Small-view blind area high-frequency incision knife based on partial insulation of knife bar

Abstract

The invention discloses a small-view blind area high-frequency incision knife based on knife bar partial insulation, and belongs to the technical field of medical instruments, the incision knife comprises an outer tube and a knife bar slidably arranged in the outer tube, and the far end of the knife bar can extend out of the far end of the outer tube; the cutter bar has the overall extension length from the far end face of the cutter bar, and a conductive working section located at the far end of the cutter bar and used for tissue cutting. The overall extension length is 3.5 mm to 4 mm; the axial length of the conductive working section is limited to be 1.5 mm to 2 mm; an insulating layer is arranged on the part, positioned on one side of the near end of the conductive working section, of the cutter bar; the angle of a blind area formed by shielding of the insulating base under the visual field of an endoscope is directly reduced, a doctor can clearly observe the overall shape and the extending position of the cutter bar and the contact relation between the cutter bar and focus tissue, and a direct visual basis is provided for judging the cutting boundary and controlling the cutting path. And meanwhile, the risk of excessive thermal damage, mis-cutting or perforation of tissues possibly caused by the too long cutter bar is avoided.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a high-frequency cutting knife with a small field of view blind zone based on partial insulation of the blade shaft. Background Technology

[0002] The high-frequency cutting knife is an indispensable medical instrument in endoscopic submucosal dissection, mainly used in conjunction with high-frequency electricity to remove lesions of the digestive tract mucosa (such as gastric mucosa, colorectal mucosa, and esophageal mucosa). Its working principle involves operating a handle to extend the blade located at the front end of the outer tube. High-frequency current is conducted through the blade to the lesion tissue, and the high temperature generated by the discharge carbonizes and separates the tissue or stops bleeding, thereby achieving electrocautery or electrocoagulation.

[0003] Currently, mainstream high-frequency cutting knives on the market, such as the common T-type water-injected high-frequency cutting knife, typically have a blade extension length of 1.5mm or 2mm. This is to control the length of the conductive working area, ensuring safety during surgical cutting and avoiding the risk of accidentally cutting healthy tissue or causing perforation due to an excessively long blade. Therefore, the entire area extending from the blade is the conductive working area; that is, the length of the blade extension determines its conductive working length.

[0004] However, existing technologies have the following limitations in practical clinical applications: Due to the short extension length of the scalpel, a large portion of the scalpel is easily obscured by the insulating base under endoscopic visualization, creating a significant blind spot. Surgeons cannot clearly observe the actual position of the scalpel and its relative relationship to the lesion tissue, relying solely on experience and touch for judgment, which poses a significant challenge to precise cutting of the lesion edge and control of the cutting path. Furthermore, in certain special surgical scenarios, such as when the cutting site is far away, located deep in organ folds, or partially obscured by other tissues, the existing short scalpel may not effectively reach the target lesion, causing cutting difficulties and even requiring instrument replacement or a change in surgical approach, increasing the complexity and time cost of the surgery.

[0005] To address the blind spot problem, some existing designs attempt to improve the viewing angle by increasing the radius of the insulating base. However, limited by the overall size and structural strength of the product, the improvement effect of this method is extremely limited and cannot fundamentally eliminate the blind spot. Simply increasing the extension length of the tool holder to improve the field of view would directly lead to a simultaneous increase in the conductive working length, thereby creating new safety hazards—an excessively long conductive area is highly susceptible to thermal damage to non-target tissues, significantly increasing the risk of accidental cutting and perforation. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a high-frequency cutting tool with a small field of view blind zone based on the insulation of the tool holder, thereby solving the problems in the background art.

[0007] To achieve the above-mentioned objectives, the first aspect of the present invention proposes a high-frequency cutting knife with a small field of view blind zone based on partial insulation of the cutting bar, comprising an outer tube and a cutting bar slidably disposed within the outer tube, wherein the distal end of the cutting bar can extend from the distal end of the outer tube; the cutting bar has an overall extension length (H) measured from its distal end face, and a conductive working section located at its distal end for tissue cutting; The overall protrusion length is 3.5mm to 4mm; The axial length of the conductive working section is limited to 1.5 mm to 2 mm; An insulating layer is provided on the portion of the cutter bar located near the conductive working section, so that when the cutter bar is extended, only the conductive working section is exposed for conductive cutting.

[0008] Optionally, the insulating layer is an insulating coating applied to the surface of the tool holder.

[0009] Optionally, the insulating coating is made of PTFE, FEP or PET.

[0010] Optionally, the insulating layer is a heat shrink tubing sleeved on the tool holder.

[0011] Optionally, the tool holder is provided with a boss for axially limiting the heat shrink tubing.

[0012] Optionally, the boss is located 1.5mm to 2mm from the distal end face of the tool holder.

[0013] Optionally, the insulating layer is an insulating rigid tube sleeved on the tool holder.

[0014] Optionally, the tool holder has a stepped structure, and the insulating rigid tube is sleeved on the stepped structure of the tool holder.

[0015] Optionally, the proximal end of the cutter bar is connected to the traction wire via a connecting pipe, and the rear end of the insulating rigid tube abuts against the distal end of the connecting pipe.

[0016] Optionally, the insulating rigid tube is made of ceramic or PTFE.

[0017] The beneficial effects of this invention are: 1. The present invention relates to a high-frequency cutting knife with a small blind zone based on partial insulation of the cutting rod. By setting the overall extension length of the cutting rod to 3.5mm to 4mm, compared to the 1.5mm to 2mm of existing conventional products, the overall extension length is increased by 1.5mm to 2mm. This directly reduces the blind zone angle formed by the insulating seat obstructing the endoscopic view, allowing doctors to clearly observe the overall shape of the cutting rod, its extension position, and its contact relationship with the lesion tissue, providing direct visual evidence for accurately judging the cutting boundary and controlling the cutting path. Simultaneously, by setting an insulating layer on the proximal side of the distal end of the cutting rod, the axial length of the conductive working section actually used for tissue cutting is strictly limited to the range of 1.5mm to 2mm. Even with the increased overall extension length of the cutting rod, the working area participating in high-frequency discharge remains consistent with existing mainstream products, thereby effectively avoiding the risk of excessive tissue thermal damage, accidental cutting, or perforation caused by an excessively long cutting rod. This solves the two major technical problems of blind zone and safety risks.

[0018] 2. This invention, a high-frequency cutting knife with a small field of view and blind zone based on partial insulation of the blade shank, provides multiple alternative implementation schemes through insulation treatment of the rear end of the blade shank to adapt to different production process requirements and cost considerations. Specifically, materials such as PTFE, FEP, or PET can be directly coated onto the surface of the blade shank, which is simple, convenient to implement, and suitable for mass production. By setting a boss on the blade shank to axially limit the heat shrink tubing, the positional stability of the insulation layer during repeated extension and retraction of the blade shank is ensured, further improving the reliability of the product. The step structure and the cooperation of the connecting tube to fix the insulating rigid tube bidirectionally provides high structural strength, making it particularly suitable for surgical scenarios with higher requirements for lateral rigidity and wear resistance. The parallel protection of multiple solutions not only reflects the technical depth of this invention but also provides a solid barrier for subsequent product iteration and design avoidance.

[0019] 3. The high-frequency cutting knife of this invention, with its partially insulated blade shaft, allows for easy access to lesions inaccessible to traditional short blade shafts, such as the posterior wall of the stomach fundus or the colorectal fold. In complex situations where the lesion is far away or partially obscured by normal tissue, the surgeon does not need to frequently adjust the endoscope angle or change instruments; the cutting operation can be completed simply by extending the extended blade shaft. This effectively reduces the difficulty of the surgical procedure, shortens the operation time, and minimizes patient discomfort and medical risks. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the high-frequency cutting tool with a small field of view and blind zone based on the insulation of the tool holder part of the present invention; Figure 2This is a schematic diagram of the structure of the high-frequency cutting knife with a small field of view blind zone based on the insulation of the blade shank part of the present invention when the insulation layer is an insulating coating; Figure 3 This is a schematic diagram of the structure of the high-frequency cutting knife with a small field of view blind zone based on the insulation of the blade bar part of the present invention when the insulation layer is heat shrink tubing; Figure 4 This is a schematic diagram of the structure of the high-frequency cutting knife with a small field of view blind zone based on the insulation of the blade holder part of the present invention when the insulation layer is an insulating hard tube; Figure 5 For reference only for existing products Figure 1 ; Figure 6 For reference only for existing products Figure 2 ; Figure 7 For reference only for existing products Figure 3 .

[0021] Explanation of reference numerals in the attached figures: 100. Outer tube; 200. Tool holder; 210. Conductive working section; 220. Boss; 230. Stepped structure; 310. Insulating coating; 320. Heat shrink tubing; 330. Insulating rigid tube; 400. Connecting tube; 500. Traction wire.

[0022] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Reference Figures 1-7An embodiment of the present invention provides a small field-of-view blind zone high-frequency cutting knife based on partial insulation of the cutting rod, comprising an outer tube 100 and a cutting rod 200 slidably disposed within the outer tube 100, the distal end of the cutting rod 200 being able to extend from the distal end of the outer tube 100; the cutting rod 200 having an overall extension length (H) measured from its distal end face, and a conductive working section 210 located at its distal end for tissue cutting; the overall extension length is 3.5 mm to 4 mm; the axial length of the conductive working section 210 is limited to 1.5 mm to 2 mm; an insulating layer is provided on the portion of the cutting rod 200 located on the proximal side of the conductive working section 210, so that after the cutting rod 200 is extended, only the conductive working section 210 is exposed for conductive cutting.

[0026] During operation, the doctor controls the handle to extend the distal end of the blade 200 from the distal end of the outer tube 100 to perform high-frequency electrocautery or electrocoagulation surgery.

[0027] To address the problems in existing technologies, such as large blind spots in the endoscopic field of view and difficulty in accessing cutting sites due to the excessively short extension of the scalpel (typically 1.5mm-2mm), this invention first sets the overall extension length H of the scalpel 200 to 3.5mm to 4mm. The overall extension length H refers to the distance from the farthest end face of the scalpel 200 to the point where it intersects with the farthest end face of the outer tube 100. By extending the overall extension length H by 1.5mm to 2mm (compared to the existing 1.5mm-2mm extension length), the blind spot angle under endoscopic view can be significantly reduced. The longer scalpel 200 exposes the main body of the scalpel 200, which was originally obscured by the insulating seat, allowing the doctor to clearly observe the overall shape and position of the scalpel 200, which is crucial for precise cutting and path control at the edges of complex lesions. Especially in extreme situations where the cutting site is far away or obscured by other tissues, such as deep in the gastric fundus or colorectal folds, the extended blade 200 can smoothly reach the target lesion, avoiding the predicament of having to change instruments or surgical approaches because the instruments "cannot reach" the lesion, effectively improving the flexibility and success rate of the surgery.

[0028] However, simply lengthening the scalpel 200 introduces new safety issues: an excessively long conductive portion may cause accidental thermal damage to non-target tissues, increasing the risk of perforation. Therefore, this invention incorporates an insulating design for the scalpel 200. The distal end of the scalpel 200 is defined as a conductive working section 210 for tissue cutting, with its axial length strictly controlled between 1.5mm and 2mm, consistent with the conductive length of existing mainstream high-frequency cutting scalpels. An insulating layer is provided on the portion of the scalpel 200 located proximal to the conductive working section 210. When the scalpel 200 extends to its overall length of 3.5mm-4mm, only the front 1.5mm-2mm (i.e., the conductive working section 210) is exposed and participates in conductive cutting; the remaining portion is covered by the insulating layer and does not participate in discharge. This cleverly balances the contradiction between a "large field of view" and "high safety": the surgeon can obtain a clear field of view while ensuring that the cutting depth and range are consistent with established surgical practices, thus solving the problem of blind spots without altering the surgeon's operational feel and safety perception.

[0029] To achieve partial insulation of the tool holder 200, the present invention provides a variety of specific and industrially producible implementation schemes, which can be used individually or combined or equivalently replaced according to cost and performance requirements.

[0030] In the first implementation scheme, refer to Figure 2 The insulating layer is an insulating coating 310 directly coated onto the surface of the tool holder 200. Specifically, it can be a polymer material with good biocompatibility, insulation, and high-temperature resistance, such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), or PET (polyethylene terephthalate). A dense, uniform, and robust insulating coating 310 is formed on the surface of the tool holder 200 through processes such as spraying, dip coating, or electrostatic spraying. It is important to note that the coating thickness needs to be precisely controlled to ensure reliable insulation performance without being too thick and affecting the smooth sliding of the tool holder 200 within the outer tube 100. Typically, the coating thickness is controlled between a few micrometers and tens of micrometers. The distal boundary of the coating must be precisely controlled to ensure that the length of the conductive working section 210 is 1.5 mm to 2 mm. This simplifies the process, reduces cost, and minimizes the impact on the original structure of the tool holder 200.

[0031] In the second implementation scheme, refer to Figure 3The insulating layer is a heat-shrink tubing 320 sleeved on the tool holder 200. The heat-shrink tubing 320 is preferably made of materials such as PTFE, FEP, or PET. During assembly, the heat-shrink tubing 320 is sleeved onto the tool holder 200 at a predetermined position, and then heated to shrink it tightly and cover the tool holder 200. To prevent the heat-shrink tubing 320 from axially shifting due to repeated expansion and contraction of the tool holder 200 during use, thus affecting the stability of the insulation length, the present invention designs a boss 220 for axial positioning on the tool holder 200. Figure 3 As shown, the boss 220 can be a tiny protrusion formed by stamping or turning the tool holder 200 itself. More preferably, the boss 220 is precisely positioned 1.5 mm to 2 mm from the distal end face of the tool holder 200, i.e., near the boundary of the conductive working section 210. After the heat shrink tubing 320 shrinks, its front end rests against the boss 220, thus being firmly fixed. The insulation layer of the heat shrink tubing 320 is thicker and more uniform than the coating, resulting in higher insulation reliability. As an equivalent alternative to the boss 220 design, a tiny metal ring can be laser-welded onto the tool holder 200, or an annular groove can be machined onto the tool holder 200 to accommodate the insertion of the end of the heat shrink tubing 320, as long as the axial positioning purpose is achieved.

[0032] In the third implementation scheme, refer to Figure 4 The insulating layer is an insulating rigid tube 330 sleeved on the tool holder 200. The insulating rigid tube 330 is a rigid tube with a predetermined length and wall thickness, and its material can be ceramic (such as zirconia ceramic, alumina ceramic) or PTFE, which have excellent insulation properties and mechanical strength. Since the insulating rigid tube 330 itself is non-contractile, its fixing method to the tool holder 200 requires special design. For this purpose, a stepped structure 230 is provided on the tool holder 200. During assembly, the insulating rigid tube 330 is sleeved on the stepped structure 230 of the tool holder 200 with a smaller diameter, and its rear end abuts against the distal end of a key component—the connecting tube 400. The connecting tube 400 is used to connect the proximal end of the tool holder 200 and the traction wire 500 used for control. When the traction wire 500 pulls the tool holder 200, the insulating rigid tube 330 is pressed tightly by the connecting tube 400 at its rear end, while its front end cannot move forward due to the stepped structure 230. This achieves bidirectional fixation on the tool holder 200, completely preventing movement during use. The ceramic material not only provides excellent insulation performance but also has extremely high hardness and wear resistance, effectively protecting the internal tool holder 200.

[0033] The three insulation solutions described above (insulating coating 310, heat shrink tubing 320, and insulating rigid tubing 330) are not mutually exclusive, and those skilled in the art can combine them according to actual needs. For example, based on the use of insulating rigid tubing 330, a thin layer of insulating adhesive can be applied to the joint between the conductive working section 210 and the insulating rigid tubing 330 to further enhance the reliability of the insulation. Alternatively, in the heat shrink tubing 320 solution, in addition to the boss 220, a coupling agent can be applied to the surface of the tool holder 200 to enhance the bonding force between the heat shrink tubing 320 and the tool holder 200.

[0034] In summary, this invention successfully developed a high-frequency cutting knife that combines clear vision, precise control, and safe use by decoupling the overall extension length of the blade shank 200 from the conductive working length and providing multiple reliable solutions for partial insulation. Its beneficial effects are as follows: Firstly, the overall extension length (H) of 3.5mm to 4mm significantly reduces the blind spot under endoscopy, allowing doctors to clearly observe the contact between the blade tip and tissue and complete the cut at the extreme position; secondly, by strictly limiting the conductive working section 210 to 1.5mm to 2mm through the insulation layer, the same safety as existing mainstream products is ensured, effectively avoiding the risk of accidental cutting and perforation caused by excessive blade length 200, greatly improving the convenience and safety of ESD surgery.

[0035] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A high-frequency cutting blade with a small field of view blind zone based on partial insulation of the blade shank, comprising an outer tube (100) and a blade shank (200) slidably disposed within the outer tube (100), wherein the distal end of the blade shank (200) can extend from the distal end of the outer tube (100); characterized in that, The blade holder (200) has an overall extension length (H) measured from its distal end face, and a conductive working section (210) located at its distal end for tissue cutting. The overall protrusion length is 3.5mm to 4mm; The axial length of the conductive working section (210) is limited to 1.5 mm to 2 mm; An insulating layer is provided on the portion of the cutter bar (200) located near the conductive working section (210) so that when the cutter bar (200) is extended, only the conductive working section (210) is exposed for conductive cutting.

2. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 1, is characterized in that... The insulating layer is an insulating coating (310) applied to the surface of the tool holder (200).

3. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 2, is characterized in that... The insulating coating (310) is made of PTFE, FEP or PET.

4. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 1, is characterized in that... The insulating layer is a heat shrink tubing (320) sleeved on the knife bar (200).

5. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 4, is characterized in that... The tool holder (200) is provided with a boss (220) for axially limiting the heat shrink tubing (320).

6. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 5, is characterized in that... The boss (220) is located 1.5 mm to 2 mm away from the far end face of the tool holder (200).

7. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 1, is characterized in that... The insulating layer is an insulating rigid tube (330) sleeved on the knife bar (200).

8. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 7, is characterized in that... The tool holder (200) has a stepped structure (230), and the insulating hard tube (330) is sleeved on the stepped structure (230) of the tool holder (200).

9. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 8, is characterized in that... The proximal end of the blade (200) is connected to the traction wire (500) via a connecting pipe (400), and the rear end of the insulating rigid tube (330) abuts against the distal end of the connecting pipe (400).

10. The high-frequency cutting tool with a small field of view blind zone based on partial insulation of the cutting shank, as described in claim 8, is characterized in that... The insulating rigid tube (330) is made of ceramic or PTFE.

Images