dilator

Abstract

The application provides an expander, which comprises a primary expander tube and a secondary expander tube; the primary expander tube comprises a primary expander outer tube and a primary expander inner tube; the inner diameter of the primary expander outer tube is matched with the outer diameter of the primary expander inner tube, and one end of the primary expander inner tube is connected with one end of the primary expander outer tube; the secondary expander tube comprises a secondary expander outer tube and a secondary expander inner tube; the inner diameter of the secondary expander outer tube is matched with the outer diameter of the secondary expander inner tube, and one end of the secondary expander inner tube is connected with one end of the secondary expander outer tube; the inner diameter of the secondary expander outer tube is not less than the outer diameter of the primary expander inner tube, and the inner diameter of the secondary expander inner tube is less than the outer diameter of the primary expander outer tube; the secondary expander outer tube is sleeved on the primary expander outer tube, and the secondary expander inner tube is sleeved on the primary expander inner tube. The expander effectively controls the expansion depth by sleeving the secondary expander tube on the primary expander tube, reduces the risk of passage loss, ensures the accuracy and safety of the operation, and shortens the operation time.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more specifically, to an expander. Background Technology

[0002] Taking percutaneous nephrolithotomy (PCNL) as an example, PCNL is a minimally invasive surgery for the treatment of kidney stones. During the operation, the surgeon establishes a percutaneous nephrolithotomy channel using a fascia dilator.

[0003] Currently, most dilators consist of multiple cannulas of different diameters, each placed independently. During dilation, the appropriate diameter cannula is selected step by step to expand the channel, depending on the size of the stone and the patient's condition. That is, during dilation, a smaller dilator is first placed along the guidewire to form a channel, and then the lower-sized dilator is removed before a larger dilator is inserted.

[0004] However, most current expanders use a step-by-step expansion channel method, which is complicated to operate and the expansion depth is inconsistent with each entry and exit operation, resulting in expansion depth that is too deep or too shallow, causing tissue damage or the risk of losing the channel. Summary of the Invention

[0005] The purpose of this application is to provide an expander that improves the ease of use of the expander.

[0006] This application provides an expander, including a primary expander tube and a secondary expander tube; the primary expander tube includes a primary expander outer tube and a primary expander inner tube; the inner diameter of the primary expander outer tube is adapted to the outer diameter of the primary expander inner tube, and the end face or side face of the primary expander inner tube is connected to the end face or side face of the primary expander outer tube; the secondary expander tube includes a secondary expander outer tube and a secondary expander inner tube; the inner diameter of the secondary expander outer tube is adapted to the outer diameter of the secondary expander inner tube, and the end face or side face of the secondary expander inner tube is connected to the end face or side face of the secondary expander outer tube; wherein, the inner diameter of the secondary expander outer tube is greater than or equal to the outer diameter of the primary expander inner tube, and the inner diameter of the secondary expander inner tube is smaller than the outer diameter of the primary expander outer tube; the secondary expander outer tube is sleeved outside the primary expander outer tube, and the secondary expander inner tube is sleeved outside the primary expander inner tube.

[0007] The aforementioned expander, by placing the secondary expander tube outside the primary expander tube, eliminates the need for repeated advances and retreats, thus effectively controlling the expansion depth. Furthermore, it effectively reduces the risk of channel loss, ensuring surgical precision and safety, while also shortening surgical time, bringing great convenience to both patients and doctors.

[0008] Optionally, the length of the primary expansion outer tube is A1; the primary expansion tube has a primary diameter-changing section located between the primary expansion inner tube and the primary expansion outer tube, and the length of the primary diameter-changing section is ΔL1; the length of the primary expansion inner tube is A2; the length of the secondary expansion outer tube is B1; the secondary expansion tube has a secondary diameter-changing section located between the secondary expansion inner tube and the secondary expansion outer tube, and the length of the secondary diameter-changing section is ΔL2; the length of the secondary expansion inner tube is B2; wherein, B2=A2-ΔL1-a, a≥0; B1-A1-ΔL2 is the compensation length difference between the primary expansion outer tube and the secondary expansion outer tube.

[0009] The aforementioned expander, by defining B2 = A2 - ΔL1 - a, and even when the expander includes multiple stages of expander tubes, uses a similar relationship to progressively limit each stage. This ensures that when each expander tube slides on a lower-level expander tube, its tip is aligned when it is stopped at the connection point of that lower-level expander tube. Thus, during surgical procedures, the surgeon typically only needs to slide each expander tube sequentially until it is stopped by the lower-level expander tube before operating on the next stage. This further simplifies the channel establishment process in minimally invasive surgery and avoids inadequate or excessive expansion caused by uneven expander tube tips during progressive expansion. Furthermore, by defining the compensating length difference between each stage of the expander tubes as B1 - A1 - ΔL2, and even when the expander includes multiple stages of expander tubes, using a similar relationship to progressively limit each stage, manufacturing tolerances between each stage of the expander tubes can be offset during manufacturing. This further ensures that when each expansion tube slides on a lower-level expansion tube, and is stopped by the connection point on that lower-level expansion tube, the front ends of each expansion tube can be aligned.

[0010] Optionally, 0mm ≤ |B1-A1-ΔL21| ≤ 5mm.

[0011] The aforementioned expander simplifies the process requirements by further limiting the compensation length difference between each stage of the expansion outer tube to within the range of [0 mm, 5 mm], and then using ΔL to compensate for the manufacturing tolerances between each stage of the expansion outer tube. This improves the efficiency of manufacturing the expander provided in this application.

[0012] Optionally, where 0 < a < 300 mm.

[0013] The aforementioned expander, by limiting 0 < a < 300 mm, ensures that when the various expansion tubes at the tail end of the expander are flush, a certain distance of each tube remains exposed for gripping. This further enhances the ease of use of the expander.

[0014] Optionally, it further includes a positioning element; the positioning element includes: a primary positioning part and a secondary positioning part; the diameter of the primary positioning part is adapted to the inner diameter of the secondary expansion outer tube, and the diameter of the secondary positioning part is larger than the inner diameter of the secondary expansion outer tube; a step is formed at the connection between the primary positioning part and the secondary positioning part; the primary positioning part is inserted into the end of the secondary expansion outer tube away from the secondary expansion inner tube, and abuts against the end face of the primary expansion outer tube away from the primary expansion inner tube; the step abuts against the end face of the secondary expansion outer tube away from the secondary expansion inner tube.

[0015] In the aforementioned expander, with the positioning element inserted at the tail end, each step abuts against the tail end of the corresponding inner expansion tube. Because the positioning elements at each level are stepped, the tail ends of each inner expansion tube contract inwards sequentially from the outside to the inside. Correspondingly, the tail ends of each outer expansion tube extend outwards sequentially from the outside to the inside. Ultimately, the tail ends of each outer expansion tube protrude to a length corresponding to the length of each positioning element. Furthermore, the positioning element prevents the expansion tubes at each level from extending towards their tail ends or even detaching.

[0016] Optionally, the positioning element is fixedly connected to one end of the primary expansion inner tube that is away from the secondary expansion outer tube.

[0017] The aforementioned expander, by fixing the first-stage expansion inner tube to the positioning element, prevents the positioning element from falling off the expander, thereby further preventing the expansion tubes at each stage from extending towards the tail end or even falling off.

[0018] Optionally, where 0 < ΔL2 ≤ A2.

[0019] The aforementioned expander, by limiting 0 < ΔL2 ≤ A2, not only ensures that the connection between the first-stage expansion inner tube and the first-stage expansion outer tube can limit the sliding of the second-stage expansion tube, but also reduces the overall length of the expander.

[0020] Optionally, the expansion tube has at least three layers.

[0021] The aforementioned expander, with at least three layers of expansion tubes, enables the expansioner to create channels of more different diameters during surgery, thereby further improving the expander's applicability.

[0022] Optionally, the primary expansion tube is used to establish a working channel or place instruments, and A2 ≥ 2*A1.

[0023] The aforementioned expander, with its innermost layer guided by intraoperative guide wires and other instruments, further facilitates the establishment of the surgical channel. Furthermore, the limitation that A2 ≥ 2 * A1 ensures both the effective working length of the expander and its overall length, reducing its space requirements and making it easier for the surgeon to operate.

[0024] Optionally, the end of the outer expansion tube at each stage that is away from the inner expansion tube has a constriction.

[0025] In the aforementioned expander and its implementation, by setting constrictions at the distal ends of each level of the expansion tube, the constrictions at the distal ends play a smooth transition role during the process of establishing channels in human tissue, thereby further improving the ease of use of the expander.

[0026] In summary, the expander provided in this application effectively controls the expansion depth by placing a secondary expansion tube outside the primary expansion tube, eliminating the need for repeated advances and retreats. Furthermore, it effectively reduces the risk of channel loss, ensuring surgical precision and safety, while shortening surgical time and providing significant convenience for both patients and doctors. By limiting B2 = A2 - ΔL1 - a, and even when the expander includes multiple stages of expansion tubes, a similar relationship is used to progressively limit the expansion depth, further simplifying the channel establishment process during minimally invasive surgery and preventing inadequate or excessive expansion due to uneven expansion tube tips during progressive expansion. By further limiting the compensation length difference between each stage of expansion tubes to within the range of [0mm, 5mm], ΔL is used to compensate for manufacturing tolerances between each stage of expansion tubes, simplifying the process requirements. By configuring positioning elements for the expander, the tail ends of each expansion tube protrude to a length corresponding to the length of the positioning section at each stage. Furthermore, the positioning elements prevent each stage of expansion tubes from extending towards the tail end or even falling off. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of a first structure of the expander provided in an embodiment of this application;

[0029] Figure 2 A schematic diagram of a first-stage expansion tube in an expander provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of the secondary expansion tube in the expander provided in the embodiments of this application;

[0031] Figure 4 This is a schematic diagram of a first structure of the expander tail provided in an embodiment of this application;

[0032] Figure 5 This is a schematic diagram of the structure of the expander in a flush state according to an embodiment of this application;

[0033] Figure 6 A schematic diagram of the structure of the expander with its tail end flush with the embodiment of this application;

[0034] Figure 7 A schematic diagram of the third structure of the expander provided in the embodiments of this application;

[0035] Figure 8 This is a schematic diagram of the positioning element in the expander provided in the embodiments of this application;

[0036] Figure 9 This is a schematic diagram of a second structure of the primary expansion tube in the expander provided in the embodiments of this application.

[0037] Icons: 100, Expander; 110, Primary expansion tube; 111, Primary expansion outer tube; 112, Primary expansion inner tube; 113, Primary reducing section; 120, Secondary expansion tube; 121, Secondary expansion outer tube; 122, Secondary expansion inner tube; 123, Secondary reducing section; 130, Tertiary expansion tube; 131, Tertiary expansion outer tube; 132, Tertiary expansion inner tube; 140, Quaternary expansion tube; 141, Quaternary expansion outer tube; 142, Quaternary expansion inner tube; 150, Positioning component; 151, Primary positioning part; 152, Secondary positioning part; 153, Tertiary positioning part; 154, Quaternary positioning part. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0043] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] Please refer to Figures 1 to 4 , Figure 1 This is a schematic diagram of the first structure of the expander 100 provided in the embodiments of this application; Figure 2 This is a schematic diagram of the first structure of the primary expansion tube 110 in the expander 100 provided in this application embodiment; Figure 3 This is a schematic diagram of the structure of the secondary expansion tube 120 in the expander 100 provided in the embodiments of this application; Figure 4This is a schematic diagram of the first structural configuration of the expander 100 provided in this application embodiment. The expander 100 provided in this application embodiment may include a primary expander tube 110 and a secondary expander tube 120. The primary expander tube 110 may include a primary expander outer tube 111 and a primary expander inner tube 112. The inner diameter of the primary expander outer tube 111 may be adapted to the outer diameter of the primary expander inner tube 112, and the end face or side face of the primary expander inner tube 112 may be connected to the end face or side face of the primary expander outer tube 111. The secondary expander tube 120 may include a secondary expander outer tube 121 and a secondary expander inner tube 122. The inner diameter of the secondary expander outer tube 121 may be adapted to the outer diameter of the secondary expander inner tube 122, and the end face or side face of the secondary expander inner tube 122 may be connected to the end face or side face of the secondary expander outer tube 121. The inner diameter of the secondary expander outer tube 121 may be greater than or equal to the outer diameter of the primary expander inner tube 112, and the inner diameter of the secondary expander inner tube 122 may be less than the outer diameter of the primary expander outer tube 111. The secondary expansion outer tube 121 can be fitted outside the primary expansion outer tube 111, and the secondary expansion inner tube 122 can be fitted outside the primary expansion inner tube 112.

[0045] In other words, the primary expansion tube 110 can be formed by connecting two tubes of different diameters together, such as by welding or bonding. The primary expansion tube 110 can also be integrally formed. Similarly, the secondary expansion tube 120 can be formed by connecting two tubes of different diameters together, such as by welding or bonding. The secondary expansion tube 110 can also be integrally formed. The secondary expansion outer tube 121 and secondary expansion inner tube 122 of the secondary expansion tube 120 correspond to the primary expansion outer tube 111 and primary expansion inner tube 112 of the primary expansion tube 110, and are sleeved outside the primary expansion tube 110. Furthermore, the secondary expansion tube 120 can slide on the primary expansion tube 110.

[0046] Of course, those skilled in the art can, according to actual needs, progressively install tertiary expansion tubes 130, quaternary expansion tubes 140, etc., on the secondary expansion tube 120. Among them, the structure of the tertiary expansion tube 130, quaternary expansion tube 140, etc., is similar to that of the primary expansion tube 110 and the secondary expansion tube 120.

[0047] During use, the primary dilator 110 is first inserted into the body wall along the guidewire to establish the required surgical channel. Then, the secondary dilator 120 is slid over the primary dilator 110 to be inserted into the body wall to the same depth as the primary dilator 110. Furthermore, because the inner diameter of the secondary inner dilator 122 is smaller than the outer diameter of the primary dilator 110, when the secondary inner dilator 120 slides to a specific position on the primary dilator 110, the end of the secondary inner dilator 122 facing the secondary outer dilator 121 will abut against the connection point of the primary inner dilator 112 and the primary outer dilator 111. This serves as a limiting mechanism. Depending on actual needs, similar procedures can be used to insert tertiary dilators 130, quaternary dilators 140, etc., into the body wall to form a channel of the required size for the surgery.

[0048] In the aforementioned process, by placing the secondary dilator 120 outside the primary dilator 110, the dilator 100 does not need to be repeatedly advanced or retracted during the operation, thus effectively controlling the dilation depth. Furthermore, this effectively reduces the risk of channel loss, ensuring the precision and safety of the surgery, while also shortening the operation time, bringing great convenience to both patients and doctors.

[0049] Please refer to Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the structure of the expander 100 in the form of a flush front end provided in the embodiment of this application; Figure 6 This is a schematic diagram of the expander 100 with its tail end flush with the embodiment of this application. In some optional embodiments, the length of the primary expansion outer tube 111 can be A1; the primary expansion tube 110 can have a primary diameter-changing section 113, which can be located between the primary expansion inner tube 112 and the primary expansion outer tube 111, and the length of the primary diameter-changing section 113 can be ΔL1; the length of the primary expansion inner tube 112 can be A2; the length of the secondary expansion outer tube 121 can be B1; the secondary expansion tube 120 can have a secondary diameter-changing section 123, which can be located between the secondary expansion inner tube 122 and the secondary expansion outer tube 121, and the length of the secondary diameter-changing section 123 is ΔL2; the length of the secondary expansion inner tube 122 is B2; wherein, B2=A2-ΔL1-a, a≥0; B1-A1-ΔL2 is the compensation length difference between the primary expansion outer tube 111 and the secondary expansion outer tube 121.

[0050] The primary diameter-changing section can be the length of the insertion portion of the primary expansion inner tube into the primary expansion outer tube, or it can be a section where the outer diameter of the primary expansion tube gradually changes when the primary expansion inner tube and primary expansion outer tube are integrally formed. The definition of the secondary diameter-changing section can be the same as that of the primary diameter-changing section.

[0051] Since B2 = A2 - ΔL1 - a, it is possible to make the front end of the primary expansion tube 110 and the secondary expansion tube 120 (that is, the end of the primary expansion tube 111 that is far away from the primary expansion tube 112 and the end of the secondary expansion tube 121 that is far away from the secondary expansion tube 122) level during the sliding process of the secondary expansion tube 120.

[0052] Of course, those skilled in the art can also configure the expander 100 with a three-stage expansion tube 130 and a four-stage expansion tube 140 according to actual needs. The length of the three-stage expansion outer tube 131 can be C1, the insertion length of the three-stage expansion inner tube 132 into the three-stage expansion outer tube 131 can be ΔL3, and the length of the three-stage expansion inner tube 132 can be C2. The length of the four-stage expansion outer tube 141 can be D1, the insertion length of the four-stage expansion inner tube 142 into the four-stage expansion outer tube 141 can be ΔL4, and the length of the four-stage expansion inner tube 142 can be D2. Based on the compensation length difference between the first-stage and second-stage expansion outer tubes being B1-A1-ΔL2, correspondingly, the compensation length difference between the second-stage and third-stage expansion outer tubes can be B2-A2-ΔL3, the compensation length difference between the third-stage and fourth-stage expansion outer tubes can be B3-A3-ΔL4, and so on. Similarly, by using similar length relationships, the front ends of the primary expansion tube 110, secondary expansion tube 120, tertiary expansion tube 130, and quaternary expansion tube 140 can be aligned. Furthermore, if each expansion tube is aligned at the tail end of the expander 100 (the end opposite to the front end), the distance between the exposed front ends of each expansion tube is 'a'. This distance can also be used as the holding distance for each expansion tube.

[0053] Furthermore, ideally, B1-A1-ΔL2 should be 0. In cases where the expander 100 includes three-stage expander tubes 130, four-stage expander tubes 140, etc., B2-A2-ΔL3 should be 0, B3-A3-ΔL4 should be 0, and so on. This ensures that when each expander tube slides on a lower-level expander tube, its front ends are flush when it reaches the connection point on that lower-level expander tube. However, in actual manufacturing, manufacturing tolerances can easily cause discrepancies between different levels of the tubes. Therefore, the values ​​of ΔL1, ΔL2, ΔL3, ΔL4… can be adjusted using the previously defined compensation length difference to offset these manufacturing tolerances.

[0054] In the above implementation process, by defining B2 = A2 - ΔL1 - a, and even when the expander 100 includes multiple stages of expander tubes, a similar relationship is used to limit each stage step by step. This ensures that when each stage of expander tube slides on a lower-level expander tube, its front ends are aligned when it is stopped at the connection point on that lower-level expander tube. Thus, during surgical operations, the surgeon typically only needs to slide each stage of expander tube step by step until it is stopped by the lower-level expander tube to operate on the next stage expander tube 110. This further simplifies the channel establishment process during minimally invasive surgery and avoids incomplete or excessive expansion caused by uneven front ends of the expander tubes during step-by-step expansion. Furthermore, by defining the compensation length difference between each stage of the expander tubes as B1 - A1 - ΔL2, and even when the expander 100 includes multiple stages of expander tubes, a similar relationship is used to limit each stage step by step, enabling the manufacturing tolerances between each stage of the expander tubes to be offset during manufacturing. This further ensures that when each expansion tube slides on a lower-level expansion tube, and is stopped by the connection point on that lower-level expansion tube, the front ends of each expansion tube can be aligned.

[0055] Please refer to the figure. In some optional embodiments, 0mm≤|B1-A1-ΔL2|≤5mm.

[0056] Accordingly, when the expander 100 includes a three-stage expansion tube 130, a four-stage expansion tube 140, etc., 0mm≤|C1-B1-ΔL3|≤5mm, 0mm≤|D1-C1-ΔL4|≤5mm… that is, the manufacturing compensation length difference between the first-stage expansion outer tube 111, the second-stage expansion outer tube 121, and the multi-stage expansion outer tubes is within the range of [0mm, 5mm]. Furthermore, based on the previous embodiment, when the compensation length difference between each stage of the expansion outer tube is within the range of [0mm, 5mm], ΔL (ΔL1, ΔL2, ΔL3, ΔL4…) is used to compensate for this manufacturing tolerance.

[0057] In the above implementation process, by further limiting the compensation length difference between each stage of the expansion outer tube to within the range of [0 mm, 5 mm], ΔL is used to compensate for the manufacturing tolerance between each stage of the expansion outer tube, simplifying the process requirements. This improves the efficiency of manufacturing the expander 100 provided in the embodiments of this application.

[0058] Please continue to refer to Figure 5 and Figure 6 In some alternative implementations, 0 < a < 300 mm.

[0059] As can be seen from the previous embodiments, when a = 0, when each stage of the expansion tubes at the tail end of the expander 100 is aligned, the exposed gripping distance of each stage of the expansion tubes at the tail end is also aligned, meaning the gripping distance of each stage of the expansion tubes at the tail end is 0. When a ≠ 0, the exposed gripping distance of each stage of the expansion tubes at the tail end of the expander 100 is not 0. Of course, when the expander 100 includes three or more stages of expansion tubes, the exposed gripping distance of each stage can be different. Therefore, here 'a' can represent the gripping length exposed by the stage with the longest exposed distance.

[0060] In the above implementation process, by limiting 0 < a < 300 mm, when the various expansion tubes at the tail end of the expander 100 are flush, a certain distance of the various expansion tubes at the tail end of the expander 100 can be exposed for gripping. This further improves the ease of use of the expander 100.

[0061] Please refer to Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the third structure of the expander 100 provided in the embodiments of this application; Figure 8 This is a schematic diagram of the positioning element 150 in the expander 100 provided in this application embodiment. In some optional embodiments, the expander 100 provided in this application embodiment may further include the positioning element 150. The positioning element 150 may include: a primary positioning part 151 and a secondary positioning part 152. The diameter of the primary positioning part 151 may be adapted to the inner diameter of the secondary expansion outer tube 121, and the diameter of the secondary positioning part 152 may be larger than the inner diameter of the secondary expansion outer tube 121. A step may be formed at the connection between the primary positioning part 151 and the secondary positioning part 152. The primary positioning part 151 may be inserted into the end of the secondary expansion outer tube 121 away from the secondary expansion inner tube 122, and may abut against the end face of the primary expansion outer tube 111 away from the primary expansion inner tube 112. The step may abut against the end face of the secondary expansion outer tube 121 away from the secondary expansion inner tube 122.

[0062] When the expander 100 includes a three-stage expansion tube 130, a four-stage expansion tube 140, etc., the positioning member 150 may also include a three-stage positioning part 153, a four-stage positioning part 154, etc. The diameter of the two-stage positioning part 152 is adapted to the inner diameter of the three-stage expansion outer tube 131, and the diameter of the three-stage positioning part 153 is larger than the inner diameter of the two-stage expansion outer tube 121; the diameter of the three-stage positioning part 153 is adapted to the inner diameter of the four-stage expansion outer tube 141, and the diameter of the four-stage positioning part 154 is larger than the inner diameter of the three-stage expansion outer tube 131; and so on. Steps may be formed between each level of positioning part.

[0063] In the above-described process, when the positioning element 150 is inserted into the tail end of the expander 100, each step abuts against the tail end of the corresponding inner expansion tube. Because the positioning parts at each level are stepped, the tail ends of each inner expansion tube contract inwards sequentially from the outside to the inside. Correspondingly, the tail ends of each outer expansion tube extend outwards sequentially from the outside to the inside. Ultimately, the tail ends of each outer expansion tube are exposed to a length corresponding to the length of each positioning part. Furthermore, the positioning element 150 prevents the expansion tubes at each level from extending towards the tail end or even falling off.

[0064] Please continue to refer to Figure 8 In some alternative embodiments, the lengths of the primary positioning part 151 and the secondary positioning part 152 may be equal.

[0065] When the expander 100 includes a three-stage expansion tube 130, a four-stage expansion tube 140, etc., the lengths of the three-stage positioning part 153, the four-stage positioning part 154, etc. of the positioning member 150 can also be equal.

[0066] The length of each positioning section can be represented by b. Based on the description of the previous embodiment, the length exposed at the tail end of the expansion tube is a+b.

[0067] In the above implementation process, by designing that the lengths of the positioning parts at each level on the positioning member 150 are equal, the exposed lengths of the tail ends of each level of the expansion tube are also equal when the positioning member 150 is inserted into the expander 100. This further ensures that each level of the expansion tube has a suitable gripping length.

[0068] In some alternative implementations, the positioning element 150 may be fixedly connected to one end of the primary expansion inner tube 112 away from the secondary expansion outer tube 121.

[0069] Fixed connections can be made by methods such as adhesive bonding and heat fusion bonding.

[0070] In the above implementation process, by fixing the first-stage expansion inner tube 112 to the positioning member 150, the positioning member is prevented from falling off the expander 100, thereby further preventing the expansion tubes of each stage from extending towards the tail end or even falling off.

[0071] In some alternative implementations, 0 < ΔL2 ≤ A2.

[0072] In other words, A2, as the length of the first-stage expansion inner tube 112, does not need to be the same as the length of other stage expansion inner tubes. It only needs to have a smaller length to ensure that the connection between it and the first-stage expansion outer tube 111 can limit the sliding of the second-stage expansion tube 120.

[0073] In the above implementation process, by limiting 0 < ΔL2 ≤ A2, the overall length of the expander 100 is reduced while ensuring that the connection between the first-stage expansion inner tube 112 and the first-stage expansion outer tube 111 can limit the sliding of the second-stage expansion tube 120.

[0074] Please refer to Figures 4 to 7 In some optional embodiments, the expansion tube has at least three layers.

[0075] In other words, the expander includes at least a primary expansion tube 110, a secondary expansion tube 120, and a tertiary expansion tube 130.

[0076] In the above implementation process, with the expansion tube having no less than three layers, the expander can establish more channels of different diameters during surgery, thereby further improving the applicability of the expander 100.

[0077] Please refer to Figure 9 , Figure 9 This is a schematic diagram of a second structure of the primary expansion tube in the expander provided in this application embodiment. In some optional embodiments, the primary expansion tube 110 is used to establish a working channel or place an instrument, and A2 ≥ 2*A1.

[0078] Based on the structure that the inner diameter of the primary expansion outer tube 111 is equal to the inner diameter of the primary expansion inner tube 112, the primary expansion tube 110 can be integrally formed, or a tube with the same length as the primary expansion tube 110, the same inner diameter as the primary expansion inner tube 112, and the same outer diameter as the primary expansion inner tube 112 can be manufactured first, and then a tube with the same length as the primary expansion outer tube 111 can be fitted over the previously manufactured tube.

[0079] Hollow catheters can be used to create the smallest possible channel initially during the procedure. Instruments placed within can then be used for surgical procedures after the channel is established, such as image acquisition and stone retrieval.

[0080] In the above-described process, the establishment of the surgical channel is further facilitated by the innermost layer under the guidance of intraoperative guide wires and other guiding instruments. Furthermore, by placing the instruments within the hollow catheter, related surgical operations can be performed using the instruments after the channel is established. Moreover, by limiting A2 to ≥ 2*A1, the effective working length of the dilator 100 is ensured while also limiting the overall length of the dilator 100, reducing its space occupation and making it more convenient for the surgeon to operate.

[0081] Please refer to Figures 4 to 6 In some optional embodiments, the end of the outer tube of each expansion stage away from the inner tube of expansion has a constriction.

[0082] That is, the distal end of each stage of the expansion tube has a constriction. This constriction can be a conical side, an arc-shaped surface, or a spherical surface, etc.

[0083] In the above implementation process, by setting a constriction at the distal end of each level of expansion tube, the constriction at the distal end plays a smooth transition role in the process of each level of expansion tube entering human tissue to establish a channel, thereby further improving the ease of use of the expander 100.

[0084] In summary, the expander 100 provided in the various embodiments of this application effectively controls the expansion depth by sleeved secondary expansion tube 120 outside primary expansion tube 110, eliminating the need for repeated advance and retreat of the expander. Furthermore, it effectively reduces the risk of channel loss, ensuring surgical precision and safety, while shortening surgical time and providing significant convenience for both patients and doctors. By limiting B2 = A2 - ΔL1 - a, and even when the expander 100 includes multiple stages of expansion tubes, a similar relationship is used to limit each stage, further simplifying the channel establishment process during minimally invasive surgery and preventing inadequate or excessive expansion due to uneven front ends of the expansion tubes during progressive expansion. By further limiting the compensation length difference between each stage of expansion tubes to within the range of 0 mm to 5 mm, ΔL is used to compensate for manufacturing tolerances between each stage of expansion tubes, simplifying process requirements. By configuring positioning elements 150 on the expander 100, the tail ends of each expansion tube protrude to a length corresponding to the length of each positioning part. Furthermore, the positioning element 150 prevents the expansion tubes at each stage from extending towards the tail end or even falling off.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An expander, characterized in that, Includes primary expansion tubes and secondary expansion tubes; The primary expansion tube includes a primary expansion outer tube and a primary expansion inner tube; the inner diameter of the primary expansion outer tube is adapted to the outer diameter of the primary expansion inner tube, and the end face or side face of the primary expansion inner tube is connected to the end face or side face of the primary expansion outer tube. The secondary expansion tube includes a secondary expansion outer tube and a secondary expansion inner tube; the inner diameter of the secondary expansion outer tube is adapted to the outer diameter of the secondary expansion inner tube, and the end face or side face of the secondary expansion inner tube is connected to the end face or side face of the secondary expansion outer tube. Wherein, the inner diameter of the secondary expansion outer tube is greater than or equal to the outer diameter of the primary expansion inner tube, and the inner diameter of the secondary expansion inner tube is less than the outer diameter of the primary expansion outer tube; The secondary expansion outer tube is sleeved outside the primary expansion outer tube, and the secondary expansion inner tube is sleeved outside the primary expansion inner tube; The expander further includes a positioning element; the positioning element includes a primary positioning part and a secondary positioning part; The diameter of the primary positioning part is adapted to the inner diameter of the secondary expansion outer tube, and the diameter of the secondary positioning part is larger than the inner diameter of the secondary expansion outer tube; The steps between the primary positioning part and the secondary positioning part; The primary positioning part is inserted into the end of the secondary expansion outer tube away from the secondary expansion inner tube, and abuts against the end face of the primary expansion outer tube away from the primary expansion inner tube. The step abuts against the end face of the secondary expansion outer tube away from the secondary expansion inner tube.

2. The expander according to claim 1, characterized in that, The length of the primary expansion outer tube is A1; The primary expansion tube has a primary diameter-changing section, which is located between the primary expansion inner tube and the primary expansion outer tube, and the length of the primary diameter-changing section is [length missing]. L1; The length of the primary expansion inner tube is A2; The length of the secondary expansion outer tube is B1; The secondary expansion tube has a secondary diameter-changing section, which is located between the secondary expansion inner tube and the secondary expansion outer tube, and the length of the secondary diameter-changing section is [missing information]. L2; The length of the secondary expansion inner tube is B2; Where, B2 = A2 - L1-a, a≥0; B1-A1- L2 is the compensation length difference between the primary expansion outer tube and the secondary expansion outer tube.

3. The expander according to claim 2, characterized in that, 0mm ≤ | B1-A1- L2 | ≤5mm.

4. The expander according to claim 2, characterized in that, in, 0 < a < 300 mm.

5. The expander according to claim 1, characterized in that, The positioning element is fixedly connected to one end of the primary expansion inner tube that is away from the secondary expansion outer tube.

6. The expander according to claim 2, characterized in that, in, 0< L2≤A2。 7. The expander according to claim 1, characterized in that, The expansion tube has no fewer than three layers.

8. The expander according to claim 2, characterized in that, The primary expansion tube is used to establish a working channel or place instruments, and A2≥2 A1.

9. The expander according to claim 1, characterized in that, Each of the various levels of the expansion outer tube has a constricted end at the end furthest from the expansion inner tube.

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