Disposable ureteral stent

Abstract

The utility model relates to the technical field of medical instruments, in particular to a disposable ureter support which comprises a connecting pipe section, a pelvis pipe section and a bladder pipe section, one end of the connecting pipe section is connected with the pelvis pipe section, the other end of the connecting pipe section is connected with the bladder pipe section, and flow guide holes are formed in the head ends and the tail ends of the pelvis pipe section, the bladder pipe section and the connecting pipe section. The end, close to the bladder tube section, of the connecting tube section protrudes inwards to form a flow limiting channel gradually contracting in the direction from the pelvis tube section to the bladder tube section, valves distributed in the circumferential direction of the inner wall of the connecting tube section are installed at the position of an input end port of the flow limiting channel, and the fluid resistance gradient of the flow limiting channel is in dynamic sealing fit with the elastic valves. And the flow limiting channel can maintain a low-pressure area, the difficulty of reversely entering the flow limiting channel is increased through liquid tension, reverse flow pressure is prevented from being conducted to the renal pelvis, reverse flow resistance is prevented from being increased, and the reverse flow speed is reduced.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a disposable ureteral stent. Background Technology

[0002] Ureteral stents (double pigtail catheters, or DJ stents) are widely used in urological surgeries. They are suitable for upper urinary tract surgeries such as those for kidney stones, ureteral stones, hydronephrosis, kidney transplantation, and benign tumors of the kidney and ureter, as well as for treatments such as lithotripsy and dilation of ureteral strictures. After implantation in the ureter, they play a crucial role in draining urine and preventing ureteral stricture and adhesions. Clinically used DJ stents are mostly made of silicone rubber or polyurethane polymer materials.

[0003] Existing ureteral stents generally use one-way valves or narrowing sections to achieve the anti-reflux function, but in practical applications, they have the following technical defects: traditional one-way valves have poor sealing performance under low pressure, and are prone to reflux due to viscous urine or sediment residue; although narrowing sections can limit reflux, they significantly reduce the forward urine flow rate and increase renal pelvis pressure; the anti-reflux structure has low integration with the stent section, and is prone to displacement or deformation after long-term use. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to overcome the problems of poor sealing performance of traditional one-way valves under low pressure, which easily leads to backflow due to viscous urine or sediment residue; and although the narrow section can limit backflow, it significantly reduces the forward urine flow rate and increases renal pelvis pressure, a disposable ureteral stent is provided.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a disposable ureteral stent, including a connecting tube segment, a renal pelvis segment and a bladder segment, one end of the connecting tube segment is connected to the renal pelvis segment and the other end is connected to the bladder segment, and the renal pelvis segment, the bladder segment and the connecting tube segment all have drainage holes at their beginning and end;

[0006] The end of the connecting tube near the bladder segment protrudes inward to form a flow-limiting channel that gradually narrows from the renal pelvis segment toward the bladder segment. A valve distributed circumferentially along the inner wall of the connecting tube segment is installed at the inlet port of the flow-limiting channel. Through the fluid resistance gradient of the flow-limiting channel and the dynamic sealing of the elastic valve, the backflow inhibition efficiency is significantly improved. The flow-limiting channel can maintain a low-pressure area and use fluid tension to increase the difficulty of backflow into the flow-limiting channel, preventing backflow pressure from being transmitted to the renal pelvis and increasing backflow resistance, thereby reducing the backflow velocity.

[0007] To address the issue of insufficient backflow prevention efficiency of a single systolic segment, the system further includes a flow-limiting channel comprising a first-order systolic segment, a first-order straight segment, a second-order systolic segment, and a second-order straight segment connected sequentially. The first-order systolic segment is positioned close to the valve, and the valve is positioned between the renal pelvis segment and the first-order systolic segment.

[0008] To address the issue of valve reversal leading to seal failure, the valve is further designed to be elastic and deflected toward the bladder segment.

[0009] To address the issue of insufficient sealing performance of single-layer valves, the valve further includes at least two layers of staggered crescent-shaped valves, or 2-4 layers of valves, with the opening and closing directions of adjacent valve layers staggered at 30°-180°.

[0010] To address the issue of urate crystals adhering to the valve surface, a further step is to coat the valve surface with a nano-hydrophobic coating.

[0011] To address the issue of drainage interruption caused by blockage of the main channel, the system further includes a drainage channel formed by a recess on the connecting tube segment, extending axially along the connecting tube segment. The first end of the drainage channel is located at the renal pelvis segment, and the tail end of the drainage channel is distributed at intervals with the bladder segment.

[0012] To address the issue of turbulence at the tail end of the guide channel interfering with bladder function, a further step is to increase the distance between the tail end of the guide channel and the bladder segment to 10-30 mm.

[0013] The beneficial effects of this utility model are: the disposable ureteral stent provided by this utility model significantly improves the backflow inhibition efficiency through the fluid resistance gradient of the flow-limiting channel and the dynamic sealing of the elastic valve. The flow-limiting channel can maintain a low-pressure area and increase the difficulty of backflow into the flow-limiting channel by using liquid tension, preventing backflow pressure from being transmitted to the renal pelvis and increasing backflow resistance, thereby reducing the backflow velocity. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the rear view structure of this utility model;

[0017] Figure 3 This is a cross-sectional view of the connecting pipe section of this utility model at the guide groove.

[0018] Figure 4 This is a cross-sectional view of the connecting pipe section of this utility model at the flow restriction channel.

[0019] In the diagram: 1. Connecting tube segment, 11. Flow restriction channel, 111. Primary systolic segment, 112. Primary straight segment, 113. Secondary systolic segment, 114. Secondary straight segment, 12. Valve, 13. Drainage groove, 2. Renal pelvis segment, 3. Bladder segment, 4. Drainage hole. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0021] like Figure 1 This is a schematic diagram of the structure of the present invention. A disposable ureteral stent includes a connecting tube segment 1, a renal pelvis segment 2, and a bladder segment 3. One end of the connecting tube segment 1 is connected to the renal pelvis segment 2, and the other end is connected to the bladder segment 3. The renal pelvis segment 2, the bladder segment 3, and the connecting tube segment 1 all have drainage holes 4 at their beginning and end.

[0022] like Figure 1 , 4 As shown, the end of the connecting tube segment 1 near the bladder segment 3 protrudes to form a flow-limiting channel 11 that gradually narrows from the renal pelvis segment 2 toward the bladder segment 3. A valve 12 is installed at the input port of the flow-limiting channel 11 and is distributed circumferentially along the inner wall of the connecting tube segment 1. Through the fluid resistance gradient of the flow-limiting channel 11 and the dynamic sealing cooperation of the elastic valve 12, the backflow inhibition efficiency is significantly improved. The flow-limiting channel 11 can maintain a low-pressure area and use the fluid tension to increase the difficulty of backflow into the flow-limiting channel 11, preventing backflow pressure from being transmitted to the renal pelvis and increasing backflow resistance, thereby reducing the backflow velocity.

[0023] like Figure 4 As shown, the flow-limiting channel 11 includes a first-stage systolic segment 111, a first-stage straight segment 112, a second-stage systolic segment 113, and a second-stage straight segment 114 connected in sequence. The first-stage systolic segment 111 is located close to the valve 12, and the valve 12 is located between the renal pelvis segment 2 and the first-stage systolic segment 111. The first-stage and second-stage systolic segments 111 and 113 increase the backflow resistance in stages to avoid the negative impact of a single narrow segment on the forward flow.

[0024] First-stage contraction segment 111: Initially increases the resistance to backflow and reduces the backflow velocity; First-stage straight segment 112: Stabilizes the fluid state and avoids turbulence interfering with the forward flow; Second-stage contraction segment 113: Further compresses the cross-sectional area of ​​the backflow, forming a superposition effect with the resistance of the preceding segment; Second-stage straight segment 114: Maintains the low-pressure zone and prevents the backflow pressure from being transmitted to the renal pelvis.

[0025] In the embodiment, the contraction angle of the primary and secondary contraction sections 111 and 113 is designed to be 15°-30°.

[0026] In forward flow, in an incompressible fluid, the fluid pressure decreases as the flow velocity increases, and the cross-sectional area of ​​the flow-limiting channel 11 gradually decreases. During forward flow, the urine flow velocity increases and the pressure decreases, forming a low-pressure zone that promotes the flow of urine towards the bladder. During reverse flow, the urine needs to flow backward from the wide cross-section (bladder side) to the narrow cross-section (renal pelvis side), forcing the flow velocity to decrease and the pressure to increase, thus forming reverse resistance.

[0027] like Figure 4 As shown, valve 12 is elastic and deflects towards the bladder segment 3. The elastic deflection design increases the reverse resistance and ensures the stability of unidirectional opening and closing of valve 12.

[0028] The valve 12 comprises at least two layers of staggered crescent-shaped valves 12, and the valve 12 comprises 2-4 layers of valves 12. The opening and closing directions of adjacent layers of valves 12 are staggered at 30°-180°. The multi-layered staggered valves 12 form multiple sealing interfaces, which improves the anti-backflow effect under low pressure conditions.

[0029] The surface of valve 12 is covered with a nano-hydrophobic coating, which reduces deposit adhesion and extends valve life. The nano-hydrophobic coating contains fluorinated silica nanoparticles and has a thickness of 50-200 nm.

[0030] like Figure 2 , 3 As shown, a guide channel 13 extending axially along the connecting pipe section 1 is formed in the recess on the connecting pipe section 1. The first end of the guide channel 13 is located at the renal pelvis section 2, and the tail end of the guide channel 13 is distributed at intervals with the bladder section 3. The guide channel 13 provides a backup drainage path to ensure the reliability of the forward flow.

[0031] The distance between the end of the drainage channel 13 and the bladder segment 3 is 10-30mm. The spacing design avoids urine directly impacting the bladder wall and reduces irritation.

[0032] Forward flow: Urine enters the connecting tube segment 1 from the renal pelvis segment 2 through the drainage hole 4, pushing the elastic valve 12 to open towards the bladder segment 3, and passes through the primary contraction segment 111 and the secondary contraction segment 113 in sequence. The gradually narrowing structure of the flow-limiting channel 11 accelerates the flow of urine, while the drainage 1 provides an auxiliary drainage path.

[0033] Reverse blockage: When bladder pressure increases, reverse urine pushes valve 12 to close towards the renal pelvis. The multi-layered interlaced valve 12 forms multiple sealing interfaces. The contraction section of the flow-limiting channel 11 generates eddy current resistance. Combined with the tail end spacing design of the flow guide groove 13, it disrupts the continuity of the reverse flow fluid.

[0034] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A disposable ureteral stent, characterized in that, It includes a connecting tube segment (1), a renal pelvis segment (2) and a bladder segment (3). One end of the connecting tube segment (1) is connected to the renal pelvis segment (2) and the other end is connected to the bladder segment (3). The renal pelvis segment (2), the bladder segment (3) and the connecting tube segment (1) all have drainage holes (4) at their beginning and end. The connecting tube segment (1) protrudes inward at one end near the bladder tube segment (3) to form a flow-limiting channel (11) that gradually narrows from the renal pelvis tube segment (2) toward the bladder tube segment (3). A valve (12) is installed at the input port of the flow-limiting channel (11) and is distributed circumferentially along the inner wall of the connecting tube segment (1).

2. The disposable ureteral stent as described in claim 1, characterized in that: The flow-limiting channel (11) includes a first-level contraction segment (111), a first-level straight segment (112), a second-level contraction segment (113), and a second-level straight segment (114) connected in sequence. The first-level contraction segment (111) is arranged close to the valve (12), and the valve (12) is arranged between the renal pelvis segment (2) and the first-level contraction segment (111).

3. The disposable ureteral stent as described in claim 1, characterized in that: The valve (12) is elastic and the valve (12) is deflected toward the bladder segment (3).

4. The disposable ureteral stent as described in claim 1, characterized in that: The valve (12) comprises at least two layers of staggered crescent-shaped valves (12), and the valve (12) comprises 2-4 layers of valves (12), with the opening and closing directions of adjacent layers of valves (12) staggered at 30°-180°.

5. The disposable ureteral stent as described in claim 1, characterized in that: The surface of the valve (12) is covered with a nano-hydrophobic coating.

6. The disposable ureteral stent as described in claim 1, characterized in that: The connecting pipe segment (1) has a recessed drainage groove (13) extending axially along the connecting pipe segment (1). The first end of the drainage groove (13) is located at the renal pelvis segment (2), and the tail end of the drainage groove (13) is distributed at intervals with the bladder segment (3).

7. The disposable ureteral stent as described in claim 6, characterized in that: The distance between the tail end of the guide channel (13) and the bladder tube segment (3) is 10-30mm.

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