CN211584805U - Catheter capable of preventing edges and corners from directly contacting urethra - Google Patents

Abstract

The utility model relates to a catheter for preventing edges and corners from directly contacting urethra, which comprises an outer tube and a protection part arranged on the outer tube, wherein the outer tube is provided with an expansion part which is arranged inside the protection part, the expansion part is used for passing through the protection part and expanding outwards under the action of internal pressure and is used for being accommodated in the protection part after internal pressure is lost; the utility model provides a catheter, moreover, the steam generator is simple in structure, and reasonable in design, in the in-service use process, both can make the outside inflation of inflation portion of outer tube and form saccular arch through the pressure boost to the outer tube, so that the card is in urethra department, the realization is fixed to the catheter, avoid the catheter to drop, can be when demolising the catheter again, make inflation portion after the decompression becomes flat can accomodate in the protection portion, avoid the sharp-pointed edges and corners that inflation portion formed directly to expose outside the outer tube, thereby can effectively avoid edges and corners and urethra direct contact, reach the protection urethra, improve patient comfort's purpose.

Description

Catheter capable of preventing edges and corners from directly contacting urethra

Technical Field

The utility model relates to the technical field of medical equipment, concretely relates to prevent catheter of edges and corners direct contact urethra.

Background

The urinary catheter is a conduit inserted into the urinary bladder from the urethra to drain urine, and is generally made of soft materials such as natural rubber, silicone rubber or polyvinyl chloride (PVC), and is widely used in clinical practice.

The catheters commonly used in the prior art are divided according to structures and can be generally divided into a single-cavity catheter, a double-cavity catheter and a three-cavity catheter, wherein the single-cavity catheter only has one channel for catheterization, is inconvenient to fix and has short retention time; the double-cavity catheter is provided with two cavities, the two cavities are formed by an inner tube and an outer tube which are sleeved together, as shown in the attached drawing 1, a liquid inlet communicated with the inner tube is formed in the head end of the double-cavity catheter, and a liquid outlet communicated with the inner tube and a valve (a valve for injecting water or a valve for inflating) communicated with the outer tube are respectively formed in the tail end of the double-cavity catheter; when the catheter is required to be pulled out, the air or water in the outer tube is discharged through the valve, so that the outward protruding balloon can be eliminated, the original shape of the balloon is recovered, and smooth catheter pulling is facilitated; compared with a double-cavity catheter, the three-cavity catheter is additionally provided with a drug injection cavity and is mainly used for occasions of short-term indwelling catheterization, intravesical liquid medicine instillation, flushing, drainage and the like.

In order to facilitate the fixation and detachment prevention of the urinary catheter, the patents on the urinary catheter disclosed in the prior art generally adopt the following technical schemes: the local area of the outer tube is expanded in a water injection or inflation state to form a saccule (such as the outer tube in the double-cavity catheter), so that the saccule is clamped at the urethral orifice, and the catheter is fixed and prevented from falling off; although the technical scheme has better fixing and anti-dropping effects in clinic, in the actual use process, people never notice: when water or air is removed from the outer tube (i.e., after the internal pressure is lost), the expanded region of the outer tube is generally difficult to recover to its original shape and to maintain its smooth surface, and in fact, the region is generally collapsed and formed into one or more circumferentially arranged corners that extend along the length of the outer tube, which are generally sharp and rigid and are not conducive to tube drawing; for example, when air or water in the outer tube shown in fig. 2 is pumped out, an edge angle as shown in fig. 3 is formed in the area where the balloon is formed, on one hand, the edge angle is very easy to cause injury to the urethra during the tube drawing process, and even cause infection of the urethra; on the other hand, the patient feels very uncomfortable in the process of tube drawing because the outer tube is not smooth; however, the person skilled in the art has not yet noticed this problem and lacks effective means to solve it.

SUMMERY OF THE UTILITY MODEL

For solving the problem that prior art exists, the utility model provides a catheter, this catheter both can make the outside inflation of local area and form saccular arch through the pressure boost to the outer tube, realize fixed and the anticreep function to the catheter, can avoid again the outer tube decompression back directly expose outside at the edges and corners that local area formed to the edges and corners is direct to can effectively avoid edges and corners and urethra direct contact, reach the purpose of protecting the urethra, improve patient's comfort.

The utility model adopts the technical proposal that:

the utility model provides a prevent catheter of edges and corners direct contact urethra, include the outer tube with set up in the protection portion of outer tube, the outer tube is provided with inflation portion, just inflation portion set up in the inside of protection portion, inflation portion are used for passing protection portion and outside inflation under the effect of interior pressure, and are used for accomodating in the protection portion after losing interior pressure. In the scheme, the protection part is arranged on the outer side of the expansion part, when the catheter is inserted in place and needs to be fixed, the expansion part arranged on the outer tube can expand outwards under the action of the internal pressure of the outer tube to form a sac-shaped bulge, so that the expansion part can be clamped at the urethral orifice of a patient, the fixation of the catheter is realized, the automatic falling of the catheter can be effectively avoided, and the aim of preventing the catheter from falling off is fulfilled; when the catheter is pulled out to needs, need let out earlier the interior pressure of removing the outer tube, after the outer tube loses interior pressure, inflation portion can become flat and automatic inside of accomodating the protection portion for the edges and corners that form after the inflation portion decompression is located the inside of protection portion, and protection portion can reach the purpose of keeping apart inflation portion through sheltering from to inflation portion promptly, thereby avoids edges and corners and urethra direct contact not only can effectively protect patient's urethra at the in-process of pulling out the pipe, avoid the damage of urethra, can make the tube drawing process more smooth and easy moreover, thereby effectively strengthen patient's comfort.

Preferably, the protection portion is smoothly provided to the outer tube. That is, the protection part is not only fixed in the outer tube, and there is not edges and corners or any place that is not smooth between protection part and the outer tube moreover to make this catheter neither cause the damage of urethra in the process of intubate and extubation, can not cause patient's discomfort again.

Preferably, the protection part comprises a protection cylinder with a cylindrical structure, the protection cylinder is made of hard materials, and one or more through holes are formed in the side wall of the protection cylinder and are used for allowing the expansion part to expand outwards. The protection cylinder is made of hard materials, so that the phenomenon that the shielding effect of the internal expansion part is influenced due to large deformation in the use process is avoided; because the outer tube is the pipe usually, when the protection section of thick bamboo adopted the cylinder structure, can realize seamless, the smooth connection of protection portion and outer tube, and the setting of through-hole is favorable to the inflation portion outwards to expand and form saccular protrusion, reaches the purpose of blocking the urethral orifice.

Preferably, the through hole is a circular hole, an elliptical hole or a strip-shaped hole. The shape of the through hole can be various as long as the requirement of outward expansion of the expansion part can be met.

Preferably, when the number of the through holes is multiple, the through holes are uniformly distributed along the circumferential direction of the protection cylinder respectively. After the inflation portion expands under the effect of outer tube internal pressure, can extend a protection section of thick bamboo through each through-hole respectively to it is protruding to form a plurality of sacks in the circumferencial direction of a protection section of thick bamboo, more is favorable to realizing the fixed to the catheter, also is favorable to realizing the anticreep function simultaneously.

Further, the edge of through-hole is provided with the arc transition. So as to eliminate the edge at the edge of the through hole, not only can avoid damaging the expansion part, but also can avoid the damage to the urethra in the process of inserting/pulling the ureter, and achieve the aim of further protecting the urethra.

Further, the outer diameter of the protection cylinder is equal to the outer diameter of the outer pipe. Therefore, no edges or non-smooth places are arranged between the protective barrel and the outer tube, and the urethral canal is not damaged and discomfort of a patient is not caused in the process of intubation and tube drawing.

In one scheme, a protective layer is arranged on the outer side of the protective barrel and connected with the outer tube, and the protective layer is made of the same material as that of the outer tube. The outer tube adopts soft rubber materials to make usually, and the protective layer adopts the material the same with the outer tube, and the texture is soft, can realize the function of buffering, avoids the direct urethra contact of a protection section of thick bamboo of stereoplasm, is convenient for make again.

In another scheme, the protection cylinder is embedded in the outer pipe, the outer pipe is provided with an opening corresponding to the through hole, and the expansion part is arranged in the outer pipe and at a position corresponding to the protection cylinder. That is, in this aspect, the expansion portion is not formed integrally with the outer tube, but is formed separately from the outer tube, and the film having elastic deformability is expanded by the internal pressure to form the bag-like protrusion.

Preferably, the outer tube and/or the expansion part are made of rubber materials respectively, and the thickness of the expansion part is smaller than that of the outer tube. So that the expansion part has certain elasticity and can be expanded outwards under certain internal pressure to form a saccular bulge.

In more perfect scheme, still include the inner tube, the inner tube set up in the inside of outer tube, the inner tube is used for the catheterization, and the one end of inner tube is provided with the inlet, and the other end is provided with the liquid outlet, keep away from on the outer tube the one end of inflation portion is provided with the valve, the valve is used for maintaining the interior pressure of outer tube.

Preferably, the valve is a water injection soft valve or an inflation valve.

Compared with the prior art, use the utility model provides a pair of prevent that crest angle that decompression formed from harming urethral catheter, moreover, the steam generator is simple in structure, and reasonable in design, in the in-service use, both can make the outside inflation of inflation portion of outer tube and form saccular arch through the pressure boost to the outer tube, so that the card is in urethra department, the realization is fixed to the catheter, avoid the catheter to drop, can be when demolising the catheter again, make the inflation portion after the decompression becomes flat can accomodate in the protection part, avoid the sharp-pointed crest angle that inflation portion formed directly to expose outside the outer tube, thereby can effectively avoid crest angle and urethra direct contact, reach the protection urethra, improve the purpose of patient comfort.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural view (real photograph) of a dual lumen catheter of the prior art prior to use.

Fig. 2 is a schematic view (real photograph) of the catheter provided in fig. 1, when in use, a fluid is injected into the outer tube to form a capsular bulge.

Fig. 3 is a schematic view (real photograph) of the fluid in the outer tube (internal pressure is removed) and the bladder-shaped bulge is collapsed to form an angle.

Fig. 4 is a schematic structural view of a urinary catheter provided in embodiment 1 of the present invention.

Fig. 5 is a partial schematic view of fig. 4.

Fig. 6 is a view (schematic longitudinal sectional view) along a-a direction of fig. 5.

Fig. 7 is a view from the direction B-B of fig. 5 (cross-sectional view).

Fig. 8 is a schematic cross-sectional view of a urinary catheter according to embodiment 1 of the present invention, in which the bulge portion is expanded outward by internal pressure to form a capsular bulge.

Fig. 9 is a cross-sectional view of the catheter provided in fig. 8, wherein the balloon portion collapses upon loss of internal pressure and forms an angle within the interior of the protective sleeve.

Fig. 10 is a schematic cross-sectional view of a urinary catheter provided in example 1 of the present invention, before use.

Fig. 11 is a schematic cross-sectional view of the catheter of fig. 10, wherein the balloon-like protrusion is formed by outward expansion of the expanded portion under internal pressure.

Fig. 12 is a cross-sectional view of the urinary catheter provided in fig. 11, wherein the bulge has collapsed after the internal pressure is lost and has been angled inside the protective sleeve.

Fig. 13 is a longitudinal cross-sectional structural schematic view of another urinary catheter provided in example 1 of the present invention.

Fig. 14 is a schematic longitudinal sectional structure view of a urinary catheter according to embodiment 2 of the present invention.

Fig. 15 is a schematic cross-sectional structure of fig. 14.

Description of the drawings

Outer tube 100, saccular protrusion 101, edge 102, valve 103,

An inner tube 200, a liquid inlet 201, a liquid outlet 202,

An expansion part 300,

Protection part 400, protection cylinder 401, through hole 402, arc transition 403, protective layer 404.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

Referring to fig. 4, 5, 6 and 7, the catheter for preventing the corner from directly contacting the urethra according to the present embodiment includes an outer tube 100 and a protection portion 400 disposed on the outer tube 100, the outer tube 100 is provided with a swelling portion 300, the swelling portion 300 is disposed inside the protection portion 400, and the swelling portion 300 is configured to penetrate through the protection portion 400 and swell outwards under the effect of internal pressure, and is configured to be received in the protection portion 400 after the internal pressure is lost. In the scheme provided by this embodiment, by providing the protection portion 400 at the outer side of the expansion portion 300, when the urinary catheter is inserted in place and needs to be fixed, the expansion portion 300 provided in the outer tube 100 can be expanded outwards under the action of the internal pressure of the outer tube 100 (the internal pressure can be formed by injecting water or inflating air into the outer tube 100) to form the bag-shaped protrusion 101, so as to be clamped at the urethral orifice of a patient, thereby fixing the urinary catheter, and effectively preventing the urinary catheter from falling off automatically, thereby achieving the purpose of preventing the urinary catheter from falling off; when the catheter needs to be pulled out, need first to let out the interior pressure of removing outer tube 100, after outer tube 100 lost interior pressure, inflation portion 300 can become flat and automatic inside of accomodating protection portion 400, make inflation portion 300 lose the inside that the edges and corners 102 that form after the pressure hide protection portion 400, protection portion 400 can reach the purpose of keeping apart inflation portion 300 through sheltering from to inflation portion 300 promptly, thereby avoid edges and corners 102 and urethra direct contact, not only can effectively protect patient's urethra at the in-process of pulling out the pipe, avoid the damage of urethra, and can make the process of pulling out the pipe more smooth and easy, thereby effectively strengthen patient's comfort.

As described in the background of the invention, fig. 1, 2 and 3, in combination with clinical trials, the prior art catheters are pressurized to form the capsular protrusion 101, and after being deflated due to the pressure loss, the outer tube 100 is inevitably formed with the corner 102, as shown in fig. 3, and in order to eliminate the influence of the corner 102, those skilled in the art can easily think of some conventional solutions, which generally cannot completely, completely and effectively solve the problem; for example, one solution is: the thickness of the expanded portion 300 can be reduced so that the formed corner 102 has less rigidity, and although the damage to the urethra can be reduced, the influence of the corner 102 on the urethra cannot be completely eliminated; as another example, another scheme is: the internal pressure value is strictly controlled (namely, the water injection amount or the air inflation amount is strictly controlled), so that the internal pressure is kept in a proper range, the expansion part 300 can form the saccular protrusion 101 under the action of the internal pressure, the over-expansion of the expansion part 300 can be avoided, more serious inelastic deformation occurs, the edge angle 102 formed after the internal pressure is lost is sharper, and the range is larger, but in actual operation, medical workers hardly precisely control the water injection amount and the air inflation amount, so that the formation of the edge angle 102 cannot be completely avoided, and the problems existing in the background art cannot be effectively solved, wherein the description is not given one by one.

In a preferred embodiment, the protection part 400 is smoothly disposed on the outer tube 100, as shown in fig. 4. That is, the protecting part 400 is not only fixed to the outer tube 100, but also there is no corner 102 or any unsmooth place between the protecting part 400 and the outer tube 100, so that the catheter will not cause damage to the urethra and discomfort to the patient during intubation and extubation.

In a preferred embodiment provided by the present embodiment, the protection part 400 includes a protection cylinder 401 having a cylindrical structure, as shown in fig. 4-12, the protection cylinder 401 is made of a hard material, so as to avoid large deformation during use, thereby affecting the shielding effect on the inner expansion part 300; the side wall of the protective cylinder 401 is provided with one or more through holes 402, and the through holes 402 are used for outward expansion of the expansion part 300; because the outer tube 100 is usually a circular tube, when the protection cylinder 401 adopts a cylindrical structure, seamless and smooth connection between the protection part 400 and the outer tube 100 can be realized, and the arrangement of the through hole 402 is beneficial to the outward expansion of the expansion part 300 and the formation of the saccular protrusion 101, so that the purpose of clamping the urethral orifice is achieved. 4-9, the side wall of the protective cylinder 401 may be provided with one through hole 402, two through holes 402, three through holes 402 … …, and the number of the through holes 402 may be determined according to actual situations; in a further aspect, when the number of the through holes 402 is plural, the through holes 402 may be uniformly distributed along the circumferential direction of the protective cylinder 401. After the expansion part 300 expands under the action of the internal pressure of the outer tube 100, the through holes 402 can respectively extend out of the protective tube 401, and a plurality of saccular protrusions 101 are formed in the circumferential direction of the protective tube 401, so that the catheter can be fixed more favorably, and the anti-falling function can be realized more favorably.

In this embodiment, the shape of the through hole 402 is not limited, so that the shape of the through hole 402 may be various, as long as the requirement of outward expansion of the expansion part 300 is satisfied, but in a preferred embodiment, the through hole 402 may be a circular hole, an elliptical hole, or an elongated hole.

As an example, as shown in fig. 4-9, a circular through hole 402 is formed on the side surface of the protection cylinder 401; under the action of the internal pressure, the expansion part 300 can extend out of the protection cylinder 401 through the circular through hole 402 and form a bag-shaped bulge 101 outside the protection cylinder 401, as shown in fig. 8; when the internal pressure of the outer tube 100 is reduced, the saccular protrusion 101 is deflated and automatically retracts into the protection tube 401, and even if the ridge 102 is formed on the expansion part 300, the ridge 102 is inevitably inside the protection tube 401, so that the protection tube 401 can isolate the ridge 102 from the urethra, thereby completely and completely eliminating the influence of the ridge 102 on the urethra and the patient.

As another example, the side surface of the protection cylinder 401 is provided with three circular through holes 402, and the three circular through holes 402 are respectively and uniformly distributed along the circumferential direction of the protection cylinder 401, as shown in fig. 10-12; under the action of the internal pressure, the expansion part 300 can extend out of the protection cylinder 401 through the circular through hole 402, and three saccular protrusions 101 are formed outside the protection cylinder 401, as shown in fig. 12; when the internal pressure of the outer tube 100 is reduced, the saccular protrusion 101 is deflated and automatically retracts into the protection tube 401, and even if the expansion part 300 is provided with the corners 102 (usually three corners 102), the corners 102 are necessarily in the protection tube 401, so that the protection tube 401 can isolate all the corners 102 from the urethra, thereby completely and completely eliminating the influence of the corners 102 on the urethra and the patient.

In a further aspect, the edge of the through hole 402 is provided with an arc transition 403, as shown in fig. 7 or fig. 10; so as to eliminate the edge of the through hole 402, not only can avoid damaging the expansion part 300, but also can avoid the damage of the urethra in the process of inserting/pulling the ureter, and achieve the purpose of further protecting the urethra.

As shown in fig. 6 to 12, in a preferred embodiment, the outer diameter of the protection cylinder 401 is equal to the outer diameter of the outer tube 100. Therefore, the edge angle 102 or any non-smooth place is not arranged between the protective barrel 401 and the outer tube 100, so that the urethral canal can not be damaged and the discomfort of a patient can not be caused in the process of intubation and tube drawing of the catheter.

The expansion part 300 may be preferably made of a rubber material so as to have an elastic deformation capability, and may be elastically deformed to expand by the internal pressure; in a preferred embodiment, the outer tube 100 and/or the expansion part 300 may be made of rubber material, and the thickness of the expansion part 300 is smaller than that of the outer tube 100, as shown in fig. 6-12, which is more convenient for the expansion part 300 to expand outwards under a certain pressure and form the capsular protrusion 101.

In a further scheme provided in this embodiment, a protective layer 404 is disposed outside the protective cylinder 401, as shown in fig. 13, the protective layer 404 is connected to the outer tube 100, and the material of the protective layer 404 is the same as that of the outer tube 100. The outer tube 100 is usually made of soft rubber material, the protective layer 404 can be made of the same material as the outer tube 100, the texture is soft, the buffer function can be realized, the hard protective tube 401 is prevented from directly contacting with the urethra, the manufacturing is convenient, and the cost is low.

As shown in fig. 4 and 5, in a more complete scheme, the urinary catheter further includes an inner tube 200, the inner tube 200 is disposed inside the outer tube 100, the inner tube 200 is used for guiding urine, one end of the inner tube 200 is provided with a liquid inlet 201, the other end is provided with a liquid outlet 202, one end of the outer tube 100, which is far away from the expansion portion 300, is provided with a valve 103 (or called a joint), and the valve 103 is used for maintaining the internal pressure of the outer tube 100. It is understood that the valve 103 can be a water filling soft valve or an inflation valve commonly used in the existing catheter; when the catheter is used, a medical staff can connect the valve 103 by using a syringe and fill water or ventilate the outer tube 100 by using the syringe, so that the internal pressure of the inner tube 200 is increased, the expansion part 300 can expand under the action of the internal pressure to form the saccular protrusion 101, and after the medical staff takes off the syringe, the valve 103 is automatically closed, so that the pressure in the outer tube 100 is kept unchanged, the size of the saccular protrusion 101 is kept unchanged, and the catheter can be stably arranged in a urethra for a long time; when needing to remove this catheter, medical personnel need connect valve 103 from new syringe to utilize the syringe to take out water or the air in outer tube 100, reduce the interior pressure of outer tube 100, thereby make inflation portion 300 can become flat and retract in protection section of thick bamboo 401, thereby be convenient for smooth pulling out this catheter.

Example 2

The main difference between this embodiment 2 and the above embodiment 1 is that in the urinary catheter provided in this embodiment, the protective cylinder 401 is embedded in the outer tube 100, the outer tube 100 is provided with an opening corresponding to the through hole 402, and the expansion part 300 is disposed in the outer tube 100 at a position corresponding to the protective cylinder 401; as shown in fig. 14 and fig. 15, in this embodiment, the expansion part 300 may not be integrally formed with the outer tube 100, but may be a film separately disposed in the outer tube 100 and having elastic deformation capability, under the action of the internal pressure, the expansion part 300 may expand and extend out of the outer tube 100 through the through hole 402 and the opening to form the saccular protrusion 101, which results in the purpose of fixing the urinary catheter and preventing the urinary catheter from automatically falling off, in this process, the hard protection barrel 401 may keep the shape of the outer tube 100 unchanged, and when the outer tube 100 loses pressure, the saccular protrusion 101 may be deflated and automatically retract into the protection barrel 401, and the protection barrel 401 forms the edge 102, at this time, the protection barrel 401 may isolate the expansion part 300 from the urethra, thereby completely and completely eliminating the influence of the edge 102 on the urethra and the patient.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention.

Claims (10)

1. The utility model provides a catheter, its characterized in that, include the outer tube with set up in the protection portion of outer tube, the outer tube is provided with inflation portion, just inflation portion set up in the inside of protection portion, inflation portion are used for passing protection portion and outside inflation under the effect of internal pressure, and are used for accomodating in the protection portion after losing internal pressure.

2. A catheter according to claim 1, wherein said protecting portion is smoothly provided to said outer tube.

3. A catheter according to claim 1, wherein the protective part comprises a protective cylinder of cylindrical configuration, said protective cylinder being made of a hard material, the side wall of the protective cylinder being provided with one or more through holes for outward expansion of the bulge.

4. A catheter according to claim 3 wherein said through holes are circular or elliptical or elongated holes.

5. A catheter according to claim 3, wherein when the number of said through holes is plural, the through holes are uniformly distributed along the circumferential direction of said protective cylinder.

6. A catheter according to claim 3, wherein the edges of the through-holes are provided with an arcuate transition.

7. A catheter according to any of claims 3-6 wherein a protective layer is provided on the outside of the protective sleeve, said protective layer being attached to the outer tube and being of the same material as the outer tube.

8. A catheter according to any of claims 3-6, wherein said protective barrel is embedded in said outer tube, and said outer tube is provided with openings corresponding to said through holes, and said bulge is provided in said outer tube at a position corresponding to said protective barrel.

9. A catheter according to any of claims 1-6 wherein the outer tube and/or the expanded portion are each made of a rubber material and the thickness of the expanded portion is smaller than the thickness of the outer tube.

10. A catheter according to any of claims 1 to 6, further comprising an inner tube arranged inside said outer tube, said inner tube being adapted for urinary catheterisation, said inner tube being provided with a liquid inlet at one end and a liquid outlet at the other end, said outer tube being provided with a valve at the end remote from said expanded portion, said valve being adapted to maintain the internal pressure of the outer tube.

Images