Helical cutting capillary structure for endoscopic mucosal incision knife
By setting a spiral slit and parallel conductive path on the conductive substrate of the mucosal cutting knife, combined with a variable pitch design, the shortcomings of the mucosal cutting knife in terms of conductivity and flexibility are solved, achieving efficient and safe cutting performance and low-cost production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG CHUANGXIANG MEDICAL TECH CO LTD
- Filing Date
- 2026-05-21
- Publication Date
- 2026-07-14
AI Technical Summary
Existing mucosal incision knives, while meeting the requirements of water injection, conductivity, and flexibility, suffer from problems such as high cost, sudden increase in resistance, and poor cutting performance, which affect surgical efficiency and patient comfort.
It adopts a spiral-cut capillary structure with spiral slits on a conductive substrate. By setting multiple spiral strips to form parallel conductive paths and with the addition of reserved sections, the overall impedance is reduced. Combined with a variable pitch design, flexibility and conductivity are simultaneously satisfied.
It reduces overall resistance, improves cutting performance, reduces operation time, enhances clinical applicability and safety, while also fulfilling the water injection function and reducing manufacturing costs.
Smart Images
Figure CN122376244A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of surgical instrument technology, specifically to a spiral cutting capillary structure for an endoscopic mucosal incision knife. Background Technology
[0002] A mucosal incision knife is a specialized instrument used in endoscopic surgery to remove diseased mucosal tissue in the digestive tract, respiratory tract, and other areas. It is commonly used in endoscopic mucosal dissection or endoscopic mucosal resection.
[0003] To simultaneously meet the functional requirements of water injection, conductivity, and flexibility, the traction rope connecting the blade head and the conductive plug of the handle of existing mucosal incision knives must be conductive and hollow inside.
[0004] Traditionally, there are two solutions: First, multi-strand braided hollow steel rope, which can meet the requirements of water and electricity supply as well as flexibility, allowing instruments to smoothly pass through bends in the endoscope forceps channel. However, the disadvantage is that the cost is very high, and mass production is not very meaningful for disposable instruments, especially under the pressure of centralized procurement. Second, cutting hollow stainless steel tubes, which can meet the requirements of water supply and flexibility. However, the disadvantage is that the overall impedance is relatively high. This is because the conductive path becomes longer after spiral cutting, and the resistance increases sharply. In actual clinical cutting, it is relatively blunt, prolonging the operation time and increasing patient suffering. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a spiral cutting capillary structure for an endoscopic mucosal incision knife, thereby solving the problems mentioned in the background art.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a spiral cutting capillary structure for an endoscopic mucosal incision knife, comprising a conductive substrate, wherein the conductive substrate is provided with spiral slits extending along its length direction, the number of spiral slits N≥2, and when N=2, the conductive substrate comprises a first conductive spiral band and a second conductive spiral band, the first conductive spiral band and the second conductive spiral band are obtained by the conductive substrate being divided by the spiral slits, the first conductive spiral band and the second conductive spiral band form a parallel dual conductive path, and the phase difference between the first conductive spiral band and the second conductive spiral band in the circumferential direction is 180°.
[0007] Preferably, the spiral cut is centrally symmetrical with respect to the central axis of the conductive substrate.
[0008] Preferably, the pitch of the helical cut is a variable pitch.
[0009] Preferably, when the pitch of the helical cut is variable, the pitch gradually increases from the front to the end along the extension direction of the conductive substrate, and the pitch at the front is smaller than the pitch at the end.
[0010] Preferably, when the pitch of the spiral cut is variable, the pitch range is 2mm to 6mm.
[0011] Preferably, the conductive substrate further includes at least one reserved section, which is a solid section without the cut, to enhance local conductivity.
[0012] Preferably, the phase difference between each spiral conductive strip of the spiral cut is 360° / N. When N=3, the conductive substrate is divided into three parts by the spiral cut, namely the first conductive spiral strip, the second conductive spiral strip, and the third conductive spiral strip.
[0013] Preferably, the pitch of the N slits in the spiral cut is a variable pitch.
[0014] Preferably, the conductive substrate is made of medical-grade stainless steel, specifically SUS304, which has good biocompatibility, corrosion resistance and mechanical strength.
[0015] Preferably, the width of the spiral slit is 0.02mm to 0.05mm, and the width of each spiral slit is consistent to ensure that the cross-sectional area of each conductive spiral strip is uniform and the current distribution is balanced.
[0016] Preferably, the length of the retaining section is 5mm to 20mm, and the retaining section is disposed at least at the front end, middle end, or rear end of the conductive substrate. The front retaining section can enhance the conductivity near the cutter head and improve cutting efficiency; the middle retaining section can reduce the overall resistance and increase the stability of the structure; the rear retaining section can enhance the conductivity and mechanical strength of the connection part with the handle.
[0017] Preferably, the cross-section of the conductive spiral strip is rectangular, and the ratio of the width of the rectangle to the wall thickness of the conductive substrate is 1:1 to 3:1, so as to maximize the conductive cross-sectional area and reduce the resistance while ensuring flexibility.
[0018] Preferably, the outer surface of the conductive substrate is provided with an insulating coating. This insulating coating only covers the spiral slit area, while the retained section and the connection areas at both ends are not covered by the insulating coating. The insulating coating can prevent current leakage, avoid unnecessary damage to normal tissue, and improve the safety of the surgery.
[0019] Preferably, the insulating coating has a thickness of 5μm to 20μm and has good insulation properties, biocompatibility and wear resistance.
[0020] Preferably, the conductive substrate has a blade connection part at the front end and a handle connection part at the rear end. Both the blade connection part and the handle connection part are solid structures without slits, which facilitates reliable welding or crimping connection with the blade and the handle.
[0021] Preferably, the length of the blade head connecting part is 3mm to 10mm, and the length of the handle connecting part is 10mm to 30mm, to ensure the firmness and conductivity of the connection.
[0022] Preferably, the outer diameter of the conductive substrate is 0.6mm to 1.2mm, the inner diameter is 0.4mm to 1.0mm, and the overall length is 1.5m to 3.0m, which can be adjusted according to different endoscope models and surgical requirements.
[0023] Preferably, when N=4, the conductive substrate is divided into four parts by a spiral cut, namely a first conductive spiral strip, a second conductive spiral strip, a third conductive spiral strip and a fourth conductive spiral strip. The phase difference between each conductive spiral strip in the circumferential direction is 90°, forming four parallel conductive paths, which further reduces the overall resistance.
[0024] Preferably, the spiral slit is made by laser cutting process, with a surface roughness Ra≤0.8μm, high cutting precision, smooth cut, no burrs, and avoids scratching the endoscope channel during use.
[0025] Preferably, the inner surface of the conductive substrate is polished to a surface roughness Ra≤0.4μm to reduce liquid flow resistance, ensure smooth water injection, and reduce the risk of liquid residue and bacterial growth.
[0026] This invention provides a spiral cutting capillary structure for an endoscopic mucosal incision knife. It has the following beneficial effects:
[0027] 1. The spiral cutting capillary structure for an endoscopic mucosal incision knife, by setting a conductive substrate and at least two spiral slits on it, utilizes the multiple conductive spiral bands formed by the spiral slits to form a specific phase difference in the circumferential direction, thus forming a parallel conductive path. Combined with the reserved section set in the conductive substrate, the overall impedance is reduced, and the cutting performance is improved.
[0028] 2. This spiral cutting capillary structure for endoscopic mucosal incision knife, by setting a conductive substrate and adopting a variable pitch spiral cut, utilizes the distribution of a smaller pitch at the front and a larger pitch at the end to make the conductive substrate itself directly form an integrated flexible conductive channel without additional weaving or assembly, thus achieving simultaneous satisfaction of the requirements for water injection, conductivity and flexibility, and ultimately improving clinical applicability without increasing manufacturing costs.
[0029] 3. This spiral cutting capillary structure for endoscopic mucosal incision integrates conductivity, water permeability, and flexibility into one unit, eliminating the need for additional components. The hollow conductive substrate can simultaneously serve as a water injection channel, enabling irrigation, hemostasis, and exposure of the surgical field during surgery. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of the cross-section of a hollow steel rope in the prior art;
[0031] Figure 2 This is a schematic diagram of a spiral-cut stainless steel capillary structure in the prior art.
[0032] Figure 3 This is a schematic diagram of the overall structure of one embodiment of the present invention;
[0033] Figure 4 This is a cross-sectional view of the internal structure of one embodiment of the present invention;
[0034] Figure 5 This is a schematic diagram of the overall structure of the variable pitch screw of the present invention;
[0035] Figure 6 This is a cross-sectional schematic diagram of the internal structure of the variable pitch screw of the present invention;
[0036] Figure 7 This is a schematic diagram of the overall structure of another embodiment of the present invention;
[0037] Figure 8 This is a cross-sectional view of the internal structure of another embodiment of the present invention.
[0038] In the figure: 1. Conductive substrate; 2. Spiral cut; 3. First conductive spiral strip; 4. Second conductive spiral strip; 5. Third conductive spiral strip. Detailed Implementation
[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0040] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.
[0041] Example 1
[0042] Please see Figure 1-2 These are two existing technical solutions. Figure 1 It is a multi-strand braided hollow steel rope. Hollow steel rope can meet the requirements of water and electricity transmission as well as flexibility. However, its disadvantage is that it is very expensive, and mass production is not very meaningful under the pressure of centralized procurement. Figure 2 For a 2.4-meter-long SUS304 stainless steel capillary tube with an outer diameter of 0.8mm, an inner diameter of 0.6mm, and a length, the overall impedance is approximately 7.9Ω. After being laser-cut with a pitch of 1.5mm and a width of 0.03mm to form a helical spring, the overall impedance suddenly increases to about 21Ω. Clinical feedback indicates that the cut is blunt, prolonging the operation time and increasing patient suffering.
[0043] Please see Figure 3-6 The present invention provides a technical solution: a spiral cutting capillary structure for an endoscopic mucosal incision knife, comprising a conductive substrate 1, wherein the conductive substrate 1 is provided with spiral slits 2 extending along its length direction, the number of spiral slits 2 N≥2, the conductive substrate 1 includes a first conductive spiral band 3 and a second conductive spiral band 4, the first conductive spiral band 3 and the second conductive spiral band 4 are obtained by the conductive substrate 1 being divided by the spiral slits 2, the first conductive spiral band 3 and the second conductive spiral band 4 form a parallel dual conductive path, and the phase difference between the first conductive spiral band 3 and the second conductive spiral band 4 in the circumferential direction is 180°, and the spiral slits 2 are centrally symmetrical with respect to the central axis of the conductive substrate;
[0044] The pitch of the spiral cut 2 is a variable pitch. The pitch gradually increases from the front to the end along the extension direction of the conductive substrate 1, and the pitch of the front section is 3mm and the pitch of the end section is 5mm.
[0045] A reserved section is provided on the conductive substrate 1. The reserved section is located in the middle of the conductive substrate 1 and has a length of 10mm. It is a solid section without slits to enhance local conductivity.
[0046] The conductive substrate 1 is made of SUS304 medical stainless steel, with an outer diameter of 0.8 mm, an inner diameter of 0.6 mm, and an overall length of 2.4 m. The inner surface of the conductive substrate 1 is polished, and the surface roughness Ra≤0.4 μm.
[0047] The width of the spiral slit 2 is 0.03 mm, and it is made by laser cutting process. The roughness of the cut surface Ra≤0.8μm;
[0048] The cross-section of the conductive spiral strip is rectangular, and the ratio of the width of the rectangle to the wall thickness of the conductive substrate 1 is 2:1.
[0049] The conductive substrate 1 has a 5mm long blade connection part at the front end and a 20mm long handle connection part at the rear end. Both the blade connection part and the handle connection part are solid structures without slits.
[0050] The conductive substrate 1 is made of SUS304 stainless steel. An insulating coating is provided on the outer surface of the conductive substrate 1. The insulating coating only covers the spiral cut area 2, and does not cover the reserved section and the connection area at both ends. The thickness of the insulating coating ranges from 5μm to 20μm.
[0051] Next, taking a capillary tube with an outer diameter of 0.8 mm, an inner diameter of 0.6 mm, and a length of 2.4 meters as an example, we will calculate the initial resistance:
[0052] radius:
[0053]
[0054]
[0055] Cross-sectional area
[0056]
[0057]
[0058]
[0059] Length: L = 2.4m
[0060] Resistance: R = ρL / A
[0061] The calculation yielded:
[0062] The original resistance was approximately 7.9Ω.
[0063] A spring tube with a width of 0.03 mm and a pitch of 1.5 mm was laser-cut. After helical cutting, the current can only flow along the helical metal strip. The subsequent resistance calculation is as follows:
[0064] Median diameter: D m =0.7mm
[0065] Circumference: C=πD m =2.20mm
[0066] Length of each spiral turn:
[0067] L h =√(C 2 +P 2 )
[0068] L h =√(2.20 2 +1.5 2 )
[0069] L h ≈2.66mm
[0070] The axial advance was 1.5mm, but the actual travel distance was 2.66mm.
[0071] Length ratio = 2.66 / 1.5 = 1.77
[0072] Consider cutting the seam:
[0073] Effective pitch =
[0074] Correction factor ≈ 1.81
[0075] When the conductive cross-sectional area decreases
[0076] Original cross-sectional area: 0.2199 mm 2
[0077] Spiral metal strip width: 1.47mm
[0078] Cross-sectional area: A new =0.1 × 1.47 = 0.147 mm 2
[0079] Area ratio: 0.147 / 0.2199 = 0.668
[0080] Resistance ratio: R new / R old =Length ratio / Area ratio = 1.81 / 0.668 ≈ 2.7
[0081] final:
[0082] Original resistance: ≈7.9Ω
[0083] After spiral cutting: ≈21Ω
[0084] Multiplier: Approximately 2.7x
[0085] The resistance calculation process after constructing a symmetrical double helix and increasing the pitch to 3mm:
[0086] Conductive path after double helix
[0087] Median diameter: D m =0.7mm
[0088] Circumference: C=πD m ≈2.20mm
[0089] Pitch: P=3mm
[0090] Single turn helix length: L h =√(C 2 +P 2 )L h =√(2.22+3 2 )L h ≈3.72mm
[0091] Axial advance of 3mm resulted in actual travel of 3.72mm.
[0092] Length ratio = 3.72 / 3 ≈ 1.24
[0093] Therefore, the conductive path only increases by about 24%.
[0094] When the kerf is 0.03mm:
[0095] Metal bandwidth:
[0096] However, due to the symmetrical cutting of the double helix, two parallel conductive paths are actually formed.
[0097] The equivalent cross-sectional area is approximately restored to the original level, so the area loss is almost entirely compensated by the parallel connection.
[0098] The path becomes 1.24 times longer, therefore R new ≈7.9×1.24≈9.8Ω
[0099] The calculations above show that by increasing the pitch and using a symmetrical helical cutting method, the required performance can be achieved while reducing resistance, thus satisfying the usage requirements.
[0100] In use, the front end of the conductive substrate 1 with the spiral cut 2 is connected to the cutter head, and the rear end is connected to the conductive plug of the handle.
[0101] During the surgery, the instruments are introduced into the body through the endoscope channel. After being energized, the current is transmitted through the dual parallel path formed by the first conductive spiral band 3 and the second conductive spiral band 4, and the local conductivity is enhanced by the retained section.
[0102] Simultaneously, liquid is injected through the hollow cavity of the conductive substrate 1. The conductive substrate 1 achieves smooth bending by relying on the distribution of the front pitch being smaller than the end pitch, and completes low-resistance cutting of the target tissue under liquid flow conditions.
[0103] Example 2
[0104] Please see Figure 7-8 Based on Embodiment 1, the present invention provides a technical solution: the number of spiral cuts 2 is N=3, the conductive substrate 1 is divided into three parts by the spiral cuts 2, namely the first conductive spiral strip 3, the second conductive spiral strip 4, and the third conductive spiral strip 5, the phase difference of each conductive spiral strip in the circumferential direction is 120°, forming three parallel conductive paths;
[0105] The pitch of the spiral cut 2 is a variable pitch. The pitch gradually increases from the front to the end along the extension direction of the conductive substrate 1. The pitch at the front is 2 mm and the pitch at the end is 6 mm.
[0106] The rest of the content is consistent with the content described in Example 1.
[0107] When in use, after being powered on, the current is transmitted through three parallel paths formed by the first conductive spiral band 3, the second conductive spiral band 4, and the third conductive spiral band 5, which are divided by the spiral slit 2. The total resistance is further reduced to about 7.5Ω, which is close to the resistance value of the original capillary.
[0108] Meanwhile, the conductive substrate 1 achieves smooth bending by relying on the variable pitch that gradually increases from the front to the end, and completes low-resistance cutting of the target tissue in the liquid flow state.
[0109] Example 3
[0110] Based on Embodiment 1, this embodiment provides a double helix structure with multiple retained segments:
[0111] The conductive substrate 1 has three retention sections, located at the front end, middle end and rear end respectively;
[0112] The front end retains a 5mm length, which is close to the cutter head connection part, and is used to enhance the conductivity near the cutter head and improve cutting efficiency;
[0113] The middle section is 10mm long and is located in the middle of the conductive substrate 1. It is used to reduce the overall resistance and increase the stability of the structure.
[0114] The rear end retains a 15mm length, which is adjacent to the handle connection part, and is used to enhance the conductivity and mechanical strength of the connection part with the handle;
[0115] The pitch of the spiral cut 2 varies from 3.2mm to 4.8mm, with a pitch of 3.2mm at the beginning and 4.8mm at the end.
[0116] The conductive substrate 1 is made of SUS316L medical-grade stainless steel, which has better corrosion resistance and biocompatibility.
[0117] An insulating coating is provided on the outer surface of the conductive substrate 1. The coating thickness is 10μm and it only covers the spiral cut 2 area. The reserved section, the cutter head connection part and the handle connection part are not covered by the insulating coating.
[0118] The rest of the content is consistent with the content described in Example 1.
[0119] In use, the three retained sections work synergistically to further reduce overall resistance while improving structural stability and reliability. The insulating coating effectively prevents current leakage, avoids thermal damage to normal tissue, and enhances surgical safety.
[0120] Example 4
[0121] Based on Example 1, this example provides a double helix structure with different pitch variation methods:
[0122] The pitch of the spiral cut 2 adopts a segmented variable pitch design, specifically divided into three segments:
[0123] Front section (0-800mm): The pitch is 3mm, which has the best flexibility and makes it easy to pass through the curved parts of the endoscope forceps channel;
[0124] Middle section (800mm~1600mm): The pitch is 4mm, with moderate flexibility and rigidity, serving as a transition;
[0125] Rear section (1600mm~2400mm): The pitch is 5mm, which provides the best rigidity and makes it easier for doctors to precisely control the blade.
[0126] The conductive substrate 1 has two retention sections, located at the junction of the middle section and the rear section, and at the junction of the rear section and the handle connection, respectively. The length of each retention section is 8mm.
[0127] The outer surface of the conductive substrate 1 is provided with a layer of parylene insulating coating with a coating thickness of 15 μm;
[0128] The rest of the content is consistent with the content described in Example 1.
[0129] In use, the segmented pitch design allows for a more precise distribution of flexibility in the conductive substrate, better adapting to the bending requirements of different parts. Two retained segments further enhance the structure's stability and conductivity, ensuring stable and reliable performance during prolonged surgical procedures.
[0130] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A spiral cutting capillary structure for an endoscopic mucosal incision knife, comprising a conductive substrate (1), characterized in that: The conductive substrate (1) is provided with a spiral cut (2) extending along its length direction. The number of spiral cuts (2) is N≥2. When N=2, the conductive substrate (1) includes a first conductive spiral strip (3) and a second conductive spiral strip (4). The first conductive spiral strip (3) and the second conductive spiral strip (4) are obtained by the conductive substrate (1) being divided by the spiral cut (2). The first conductive spiral strip (3) and the second conductive spiral strip (4) form a parallel dual conductive path, and the phase difference between the first conductive spiral strip (3) and the second conductive spiral strip (4) in the circumferential direction is 180°.
2. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 1, characterized in that: The spiral cut (2) is centrally symmetrical with respect to the central axis of the conductive substrate.
3. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 1, characterized in that: The pitch of the spiral cut (2) is a variable pitch.
4. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 3, characterized in that: When the pitch of the spiral cut (2) is variable, the pitch gradually increases from the front to the end along the extension direction of the conductive substrate (1), and the pitch of the front section is smaller than the pitch of the end section.
5. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 4, characterized in that: When the pitch of the spiral cut (2) is variable, the pitch range is 2mm to 6mm.
6. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 1, characterized in that: The conductive substrate (1) is further provided with at least one reserved section, which is a solid section without the cut to enhance local conductivity.
7. A spiral cutting capillary structure for an endoscopic mucosal incision knife according to any one of claims 1 to 6, characterized in that: The phase difference between each spiral conductive strip of the spiral cut (2) is 360° / N. When N=3, the conductive substrate (1) is divided into three parts by the spiral cut (2), namely the first conductive spiral strip (3), the second conductive spiral strip (4), and the third conductive spiral strip (5).
8. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 7, characterized in that: The pitch of the N slits in the spiral slit (2) is a variable pitch.
9. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 1, characterized in that: The conductive substrate (1) is made of medical stainless steel, specifically SUS304. The outer diameter of the conductive substrate (1) ranges from 0.6mm to 1.2mm, the inner diameter ranges from 0.4mm to 1.0mm, and the overall length ranges from 1.5m to 3.0m.
10. The spiral cutting capillary structure for an endoscopic mucosal incision knife according to claim 9, characterized in that: The outer surface of the conductive substrate (1) is provided with an insulating coating. The insulating coating only covers the spiral cut area (2), and does not cover the reserved section and the connection area at both ends. The thickness of the insulating coating ranges from 5μm to 20μm.