A radiopacity-enhanced coating, a method of making a coating, an ultrasound-guided nerve block needle comprising a coating, and a method of making a block needle

Abstract

This invention relates to the field of medical devices, specifically disclosing a radiopaque coating, a method for preparing the coating, an ultrasound-guided nerve block needle containing the coating, and a method for preparing the nerve block needle. The coating is prepared using isocyanate, a resin containing active carboxyl groups, a foam stabilizer, diluent A, a chain extender, a wetting agent, and a leveling agent as main raw materials. The resin containing active carboxyl groups is prepared using acrylic acid, acrylate, diluent B, and a crosslinking agent as main raw materials, or using polybasic acid, isocyanate, diluent B, and dibutyltin dilaurate as main raw materials. The ultrasound radiopaque coating contains microbubbles. The coating liquid prepared by this invention is applied to the surface of the nerve block needle by dip coating, and then thermosetting to form multiple solid-gas discontinuous interfaces on the surface of the nerve block needle, reducing specular reflection and generating more diffuse reflection, thereby enhancing the echo signal received by the ultrasound probe and improving the visibility of the nerve block needle.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to a radiopaque coating, a method for preparing the coating, an ultrasound-guided nerve block needle containing the coating, and a method for preparing the block needle. Background Technology

[0002] In recent years, with continuous research into visualization in clinical practice, ultrasound-guided nerve block techniques have become increasingly popular. Compared with ordinary nerve block needles and nerve stimulation needles, ultrasound technology can visualize the puncture path, enabling precise treatment, avoiding nerve damage, and reducing the possibility of anesthetic complications. The principle of ultrasound imaging is as follows: the generator and receiver of the ultrasound probe are integrated. When ultrasound waves encounter the interface between two materials with different acoustic impedances, part of the waves penetrates while the other part is reflected, and the receiver receives the reflected waves to form an image. However, the surface of a typical nerve block needle is relatively smooth, and most of the ultrasound waves emitted by the ultrasound probe return through specular reflection. As the puncture angle increases, most or all of the ultrasound waves cannot return to the probe's sensor through specular reflection. The less ultrasound waves are reflected back and received, the worse the imaging effect. Nerve block needle punctures often need to be performed at large angles, resulting in low visibility of the nerve block needle on ultrasound images. However, with the increase in the obese population, large-angle methods will be used more and more.

[0003] Currently, medical devices on the market that improve the visibility of ultrasound images are all achieved through the processing of physical structures such as threads, triangular pyramids, and grooves. Their characteristic is to increase the echo signal received by the ultrasound probe by increasing the diffuse reflection of ultrasound waves and reducing the reduction of echo signal caused by specular reflection. However, this physical processing method often has poor imaging effect at large angles or on obese patients. Changes in physical structure may also damage the structure of the medical device itself, resulting in a reduction in rigidity and strength. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to address the shortcomings of the prior art by providing a contrast-enhanced ultrasound-guided nerve block needle coating and its preparation method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A development-enhancing coating is characterized by having microbubbles inside, wherein the microbubbles are capable of forming multiple solid-gas discontinuous interfaces on the surface of the blocking needle, and the diameter of the microbubbles is 1μm-50μm; comprising the following components by weight: 40-60 parts isocyanate, 30-50 parts resin containing active carboxyl groups, 0.5-1 part foam stabilizer, 0-20 parts diluent A, 0-3 parts chain extender, 0-1.5 parts wetting agent, and 0-2 parts leveling agent;

[0007] The resin containing active carboxyl groups includes aliphatic resins containing active carboxyl groups or aromatic resins containing active carboxyl groups.

[0008] The isocyanate includes any one or more of toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and their polymers.

[0009] The diluent A includes any one or more of tetrahydrofuran, propylene glycol methyl ether acetate, acetone, and cyclohexanone;

[0010] The ultrasonic imaging coating contains microbubbles with a diameter of 1μm-50μm.

[0011] As a further improvement of the present invention, the chain extender includes any one of 1,4-butanediol, 1,6-hexanediol, and ethylene glycol.

[0012] This invention also provides a method for preparing a developer-enhanced coating, characterized by comprising the following steps:

[0013] S1 Preparation of resins containing active carboxyl groups

[0014] Acrylic acid, acrylate, diluent B, and crosslinking agent are added to a reaction vessel and stirred until homogeneous. The reaction is carried out under nitrogen protection at a temperature of 80℃-90℃ for 2-3 hours. Alternatively, polybasic acid, isocyanate, diluent B, and dibutyltin dilaurate are added to a reaction vessel and stirred until homogeneous. The reaction is carried out under nitrogen protection at a temperature of 80℃-110℃ for 1.5-2 hours. Resin containing active carboxyl groups can be prepared by either of the following steps:

[0015] The components, by weight, are as follows: 2-5 parts acrylic acid, 18-25 parts acrylate, 70-80 parts diluent B, 0.3-1.2 parts crosslinking agent; 40-55 parts polybasic acid, 15-45 parts isocyanate, 30-55 parts diluent B, and 0.5-1 part dibutyltin dilaurate; the acrylate includes any one of butyl methacrylate, methyl methacrylate, and propyl methacrylate; the polybasic acid includes any one of terephthalic acid and butyric acid.

[0016] S2 Preparation of Development Enhancement Coating Solution

[0017] Isocyanate and resin containing active carboxyl groups prepared in S1 are added to a reaction vessel and stirred evenly. Foam stabilizer, diluent A, chain extender, wetting agent and leveling agent are added and stirred evenly to prepare a developing enhanced coating liquid.

[0018] S3 is used to prepare a development-enhancing coating.

[0019] The imaging-enhancing coating liquid prepared by S2 is placed in a liquid tank. The ultrasound-guided nerve block needle is fixed on the dip coating device and dipped vertically into the liquid tank. The coated ultrasound-guided nerve block needle is then placed in an oven and heated to dry, resulting in an imaging-enhancing coating containing discontinuous hollow microbubbles.

[0020] As a further improvement of the present invention, the diluent B in S1 includes acetone; the crosslinking agent includes 2,2'-azobisisobutyronitrile; and the foam stabilizer in S2 includes silicone oil.

[0021] As a further improvement of the present invention, the wetting agent includes any one of polyether-modified siloxane solution, modified organic fluorine compound solution, unsaturated polycarboxylic acid polyamine amide solution, and polyether siloxane copolymer.

[0022] As a further improvement of the present invention, the leveling agent includes any one of polyether-modified polydimethylsiloxane solution, polyester-modified siloxane solution, aralkyl-modified polysilane, polyether-modified silicone oil, polyether-modified silane solution, fluorinated acrylate copolymer solution, and polyether siloxane polymer.

[0023] The present invention also provides an ultrasound-guided nerve block needle prepared by an imaging-enhanced coating. The surface of the block needle has multiple solid-gas discontinuous interfaces. The body and tip of the block needle are visible under ultrasound at puncture angles of 20°-70°. The coating is applied sequentially from the tip of the needle to the base of the needle. The thickness of the coating is 1μm-20μm and the length of the coating is ≥2cm.

[0024] As a further improvement of the present invention, the diameter of the nerve blocking needle is 0.7 mm, and it needs to be sandblasted under an air pressure of 0.1 MPa-1.2 MPa before coating. The sand includes quartz sand, corundum, and sea sand.

[0025] This invention also provides a method for preparing an ultrasound-guided nerve block needle using a imaging-enhanced coating. The method is characterized by applying the prepared coating liquid to the surface of the ultrasound-guided nerve block needle via dip-coating, followed by thermosetting to form multiple solid-gas discontinuous interfaces on the surface of the needle. The dip-coating time is 10-30 seconds, the lifting speed is 3-8 mm / s, and the thermosetting temperature is 60℃-130℃ for 3-10 hours.

[0026] As a further improvement of the present invention, before coating, the tip of the nerve blocking needle needs to be sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the needle tip, and the solid polymer material is pulled out after coating.

[0027] The beneficial effects of this invention are:

[0028] 1. This invention uses ultrasonic waves of a certain energy to cause a certain deformation at the solid-gas interface formed between the solid coating and the gas, thereby changing the angle and direction of ultrasonic reflection, reducing specular reflection and enhancing diffuse ultrasonic reflection, thus enhancing the imaging of the nerve block needle tip and tube body. This improves the visibility of nerve block needle treatment under ultrasound guidance, and can increase the visibility of the nerve block needle tube body and needle tip at any angle without compromising the mechanical properties of the device.

[0029] 2. This invention involves reacting a resin containing carboxyl active groups with isocyanate, which has a much lower reactivity than isocyanate reacting with water. This reaction generates CO2 gas during heating, which is then fixed on the surface of the nerve block needle, creating multiple discontinuous solid-gas interfaces. This solves the problem of uneven microbubbles caused by excessively rapid reaction during the coating process and extends the service life of the coating solution. Ultrasonic waves reduce specular reflection at the solid-gas interface while generating more diffuse reflection, thereby enhancing the echo signal received by the ultrasonic probe and improving the visibility of the nerve block needle.

[0030] 3. In this invention, the ratio of resin containing carboxyl active groups to isocyanate is 1:1 to 1:1.5, and the microbubble size is 1-50 μm. By controlling the ratio of resin containing carboxyl active groups to isocyanate to 1:1.3, the amount of microbubbles generated is further controlled, and the microbubble size is 10-20 μm, resulting in the optimal development enhancement effect. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Appendix Figure 1 This is a basic schematic diagram of the development-enhanced coating preparation method.

[0033] Appendix Figure 2 The image shows the microbubbles inside the development-enhanced coating of Example 4 at 100× magnification under a microscope.

[0034] Appendix Figure 3 The image shows the microbubbles inside the development-enhanced coating of Example 4 under a microscope at 200×.

[0035] Appendix Figure 4 The image shows the microbubbles inside the development-enhanced coating of Example 4 under a microscope at 400×.

[0036] Appendix Figure 5 This is a visualization of the nerve block needle after coating in Example 4, at a puncture angle of 24°.

[0037] Appendix Figure 6 This is a visualization of the nerve block needle after coating in Example 4, at a puncture angle of 40°.

[0038] Appendix Figure 7 This is a visualization of the nerve block needle after coating in Example 4, at a puncture angle of 65°.

[0039] Appendix Figure 8 This is a contrast image of the nerve block needle in Comparative Example 1 when the puncture angle is 24°.

[0040] Appendix Figure 9 This is a contrast image of the nerve block needle in Comparative Example 1 when the puncture angle is 40°.

[0041] Appendix Figure 10 This is a contrast image of the nerve block needle in Comparative Example 1 when the puncture angle is 65°.

[0042] Appendix Figure 11 The image shows the contrast effect of the nerve block needle with a triangular pyramid structure in Comparative Example 2 when the puncture angle is 24°.

[0043] Appendix Figure 12 The image shows the imaging effect of the nerve block needle with a triangular pyramid structure in Comparative Example 2 when the puncture angle is 40°.

[0044] Appendix Figure 13 The image shows the contrast effect of the nerve block needle with a triangular pyramid structure in Comparative Example 2 when the puncture angle is 65°.

[0045] Appendix Figure 14 This is a comparison of the average grayscale values ​​of the nerve block needle with the triangular pyramid structure in Comparative Example 2 and the nerve block needle after coating in Example 4.

[0046] Appendix Figure 15 This is a contrast image of the nerve block needle in Comparative Example 3 when the puncture angle is 24°. Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1

[0048] Preparation of S1 resin containing active carboxyl groups

[0049] Add 3.5 parts of acrylic acid, 25 parts of butyl methacrylate, 75 parts of acetone, and 0.3 parts of 2,2'-azobisisobutyronitrile to a reaction vessel, stir until homogeneous, and then react at 90°C for 2 hours under nitrogen protection to prepare a resin containing active carboxyl groups.

[0050] Preparation of S2 developer-enhanced coating solution

[0051] Take 50 parts of toluene diisocyanate and 40 parts of the resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 1 part of silicone oil, 6 parts of propylene glycol methyl ether acetate, 3 parts of cyclohexanone, 2 parts of 1,4-butanediol, 1.2 parts of polyether-modified siloxane solution, and 1.5 parts of polyether-modified polydimethylsiloxane solution. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0052] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0053] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 15 seconds. The lifting speed was 3 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0054] Surface curing of S4 ultrasound-guided nerve block needle

[0055] The coated ultrasound-guided nerve block needle was placed in a 100°C oven and dried for 6 hours to obtain an ultrasound-guided nerve block needle with enhanced imaging and containing discontinuous hollow microbubbles inside.

[0056] Example 2:

[0057] Preparation of S1 resin containing active carboxyl groups

[0058] Add 3 parts acrylic acid, 22 parts methyl methacrylate, 70 parts acetone, and 0.3 parts 2,2'-azobisisobutyronitrile to a reaction vessel, stir until homogeneous, and then react at 80°C for 2.5 h under nitrogen protection to prepare a resin containing active carboxyl groups.

[0059] Preparation of S2 developer-enhanced coating solution

[0060] Take 57 parts of toluene diisocyanate dimer and 42 parts of acrylic resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 0.6 parts of silicone oil, 8 parts of tetrahydrofuran, 2 parts of cyclohexanone, 2.5 parts of 1,6-hexanediol, 1.5 parts of polyether-modified siloxane solution, and 2 parts of polyester-modified siloxane solution. After stirring evenly, a development-enhanced coating liquid is obtained.

[0061] S3 ultrasound-guided nerve block needle coating

[0062] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 5 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0063] Surface curing of S4 ultrasound-guided nerve block needle

[0064] The coated nerve block needle was placed in a 90°C oven and dried for 7 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles.

[0065] Example 3

[0066] Preparation of S1 resin containing active carboxyl groups

[0067] Add 3 parts acrylic acid, 24 parts propyl methacrylate, 80 parts acetone, and 0.3 parts 2,2'-azobisisobutyronitrile to a reaction vessel, stir evenly, and react at 90°C for 3 hours under nitrogen protection to prepare a resin containing active carboxyl groups.

[0068] Preparation of S2 developer-enhanced coating solution

[0069] Take 60 parts of diphenylmethane diisocyanate and 50 parts of the resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 0.8 parts of silicone oil, 12 parts of acetone, 1.8 parts of 1,4-butanediol, 1.2 parts of modified organic fluorine compound solution, and 1.4 parts of aralkyl modified polysilane. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0070] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0071] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 8 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0072] Surface curing of S4 ultrasound-guided nerve block needle

[0073] The coated nerve block needle was placed in a 90°C oven and dried for 7 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles. Example 4

[0074] Preparation of S1 resin containing active carboxyl groups

[0075] Add 45 parts of terephthalic acid, 23 parts of hexamethylene diisocyanate, 32 parts of acetone, and 0.6 parts of dibutyltin dilaurate to a reaction vessel, and heat at 80°C for 2 hours under nitrogen protection to prepare a resin containing active carboxyl groups.

[0076] Preparation of S2 developer-enhanced coating solution

[0077] Take 52 parts of hexamethylene diisocyanate trimer and 40 parts of the resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 0.7 parts of silicone oil, 5 parts of propylene glycol methyl ether acetate, 8 parts of cyclohexanone, 1.4 parts of 1,6-hexanediol, 1.4 parts of modified organic fluorine compound solution, and 2 parts of aralkyl-modified polysilane. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0078] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0079] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 3 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0080] Surface curing of S4 ultrasound-guided nerve block needle

[0081] The coated nerve block needle was placed in a 120°C oven and dried for 5 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles. Example 5

[0082] Preparation of S1 resin containing active carboxyl groups

[0083] Add 50 parts of terephthalic acid, 20 parts of toluene diisocyanate dimer, 30 parts of acetone, and 0.7 parts of dibutyltin dilaurate to a reaction vessel, and heat at 90°C for 1.5 h under nitrogen protection to prepare a resin containing active carboxyl groups.

[0084] Preparation of S2 developer-enhanced coating solution

[0085] Take 55 parts of polyhexamethylene diisocyanate and 40 parts of the resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 0.9 parts of silicone oil, 7 parts of propylene glycol methyl ether acetate, 3 parts of acetone, 1.2 parts of ethylene glycol, 1.5 parts of modified organic fluorine compound solution, and 2 parts of polyether modified silicone oil. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0086] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0087] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 5 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0088] Surface curing of S4 ultrasound-guided nerve block needle

[0089] The coated nerve block needle was placed in an 80°C oven and dried for 6 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles. Example 6

[0090] Preparation of S1 resin containing active carboxyl groups

[0091] Add 50 parts of terephthalic acid, 20 parts of toluene diisocyanate dimer, 30 parts of acetone, and 0.7 parts of dibutyltin dilaurate to a reaction vessel, and heat at 90°C for 1.5 h under nitrogen protection to prepare a resin containing active carboxyl groups.

[0092] Preparation of S2 developer-enhanced coating solution

[0093] Take 28 parts of hexamethylene diisocyanate, 20 parts of toluene diisocyanate, and 45 parts of the resin containing active carboxyl groups prepared in S1, stir evenly, add 0.5 parts of silicone oil, 7 parts of propylene glycol methyl ether acetate, 3 parts of acetone, 1.2 parts of ethylene glycol, 1.5 parts of polyether siloxane copolymer, and 1.8 parts of polyether modified silane solution, stir evenly to obtain a developing and enhanced coating liquid.

[0094] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0095] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 5 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0096] Surface curing of S4 ultrasound-guided nerve block needle

[0097] The coated nerve block needle was placed in a 110°C oven and dried for 4 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles. Example 7

[0098] Preparation of S1 resin containing active carboxyl groups

[0099] Add 50 parts of terephthalic acid, 20 parts of toluene diisocyanate dimer, 30 parts of acetone, and 0.7 parts of dibutyltin dilaurate to a reaction vessel, and heat at 90°C for 1.5 h under nitrogen protection to prepare a resin containing active carboxyl groups.

[0100] Preparation of S2 developer-enhanced coating solution

[0101] Take 45 parts of polyhexamethylene diisocyanate and 40 parts of the resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 1 part of silicone oil, 6 parts of propylene glycol methyl ether acetate, 2 parts of acetone, 1.5 parts of ethylene glycol, 0.8 parts of polyether siloxane copolymer, and 1 part of polyether siloxane polymer. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0102] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0103] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 5 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0104] Surface curing of S4 ultrasound-guided nerve block needle

[0105] The coated nerve block needle was placed in a 90°C oven and dried for 7 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles.

[0106] Example 8

[0107] Preparation of S1 resin containing active carboxyl groups

[0108] Add 40 parts butyric acid, 45 parts diphenylmethane diisocyanate, 30 parts acetone, and 0.8 parts dibutyltin dilaurate to a reaction vessel, and heat at 110°C for 2 hours under nitrogen protection to obtain a resin containing active carboxyl groups.

[0109] Preparation of S2 developer-enhanced coating solution

[0110] Take 60 parts of polyhexamethylene diisocyanate and 42 parts of the resin containing active carboxyl groups prepared in S1 and stir them evenly. Add 0.8 parts of silicone oil, 8 parts of propylene glycol methyl ether acetate, 4 parts of cyclohexanone, 2 parts of ethylene glycol, 1.4 parts of polyether-modified siloxane solution, and 1.6 parts of polyether-modified polydimethylsiloxane solution. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0111] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0112] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 5 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0113] Surface curing of S4 ultrasound-guided nerve block needle

[0114] The coated nerve block needle was placed in a 120°C oven and dried for 3 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles.

[0115] Comparative Example 1

[0116] Using an unstructured nerve block needle as comparative example 1, the needle was not coated with the coating prepared in this invention.

[0117] The contrast effect was tested in the vascular puncture membrane using different puncture angles. Figure 3 It can be seen that the unstructured nerve block needle is not visible under ultrasound at puncture angles of 24°-65°; only the needle tip is somewhat blurred. Figure 8 , Figure 9 , Figure 10 The development effect was significantly weaker than that of the sample in Example 4.

[0118] Comparative Example 2

[0119] A nerve block needle with a triangular pyramidal structure was used as Comparative Example 2, without the coating prepared in this invention.

[0120] The contrast effect was tested in the vascular puncture membrane using different puncture angles. Figure 4 The triangular pyramidal nerve block needle is visible under ultrasound at puncture angles of 24°-65°, such as... Figure 11 , Figure 12 , Figure 13 However, the development effect was weaker than that of the sample in Example 4. The development results of the nerve block needle with the triangular pyramid structure and the nerve block needle prepared in Example 4 were compared using ImageJ software to measure the average gray value (gray value refers to the color depth of a point in a black and white image, generally ranging from 0 to 255, with white being 255 and black being 0). The results are as follows. Figure 14 The average gray value of the radiopaque nerve block needle prepared in Example 4 was significantly higher than that of the nerve block needle with the triangular pyramid structure, indicating that the radiopaque nerve block needle prepared in Example 4 has a better radiopaque effect.

[0121] Comparative Example 3

[0122] Compared with Example 4, this comparative example is completely identical to Example 4 except that hexamethylene diisocyanate trimer is not added in the preparation of the development-enhanced coating solution in step S2. The specific steps are as follows:

[0123] Preparation of S1 resin containing active carboxyl groups

[0124] Add 45 parts of terephthalic acid, 23 parts of hexamethylene diisocyanate, 32 parts of acetone, and 0.6 parts of dibutyltin dilaurate to a reaction vessel, and heat at 80°C for 2 hours under nitrogen protection to prepare a resin containing active carboxyl groups.

[0125] Preparation of S2 developer-enhanced coating solution

[0126] Take 40 parts of the resin containing active carboxyl groups prepared in S1, add 0.7 parts of silicone oil, 5 parts of propylene glycol methyl ether acetate, 8 parts of cyclohexanone, 1.4 parts of 1,6-hexanediol, 1.4 parts of modified organic fluorine compound solution, and 2 parts of aralkyl-modified polysilane. After stirring evenly, a developing and enhanced coating liquid is obtained.

[0127] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0128] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 3 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0129] Surface curing of S4 ultrasound-guided nerve block needle

[0130] The coated nerve block needle was placed in a 120°C oven and dried for 5 hours to obtain an ultrasound-enhanced nerve block needle containing discontinuous hollow microbubbles.

[0131] The obtained samples were tested for contrast enhancement in the vascular puncture membrane, such as... Figure 15 The development effect was very weak, and the needle was basically invisible, so no further operation was performed.

[0132] Comparative Example 4

[0133] Compared with Example 4, this comparative example is completely identical to Example 4 except that no active carboxyl group resin is added in the preparation of the development-enhanced coating solution in step S2. The specific steps are as follows:

[0134] Preparation of S1 resin containing active carboxyl groups

[0135] Add 45 parts of terephthalic acid, 23 parts of hexamethylene diisocyanate, 32 parts of acetone, and 0.6 parts of dibutyltin dilaurate to a reaction vessel, and heat at 80°C for 2 hours under nitrogen protection to prepare a resin containing active carboxyl groups.

[0136] Preparation of S2 developer-enhanced coating solution

[0137] Take 52 parts of hexamethylene diisocyanate trimer, add 0.7 parts of silicone oil, 5 parts of propylene glycol methyl ether acetate, 8 parts of cyclohexanone, 1.4 parts of 1,6-hexanediol, 1.4 parts of modified organic fluorine compound solution, and 2 parts of aralkyl-modified polysilane. After stirring evenly, a developing and enhanced coating solution is obtained.

[0138] S3 imaging-enhanced ultrasound-guided nerve block needle coating

[0139] The imaging-enhanced coating liquid prepared by S2 was placed in a liquid tank. The tip of the nerve block needle was sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the tip. Then, the ultrasound-guided nerve block needle was fixed on the dip coating device and dipped vertically into the liquid tank for 10 seconds. The lifting speed was 3 mm / s. After the coating was completed, the solid polymer material was pulled out.

[0140] Surface curing of S4 ultrasound-guided nerve block needle

[0141] The coated nerve block needle was placed in a 120°C oven and dried for 5 hours to obtain an ultrasound-enhanced nerve block needle.

[0142] The coating on the obtained sample surface was not completely cured, so the developing needle could not be used after coating, and subsequent developing tests were not conducted.

[0143] Table 1 Results of Examples 1-8 and Comparative Examples 1-4

[0144]

[0145] Table 1 shows the results of Examples 1-8 and Comparative Examples 1-4 regarding whether they contain resins with active carboxyl groups, whether they contain isocyanate, whether microbubbles are generated, whether the needle surface has a physical (triangular pyramidal) structure, microbubble diameter, and development effect; as can be seen from Table 1:

[0146] Comparative Examples 1-4: The contrast enhancement of nerve block needles in the vascular puncture membrane in Comparative Examples 1 and 2; the unconstructed contrast enhancement needle in Comparative Example 1 showed only weak contrast enhancement at the needle tip, such as... Figure 8 , Figure 9 , Figure 10 As shown; in Comparative Example 2, only the triangular pyramid structure is visible, but the visibility is generally poor, such as... Figure 11 , Figure 12 , Figure 13 As shown; Comparative Example 3 only contains active carboxyl resin, and no microbubbles are generated after curing, so the development effect is basically invisible, as shown. Figure 15 As shown; Comparative Example 4 only contains isocyanate and no active carboxyl group resin, so the coating cannot be cured and no sample can be obtained.

[0147] Examples 1-8: The developer-enhancing coating solution was prepared by adding a resin containing active carboxyl groups and isocyanate, resulting in developer-enhanced coatings containing microbubble structures. The reaction principle is as follows: Figure 1 Carboxyl groups and isocyanates generate CO2 gas under heating conditions, forming microbubbles with a size of 1-50 μm. The microbubbles are clearly visible on the coated area of ​​the developing needle. By controlling the ratio of resin containing carboxyl active groups to isocyanate at 1:1.3, the amount of microbubbles generated can be further controlled. The microbubbles are fixed on the surface of the nerve blocking needle, creating multiple discontinuous solid-gas interfaces, effectively solving the problem of uneven microbubble formation caused by excessively rapid reaction during the coating process. To better observe the microbubble diameter, in Example 4, the coating liquid was applied to a glass slide and observed under a microscope at 100X, 200X, and 400X respectively. Figure 2 , Figure 3 , Figure 4The microbubble diameter is 10μm-20μm. The imaging effect was tested under ultrasound at different puncture angles in the vascular puncture membrane. The imaging effect was basically not limited by the angle. Figure 5 , Figure 6 , Figure 7 The imaging results of the contrast-enhanced nerve block needles prepared in Comparative Example 2 and Example 4 were compared using ImageJ software based on their average grayscale values ​​(grayscale value refers to the color depth of a point in a black and white image, generally ranging from 0 to 255, with white being 255 and black being 0). The results are as follows. Figure 14 As shown, the average gray value of the radiopaque nerve block needle prepared in Example 4 is significantly higher than that of the nerve block needle with the triangular pyramid structure, indicating that the radiopaque nerve block needle prepared in Example 4 has a better radiopaque effect.

[0148] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

[0149] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0150] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0151] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0152] The above are the implementation methods of the embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the embodiments of this application, and these improvements and modifications are also considered to be within the protection scope of this application.

Claims

1. An ultrasonically guided nerve block needle with a coating, characterized in that, The surface of the blocking needle has multiple solid-gas discontinuous interfaces, and the blocking needle body and needle tip are visible under ultrasound when the puncture angle is 20°-70°; the coating is applied sequentially from the needle tip to the needle seat, the thickness of the coating is 1μm-20μm, and the length of the coating is ≥2cm. The coating contains microbubbles, which can form multiple solid-gas discontinuous interfaces on the surface of the blocking needle. The diameter of the microbubbles is 10μm-20μm. The coating is prepared by dip coating onto the surface of the ultrasound-guided nerve block needle, and then multiple solid-gas discontinuous interfaces are formed on the surface of the ultrasound-guided nerve block needle by thermosetting. The coating liquid comprises the following components by weight: 40-60 parts isocyanate, 30-50 parts resin containing active carboxyl groups, 0.5-1 part foam stabilizer, 0-20 parts diluent A, 0-3 parts chain extender, 0-1.5 parts wetting agent, and 0-2 parts leveling agent. The resin containing active carboxyl groups includes any one or more of aliphatic resins or aromatic resins containing active carboxyl groups; the isocyanate includes any one or more of toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and their polymers.

2. The coated ultrasound-guided nerve block needle of claim 1, wherein, The diluent A includes any one or more of tetrahydrofuran, propylene glycol methyl ether acetate, acetone, and cyclohexanone; the chain extender includes any one of 1,4-butanediol, 1,6-hexanediol, and ethylene glycol.

3. The coated ultrasound-guided nerve block needle of claim 1, wherein, The preparation method of the coating mainly includes the following steps: S1 Preparation of resins containing active carboxyl groups A resin containing active carboxyl groups can be prepared by any of the following steps: ① Add acrylic acid, acrylate, diluent B, and crosslinking agent to the reaction vessel, stir until homogeneous, and then react for 2-3 hours under nitrogen protection at a temperature of 80℃-90℃. ② Add polybasic acid, isocyanate, diluent B and dibutyltin dilaurate to the reaction vessel and stir until homogeneous. Under nitrogen protection, set the temperature to 80℃-110℃ and react for 1.5h-2h. The components, by weight, are as follows: 2-5 parts acrylic acid, 18-25 parts acrylate, 70-80 parts diluent B, 0.3-1.2 parts crosslinking agent; 40-55 parts polybasic acid, 15-45 parts isocyanate, 30-55 parts diluent B, and 0.5-1 part dibutyltin dilaurate; the acrylate is one of butyl methacrylate, methyl methacrylate, and propyl methacrylate; the polybasic acid is terephthalic acid. S2 prepares a developing-enhancing coating solution. Isocyanate and resin containing active carboxyl groups prepared in S1 are added to a reaction vessel and stirred evenly. Foam stabilizer, diluent A, chain extender, wetting agent and leveling agent are added and stirred evenly to prepare a developing and enhanced coating liquid. S3 is used to prepare a development-enhancing coating. The imaging-enhancing coating liquid prepared by S2 is placed in a liquid tank. The ultrasound-guided nerve block needle is fixed on the dip coating device and dipped vertically into the liquid tank. The coated ultrasound-guided nerve block needle is then placed in an oven and heated to dry, resulting in an imaging-enhancing coating containing discontinuous hollow microbubbles.

4. The coated ultrasound-guided nerve block needle of claim 3, wherein, The diluent B in S1 includes acetone; the crosslinking agent includes 2,2'-azobisisobutyronitrile; and the foam stabilizer in S2 includes silicone oil.

5. The coated ultrasound-guided nerve block needle of claim 3, wherein, The wetting agent includes any one of the following: a modified organic fluorine compound solution, a polyamine amide solution of an unsaturated polycarboxylic acid, and a polyether siloxane copolymer, wherein the polyether siloxane copolymer includes a polyether-modified siloxane solution.

6. The coated ultrasound-guided nerve block needle of claim 3, wherein, The leveling agent includes any one of polyester-modified siloxane solution, aralkyl-modified polysilane, fluorinated acrylate copolymer solution, and polyether siloxane polymer, wherein the polyether siloxane polymer includes polyether-modified polydimethylsiloxane solution.

7. The coated ultrasound-guided nerve block needle of claim 1, wherein, The coated ultrasound-guided nerve block needle has a diameter of 0.7 mm. Before coating, it needs to be sandblasted under an air pressure of 0.1 MPa-1.2 MPa. The sand includes quartz sand, corundum, and sea sand.

8. A method of making a coated ultrasound-guided nerve block needle as defined in claim 1, wherein, The prepared coating liquid is applied to the surface of the ultrasound-guided nerve block needle by dip coating, and then multiple solid-gas discontinuous interfaces are formed on the surface of the ultrasound-guided nerve block needle by thermosetting. The dip coating time is 10-30s, the thermosetting temperature is 60℃-130℃, and the heating time is 3h-10h.

9. The method of claim 8, wherein the coated ultrasound-guided nerve block needle is prepared by, Before coating, the needle tip of the nerve block needle needs to be sealed by inserting a solid polymer material of the same inner diameter into the steel needle core from the needle tip. After coating, the solid polymer material is pulled out.

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