wherein the openings of the first group of external openings extend along a straight first external line parallel to the central axis.

[0191] 24. The catheter according to embodiment 22 or 23, wherein the openings of the second group of external openings extend along a straight second external line parallel to the central axis.

[0192] 25. The catheter according to any one of embodiments 17 to 24, wherein the drainage opening has a cross-sectional area of less than 0.4 mm 2 26. The catheter according to any one of embodiments 17 to 25, wherein the proximal insertion end forms a closure tip.

[0193] 27. The catheter according to embodiment 26, defining a non-drainage portion on the distal side of the tip and a drainage portion on the distal side of the non-drainage portion, and a plurality of drainage openings are provided in the drainage portion.

[0194] 27. The catheter according to embodiment 26, defining a non-drainage portion on the distal side of the tip and a drainage portion on the distal side of the non-drainage portion, and a plurality of drainage openings are provided in the drainage portion.

[0195] 28. The catheter according to any one of Embodiments 17 to 27, wherein the sum of the cross-sectional areas of the drainage openings is larger than the cross-sectional area of the drainage conduit.

[0196] 29. A method of manufacturing an intermittent urethral catheter, comprising providing a tube made of a base material and defining a tubular shape having an inner surface facing the inner drainage conduit and an outer surface facing away from the inner drainage conduit, and providing a plurality of drainage openings extending between an inner opening on the inner surface and an outer opening on the outer surface by laser ablation of the base material, wherein the laser ablation is performed with a laser beam emitted from a light emitter point outside the drainage conduit at an emission angle such that a first emission angle is provided for a first group of the drainage openings and a second emission angle is provided for a second group of the drainage openings.

[0197] 30. The method according to Embodiment 29, wherein the drainage openings are provided in pairs, each pair including one drainage opening from the first group of drainage openings and one drainage opening from the second group of drainage openings, and the light emitter point moves relative to the tube between each pair of drainage openings.

[0198] 31. The method according to Embodiment 29 or 30, wherein the distance from the light emitter point to the outer surface is maintained constant when providing the drainage openings.

[0199] 32. The method according to any one of Embodiments 29 to 31, wherein the drainage openings are provided by ablation while the pressure inside the drainage conduit changes relative to the pressure outside the drainage conduit.

[0200] 33. The method according to any one of Embodiments 29 to 32, wherein the outer surface is coated with a hydrophilic material before providing the drainage openings.

[0201] 34. A method of reducing the local suction peak pressure at the drainage opening in the bladder as a result of occlusion of the drainage opening by using the intermittent urethral catheter according to any one of Embodiments 17 to 28.

[0202] An intermittent urethral catheter defining a drainage conduit extending along a central axis from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a plurality of drainage conduits, each drainage conduit extending along a corresponding center line from an inner surface facing the drainage conduit to an outer surface facing away from the drainage conduit, the drainage openings being formed in pairs, one pair of drainage openings including a first drainage opening and a second drainage opening both having the same center line.

[0203] 36. The catheter according to embodiment 35, wherein the first drainage opening and the second drainage opening are on opposite sides of the central axis.

[0204] 37. Each drainage opening is defined by a wall extending from an inner surface facing the drainage conduit to an outer surface facing away from the drainage conduit, the wall of the first drainage opening tapering in the direction from the outer surface to the inner surface, and the wall of the second drainage opening flaring in the direction from the outer surface to the inner surface. The catheter according to embodiment 35 or 36.

[0205] 38. The catheter according to any one of embodiments 35 to 37, wherein the first drainage opening and the second drainage opening have different dimensions.

[0206] 39. The catheter according to any one of embodiments 35 to 38, wherein the drainage opening has a cross-sectional area of less than 0.4 mm 2 2.

[0207] 40. The catheter according to any one of embodiments 35 to 39, wherein the proximal insertion end forms a closed tip.

[0208] 41. The catheter according to embodiment 40, defining a non-drainage portion on the distal side of the tip and a drainage portion on the distal side of the non-drainage portion, and a plurality of drainage openings are provided in the drainage portion.

[0209] 42. The catheter according to any one of embodiments 35 to 41, wherein the sum of the cross-sectional areas of the drainage openings is larger than the cross-sectional area of the drainage conduit.

[0210] 43. A method of manufacturing an intermittent urinary catheter, comprising providing a tube made of a base material and defining a drainage conduit that extends along a central axis from a proximal insertion end configured to be inserted into a body cavity to a distal outlet end configured to drain urine from the drainage conduit, and providing a plurality of drainage openings extending between an internal opening on an inner surface facing the drainage conduit and an external opening on an outer surface facing away from the drainage conduit, wherein the drainage openings are created by laser ablation of the base material, and the laser ablation is performed by simultaneous ablation of the base material along a common centerline on both sides of the central axis to form a pair of drainage openings including a first drainage opening and a second drainage opening.

[0211] 44. The method according to embodiment 43, wherein the laser light is emitted from a light emitter point outside the drainage conduit through the internal drainage conduit.

[0212] 45. The method according to embodiment 43 or 44, wherein the laser light is emitted in at least two successive pulses.

[0213] 46. The method according to any one of embodiments 43 to 45, wherein the pore size is determined for at least one of the first drainage opening and the second drainage opening, and the laser ablation is performed with a number of shots determined by the pore size.

[0214] 47. A method of reducing the local suction peak pressure at the drainage opening in the bladder as a result of occlusion of the drainage opening by using the intermittent urinary catheter according to any one of embodiments 35 to 42. The present disclosure further includes the following aspects: <<Aspect 1>> An intermittent hydrophilic urethral catheter defining a drainage conduit that extends longitudinally from a proximal insertion end configured to be inserted into the urethra to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a tubular portion made of a base material and having a tubular wall defining an inner surface facing the drainage conduit and an outer surface facing away from the drainage conduit, at least an insertable portion of the outer surface being covered by a layer of hydrophilic material configured to change from a non-swollen state to a swollen state upon contact with a swelling medium, the hydrophilic material defining a hydrophilic surface with a coating thickness on the outer surface, the catheter comprising a plurality of drainage openings extending between an outlet opening on the inner surface and an inlet opening on the outer surface, the outer surface forming a protrusion surrounding the opening on the outer surface and extending above the hydrophilic material when the hydrophilic material is in the non-swollen state. <<Aspect 2>> The intermittent hydrophilic urethral catheter according to aspect 1, wherein the hydrophilic material extends above the protrusion when in the swollen state. <<Aspect 3>> The intermittent hydrophilic urethral catheter according to aspect 1 or 2, wherein the coating thickness is in the range of 15 - 20 μm in the non-swollen state. <<Aspect 4>> The intermittent hydrophilic urethral catheter according to any one of aspects 1 - 3, wherein the coating thickness is in the range of 25 - 30 μm in the swollen state. <<Aspect 5>> The intermittent hydrophilic urethral catheter according to any one of aspects 1 - 4, wherein the coating thickness decreases towards each drainage opening. <<Aspect 6>> The drainage opening has a cross-sectional area of less than 0.4 mm 2 The intermittent hydrophilic urethral catheter according to any one of aspects 1 - 5. <<Aspect 7>> The intermittent hydrophilic urethral catheter according to any one of aspects 1 - 6, wherein the proximal insertion end forms a closed tip. <<Aspect 8>> Defining a non-drainage portion on the distal side of the chip and a drainage portion on the distal side of the non-drainage portion, and the plurality of drainage openings are provided in the drainage portion, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 7. <<Aspect 9>> The sum of the cross-sectional areas of the drainage openings is larger than the cross-sectional area of the drainage conduit, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 8. <<Aspect 10>> The number of drainage openings is more than 20, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 9. <<Aspect 11>> The catheter is CH10, each drainage opening has a maximum dimension of approximately 0.4 mm on the convex outer surface of the tubular portion, and the number of drainage openings is more than 32, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 10. <<Aspect 12>> The catheter is CH12, each drainage opening has a maximum dimension of approximately 0.7 mm on the convex outer surface of the tubular portion, and the number of drainage openings is more than 15, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 11. <<Aspect 13>> Each of the drainage openings extends transversely to the longitudinal direction of the catheter, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 12. <<Aspect 14>> The drainage portion is approximately 4 cm in the longitudinal direction, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 13. <<Aspect 15>> The drainage portion is approximately 10 cm in the longitudinal direction, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 14. <<Aspect 16>> The drainage portion is approximately 15 cm in the longitudinal direction, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 15. <<Aspect 17>> The drainage portion is approximately 2 cm in the longitudinal direction, the intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 16. Aspect 18 The intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 17, wherein each drainage opening includes a drainage opening wall extending between the outlet opening on the inner surface and the inlet opening on the outer surface, and the drainage opening wall is not covered with the hydrophilic material. Aspect 19 The intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 18, wherein at least two drainage openings have a center line that intersects at an intersection outside the drainage conduit. Aspect 20 The intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 19, wherein the drainage openings are formed in pairs, and one pair of drainage openings includes a first drainage opening and a second drainage opening that both have the same center line. Aspect 21 The intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 20, wherein the pair of drainage openings is positioned at an oblique angle with respect to the longitudinal axis. Aspect 22 The intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 21, wherein the pair of drainage openings is positioned at an angle of 80 to 87 degrees, such as an angle of 85 to 87 degrees, with respect to the longitudinal axis. Aspect 23 The intermittent hydrophilic urethral catheter according to any one of Aspects 1 to 22, wherein each drainage opening is defined by a wall extending from an internal opening on the inner surface facing the drainage conduit to an external opening on the outer surface facing away from the drainage conduit, and the wall of the first drainage opening tapers in the direction from the external opening to the internal opening, and the wall of the second drainage opening flares in the direction from the external opening to the internal opening.

Claims

1. An intermittent hydrophilic urethral catheter defining a drainage conduit that extends longitudinally from a proximal insertion end configured to be inserted into the urethra to a distal outlet end configured to discharge urine from the drainage conduit, the catheter comprising a tubular portion made of a base material and having a tubular wall defining an inner surface facing the drainage conduit and an outer surface facing away from the drainage conduit, at least the insertable portion of the outer surface being covered by a layer of hydrophilic material configured to change from a non-swollen state to a swollen state upon contact with a swelling medium, the hydrophilic material defining a hydrophilic surface with a coating thickness on the outer surface, the catheter comprising a plurality of drainage openings extending between an outlet opening on the inner surface and an inlet opening on the outer surface, the outer surface forming a protrusion that surrounds the opening on the outer surface and extends above the hydrophilic material when the hydrophilic material is in the non-swollen state.

2. The intermittent hydrophilic urethral catheter according to claim 1, wherein the hydrophilic material extends above the protrusion when in the swollen state.

3. The intermittent hydrophilic urethral catheter according to claim 1 or 2, wherein the coating thickness decreases towards each drainage opening.

4. The drainage opening has a cross-sectional area of less than 0.4 mm ２ The intermittent hydrophilic urethral catheter according to any one of claims 1 to 3, having a cross-sectional area of less than

5. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 4, wherein the proximal insertion end forms a closed tip.

6. The intermittent hydrophilic urethral catheter according to claim 5, defining a non-drainage portion distal to the tip and a drainage portion distal to the non-drainage portion, the drainage portion being provided with the plurality of drainage openings.

7. The intermittent hydrophilic urethral catheter according to claim 6, wherein the drainage portion is approximately 4 cm in the longitudinal direction.

8. The intermittent hydrophilic urethral catheter according to claim 6, wherein the drainage portion is approximately 10 cm in the longitudinal direction.

9. The intermittent hydrophilic urethral catheter according to claim 6, wherein the drainage portion is approximately 15 cm in the longitudinal direction.

10. The intermittent hydrophilic urethral catheter according to claim 6, wherein the drainage portion is approximately 2 cm in the longitudinal direction.

11. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 10, wherein the sum of the cross-sectional areas of the drainage openings is greater than the cross-sectional area of the drainage conduit.

12. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 11, wherein the number of drainage openings is more than 20.

13. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 12, wherein the catheter is CH10, each drainage opening has a maximum dimension of approximately 0.4 mm on the convex outer surface of the tubular portion, and the number of drainage openings is more than 32.

14. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 11, wherein the catheter is CH12, each drainage opening has a maximum dimension of approximately 0.7 mm on the convex outer surface of the tubular portion, and the number of drainage openings is more than 15.

15. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 14, wherein each of the drainage openings extends transversely to the longitudinal direction of the catheter.

16. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 15, wherein each drainage opening includes a drainage opening wall extending between the outlet opening on the inner surface and the inlet opening on the outer surface, and the drainage opening wall is not covered with the hydrophilic material.

17. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 16, wherein at least two drainage openings have a center line intersecting at an intersection outside the drainage conduit.

18. The intermittent hydrophilic urethral catheter according to any one of claims 1 to 17, wherein the drainage openings are formed in pairs, and one pair of drainage openings includes a first drainage opening and a second drainage opening both having the same center line.

19. The intermittent hydrophilic urethral catheter according to claim 18, wherein the pair of drainage openings is positioned at an oblique angle with respect to the longitudinal axis.

20. The intermittent hydrophilic urethral catheter according to claim 18 or 19, wherein the pair of drainage openings is positioned at an angle of 85 to 87 degrees, such as an angle of 80 to 87 degrees, with respect to the longitudinal axis.

21. Each drainage opening is defined by a wall extending from an internal opening on the inner surface facing the drainage conduit toward an external opening on the outer surface facing away from the drainage conduit, and the wall of the first drainage opening tapers in the direction from the external opening to the internal opening, and the wall of the second drainage opening flares in the direction from the external opening to the internal opening. The intermittent hydrophilic urethral catheter according to any one of claims 18 to 20 has such a shape.

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