Method for optimizing release force of hemostatic clip of interventional medical instrument and hemostatic clip

Abstract

The invention relates to the technical field of hemostatic clip production, in particular to a method for optimizing release force of hemostatic clips of interventional medical instruments, which comprises the following steps: S1, testing the release force of a batch of hemostatic clips, and dividing the hemostatic clips into n groups according to the release force; the release force average values of the first group to the nth group are sequentially increased or sequentially decreased; s2, at least one of the first group to the nth group is defined as a standard group, mandrels of the hemostatic clips in the standard group are defined as standard mandrels, mechanical property testing is conducted on the standard mandrels, and mechanical property testing results of the standard mandrels are obtained; s3, determining that the material of the standard mandrel is a standard material according to a mechanical property test result of the standard mandrel; s4, material replacement is conducted on the mandrels of the other sets of hemostatic clips, wherein the mandrels of the other sets of hemostatic clips are replaced with mandrels made of standard materials. After the batch of hemostatic clip products are optimized by the method disclosed by the invention, the release force difference between the batch of hemostatic clip products is smaller, namely, the release force uniformity is better.

Description

Technical Field

[0001] This invention relates to the field of hemostatic clip manufacturing technology, specifically to a method for optimizing the release force of hemostatic clips in interventional medical devices and a hemostatic clip itself. Background Technology

[0002] Interventional medical devices play an increasingly important role in modern medicine, and are widely used in vascular intervention, tumor treatment, and endoscopic examination. Among them, hemostatic clips are an important tool in interventional medical devices, widely used for clamping and stopping bleeding in blood vessels and tissues.

[0003] For example, hemostatic clips can be used in internal surgeries such as those involving the digestive tract and laparoscopy. During hemostasis, the clips need to be released to achieve experimental purposes. The structure of a hemostatic clip is shown in the attached figure. Figure 1 As shown, when using the hemostatic clamp, the clamping action can be controlled by pushing or pulling the mandrel to move it. When it is necessary to release the clamping head of the hemostatic clamp, the sliding handle is pulled forcefully, and the clamp tube and clamping action can be detached from the rest of the hemostatic clamp as a whole.

[0004] Although hemostatic clips are widely used in production, the problem of large variations in release force between batches of clips, i.e., poor uniformity of release force, remains unresolved. Release force refers to the maximum pulling force of the sliding handle when the clip is released. The material of the mandrel affects its mechanical properties, thus influencing the release force of the hemostatic clip. Differences in mandrels between different batches lead to variations in release force between different hemostatic clips. This difference results in completely different operating feel for the same model of hemostatic clip, and may even cause some clips to jump or stop abruptly during rotation, leading to products being deemed substandard in clinical trials. Summary of the Invention

[0005] To address the technical problem of poor uniformity of release force in existing hemostatic clips, this invention provides a method for optimizing the release force of hemostatic clips in interventional medical devices. After optimizing a batch of hemostatic clip products using this method, the difference in release force between the batch of hemostatic clip products can be reduced, that is, the uniformity of release force is better, thereby improving the reliability of the hemostatic clips in use.

[0006] The technical solution provided by this invention is as follows: a method for optimizing the release force of hemostatic clips in interventional medical devices, comprising: S1, conducting a release force test on a batch of hemostatic clips, and dividing the hemostatic clips into n groups according to the magnitude of the release force; wherein, n is a positive integer greater than or equal to 2, and the average release force of the first group to the nth group increases or decreases sequentially; S2, defining at least one group from the first group to the nth group as a standard group, defining the mandrel of the hemostatic clip in the standard group as a standard mandrel, and conducting a mechanical performance test on the standard mandrel to obtain the mechanical performance test results of the standard mandrel; S3, comparing the mechanical performance test results of the standard mandrel to determine that the material of the standard mandrel is a standard material; S4, replacing the material of the mandrels of the remaining groups of hemostatic clips except for the standard group: replacing the mandrels of the remaining groups of hemostatic clips with mandrels made of the standard material.

[0007] Optionally, the method for testing the release force of a batch of hemostatic clips in step S1 is as follows: fix the handle of the hemostatic clip on the tensile testing machine, and ensure that the sliding handle on the handle and the tooling of the tensile testing machine can pull the sliding handle; insert the plastic-coated section of the hemostatic clip into the simulated clamp channel, pull the sliding handle on the handle so that the clamping piece of the hemostatic clip clamps the silicone sheet at the end of the simulated clamp channel, then start the tensile testing machine, pull the sliding handle to drive the mandrel to retract and cause the clamping piece to fall off, and the maximum force displayed on the tensile testing machine is the release force.

[0008] Optionally, the mechanical performance tests performed on the standard mandrel in step S2 include: hardness test and tensile test.

[0009] Optionally, the tensile speed of the tensile test is 5 mm / min, and the gauge length, selected length and fineness of the standard mandrel determined during the tensile test are kept consistent.

[0010] Optionally, in step S1, when the average release force of the first group to the nth group increases sequentially, the maximum release force of the hemostatic clip in the i-th group is less than the maximum release force of the hemostatic clip in the (i+1)-th group; where i is a positive integer from 1 to n-1.

[0011] Optionally, in step S1, when the average release force of the first group to the nth group decreases sequentially, the minimum release force of the hemostatic clip in the i-th group is greater than the maximum release force of the hemostatic clip in the (i+1)-th group; where i is a positive integer from 1 to n-1.

[0012] Optionally, in step S1, the hemostatic clips are divided into n groups according to the magnitude of the release force; where n is a positive integer greater than or equal to 3.

[0013] A hemostatic clip, including a mandrel, is obtained using the method described above for optimizing the release force of an interventional medical device hemostatic clip.

[0014] Optionally, the mandrel is made of 304 stainless steel wire.

[0015] Compared with the prior art, the technical solution provided by this invention has the following beneficial effects: In view of the technical problem of poor uniformity of release force of existing hemostatic clips, this invention provides a method for optimizing the release force of hemostatic clips for interventional medical devices. After optimizing a batch of hemostatic clip products by this method, the difference in release force between the batch of hemostatic clip products can be smaller, that is, the uniformity of release force is better, thereby improving the reliability of hemostatic clips. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the hemostatic clip mentioned in the background art of this invention. Detailed Implementation

[0017] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments.

[0018] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. The terms "first," "second," etc., used in this invention are for the convenience of describing the technical solutions of the invention and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solutions of the invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this invention, 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, and are only for the convenience of describing the invention and simplifying the description, not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this invention.

[0019] Example 1 This embodiment proposes a method for optimizing the release force of hemostatic clips in interventional medical devices, including: S1. A batch of hemostatic clips is tested for release force. Based on the magnitude of the release force, the hemostatic clips are divided into n groups; where n is a positive integer greater than or equal to 2, and the average release force of the first group to the nth group increases or decreases sequentially.

[0020] S2. Define at least one of the groups from group 1 to group n as the standard group, define the mandrel of the hemostatic clip in the standard group as the standard mandrel, perform mechanical property testing on the standard mandrel, and obtain the mechanical property test results of the standard mandrel.

[0021] S3. By comparing the mechanical performance test results of the standard mandrel, determine that the material of the standard mandrel is the standard material.

[0022] S4. Replace the material of the mandrel of the hemostatic clips other than the standard group: Replace the mandrel of the hemostatic clips of the other groups with a mandrel made of the standard material.

[0023] The method for testing the release force of a batch of hemostatic clips in step S1 is as follows: the handle of the hemostatic clip is fixed on the tensile testing machine, and it is ensured that the sliding handle on the handle and the tooling of the tensile testing machine can pull the sliding handle; the plastic-coated section of the hemostatic clip is inserted into the simulated clamp channel, and the sliding handle on the handle is pulled so that the clamping piece of the hemostatic clip clamps the silicone sheet at the end of the simulated clamp channel; then the tensile testing machine is started, and the sliding handle is pulled to drive the mandrel to retract, causing the clamping piece to fall off. The maximum force displayed on the tensile testing machine is the release force.

[0024] Furthermore, in step S1, as the average release force of groups 1 to n increases sequentially, the maximum release force of the hemostatic clip in group i is less than the maximum release force of the hemostatic clip in group (i+1); where i is a positive integer from 1 to n-1. Similarly, as the average release force of groups 1 to n decreases sequentially, the minimum release force of the hemostatic clip in group i is greater than the maximum release force of the hemostatic clip in group (i+1); where i is a positive integer from 1 to n-1.

[0025] Step S2 involves conducting mechanical property tests on the standard mandrel, including hardness testing and tensile testing. The tensile test is performed at a speed of 5 mm / min, and the gauge length, selected length, and fineness of the standard mandrel are kept consistent during the tensile test.

[0026] Based on the above method, a specific example is proposed here: taking a batch of hemostatic clips with 304 stainless steel wire as the core as an example, the fiber fineness diameter of the stainless steel wire is 0.45mm, the working length is 195cm, and the clip opening of the hemostatic clip is 115°.

[0027] The batch of hemostatic clips was divided into three groups according to their release force, with the average release force gradually increasing from group 1 to group 3. Specifically, the release force of the hemostatic clips in group 1 was 20N to 50N, the release force of the hemostatic clips in group 2 was 50N to 60N, and the release force of the hemostatic clips in group 3 was 60N to 80N.

[0028] The second group of hemostatic clips is defined as the standard group, and the mandrel of the hemostatic clips in the second group is the standard mandrel. Mechanical performance tests are performed on the standard mandrel used in the second group of hemostatic clips. Mechanical performance tests usually include tensile tests, compression tests, bending tests, etc., so as to evaluate the performance of the standard mandrel under different load conditions.

[0029] Specifically, the mandrel of the second set of hemostatic clips (i.e., the standard mandrel) was taken out and subjected to tensile testing in a universal tensile testing machine. By using the controlled variable method, the gauge length, selected length and fineness of the standard mandrel determined during the tensile test were kept consistent. The experimental parameters were set and the tensile speed was 5 mm / min.

[0030] Based on the mechanical property test results, the parameters for tensile fracture of the standard mandrel are determined as follows: maximum force is 360N~380N, fracture force is 130N~200N, elongation at break is 11% (±0.5), fracture time is 9.5s (±0.1), hardness is 510~600, metallographic structure is induced martensite, and out-of-roundness is 0.002.

[0031] By comparing the mechanical property test results of the standard mandrel above, the material that meets the above properties can be determined as the standard material. Finally, the mandrels of the remaining hemostatic clips (excluding the standard group) are replaced with mandrels made of the above-mentioned material.

[0032] It should be noted that the purpose of defining a standard group is to ensure better uniformity of release force in batches of hemostatic clips. Furthermore, a standard group can be defined as a group of hemostatic clips with appropriate release force, and whether the release force of the hemostatic clip is appropriate can be determined based on actual circumstances. Generally, it should be determined based on the user experience of medical personnel during clinical trials of the specific product; alternatively, it can be determined by comparing specific experimental and R&D experience.

[0033] Based on existing experience and conclusions in this field, a low breaking force of the mandrel indicates that it cannot withstand large loads, making it prone to detachment when using hemostatic clips. Mandrels with high elongation at break typically possess better plasticity, meaning that they can deform slightly without immediately breaking under applied force. This characteristic makes the hemostatic clip more forgiving during use, preventing breakage due to excessive instantaneous stress. Furthermore, mandrels with high elongation at break release force more smoothly upon load removal, avoiding sudden release and effectively reducing damage to surrounding tissues. In addition, higher elongation at break usually indicates better fatigue performance, allowing the material to withstand repeated stress and release without easily degrading due to fatigue, ensuring reliability after multiple uses.

[0034] Based on the previous example, we propose a way to define standard groups: mechanical performance tests are performed on mandrels from group 1 to group 3, and the test results are analyzed.

[0035] Group 1 of the hemostatic clips exhibited the lowest release force, requiring the least force to stretch the stainless steel wire fiber (i.e., the mandrel material) to break, specifically 335.39 N and 324.68 N. The breaking forces were 126.9 N and 112.59 N, with elongation at break of 10.3% and 9.2%, and test times of 6.3 s and 5.6 s. At these times, the release force of the hemostatic clips was low, making them prone to detachment. Therefore, Group 1 can be defined as the group with the lowest hemostatic clip release force.

[0036] Group 3 hemostatic clips exhibited the lowest release force, with a breaking elongation of 16.4%. The maximum force at break was 351.24 N, and the highest breaking force was 247.52 N. This high breaking force indicates that the clips can withstand significant loads without easily breaking. Therefore, when using hemostatic clips, a larger clamping force can be safely applied, making release somewhat difficult. Thus, Group 3 can be defined as the group with excessively high hemostatic clip release force.

[0037] In contrast, the mandrel of the second group of hemostatic clips has more balanced performance, allowing for the application of a slightly larger clamping force with relative safety while still enabling proper release of the clips. Therefore, the second group can be defined as the standard group, and the mandrel used in the second group of hemostatic clips is a standard mandrel made of a standard material. When optimizing the remaining groups of hemostatic clips using the method of this embodiment, the mandrels of the remaining groups should be replaced with mandrels made of the standard material.

[0038] In summary, to address the technical problem of poor uniformity of release force in existing hemostatic clips, this invention provides a method for optimizing the release force of hemostatic clips in interventional medical devices. After optimizing a batch of hemostatic clip products using this method, the difference in release force between the batch of hemostatic clip products can be reduced, that is, the uniformity of release force is better, thereby improving the reliability of the hemostatic clips.

[0039] Example 2 This embodiment proposes a hemostatic clip, obtained by optimizing the release force of the hemostatic clip in interventional medical devices as described in Embodiment 1. Specifically, the core shaft of the hemostatic clip in this embodiment is made of 304 stainless steel wire.

[0040] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for optimizing the release force of a hemostatic clip in interventional medical devices, characterized in that, include: S1. A batch of hemostatic clips is tested for release force. Based on the magnitude of the release force, the hemostatic clips are divided into n groups; where n is a positive integer greater than or equal to 2, and the average release force of the first group to the nth group increases or decreases sequentially. S2. Define at least one of the groups from group 1 to group n as a standard group, define the mandrel of the hemostatic clip in the standard group as a standard mandrel, perform mechanical property testing on the standard mandrel, and obtain the mechanical property test results of the standard mandrel. S3. By comparing the mechanical property test results of the standard mandrel, determine that the material of the standard mandrel is the standard material; S4. Replace the material of the mandrel of the hemostatic clips other than the standard group: Replace the mandrel of the hemostatic clips of the other groups with a mandrel made of the standard material.

2. The method for optimizing the release force of a hemostatic clip in an interventional medical device according to claim 1, characterized in that, The method for testing the release force of a batch of hemostatic clips in step S1 is as follows: fix the handle of the hemostatic clip on the tensile testing machine, and ensure that the sliding handle on the handle and the tooling of the tensile testing machine can pull the sliding handle; insert the plastic-coated section of the hemostatic clip into the simulated clamp channel, pull the sliding handle on the handle so that the clamping piece of the hemostatic clip clamps the silicone sheet at the end of the simulated clamp channel, then start the tensile testing machine, pull the sliding handle to drive the mandrel to retract and cause the clamping piece to fall off, and the maximum force displayed on the tensile testing machine is the release force.

3. The method for optimizing the release force of a hemostatic clip in an interventional medical device according to claim 1, characterized in that, The mechanical performance tests performed on the standard mandrel in step S2 include: hardness test and tensile test.

4. The method for optimizing the release force of a hemostatic clip in an interventional medical device according to claim 3, characterized in that, The tensile test was conducted at a tensile speed of 5 mm / min, and the gauge length, selected length, and fineness of the standard mandrel were kept consistent during the tensile test.

5. The method for optimizing the release force of a hemostatic clip in an interventional medical device according to claim 1, characterized in that, In step S1, when the average release force of the first group to the nth group increases sequentially, the maximum release force of the hemostatic clip in the i-th group is less than the maximum release force of the hemostatic clip in the (i+1)-th group. Where i is a positive integer from 1 to n-1.

6. The method for optimizing the release force of a hemostatic clip in an interventional medical device according to claim 1, characterized in that, In step S1, when the average release force of the first group to the nth group decreases sequentially, the minimum release force of the hemostatic clip in the i-th group is greater than the maximum release force of the hemostatic clip in the (i+1)-th group. Where i is a positive integer from 1 to n-1.

7. The method for optimizing the release force of a hemostatic clip in an interventional medical device according to claim 1, characterized in that, In step S1, the hemostatic clips are divided into n groups according to the magnitude of the release force; where n is a positive integer greater than or equal to 3.

8. A hemostatic clip, comprising a mandrel, characterized in that, The method described in any one of claims 1-7 for optimizing the release force of hemostatic clips in interventional medical devices is used.

9. A hemostatic clip according to claim 1, characterized in that, The mandrel is made of 304 stainless steel wire.

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