Catheter

Abstract

The purpose of this invention is to provide a urethral catheter which can be easily inserted into a bladder and with which, when the urethral catheter touches the bladder wall, the patient feels less unnatural.　In this catheter 100, a tip part 30 is provided at a tip of a tube part 10. The tip part 30 includes: a tapered part 31 formed to be thinner toward a tip 31a; a base end part 32 attached to the tube part 10; and a curved part 33 being longer than the tapered part 31 and curving between the tapered part 31 and the base end part 32.

Description

catheter

[0001] The present invention relates generally to catheters for urinary management.

[0002] Conventionally, catheters for managing urination in patients with dysuria or spinal cord injuries during and after surgery have been known (see, for example, Patent Document 1). This type of catheter is sometimes inserted into the bladder by the patient themselves, and various ideas have been proposed to improve the difficulty of the insertion process.

[0003] International Publication No. 2005 / 018714

[0004] However, catheters using the above-mentioned conventional techniques can sometimes be difficult to insert into a male patient's bladder. In particular, when inserting a catheter into a male patient, passing it through the bulbar urethra can be difficult. A catheter is inserted straight through the pendulum urethra, then rises steeply toward the bladder through the bulbar urethra. The shape of the bulbar urethra varies from person to person. For example, depending on the curvature of the bulbar urethra, the tip of the catheter may not bend properly along the bulbar urethra and may strike the wall of the bulbar urethra. This insertion procedure can be performed by a medical professional such as a doctor or nurse, or by the patient themselves. In either case, when inserting a catheter into the urethra, it is not possible to visually confirm that the tip of the catheter has reached the bulbar urethra, and the catheter must be inserted by feeling it with one's hands.

[0005] Furthermore, if an attempt is made to forcibly insert a catheter when it has hit the bulbar urethra, the area that hits the urethra may expand into a sac-like shape, forming a false urethra. When a false urethra is formed, with a conventional catheter, the tip of the catheter gets stuck in the depression, making it even more difficult for the catheter to stand up in the bulbar urethra.

[0006] Additionally, commonly used Cheese-tip catheters with angled tips are designed for treating urethral strictures caused by trauma, etc. Cheese-tip catheters are inserted into the urethra, pushing open the narrow, hardened urethra and then into the bladder. For this reason, the tip of a Cheese-tip catheter is made of a relatively rigid material, with a short, thin tip and a conical shape that matches the thickness of the tubing at the base. Cheese-tip catheters are sometimes used in cases of pseudourethra, but their angled tip often gets stuck in the recess of the pseudourethra, preventing the bulbar urethra from rising, making it difficult to reach the bladder. Furthermore, the particularly hard tip of Cheese-tip catheters makes them prone to urethral damage and bleeding problems.

[0007] Furthermore, for the purpose of treating urethral strictures, a procedure is performed in which a metallic urethral bougie and a guide wire are used to insert a balloon catheter into the bladder using the guide wire as a guide, but because the urethral bougie is made of hard metal, there is a risk of damaging the urethra.

[0008] For these reasons, there has been a demand for a catheter whose tip can bend smoothly along the bulbar urethra, making it less likely to create a false urethra, and which can be easily inserted into the bladder even if a false urethra has already formed.

[0009] Furthermore, when a catheter is placed in the bladder, a balloon that keeps the catheter in the bladder is inflated, and the tip with a urination hole is left in place, protruding above the inflated balloon. When urine is expelled from the bladder and the bladder contracts in this state, the protrusion at the catheter tip touches the bladder wall, causing discomfort to the patient, and endoscopic examination has sometimes revealed inflammation. For this reason, a product that does not cause discomfort to patients when the protrusion at the catheter tip touches the bladder wall as the bladder contracts has been desired. Furthermore, when the bladder contracts, the tip hole and side holes for urination formed at the tip may become embedded in the mucous membrane of the bladder wall, potentially reducing urination efficiency or preventing urination.

[0010] The present invention aims to solve the problems associated with the above-mentioned conventional techniques and to provide a urethral catheter that can be easily inserted into the bladder and that is unlikely to cause discomfort to the patient even when it comes into contact with the bladder wall.

[0011] The present invention is characterized in that a catheter has a tip portion provided at the tip of a tube portion, and the tip portion has a tapered portion that becomes thinner as it approaches the tip, a base end portion attached to the tube portion, and a curved portion that is longer than the tapered portion and curves between the tapered portion and the base end.

[0012] In this case, the tip portion may be elastic. The curved portion may have a flat cross section that becomes thinner in the curved direction. The curved portion may have a recess formed on its inner circumferential side. The curved portion may have a recess formed on its outer circumferential side. The recess may have a U-shape that widens toward the edge. The recess may have a notch that widens into a circular shape at a position away from the edge. The curved portion may have a plurality of recesses formed on its inner circumferential side and its outer circumferential side. The recess closest to the tapered portion may be formed on the inner circumferential side. The curved portion may have a multilayer structure in which a surface portion is laminated around a core portion. The surface portion may be formed of a material softer than the core portion. The base end may have a first side hole formed in fluid communication with the tubular portion. The curved portion may have a second side hole formed in fluid communication with the tubular portion. The curved portion may have a first end portion on the base end side and a second end portion on the tapered portion side, with substantially the same cross-sectional area.

[0013] The present invention can provide a urethral catheter that can be easily inserted into the bladder and that is unlikely to cause discomfort to the patient even when it comes into contact with the bladder wall.

[0014] Schematic diagram of a balloon catheter according to this embodiment placed in the bladder. FIG. 2(a) shows a side view of the tip portion, and FIG. 2(b) shows a front view of the tip portion. Schematic diagram of a balloon catheter passing through a pseudo-urethra. Schematic diagram of the tip portion hitting the bladder wall. FIG. 5(a) shows a side view of a tip portion according to a second embodiment, and FIG. 5(b) shows a front view of the tip portion according to the second embodiment. FIG. 6(a) shows a side view of a tip portion according to a third embodiment, and FIG. 6(b) shows a front view of the tip portion according to the third embodiment. FIG. 7(a) shows a side view of a tip portion according to a fourth embodiment, and FIG. 7(b) shows a front view of the tip portion according to the fourth embodiment. FIG. 8(a) shows a side view of a tip portion according to a fifth embodiment, and FIG. 8(b) shows a front view of the tip portion according to the fifth embodiment. A side view of a tip portion according to a sixth embodiment is shown.

[0015]

[0023] Preferred embodiments of the present invention will now be described with reference to the drawings. (First Embodiment) Fig. 1 shows a schematic diagram of a balloon catheter placed in the bladder, Fig. 2(a) shows a side view of the tip portion, and Fig. 2(b) shows a front view of the tip portion.

[0016] As shown in FIG. 1 , the balloon catheter 100 has a tube portion 10 , a balloon portion 20 , and a tip portion 30 .

[0017] The tube portion 10, the balloon portion 20, and the tip portion 30 are formed of silicone rubber, but may also be formed of latex, natural rubber, isoprene rubber, thermoplastic resin such as PVC and urethane rubber, fluororubber and fluororesin, etc.

[0018] The tubular portion 10 penetrates the balloon portion 20, and the balloon portion 20 is attached to the outer periphery near the tip by adhesive. That is, the balloon portion 20 is formed so as to surround the entire circumference of the tubular portion 10. Furthermore, a tip portion 30 is attached to the tip of the tubular portion 10 by adhesive. The tubular portion 10 has a urination lumen (not shown) for draining urine formed along the extension direction of the tubular portion 10. The urination lumen is fluidly connected to the outside via a first side hole (opening) 34 (see FIG. 2 ) formed in the tip portion 30, and urine flowing in from the first side hole 34 passes through the urination lumen and flows to a branch portion (not shown) provided on the proximal end of the balloon catheter 100.

[0019] The tubular portion 10 has a balloon lumen (not shown) formed along the extension direction of the tubular portion 10 for inflating the balloon portion 20. The balloon lumen is fluidly connected to the interior of the balloon portion 20 near the distal end, and the balloon portion 20 is inflated by filling it with sterilized water supplied from a branch portion on the proximal end side. As a result, the balloon catheter 100 is placed in the patient's bladder A, as shown in FIG. 1, by the inflated balloon portion 20 becoming caught and not coming out.

[0020] The tip portion 30 is made of an elastic material and is provided at the tip of the tube portion 10. As shown in Figure 2, the tip portion 30 has a tapered portion 31 that is tapered toward the tip, a base end portion 32 that is attached to the tube portion 10 (see Figure 1), and a curved portion 33 that is longer than the tapered portion 31 and curves between the tapered portion 31 and the base end portion 32. The tapered portion 31, base end portion 32, and curved portion 33 are formed integrally as a solid body.

[0021] The tapered portion 31 is formed so that the cross section perpendicular to the axis O does not expand from the tip end 33a of the curved portion 33, and the cross section perpendicular to the axis O becomes smaller the closer to the tip. The outer peripheral surface of this tapered portion 31 is formed flush with the outer peripheral surface of the tip end 33a of the curved portion 33. As a result, the tip portion 30 is formed with a continuous smooth surface from the curved portion 33 to the tapered portion 31.

[0022] The base end 32 is formed in a cylindrical shape, and the base end side is bonded to the tubular portion 10. The base end 32 has first side holes 34, 34 formed at both ends in a width direction C that is perpendicular to a bending direction B in which the bending portion 33 bends. The first side holes 34 are formed in an oval shape, and are fluidly connected to the urination lumen of the tubular portion 10.

[0023] The outer peripheral surface of the base end 32 is formed flush with the outer peripheral surface of the base end 33b of the curved portion 33. As a result, the tip portion 30 is formed with a continuous smooth surface from the base end 32 to the curved portion 33. In other words, the tip portion 30 is formed with a continuous smooth surface from the base end 32a of the base end 32 to the tip 31a of the tapered portion 31.

[0024] The curved portion 33 is formed longer along the axis O than the tapered portion 31, and therefore has a larger radius of curvature and is curved more gently. The curved portion 33 is formed so that the areas of the cross sections perpendicular to the axis O at the base end 33b and the tip end 33a are substantially the same. The curved portion 33 has a circular cross section perpendicular to the axis O, and the circular cross section has a substantially constant cross-sectional area and extends from the base end 33b to the tip end 33a.

[0025] The tip portion 30 is made of an elastic material, and when the balloon catheter 100 is inserted into the bladder A through the urethra, the curved portion 33 bends to a straight state according to the shape of the urethra, or returns to a curved state due to elastic force.

[0026] More specifically, when the tip portion 30 passes through the straight pendulum urethra, the curved portion 33 bends and becomes straight along the urethra.

[0027] After passing through the pendulum urethra, the tip portion 30 passes through the curved bulb urethra D while the curved portion 33 returns to its original curved state due to elastic force.

[0028] After passing through the bulbar urethra D, the curved portion 33 of the tip portion 30 bends and straightens again along the urethra, and the tip portion 30 advances up the urethra in a steep upward motion, and when it reaches the bladder A and no longer contacts the urethra, the curved portion 33 returns to its original curved state due to its elasticity. At this time, when urine is discharged from the bladder A and the bladder A shrinks, the bladder wall may contact the tip portion 30, but the curved portion 33 of the tip portion 30 bends further from its original curved state, providing flexibility so that it does not push back strongly against the bladder wall.

[0029] Figure 3 shows a schematic diagram of a balloon catheter passing through a false urethra. As shown in Figure 3, the balloon catheter 100 has an appropriately curved tip 30, which makes it less likely to get caught on the false urethra E when inserted into the bladder A of a male patient who has a false urethra E in the bulbar urethra D. This allows the balloon catheter 100 to bend smoothly along the bulbar urethra D while being inserted, avoiding the false urethra E.

[0030] Figure 4 shows a schematic diagram of the tip portion contacting the bladder wall. The balloon catheter 100 is placed in the bladder A with the balloon portion 20 inflated, with the tip portion 30 protruding from the balloon portion 20, as shown in Figure 4. When urine is discharged from the bladder A and the bladder A contracts, the tapered portion 31 of the tip portion 30 and the outer peripheral edge 33c of the curved portion 33 of the balloon catheter 100 gently contact the bladder wall over a wide area.

[0031] The balloon catheter 100 according to this embodiment has a tip section 30 at the distal end of the tubular section 10. The tip section 30 has a tapered portion 31 that tapers toward the distal end 31a, a base end 32 that is attached to the tubular section 10, and a curved portion 33 that is longer than the tapered portion 31 and curves between the tapered portion 31 and the base end 32. This allows the tip section 30 to be curved gently with a large radius of curvature. This allows the balloon catheter 100 to be easily inserted into the bladder A, and also reduces the patient's discomfort when the balloon catheter 100 comes into contact with the bladder wall.

[0032] Second Embodiment FIG. 5(a) shows a side view of a tip portion according to a second embodiment, and FIG. 5(b) shows a front view of the tip portion according to the second embodiment.

[0033] In the following description, the same reference numerals will be used to designate components that are substantially the same as those in the first embodiment. As shown in Fig. 5(a), the tip portion 40 according to the second embodiment has a curved portion 41 that is different from the curved portion 33 (see Fig. 2) according to the first embodiment.

[0034] The curved portion 41 has a flat cross section that becomes thinner in the curved direction. The cross sections of the curved portion 41 perpendicular to the axis O at the base end 33b and the tip end 33a are formed to have circular shapes with approximately the same area. On the other hand, the curved portion 41 is formed so that the cross section becomes flatter, i.e., changes to an elliptical cross section, as it approaches the midpoint between the base end 33b and the tip end 33a. Here, as shown in FIG. 5(b), the width of the curved portion 41 in the width direction C is approximately constant from the base end 33b to the tip end 33a.

[0035] Third Embodiment FIG. 6(a) shows a side view of a tip portion according to a third embodiment, and FIG. 6(b) shows a rear view of the tip portion according to the third embodiment.

[0036] In the following description, the same reference numerals will be used to designate components that are substantially the same as those in the first embodiment. As shown in Fig. 6(a), the tip portion 50 according to the third embodiment has a curved portion 51 and a base end portion 52 that are different from the base end portion 32 (see Fig. 2) and the curved portion 33 (see Fig. 2) according to the first embodiment.

[0037] The curved portion 51 has a second side hole 53 formed on its outer peripheral edge near the midpoint between the proximal end 33b and the distal end 33a. This second side hole 53 passes through the curved portion 51 and the proximal end 52 and is fluidly connected to the urination lumen of the tubular portion 10 (see FIG. 1). The second side hole 53 passes through the proximal end 52 along the axis O and is also fluidly connected to the pair of first side holes 34, 34 that pass through the proximal end 52 in the width direction C.

[0038] Fourth Embodiment FIG. 7(a) shows a side view of a tip portion according to a fourth embodiment, and FIG. 7(b) shows a front view of the tip portion according to the fourth embodiment.

[0039] In the following description, the same reference numerals will be used to designate components that are substantially the same as those in the first embodiment. As shown in Fig. 7(a) , the tip portion 60 according to the fourth embodiment has a curved portion 61 that is different from the curved portion 33 (see Fig. 2) according to the first embodiment.

[0040] The curved portion 61 has four recesses 62 arranged in a row on the inner peripheral edge 61a. Each recess 62 has a U-shape that widens toward the inner peripheral edge 61a, and is designed to hold a lubricant such as jelly to make it easier to insert into the urethra.

[0041] Fifth Embodiment FIG. 8(a) shows a side view of a tip portion according to a fifth embodiment, and FIG. 8(b) shows a side view of a tip portion according to a modification of the fifth embodiment.

[0042] In the following description, the same reference numerals will be used to designate components that are substantially the same as those in the first embodiment. As shown in Fig. 8(a) , the tip portion 70 according to the fifth embodiment has a curved portion 71 that is different from the curved portion 33 (see Fig. 2) according to the first embodiment.

[0043] The curved portion 71 has three recesses 73 arranged in a row on the inner peripheral edge 71a. Each recess 73 has a notch 74 cut from the inner peripheral edge 71a, which expands into a circular shape at a position away from the edge and communicates with a circular portion 75. Each recess 73 is designed to hold a lubricant such as jelly to make it easier to insert into the urethra.

[0044] 8(b), the recesses 73 may be formed on both sides of the inner peripheral edge 71a and the outer peripheral edge 71b, and in this figure, the recesses 73 are formed alternately on both sides of the inner peripheral edge 71a and the outer peripheral edge 71b. The recesses 73 closest to the tapered portion 31 are formed on the inner peripheral edge 71a, which makes it difficult for the recesses 73 to come into contact with the bladder wall when the prosthesis is placed in bladder A, thereby increasing the surface area that comes into contact with the bladder wall.

[0045] Sixth Embodiment FIG. 9 shows a side view of a tip portion according to a sixth embodiment.

[0046] In the following description, the same reference numerals will be used to designate components that are substantially the same as those in the first embodiment. As shown in Fig. 9, the tip portion 80 according to the sixth embodiment has a multilayer structure in which a surface portion 82 is layered around a core portion 81. The surface portion 82 is formed of a softer material than the core portion 81. As a result, when the tip portion 80 comes into contact with the bladder wall, the soft surface portion 82 makes contact with the bladder wall, making it less likely that the user will feel discomfort when touching the bladder wall.

[0047] Although the present invention has been described above based on the embodiments, the present invention is not limited thereto. For example, in the above embodiment, the first side hole 34 is formed in the base end portion 32, but the present invention is not limited thereto. As long as urine in the bladder A can flow into the urination lumen, a side hole may be formed in the tubular portion 10 without forming the first side hole 34 in the base end portion 32.

[0048] In the above embodiment, the recesses 62 and 73 are formed mainly on the inner periphery side, but this is not limiting. The recesses may be formed on the outer periphery side as long as it makes it easier for the tip portion to bend.

[0049] Furthermore, in the third embodiment, the second side hole 53 is formed at a position where it passes straight through the curved portion 51 from the base end portion 52, but this is not limiting. The second side hole may be formed at another position, such as the side of the curved portion 51, as long as it is fluidly connected to the urination lumen of the tubular portion 10.

[0050] DESCRIPTION OF SYMBOLS 10...Tube portion 20...Balloon portion 30...Tip portion 31...Tapered portion 31a...Tip 32...Base end portion 32a...Base end portion 33...Curved portion 33a...Tip end portion 33b...Base end portion 33c...Outer peripheral edge portion 34...First side hole 40...Tip portion 41...Curved portion 50...Tip portion 51...Curved portion 52...Base end portion 53...Second side hole 60...Tip portion 61...Curved portion 61a...Inner peripheral edge portion 62...Recessed portion 70...Tip portion 71...Curved portion 71a...Inner peripheral edge portion 71b...Outer peripheral edge portion 73...Recessed portion 74...Notched portion 75...Circular portion 80...Tip portion 81...Core portion 82...Surface portion 100...Balloon catheter A...Bladder B...Curving direction C...Width direction D...Bulbar urethra E...False urethra O...Axis

Claims

1. A catheter comprising a tip section provided at the distal end of a tube section, the tip section having a tapered section that becomes thinner as it approaches the distal end, a base end attached to the tube section, and a curved section that is longer than the tapered section and curves between the tapered section and the base end.

2. A catheter according to claim 1, characterized in that the tip portion is made of an elastic material.

3. A catheter according to claim 1, wherein the curved portion has a flat cross section that is thinner in the direction of curvature.

4. A catheter according to claim 1, characterized in that the curved portion has a recess formed on the inner circumferential side.

5. A catheter according to claim 1, characterized in that the curved portion has a recess formed on the outer periphery.

6. A catheter according to claim 4 or 5, characterized in that the recess has a U-shape that widens towards the edge.

7. A catheter according to claim 4 or 5, characterized in that the recess is formed with a notch having a shape that widens into a circular shape at a position away from the edge.

8. A catheter according to claim 1, characterized in that the curved portion has a plurality of recesses formed on the inner and outer circumferential sides.

9. A catheter according to claim 8, characterized in that the recess closest to the tapered portion is formed on the inner circumferential side.

10. A catheter according to claim 1, characterized in that it has a multi-layer structure in which a surface portion is laminated around a core portion.

11. A catheter according to claim 10, wherein the surface portion is formed of a material softer than the core portion.

12. A catheter according to claim 1, wherein the base end is formed with a first side hole that is in fluid communication with the tube portion.

13. A catheter according to claim 1, wherein the curved portion is formed with a second side hole that is in fluid communication with the tubular portion.

14. A catheter according to claim 1, wherein the cross-sectional area of the curved portion is substantially the same at the first end on the base end side and the second end on the tapered portion side.

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