Negative pressure suction double-sheath structure for percutaneous nephrolithotomy

Abstract

The application provides a double-sheath structure for percutaneous nephrolithotomy and negative pressure suction, and relates to the field of medical devices, which comprises an inner sheath pipe, a rear end of which is provided with an inner sheath end cover, and a side wall of the rear end is provided with a suction branch pipe; an outer sheath pipe, which is sleeved on the inner sheath pipe and leaves a perfusion gap between the inner sheath pipe and the outer sheath pipe, and a side wall of the outer sheath pipe is provided with a perfusion branch pipe which is in communication with the perfusion gap; and a fixing mechanism which is arranged at a part of the inner sheath pipe protruding from the outer sheath pipe and comprises a limiting component for limiting or allowing the front end of the inner sheath pipe to protrude from the front end of the outer sheath pipe and a clamping component for limiting the movement of the inner sheath pipe towards the rear end. The application has the effect of ensuring high continuity and high efficiency of the double-sheath structure for stone removal.

Description

Technical Field

[0001] This application relates to the field of medical devices, and more particularly to a negative pressure suction double sheath structure for percutaneous nephrolithotomy. Background Technology

[0002] Percutaneous nephrolithotomy (PCNL) is one of the important methods for treating kidney stones, especially suitable for cases of large or complex kidney stones. This technique creates a percutaneous renal access and uses a (micro)nephroscope and lithotripsy equipment to directly target the stones, offering advantages such as high stone fragmentation efficiency and good stone clearance rate.

[0003] Currently, a dual-sheath stone removal system is commonly used in clinical practice. This system consists of a composite sheath structure with an outer sheath and an inner sheath. The outer sheath maintains the stability of the percutaneous renal access and protects surrounding tissues, while the inner sheath connects to a negative pressure suction device for stone fragmentation and removal. An annular perfusion gap exists between the outer and inner sheaths, allowing perfusion fluid (such as saline) to continuously flow into the surgical area, maintaining a clear surgical field. Under negative pressure suction, the inner sheath aspirates the perfusion fluid along with the stone fragments, forming a "perfusion-suction" cycle. This improves stone removal efficiency while simultaneously reducing intrarenal pressure and minimizing the risk of infection.

[0004] However, when clearing the narrow renal calyx and residual stones in the upper ureter before the end of the operation, the overall outer diameter of this double-sheath structure is relatively large, making it difficult for both sheaths to enter at the same time. This forces the surgeon to withdraw the double-sheath system and replace it with a thinner single-sheath instrument to improve the stone clearance rate. This not only increases the number of surgical steps and reduces the continuity and efficiency of stone removal, but also increases the risk of kidney damage and bleeding. Utility Model Content

[0005] In order to improve the continuity of stone removal, increase efficiency and stone clearance rate, and enhance safety of the double-sheath structure, this application provides a negative pressure suction double-sheath structure for percutaneous nephrolithotomy.

[0006] The negative pressure suction double sheath structure for percutaneous nephrolithotomy provided in this application adopts the following technical solution: A negative pressure suction double sheath structure for percutaneous nephrolithotomy includes: The inner sheath tube has an inner sheath end cap at the rear end and a suction branch tube on the side wall at the rear end. An outer sheath is fitted onto the inner sheath with an infusion gap between them, and an infusion branch pipe communicating with the infusion gap is provided on the side wall. A fixing mechanism is provided at the portion of the inner sheath protruding from the outer sheath, including a limiting component for restricting or allowing the front end of the inner sheath to protrude from the front end of the outer sheath, and a clamping component for restricting the movement of the inner sheath toward the rear end.

[0007] Furthermore, the limiting component includes an outer sheath end cap and a limiting member. The outer sheath end cap is used to seal the infusion gap. The outer sheath end cap includes a cap body and a cap top. The cap body wraps around the periphery of the outer sheath tube, and the inner side of the cap top fits against the end face of the outer sheath tube. An avoidance hole is provided on the cap top for the inner sheath tube to pass through. The limiting member is provided on the inner sheath tube and is used to restrict or allow the front end of the inner sheath tube to protrude beyond the front end of the outer sheath tube.

[0008] Furthermore, the limiting member is configured as an isolation tube, which is disposed on the inner sheath tube. When the front end of the inner sheath tube is flush with the front end of the outer sheath tube, the isolation tube abuts against the outer side of the cover.

[0009] Furthermore, the isolation tube is detachably connected to the inner sheath tube using a clamp. The inner sheath tube has a first annular groove and a second annular groove on its side wall. The second annular groove is located on the side of the first annular groove near the inner sheath end cap. The inner side of the isolation tube has a limiting protrusion. When the limiting protrusion engages with the first annular groove and the front end of the inner sheath tube is flush with the front end of the outer sheath tube, the isolation tube abuts against the outer side of the cap.

[0010] Furthermore, the front end of the inner sheath is either fish-mouth shaped or wavy.

[0011] Furthermore, the clamping assembly includes a fixing ring and two clamping wings symmetrically disposed on the periphery of the fixing ring; The fixing ring is fixedly sleeved on the inner sheath and located on the side of the isolation tube near the rear end of the inner sheath; The clamping wing includes a connecting part, an operating part, and a clamping part. The connecting part is fixedly connected to the fixing ring. The operating part is located on the side of the connecting part away from the fixing ring. The clamping part is located on the side of the operating part away from the rear end of the inner sheath tube. The clamping part is provided with a hook on the side of the clamping part close to the inner sheath tube. The outer sheath is provided with a limiting ring. When the front end of the inner sheath is flush with the front end of the outer sheath, the hook part abuts against the side of the limiting ring away from the rear end of the inner sheath.

[0012] Furthermore, the outer sheath is equipped with a pressure relief device, which includes a pressure relief branch pipe and a pressure relief valve. The pressure relief branch pipe is connected to the injection gap, and the pressure relief valve is connected to the pressure relief branch pipe.

[0013] Furthermore, the outer sheath is equipped with a pressure monitoring device, which includes a pressure measuring branch and a pressure sensor. The pressure measuring branch is connected to the injection gap, and the pressure sensor is located on the pressure measuring branch.

[0014] Furthermore, the pressure sensor is configured as a liquid pressure sensor or an optical fiber pressure sensor.

[0015] In summary, this application includes at least one of the following beneficial technical effects: 1. By setting a limiting component, when retrieving stones in a spacious environment, the limiting component limits the inner sheath, preventing it from protruding beyond the outer sheath. The outer and inner sheaths establish a dual-channel perfusion and drainage system, improving stone retrieval efficiency. When it is necessary to retrieve stones through narrow spaces such as the calyx neck of the renal calyx or the upper ureter, the limiting component allows the inner sheath to protrude beyond the outer sheath, enabling the inner sheath to pass through the narrow calyx neck or the upper ureter independently. This allows switching to a single-sheath negative pressure mode, thus achieving a stone retrieval sheath structure that can freely switch between single and double sheaths to adapt to different stone retrieval environments, improve the stone clearance rate, avoid intraoperative instrument changes, and enhance the convenience and overall efficiency of the surgical procedure. 2. By installing a pressure relief branch and a pressure relief valve on the outer sheath, when the inner sheath is blocked by gravel and loses its negative pressure suction effect, the perfusion fluid cannot be discharged in time, causing the renal pelvis pressure to rise sharply. The pressure relief valve can automatically open to relieve pressure when the pressure reaches the threshold, effectively avoiding excessive intrarenal pressure, reducing the occurrence of infectious complications, and significantly improving the safety of the operation.

[0016] 3. By installing a pressure measuring branch and a pressure sensor on the outer sheath, when the inner sheath is blocked by stones and loses its negative pressure suction, the perfusion fluid cannot be discharged in time, causing a sharp increase in renal pelvis pressure. The pressure monitor can monitor the renal pelvis pressure in real time and adjust the perfusion pressure and suction negative pressure of the intelligent medical perfusion and suction platform in a feedback manner through the pressure sensor, so as to effectively reduce the renal pelvis pressure, effectively avoid excessive intrarenal pressure, reduce the occurrence of infectious complications, and significantly improve the safety of the operation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1.

[0019] Figure 2 This is an explosion diagram illustrating the separation of the outer and inner sheaths in Example 1.

[0020] Figure 3 This is a schematic diagram of the structure when the isolation tube is installed in the inner sheath tube in Embodiment 1.

[0021] Figure 4 This is a schematic diagram of the isolation tube in Example 1.

[0022] Figure 5 This is a schematic diagram of the overall structure of Embodiment 2.

[0023] Reference numerals: 1. Inner sheath tube; 11. Inner sheath end cap; 12. Suction branch tube; 13. Second annular groove; 2. Outer sheath; 21. Irrigation branch tube; 22. Limiting ring; 3. Limiting component; 31. Outer sheath end cap; 311. Cap body; 312. Cap top; 32. Isolation tube; 321. First half tube; 322. Second half tube; 323. Snap-fit ​​groove; 324. Snap-fit ​​block; 325. Limiting protrusion; 4. Pressure relief branch pipe; 5. Pressure relief valve; 6. Clamping assembly; 61. Retaining ring; 62. Clamping wing; 621. Connecting part; 622. Operating part; 623. Clamping part; 624. Hook; 7. Pressure testing branch pipe; 8. Pressure sensor. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] Example 1 This application discloses a negative pressure suction double sheath structure for percutaneous nephrolithotomy. (Refer to...) Figure 1 and Figure 2 The double-sheath structure for percutaneous nephrolithotomy using negative pressure suction includes an inner sheath 1, an outer sheath 2, and a limiting component 3.

[0026] The inner sheath tube 1 has an inner sheath end cap 11 at its rear end. The inner sheath end cap 11 is made of silicone and is threaded to the end of the inner sheath tube 1 to seal it. A suction branch tube 12 is provided on the side wall of the inner sheath tube 1 near the inner sheath end cap 11. This branch tube is used to connect to a negative pressure suction device to suction the perfusion fluid and lithotripsy within the kidney, thus enabling stone removal.

[0027] The outer sheath 2 is coaxially sleeved on the inner sheath 1, with a perfusion gap between them. A perfusion branch 21, communicating with the perfusion gap, is located on the side wall. The perfusion branch 21, connected to a perfusion source, introduces perfusion fluid into the perfusion gap to flush the kidney. The posterior end of the inner sheath 1 protrudes beyond the posterior end of the outer sheath 2 (in this text, the posterior end refers to the end of the outer sheath 2 or inner sheath 1 furthest from the patient, and the anterior end refers to the end of the outer sheath 2 or inner sheath 1 closest to the patient).

[0028] The fixing assembly is located on the portion of the inner sheath 1 that protrudes from the outer sheath 2, and includes a limiting assembly 3 for restricting or allowing the front end of the inner sheath 1 to protrude from the front end of the outer sheath 2, and a clamping assembly 6 for restricting the movement of the inner sheath 1 toward the rear end.

[0029] When retrieving stones in a spacious environment, the limiting component 3 restricts the inner sheath 1, preventing it from protruding beyond the outer sheath 2. The clamping component 6 restricts the inner sheath 1 from moving towards the rear end, fixing it relative to the outer sheath 2. The perfusion branch 21 connects to the perfusion fluid source, introducing perfusion fluid into the perfusion gap. The suction branch 12 connects to the negative pressure device, suctioning the perfusion fluid and stone fragments within the kidney. The outer sheath 2 and inner sheath 1 establish an independent perfusion and drainage channel system, improving stone retrieval efficiency. When it is necessary to retrieve stones through narrow spaces such as the renal calyx or upper ureter, the limiting component 3 allows the inner sheath 1 to protrude beyond the outer sheath 2, enabling it to enter the narrow renal calyx or upper ureter independently. The system switches to a single-sheath negative pressure mode to continue clearing residual stones, thus achieving a stone retrieval sheath structure that can freely switch between single and double sheaths to adapt to different stone retrieval environments, avoid intraoperative instrument changes, reduce kidney damage and bleeding, and improve the convenience and overall efficiency of the surgical procedure.

[0030] Specifically, such as Figure 2 As shown, the limiting component 3 includes an outer sheath end cap 31 and a limiting member. The outer sheath end cap 31 is used to seal the rear end of the outer sheath tube 2. The outer sheath end cap 31 includes a cap body 311 and a cap top 312. The cap body 311 is annular, and the cap top 312 is circular. In this embodiment, both the cap body 311 and the cap top 312 are made of elastic material, specifically medical silicone. The cap body 311 wraps around the outer sheath tube 2, and the inner side of the cap top 312 fits against the rear end face of the outer sheath tube 2, forming a seal on the rear end of the outer sheath tube 2. The limiting member is provided on the inner sheath tube 1 and is used to restrict or allow the front end of the inner sheath tube 1 to protrude beyond the front end of the outer sheath tube 2.

[0031] Specifically, refer to Figure 3 and Figure 4 The isolation tube 32 includes a first half-tube 321 and a second half-tube 322 of the same shape and size. Both the first half-tube 321 and the second half-tube 322 are semi-circular tubes. One end of the first half-tube 321 is hinged to one end of the second half-tube 322. The other ends of the first half-tube 321 and the second half-tube 322 are provided with connecting parts. The connecting part of the first half-tube 321 is provided with a snap-fit ​​groove 323. The connecting part of the second half-tube 322 is provided with a snap-fit ​​block 324. The snap-fit ​​block 324 is a silicone block. By snapping the snap-fit ​​block 324 with the snap-fit ​​groove 323, the first half-tube 321 and the second half-tube 322 can be locked, so that the isolation tube 32 is fixed on the outer sheath tube 2.

[0032] To achieve rapid positioning of the isolation tube 32, the inner sheath tube 1 is provided with a first annular groove and a second annular groove 13, such as... Figure 3As shown (the first annular groove is obscured by the isolation tube 32 and is not marked in the figure), the inner sides of the first half-tube 321 and the second half-tube 322 are both provided with limiting protrusions 325. The limiting protrusions 325 are adapted to the diameter and thickness of the first and second annular grooves 13, allowing the limiting protrusions 325 to be embedded in the first and second annular grooves 13. When the limiting protrusions 325 are engaged with the first annular groove and the front end of the inner sheath tube 1 is flush with the front end of the outer sheath tube 2, the bottom of the isolation tube 32 abuts against the outer surface of the cap 312, thus limiting the inner sheath tube 1. When it is necessary to switch to single-sheath mode, the first half-tube 321 and the second half-tube 322 are unlocked, the limiting protrusions 325 are engaged with the second annular groove 13, and the first half-tube 321 and the second half-tube 322 are locked, so that the front end of the inner sheath tube 1 protrudes beyond the front end of the outer sheath tube 2, thus achieving the switching to single-sheath mode. The operation is simple and the positioning is quick, thereby effectively improving surgical efficiency.

[0033] In addition, continue to refer to Figure 2 The clamping assembly 6 includes a fixing ring 61 and two clamping wings 62 symmetrically arranged around the fixing ring 61. The fixing ring 61 is circular and is coaxially bonded to the inner sheath tube 1 and located on the side of the isolation tube 32 near the rear end of the inner sheath tube 1. The clamping wing 62 includes an integrally formed connecting part 621, an operating part 622, and a clamping part. The connecting part 621 is a transversely arranged strip and is heat-fused to the fixing ring 61, serving as the fulcrum of the clamping wing 62. The operating part 622 is located on the side of the connecting part 621 away from the fixing ring 61, and the clamping part is located on the side of the operating part 622 away from the rear end of the inner sheath tube 1. The side of the clamping part near the inner sheath tube 1 is provided with a hook part 623 for clamping. 624. A limiting ring is coaxially fixed on the outer sheath tube 2. When the front end of the inner sheath tube 1 is flush with the front end of the outer sheath tube 2, the hooks 623 and clamping parts 624 of the two clamping wings 62 abut against the side of the limiting ring away from the rear end of the inner sheath tube 1, and cooperate with the limiting component to restrict the inner sheath from moving toward the rear end.

[0034] The clamping wings 62 are made of a slightly elastic plastic material. Their clamping function is achieved through a lever principle, with the connecting part 621 acting as a fulcrum, the operating part 622 as the power arm, and the clamping part as the resistance arm. In operation, by driving the operating parts 622 of the two clamping wings 62 closer together, the two clamping parts open, pushing the inner sheath 1 until its front end is flush with the front end of the outer sheath 2. At this point, the isolating tube 32 abuts against the outer side of the cover 312. Releasing the operating parts 622 allows the two clamping parts to move closer together under their own elasticity and abut against the side of the limiting ring away from the front end of the inner sheath 1, thus achieving the clamping function.

[0035] In the double-sheath structure, when the inner sheath 1 is blocked by stone particles, its suction efficiency for the perfusion fluid is significantly reduced. Meanwhile, the perfusion branch 21 continuously supplies perfusion fluid into the kidney, causing a sharp increase in intrarenal pressure. This leads to the reflux of bacteria and toxins from the kidney into the bloodstream, causing infectious complications and even life-threatening risks such as sepsis and septic shock. Currently, there are no effective devices on the market for monitoring intrarenal pressure. Therefore, a pressure relief device is installed on the outer sheath 2 to monitor and alleviate the high intrarenal pressure caused by the blockage of the inner sheath.

[0036] Specifically, the pressure relief device includes a pressure relief branch pipe 4 and a pressure relief valve 5. The pressure relief branch pipe 4 is inclinedly mounted on the outer sheath 2 and communicates with the irrigation gap. The pressure relief valve 5 is located at the end of the pressure relief branch pipe 4 away from the outer sheath 2. The normal renal pelvis pressure is 0~20cmH2O, and the safety threshold is 40cmH2O. When the renal pelvis pressure exceeds 40cmH2O, the risk of PCNL infection complications increases significantly, and there is a risk of sepsis. Therefore, the pressure relief value of the pressure relief valve 5 is set to 40cmH2O, that is, when the renal pelvis pressure reaches the safety threshold, the pressure relief valve 5 automatically opens to relieve pressure, thereby reducing the probability of infection complications caused by excessive renal pelvis pressure, improving surgical safety, ensuring the continuity of the surgery, and further improving the efficiency of the surgery. This embodiment uses a pressure relief valve 5, which can automatically open to relieve pressure, has a simple structure, low cost, and high versatility.

[0037] The pressure relief valve 5 is a cross-shaped silicone valve with an embedded biocompatible silicone membrane having a thickness of 0.3 ± 0.05 mm. Alternatively, a mechanical pressure relief valve can also be used.

[0038] In addition, the front end of the inner sheath 1 adopts a fish mouth or wave-shaped design to reduce the possibility of water flow obstruction caused by the inner sheath pressing against stones or tissues, and to reduce the probability of the inner sheath becoming blocked.

[0039] Example 2 Compared with Embodiment 1, the difference in this embodiment is that the isolation tube 32 is detachably connected to the inner sheath tube 1 in the form of a clamp.

[0040] Example 2 Compared with Embodiment 1, the difference in this embodiment is that the pressure relief device is removed and a pressure monitoring device is added.

[0041] For details, please refer to Figure 5 The outer sheath tube 2 is equipped with a pressure monitoring device, which includes a pressure measuring branch tube 7 and a pressure sensor 8. The pressure measuring branch tube 7 is inclinedly installed on the side wall of the outer sheath tube 2 and communicates with the perfusion gap. The pressure sensor 8 is installed on the pressure measuring branch tube 7. The end of the pressure measuring branch tube 7 is provided with an internal threaded cylinder. The pressure sensor 8 is threadedly connected and fixed to the internal threaded cylinder. The pressure of the renal pelvis is judged in real time by monitoring the pressure of the perfusion gap.

[0042] The pressure sensor 8 works in conjunction with the intelligent medical perfusion and aspiration platform. The pressure sensor 8 provides feedback to adjust the perfusion pressure and suction negative pressure of the platform, thus maintaining the renal pelvis pressure within a preset normal range. However, this method is more expensive. The pressure sensor 8 is divided into a liquid pressure sensor 8 and a fiber optic (electronic) pressure sensor 8. The former monitors the perfusion fluid pressure from the end of the pressure-measuring branch tube 7 and adjusts the medical perfusion and aspiration platform accordingly. The latter is inserted through the pressure-measuring branch tube 7, passes through the perfusion gap, and reaches the front end of the inner sheath 1. This location is close to the surgical area, allowing for more accurate real-time monitoring of the renal pelvis pressure. The fiber optic (electronic) pressure sensor 8 occupies a sufficiently small space within the perfusion gap, does not affect the perfusion flow rate, and the space between the two sheaths prevents damage from stone impacts. Therefore, the latter is the preferred option.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A negative pressure suction double sheath structure for percutaneous nephrolithotomy, characterized in that, include: The inner sheath tube has an inner sheath end cap at the rear end and a suction branch tube on the side wall at the rear end. An outer sheath is fitted onto the inner sheath with an infusion gap between them, and an infusion branch pipe communicating with the infusion gap is provided on the side wall. A fixing mechanism is provided at the portion of the inner sheath protruding from the outer sheath, including a limiting component for restricting or allowing the front end of the inner sheath to protrude from the front end of the outer sheath, and a clamping component for restricting the movement of the inner sheath toward the rear end. The limiting component includes an outer sheath end cap and a limiting member. The outer sheath end cap is used to seal the infusion gap. The outer sheath end cap includes a cap body and a cap top. The cap body wraps around the periphery of the outer sheath tube. The inner side of the cap top fits against the end face of the outer sheath tube. An avoidance hole is provided on the cap top for the inner sheath tube to pass through. The limiting member is provided on the inner sheath tube and is used to restrict or allow the front end of the inner sheath tube to protrude beyond the front end of the outer sheath tube. The limiting member is set as an isolation tube, which is disposed on the inner sheath tube. When the front end of the inner sheath tube is flush with the front end of the outer sheath tube, the isolation tube abuts against the outer side of the cover. The isolation tube is detachably connected to the inner sheath tube by means of a clamp. The inner sheath tube has a first annular groove and a second annular groove on its side wall. The second annular groove is located on the side of the first annular groove near the end cap of the inner sheath. The inner side of the isolation tube has a limiting protrusion. When the limiting protrusion is engaged with the first annular groove and the front end of the inner sheath tube is flush with the front end of the outer sheath tube, the isolation tube abuts against the outer side of the top of the cap.

2. The negative pressure suction double sheath structure for percutaneous nephrolithotomy as described in claim 1, characterized in that, The front end of the inner sheath is either fish-mouth shaped or wavy.

3. The negative pressure suction double sheath structure for percutaneous nephrolithotomy as described in claim 1, characterized in that, The clamping assembly includes a fixing ring and two clamping wings symmetrically disposed on the periphery of the fixing ring; The fixing ring is fixedly sleeved on the inner sheath and located on the side of the isolation tube near the rear end of the inner sheath; The clamping wing includes a connecting part, an operating part, and a clamping part. The connecting part is fixedly connected to the fixing ring. The operating part is located on the side of the connecting part away from the fixing ring. The clamping part is located on the side of the operating part away from the rear end of the inner sheath tube. The clamping part is provided with a hook on the side of the clamping part close to the inner sheath tube. The outer sheath is provided with a limiting ring. When the front end of the inner sheath is flush with the front end of the outer sheath, the hook part abuts against the side of the limiting ring away from the rear end of the inner sheath.

4. A negative pressure suction double sheath structure for percutaneous nephrolithotomy according to any one of claims 1-3, characterized in that, The outer sheath is equipped with a pressure relief device, which includes a pressure relief branch pipe and a pressure relief valve. The pressure relief branch pipe is connected to the injection gap, and the pressure relief valve is connected to the pressure relief branch pipe.

5. A negative pressure suction double sheath structure for percutaneous nephrolithotomy according to any one of claims 1-3, characterized in that, The outer sheath is equipped with a pressure monitoring device, which includes a pressure measuring branch and a pressure sensor. The pressure measuring branch is connected to the injection gap, and the pressure sensor is located on the pressure measuring branch.

6. The negative pressure suction double sheath structure for percutaneous nephrolithotomy as described in claim 5, characterized in that, The pressure sensor is configured as a liquid pressure sensor or an optical fiber pressure sensor.

Images