A microneedle capable of achieving intradermal injection

Abstract

The present invention discloses a microneedle capable of achieving intradermal injection, which relates to the field of medical devices. The needle body is creatively designed with a new structure, which can ensure that the piercing tip has a tip contour convenient for piercing, and enables the needle body to have a high-strength support at the root of the needle body. Since the second concave arc is a concave arc, on the basis of reliably connecting the piercing tip and the root support of the needle body, an effective necking design can be formed at the root of the piercing tip. Compared with the existing microneedles with an outward expanding arc structure design with only a convex arc at the needle tip, the width of the needle tip can be reduced while keeping the size of the injection channel unchanged and the distance between the injection channel and the leading edge unchanged, realizing the sharpening of the needle tip, which can effectively reduce the pain when the needle tip pierces the skin without affecting the puncture effect; moreover, the width of the needle tip becomes narrower and the wound becomes smaller; the needle body and needle tip designed by the present invention can meet the clinical requirements of reducing pain and shrinking the wound.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, relates to injection techniques, and particularly relates to a novel microneedle capable of achieving intradermal injection. Background Art

[0002] Microneedles are mostly used for subcutaneous injection, intradermal injection or liquid extraction, and are generally used in connection with a syringe. During use, the tip of the microneedle is tilted and inserted into the subcutaneous tissue, and then injection or extraction is performed.

[0003] With the improvement of people's requirements for medical experience, minimally invasive microneedle injection and reduction of the pain of microneedle injection have received increasing attention. However, the existing microneedles are restricted by the requirements of conventional structures and needle tip strength, and cannot meet the clinical needs of reducing pain and minimizing the wound. Based on this, the present invention proposes a microneedle that can be used for subcutaneous injection or fluid extraction. Summary of the Invention

[0004] The object of the present invention is to provide a novel microneedle capable of achieving intradermal injection. Through an innovative needle tip design, it can achieve needle tip sharpening on the premise of ensuring the needle tip strength and basic injection flow rate, so as to meet the clinical needs of reducing pain and minimizing the wound, and solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions: The present invention provides a microneedle capable of achieving intradermal injection, including a substrate and a needle body disposed on the substrate. The needle body includes: a standing profile surface protruding from the surface of the substrate, the standing profile surface being a solid structure inside, the standing profile surface including a leading edge vertical surface and side vertical surfaces symmetrically arranged on both sides of the leading edge vertical surface, and the leading edge vertical surface and the side vertical surfaces on both sides being smoothly transitionally connected; an injection channel opened on the solid structure inside the standing profile surface; an inclined cutting plane formed by obliquely cutting from the end of the standing profile surface away from the substrate towards the substrate, and the intersection line of the inclined cutting plane and the standing profile surface is the needle edge of the needle body, the intersection line of the inclined cutting plane and the injection channel is the injection and extraction port contour line of the needle body, and the intersection of the high end of the inclined cutting plane and the leading edge vertical surface is the piercing tip of the needle body; wherein, the projection contour line of the needle edge on the substrate surface is the needle edge projection line, and in the needle edge projection line: the part corresponding to the leading edge vertical surface is a first outward convex arc; the parts corresponding to the side vertical surfaces on both sides are both multi-arcs, the two multi-arcs are the same and are symmetrically arranged at both ends of the first outward convex arc. Any one of the multi-arcs includes a first inward concave arc, a second outward convex arc, a second inward concave arc, a third outward convex arc and an extension line that are sequentially tangent and transitionally connected from the high end to the low end of the inclined cutting plane. The high end of the first inward concave arc is tangent and transitionally connected to the end of the first outward convex arc; wherein, a reference point is set on the second inward concave arc, and the part of the multi-arc from the reference point to the first outward convex arc has an inwardly shrinking oblique trend towards the first outward convex arc, and the part of the multi-arc from the reference point to the end of the extension line has an outwardly expanding oblique trend towards the end of the extension line, or has a trend of first gradually expanding outward and then remaining unchanged in slope.

[0006] In some embodiments, on the inclined cutting plane, a connecting line segment between the reference points of the two second inward concave arcs is set as a reference line segment. The reference line segment, the first outward convex arc and the two multi-arcs form a closed area, and the injection and extraction port contour line is located within the closed area.

[0007] In some embodiments, in the needle edge projection line: the length of the reference line segment is 110 microns to 130 microns.

[0008] In some embodiments, on the projection contour line of the needle edge on the substrate surface: the radius of the first outward convex arc is R 1 = 30 microns to 40 microns, and the corresponding central angle γ is 60° to 65°; the radius of the second outward convex arc is R 2= 118 microns to 122 microns, and the second convex arc is smoothly transitionally connected to the first concave arc and the first convex arc; the radius of the second concave arc is R 3 = 150 microns to 160 microns, and the second concave arc is smoothly transitionally connected to the extension line through the third convex arc, and an outwardly expanding shoulder is formed at the third convex arc; the extension line is a vertical line, and the two extension lines are parallel; alternatively, the extension line is an oblique straight line or an oblique arc.

[0009] In some embodiments, one injection channel is provided in the needle body, and the projected contour line of the suction and injection port contour line on the substrate surface is a non-circular closed contour line. For any point on the non-circular closed contour line, the distance d from the corresponding position of the needle edge projection line is 35 microns ≤ d ≤ 45 microns.

[0010] In some embodiments, the non-circular closed contour line is an elliptical contour line, and the major axis of the elliptical contour line coincides with the central symmetry line of the first convex arc;

[0011] In some embodiments, the non-circular closed contour line is a symmetric polygon contour line. A fillet transition is provided at any corner position of the symmetric polygon contour line, and the symmetry axis of the symmetric polygon contour line coincides with the central symmetry line of the first convex arc.

[0012] In some embodiments, the distance between the intersection point of the central symmetry line and the first convex arc and the intersection point of the end of the non-circular closed contour line facing the first convex arc and the central symmetry line is 35 microns to 45 microns.

[0013] In some embodiments, the side vertical contour surface protrudes vertically from the substrate surface as a whole, and the angle α between the oblique cutting plane and the vertical direction of the front vertical surface is 35.2° to 36.2°.

[0014] In some embodiments, the side vertical profile surface includes: an upright segment, protruding perpendicularly from the surface of the substrate; a contraction segment, the large-end of the contraction segment being smoothly and transitionally connected to one end of the upright segment away from the substrate, the beveled plane being formed by beveling from the small-end of the contraction segment towards the substrate, and at both ends of the intersection line between the contraction segment and the upright segment, they respectively intersect with the two third convex arcs of the beveled plane; the intersection line between the vertical section plane of the side vertical profile surface and the beveled plane is a first oblique line; the central symmetry line of the first convex arc is located within the vertical section plane; the intersection line between the vertical section plane and the front-edge vertical surface in the contraction segment is a second oblique line, and the included angle β between the second oblique line and the first oblique line is 46° - 61°; the intersection line between the vertical section plane and the front-edge vertical surface in the upright segment is a straight line, and the included angle δ between the second oblique line and the straight line is 155° - 170°; in the vertical section plane: the highest point of the projection line of the pumping port contour line is at a vertical height L from the surface of the substrate 1 ; the intersection point of the first oblique line and the second oblique line is at a vertical height L from the surface of the substrate 2 ; and L 1 / L 2 The value is 7 / 8 - 9 / 10.

[0015] In some embodiments, the front-edge vertical surfaces are arranged obliquely towards the injection channels as a whole, and both side vertical surfaces protrude perpendicularly from the surface of the substrate as a whole; the intersection line between the vertical section plane of the side vertical profile surface and the beveled plane is a first oblique line; the central symmetry line of the first convex arc is located within the vertical section plane; the intersection line between the vertical section plane and the front-edge vertical surface is a second oblique line, and the included angle β between the second oblique line and the first oblique line is 36° - 39°; in the vertical section plane: the highest point of the projection line of the pumping port contour line is at a vertical height L from the surface of the substrate 1 ; the intersection point of the first oblique line and the second oblique line is at a vertical height L from the surface of the substrate 2 ; and L 1 / L 2 The value is 7 / 8 - 9 / 10.

[0016] The present invention has achieved the following technical effects compared with the prior art: The novel microneedle capable of achieving intradermal injection proposed by the present invention creatively adopts a novel structural design for the needle body. By setting a reference point on the second concave arc line and restricting the part of the multi-arc line from the reference point to the first convex arc line to have a gradually shrinking oblique trend towards the first convex arc line, it can ensure that the piercing tip has a tip contour convenient for piercing. And the part of the multi-arc line from the reference point to the tail of the extension line has a gradually expanding trend towards the tail of the extension line, which is to widen the main structure of the needle body and enable the needle body to have a high-strength support at the root of the needle body. Since the second concave arc line is a concave arc, on the basis of reliably connecting the piercing tip and the root support of the needle body, an effective diameter reduction design can be formed at the root of the piercing tip. Compared with the prior art microneedles with an outer expanding arc line structure having only a convex arc at the needle tip, under the premise of keeping the size of the injection channel unchanged and the distance between the injection channel and the leading edge unchanged, the width of the needle tip can be reduced to achieve needle tip sharpness, which can effectively reduce the pain when the needle tip pierces the skin without affecting the puncture effect; moreover, the width of the needle tip becomes narrower and the wound becomes smaller. The needle body and needle tip designed by the present invention can meet the clinical requirements of reducing pain and shrinking the wound, and are applicable to various application scenarios such as intradermal injection and subcutaneous injection.

[0017] In some technical solutions disclosed by the present invention, the cross-sectional contour of the injection channel is designed as a non-circular closed contour line, which can, on the basis of ensuring the structural strength of the needle body, maximize the cross-sectional area of the non-circular closed contour line, thereby increasing the injection flow rate or liquid extraction flow rate of each needle body.

[0018] In some technical solutions disclosed by the present invention, the side vertical contour surface adopts a two-stage structure, and a contraction section is provided at the end far from the substrate, so that the vertical leading edge surface of the side vertical contour surface becomes a bent leading edge surface. This design makes the piercing tip and the injection channel closer, so that, on the premise of keeping the hole height unchanged, compared with the prior art microneedle design, the needle height can be further reduced, and the ratio of the injection depth to the piercing depth of the microneedle can be increased. On the basis of keeping the injection volume or liquid extraction volume unchanged, the piercing depth of the needle tip is shallower, thereby further reducing the pain and wound area when the microneedle pierces, making it more in line with the painless operation characteristics of the microneedle.

[0019] In some technical solutions disclosed by the present invention, the leading edge surface of the side vertical contour surface is integrally inclined. This design makes the piercing tip and the injection channel closer, so that, on the premise of keeping the hole height unchanged, compared with the prior art microneedle design, the needle height can be further reduced, and the ratio of the injection depth to the piercing depth of the microneedle can be increased. On the basis of keeping the injection volume or liquid extraction volume unchanged, the piercing depth of the needle tip is shallower, thereby further reducing the pain and wound area when the microneedle pierces, making it more in line with the painless operation characteristics of the microneedle. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a front view schematic diagram of the microneedles disclosed in some embodiments (there are no grooves on the outer periphery of the needle body).

[0022] Figure 2 It is Figure 1 a top view schematic diagram of

[0023] Figure 3 It is Figure 2 an enlarged structural schematic diagram at C in

[0024] Figure 4 It is Figure 1 a schematic diagram of the projection profile of a single needle body on the substrate surface in

[0025] Figure 5 It is Figure 4 an enlarged structural schematic diagram of the tip of a single needle body in

[0026] Figure 6 It is Figure 1 a sectional structural schematic diagram of A-A of

[0027] Figure 7 It is a front view schematic diagram of the microneedles disclosed in some embodiments (there are grooves on the outer periphery of the needle body).

[0028] Figure 8 It is Figure 7 a top view schematic diagram of

[0029] Figure 9 It is Figure 8 an enlarged structural schematic diagram at B in

[0030] Figure 10 It is Figure 7 a sectional structural schematic diagram of D-D of

[0031] Figure 11 It is a three-dimensional structural schematic diagram of the microneedle body disclosed in some embodiments (there is no contraction section at the tip of the needle body).

[0032] Figure 12 It is a three-dimensional structural schematic diagram of the microneedle body with a contraction section provided at the tip in some embodiments.

[0033] Figure 13 It is for the microneedle sectional schematic diagram adopting the Figure 11 needle body structure in some embodiments.

[0034] Figure 14 For Figure 13 Schematic diagram of needle height and hole height in the schematic cross-section of the disclosed microneedles.

[0035] Figure 15 Schematic cross-sectional structure diagram of the overall inclination of the front edge vertical surface of the microneedle body disclosed in some embodiments.

[0036] In the figure, the reference numerals are: 100, microneedle; 1, substrate; 11, surface of the substrate; 2, needle body; 21, side vertical profile surface; 211, front edge vertical surface; 212, side vertical surface; 22, injection channel; 23, inclined cutting plane; 24, needle edge; 241, first convex arc; 242, first concave arc; 243, second convex arc; 244, second concave arc; 245, third convex arc; 246, extension line; 247, central symmetry line; 25, suction and injection port contour line; 26, piercing tip; 27, reference line segment; 28, vertical segment; 29, contraction segment; 210, junction line; 213, first oblique line; 214, second oblique line; 215, straight line; 3, groove; 31, groove projection. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] The purpose of the present invention is to provide a novel microneedle capable of realizing intradermal injection. Through an innovative needle design, it can achieve needle sharpness compared with the prior art on the premise of ensuring the needle strength and basic injection flow rate, so as to meet the clinical requirements of reducing pain and shrinking the wound, and solve the problems existing in the prior art.

[0039] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0040] Embodiment 1

[0041] Such as Figures 1 - 6As shown in the figure, this embodiment provides a microneedle 100 capable of achieving intradermal injection, which includes a substrate 1 and a needle body 2 disposed on the substrate 1. The needle body 2 includes a side standing contour surface 21 protruding from the surface of the substrate 1, an injection channel 22, and an inclined cutting plane 23. Among them, the side standing contour surface 21 protruding from the surface 11 of the substrate, the side standing contour surface 21 is a solid structure inside, and this solid structure is generally integrally designed with the substrate 1; the side standing contour surface 21 includes a leading edge vertical surface 211 and side vertical surfaces 212 symmetrically arranged on both sides of the leading edge vertical surface 211. The leading edge vertical surface 211 and the side vertical surfaces 212 on both sides are smoothly transitionally connected and jointly enclose the main structure of the needle body 2. The injection channel 22 is opened on the solid structure inside the side standing contour surface 21. The injection channel 22 is arranged along the protruding direction of the side standing contour surface 21. The injection channel 22 penetrates both the substrate 1 and the above solid structure at the same time, and the injection channel 22 is arranged close to the leading edge vertical surface 211. The inclined cutting plane 23 is obliquely cut from one end of the side standing contour surface 21 away from the substrate 1 towards the substrate 1. The intersection line of the inclined cutting plane 23 and the side standing contour surface 21 is the needle edge 24 of the needle body 2. The intersection line of the inclined cutting plane 23 and the injection channel 22 is the pumping port contour line 25 of the needle body 2. Both the pumping port contour line 25 and the needle edge 24 are exposed on the inclined cutting plane 23, and the needle edge 24 is a part of the outer contour line of the inclined cutting plane 23. The intersection of the high end of the inclined cutting plane 23 and the aforementioned leading edge vertical surface 211 is the piercing tip 26 of the needle body 2. When in use, after connecting the substrate 1 to the corresponding syringe, the piercing tip 26 of the needle body 2 is obliquely inserted downward into the subcutaneous tissue. After the insertion is in place, injection or liquid extraction can be performed through the syringe. In order to more clearly understand the innovative design of the needle body 2 of this solution, the structure is specifically described with the projection contour line of the needle edge 24 on the surface 11 of the substrate as the focus:

[0042] As Figures 2 - 5 shown, the projection contour line of the needle edge 24 on the surface 11 of the substrate is defined as the needle edge projection line. In this needle edge projection line: the part corresponding to the leading edge vertical surface 211 is the first outer convex arc 241; the parts corresponding to the side vertical surfaces 212 on both sides are both multi-arcs. The two multi-arcs are exactly the same and are symmetrically arranged at both ends of the first outer convex arc 241. Among them, any one of the multi-arcs includes a first inner concave arc 242, a second outer convex arc 243, a second inner concave arc 244, a third outer convex arc 245, and an extension line 246 that are sequentially tangent and transitionally connected from the high end to the low end of the inclined cutting plane 23. The high end of the first inner concave arc 242 is tangent and transitionally connected to the end of the first outer convex arc 241. In the above description, in order to clearly describe the structure, a method of segmentally describing the projection contour line of the needle edge 24 is adopted. However, in fact, the leading edge vertical surface 211 and the side vertical surfaces 212 on both sides are an integral structure, and the projection contour line of the needle edge 24 is also an integral structure.

[0043] It should be noted that in order to ensure that the needle edge 24 with multiple concave and convex arcs can smoothly penetrate the skin tissue, a reference point (not a structural component of the present invention) is set on the second concave arc 244 in this solution. For the part of the multiple arcs from the reference point to the first convex arc 241, it shows a gradually shrinking oblique trend towards the first convex arc 241, while for the part of the multiple arcs from the reference point to the tail of the extension line 246, it shows a gradually expanding oblique trend towards the tail of the extension line 246, or shows a trend of first gradually expanding and then remaining unchanged in slope. As Figures 2 - 4 shown, it is a schematic structural view of the part of the multiple arcs from the reference point to the tail of the extension line 246 showing a gradually expanding oblique trend towards the tail of the extension line 246, that is, the two extension lines 246 are symmetrical and gradually form a flared shape along the direction away from the piercing tip 26. The design of the extension line 246 part is similar to the existing microneedle design and will not be elaborated here.

[0044] For the design of the above-mentioned needle body 2, the contour trend of the needle edge 24 on the oblique cutting plane 23 is consistent with the contour trend of the projection contour line of the needle edge 24 on the surface 11 of the substrate. The technical effect of the needle edge 24 can be effectively deduced through the design of the projection contour line of the needle edge 24 on the surface 11 of the substrate. Based on this, by setting a reference point on the second concave arc 244 and restricting the part of the multiple arcs from the reference point to the first convex arc 241 to show a gradually shrinking oblique trend towards the first convex arc 241, it is to ensure that the piercing tip 26 has a tip contour convenient for piercing, while the part of the multiple arcs from the reference point to the tail of the extension line 246 shows a gradually expanding trend towards the tail of the extension line 246, which is to widen the main structure of the needle body 2 and make it have a high-strength needle body root support. Since the second concave arc 244 is a concave arc, on the basis of reliably connecting the piercing tip 26 and the needle body root support, an effective diameter reduction design can be formed at the root of the piercing tip 26. Compared with the existing microneedle with an outer expanding arc structure design having only a convex arc at the needle tip, under the premise of keeping the size of the injection channel 22 unchanged and the distance between the injection channel 22 and the leading edge unchanged, the needle width can be reduced to achieve needle tip sharpening. This design can effectively reduce the pain when the needle penetrates the skin, and at the same time does not affect the puncture effect; moreover, the needle width becomes narrower and the wound becomes smaller; the designed needle body and needle tip of this solution can meet the clinical requirements of reducing pain and shrinking the wound.

[0045] Meanwhile, the needle edge 24 is provided with a plurality of inward concave arcs and a plurality of outward convex arcs connected to each other. This can not only meet the trend design of needle sharpness, but also adopt a gentle arc transition at the width change, which has the effect of reducing stress concentration and strengthening the structural strength of the needle. As a result, the needle edge 24 of this solution can achieve the technical effects of reducing pain and minimizing the wound, while maintaining a relatively high structural strength, improving the performance and reliability of the microneedle 100. Moreover, the arc design of the needle edge 24 has the advantages of easy processing and low processing cost, breaking through the technical bottlenecks of current microneedles, such as limited processing difficulty and structural strength, which prevent the improvement of painless and minimally invasive effects.

[0046] In some embodiments, on the bevel plane 23, a straight line connecting segment between the reference points of the two second inward concave arcs 244 is set as the reference line segment 27, as Figure 4 shown. The reference line segment 27 and the first outward convex arc 241 and the multi-arcs form a closed area, and the profile line 25 of the injection and extraction port is located within this closed area. As shown in the figure, it is ensured that Figure 4 after the tip above the reference line segment 27 shown in the figure pierces the skin, the entire profile line 25 of the injection and extraction port also enters the skin tissue, which can avoid the situation that after the tip is inserted, a part of the outlet of the injection channel 22 is still located outside the skin surface, resulting in failure of liquid extraction or leakage of liquid during injection. It should be noted that the above reference line segment 27 is an auxiliary line used to help understand the setting position of the profile line 25 of the injection and extraction port, and is not a structural component of the needle body 2 in this solution.

[0047] In some embodiments, preferably, on the projection contour line of the needle edge 24 on the surface 11 of the substrate: the length of the reference line segment 27 is 110 microns to 130 microns, and specifically, 110 microns, 115 microns, 125 microns or 130 microns can be selected. As a further preferred solution, the reference points at both ends of the reference line segment 27 are generally located at the deepest points of the second inward concave arcs 244, that is, the reference line segment 27 represents the shortest distance between the two second inward concave arcs 244. At this time, the length of the reference line segment 27 can be used to characterize the width at the needle diameter reduction position, which is significantly smaller than that of existing microneedles.

[0048] In some embodiments, as Figure 5 shown, preferably, on the projection contour line of the needle edge 24 on the surface 11 of the substrate: the radius of the first outward convex arc 241 is R 1 = 30 microns to 40 microns, and the corresponding central angle γ is 60° to 65°. In a feasible solution, R 1 can be set to 35 microns, and the central angle γ is 65°; the radius of the second outward convex arc 243 is R 2 = 118 microns to 122 microns, and the second outward convex arc 243 is smoothly connected to the first outward convex arc 241 through the first inward concave arc 242; the radius of the second inward concave arc 244 is R3 = 150 microns to 160 microns. The second concave arc 244 is smoothly transitionally connected to the extension line 246 through the third convex arc 245, and an outwardly expanding shoulder is formed at the third convex arc 245. Above the outwardly expanding shoulder is the reduced-diameter part of the needle tip. In existing microneedles, there is no such outwardly expanding shoulder as described above, but a continuously outwardly convex structural arrangement. This further verifies that the needle tip width has been narrowed in this solution compared to existing microneedles.

[0049] In some embodiments, the extension line 246 can be a vertical line, and the two extension lines 246 are parallel; alternatively, the extension line 246 is an oblique straight line or an oblique arc, such as Figure 3 and Figure 4 shown, the extension line 246 is an arc with a gentle curvature, and the extension line 246 has an outwardly expanding trend relative to the central symmetry line 247. It should be noted that when the extension line 246 is set as Figure 3 and Figure 4 shown arc with a gentle curvature, it has the effect of making the contour of the needle edge 24 more blunt on the basis of not affecting the use effect of the needle edge 24, and can improve the structural strength of the needle edge 24.

[0050] In some embodiments, one, two or three injection channels 22 can be opened in the needle body 2 as needed. To ensure the structural strength of the needle body 2, it is preferred in this solution that one injection channel 22 is opened in the needle body 2, and the projection contour line of the pumping port contour line 25 on the surface 11 of the substrate is a non-circular closed contour line, that is, the cross-sectional contour of the injection channel 22 is a non-circular closed contour line. To maximize the cross-sectional area of the non-circular closed contour line on the basis of ensuring the structural strength of the needle body, and thus increase the injection flow rate or the liquid extraction flow rate of each needle body 2, it is preferred that the distance between any point on the non-circular closed contour line and the corresponding position of the projection contour line of the needle edge 24 on the surface 11 of the substrate is d, and 35 microns ≤ d ≤ 45 microns. This design can be regarded as a design for thinning the wall thickness of the needle body.

[0051] In some embodiments, the above non-circular closed contour line is preferably an elliptical contour line, and the major axis of the elliptical contour line coincides with the central symmetry line 247 of the first convex arc 241. The use of an elliptical contour line for the non-circular closed contour line has the technical effect of a larger injection flow rate or liquid extraction flow rate compared to the injection holes with a circular cross-section in traditional microneedles. Among them, the length a of the major axis of the elliptical contour line is preferably 100 μm to 115 μm, and correspondingly, the length of the minor axis of the elliptical contour line is 45 μm to 60 μm. Taking the major axis length a of the elliptical contour line as 100 μm and the minor axis length as 60 μm as an example, according to the liquid flow rate calculation formula Q = Sv, where Q represents the flow rate, S represents the cross-sectional area of the pipeline, and v represents the liquid flow velocity, the flow rate of a circular hole with an original aperture of 60 μm to 75 μm is Q = 0.002826*V to 0.004415625*V; while the flow rate of an elliptical hole with a major axis length a of 100 μm and a minor axis length of 60 μm is estimated to be 0.00471*V, and the flow rate has been improved compared to the existing microneedle channels.

[0052] In some embodiments, such as Figure 6 and Figure 11 shown, the side standing contour surface 21 protrudes vertically as a whole from the surface 11 of the substrate, that is, the side standing contour surface 21 is an upright surface perpendicular to the surface 11 of the substrate as a whole. As Figure 6 shown, the included angle α between the oblique cutting plane 23 and the upright direction of the front edge upright surface 211 is 35.2° to 36.2°, and specifically can be 35.2°, 35.7° or 36°.

[0053] In some embodiments, one, two or more needle bodies 2 can be arranged on the substrate 1 according to the clinical application scenario. When two or more are arranged, it is preferred that the needle bodies 2 are evenly spaced on the substrate 1.

[0054] Taking 10 girls in good physical condition aged 20 to 22 as testers, with every 5 as a group, the first group of testers used the microneedle 100 of this embodiment, and the second group used the existing microneedles with relatively blunt tips. Using the same injection solution, with the same injection volume, and physicians with comparable techniques (consistent microneedle puncture techniques), the same part of the two groups of testers was subjected to microneedle injection in the same time period. After the injection, each tester was detected for the puncture site using a pain detector of the same specification. The detection results were: the detection value of any one of the first group of testers was less than that of any one of the second group of testers, that is, the highest detection value in the first group of testers was less than the lowest detection value in the second group of testers. The test conclusion is that the microneedle 100 of this embodiment has the effect of reducing pain.

[0055] Example 2

[0056] This embodiment provides a microneedle 100 capable of achieving intradermal injection. The difference from Embodiment 1 is only that the non-circular closed contour line is a symmetric polygon contour line, and a rounded transition is provided at any corner position of the symmetric polygon contour line, and the symmetric central axis of the symmetric polygon contour line coincides with the central symmetry line 247 of the first convex arc 241.

[0057] In a feasible implementation, the symmetric polygon contour line can be an isosceles trapezoid contour line, with its small head end close to the first convex arc 241 and its large head end far from the first convex arc 241. The symmetric central axis of the isosceles trapezoid contour line is the line connecting the midpoint of the short side of the small head end and the midpoint of the long side of the large head end.

[0058] Taking 10 boys in good physical condition aged 20 - 22 as testers, with 5 in each group. The first group of testers used the microneedle 100 of this embodiment, and the second group used a microneedle with a relatively blunt existing tip. Using the same injection solution, with the same injection volume, and physicians with comparable techniques (consistent microneedle puncture techniques), the same part of the two groups of testers was subjected to microneedle injection in the same time period. After the injection, each tester was detected for the puncture site using a pain detector of the same specification. The detection results showed that the detection value of any tester in the first group was less than that of any tester in the second group, that is, the highest detection value in the first group of testers was less than the lowest detection value in the second group of testers. The test conclusion is that the microneedle 100 of this embodiment has the effect of reducing pain.

[0059] Embodiment 3

[0060] This embodiment provides a microneedle 100 capable of achieving intradermal injection. On the basis of Embodiment 1 or 2, it also performs an enlarged hole design on the injection channel 22 towards the leading edge vertical surface 211 to further improve the injection flow rate of the needle body 2. The reason for enlarging the hole towards the leading edge vertical surface 211 is that when the microneedle is used, the tip of the leading edge vertical surface 211 will surely penetrate into the skin tissue. Enlarging the hole towards both sides will reduce the structural strength of the needle body 2, and enlarging the hole in the direction away from the leading edge vertical surface 211 will cause the problem that the injection channel 22 cannot fully enter the skin tissue during injection or liquid extraction.

[0061] The enlargement of the injection channel 22 directly affects the wall thickness of the needle body 2. As a preferred solution, the distance between the midpoint of the end of the non-circular closed contour line facing the first convex arc 241 and the midpoint of the first convex arc 241 (that is, the distance between the intersection of the central symmetry line 247 and the first convex arc 241, and the intersection of the end of the non-circular closed contour line facing the first convex arc 241 and the central symmetry line 247) is 35 microns to 45 microns, specifically it can be 35 microns to 42 microns, and 36 microns, 38 microns, and 40 microns are better among them.

[0062] Embodiment 4

[0063] This embodiment provides a microneedle 100 capable of achieving intradermal injection. As shown in Figure 7 and Figure 10 , on the basis of any one of Embodiments 1 to 3, a groove 3 is further provided on the outer periphery of each needle body 2. Correspondingly, the groove projection 31 of the groove 3 on the surface 11 of the substrate is shown in Figure 8 and Figure 9 .

[0064] The groove 3 is a conventional structural arrangement in the microneedle, and will not be elaborated here specifically. The size design of the groove 3 is flexibly designed according to the structural size of the needle body 2.

[0065] Embodiment 5

[0066] This embodiment provides a microneedle 100 capable of achieving intradermal injection. The difference between it and any one of Embodiments 1 to 4 lies in that: the side standing profile surface 21 is not the upright vertical surface as shown in Figure 11 , but adopts a two-stage design. Specifically: as shown in Figure 12 , the side standing profile surface 21 includes an upright section 28 and a contraction section 29. The upright section 28 protrudes vertically from the surface 11 of the substrate. The contraction section 29 is located at the end of the upright section 28 away from the substrate 1, and the large head end of the contraction section 29 is smoothly transitionally connected to the end of the upright section 28 away from the substrate 1. Based on this, the bevel cutting plane 23 is obliquely cut from the small head end of the contraction section 29 towards the substrate 1, and both ends of the intersection line 210 between the contraction section 29 and the upright section 28 intersect with the two third convex arcs 245 of the bevel cutting plane 23 respectively. Both the contraction section 29 and the upright section 28 are smooth curved surfaces. The contraction section 29 and the upright section 28 divide the side standing profile surface 21 in the upright direction of the side standing profile surface 21, while the leading edge vertical surface 211 and the side vertical surface 212 of Embodiment 1 divide the side standing profile surface 21 according to the outer contour of the side standing profile surface 21. The two concepts of the contraction section 29 and the upright section 28 do not conflict with the two concepts of the leading edge vertical surface 211 and the side vertical surface 212. Substantially, when the bevel cutting plane 23 is not formed, both the contraction section 29 and the upright section 28 have corresponding leading edge vertical surfaces 211 and side vertical surfaces 212, and the leading edge vertical surfaces 211 and side vertical surfaces 212 of the contraction section 29 and the leading edge vertical surfaces 211 and side vertical surfaces 212 of the upright section 28 are arranged in one-to-one correspondence.

[0067] The side standing profile surface 21 adopts a two-stage design, and a contraction section 29 is provided at the end away from the substrate 1, so that the vertical leading edge vertical surface of the side standing profile surface 21 becomes a bent leading edge vertical surface, and the bending position is the location of the intersection line 210. It should be noted that the intersection line 210 is not a structural component of the side standing profile surface 21, but is only an auxiliary line set for the convenience of understanding the solution. Combining Figure 13 and Figure 14It can be seen that the intersection line of the vertical cutting plane of the side vertical profile surface 21 and the inclined cutting plane 23 is the first oblique line 213 (in Figure 13 and Figure 14 , the first oblique line 213 also refers to the inclined cutting plane 23), and this vertical cutting plane is the cutting plane passing through the central symmetry line 247. At the same time, the intersection line of the vertical cutting plane and the leading edge vertical surface 211 in the contraction section 29 is the second oblique line 214, and the included angle β between the second oblique line 214 and the first oblique line 213 is 46° - 61°, with 46°, 50° and 55° being the preferred values; the intersection line of the vertical cutting plane and the leading edge vertical surface 211 in the straight section 28 is the straight line 215, and the included angle δ between the second oblique line 214 and the straight line 215 is 155° - 170°.

[0068] In some embodiments, as Figure 14 shown, in the vertical cutting plane: the highest point of the projection line of the pumping and injection port contour line 25 is at a vertical height of the hole height L from the surface 11 of the substrate 1 ; the intersection point of the first oblique line 213 and the second oblique line 214 is at a vertical height of the needle height L from the surface 11 of the substrate 2 ; and the value of L 1 / L 2 is 7 / 8 - 9 / 10.

[0069] Combined with Figure 13 and Figure 14 it can be seen that the setting of the contraction section 29 makes the intersection point of the second oblique line 214 and the first oblique line 213 closer to the injection channel 22 than in Embodiment 1. This design makes the piercing tip 26 and the injection channel 22 closer, so that on the premise of ensuring the unchanged hole height L 1 , the needle height L 2 can be further reduced, increasing the ratio of the injection depth to the piercing depth of the microneedle 100. On the basis of keeping the injection volume or the liquid extraction volume unchanged, the piercing depth of the needle tip is shallower, thereby further reducing the pain of microneedle piercing and the wound area, making it more in line with the painless operation characteristics of microneedles.

[0070] Embodiment 6

[0071] As Figure 15 shown, this embodiment proposes a microneedle 100 capable of achieving intradermal injection, and the difference from Embodiment 5 is only that: the side vertical profile surface 21 is not two - section type, but is an integral type like Embodiment 1, but in this embodiment, the entire leading edge vertical surface 211 is inclined towards the injection channel 22. As a result, the intersection line of the vertical cutting plane and the entire leading edge vertical surface 211 is the second oblique line 214. At this time, the included angle β between the second oblique line 214 and the first oblique line 213 is 36° - 39°, with 37° and 38° being the most preferred. The vertical cutting plane is the cutting plane passing through the central symmetry line 247.

[0072] In some embodiments, asFigure 15 As shown, in the vertical section: the highest point of the projection line of the infusion port contour line 25 is at a vertical height of hole height L from the surface 11 of the substrate. 1 The intersection point of the first oblique line 213 and the second oblique line 214 is at a vertical height of needle height L from the surface 11 of the substrate. 2 And L 1 / L 2 The value is 7 / 8 to 9 / 10.

[0073] Combined Figure 15 It can be seen that the front edge vertical surface 211 is inclined as a whole towards the injection channel 22, making the intersection point of the second oblique line 214 and the first oblique line 213 closer to the injection channel 22 compared to Embodiment 1. This design makes the piercing tip 26 closer to the injection channel 22, so that on the premise of ensuring the unchanged hole height L 1 the needle height L can be further reduced, increasing the ratio of the injection depth to the piercing depth of the microneedle 100. On the basis of keeping the injection volume or the liquid extraction volume unchanged, the piercing depth of the needle tip is shallower, thereby further reducing the pain of microneedle piercing and the wound area, making it more in line with the painless operation characteristics of the microneedle. 2

[0074] The side vertical contour surface 21 of this embodiment is easier to process compared to the two-stage contour surface of Embodiment 5.

[0075] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essential significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the efficacy that the present invention can produce and the purpose that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of description and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0076] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A microneedle capable of achieving intradermal injection, comprising a substrate (1) and a needle body (2) disposed on the substrate (1), characterized in that: The needle body (2) comprises: a side profile surface (21) protruding from the surface of the substrate (1), the side profile surface (21) being a solid structure, the side profile surface (21) comprising a front edge face (211) and side faces (212) symmetrically arranged on both sides of the front edge face (211), the front edge face (211) and the side faces (212) on both sides being smoothly transitioned and connected; an injection channel (22) being opened on the solid structure in the side profile surface (21); and a beveled plane (23) being formed by beveling the side profile surface (21) away from the substrate (1) toward the substrate (1), and the beveled plane (23) being formed by beveling the side profile surface (21) at one end away from the substrate (1) toward the substrate (1), and the beveled plane (23) being The intersection line of the cutting plane (23) and the side profile surface (21) is the needle blade (24) of the needle body (2), the intersection line of the oblique cutting plane (23) and the injection channel (22) is the injection port contour line (25) of the needle body (2), and the intersection of the high end of the oblique cutting plane (23) and the front edge vertical surface (211) is the insertion tip (26) of the needle body (2); wherein the projection contour line of the needle blade (24) on the surface of the substrate (1) is the needle blade projection line, and among the needle blade projection lines: the one corresponding to the front edge vertical surface (211) is the first convex arc line (241); the ones corresponding to the side vertical surfaces (212) on both sides are A plurality of arcs, wherein two of the plurality of arcs are identical and are symmetrically arranged at both ends of the first convex arc (241), wherein any one of the plurality of arcs comprises a first concave arc (242), a second convex arc (243), a second concave arc (244), a third convex arc (245) and an extension line (246) which are sequentially tangently transitionally connected from the high end to the low end of the bevel plane (23), and the high end end of the first concave arc (242) is tangently transitionally connected to the end of the first convex arc (241); wherein a reference point is set on the second concave arc (244), and the plurality of arcs are connected from the reference point to the first convex arc (241). The portion of the convex arc line (241) shows a gradually inwardly contracting oblique trend toward the first convex arc line (241), and the portion of the multiple arc lines from the reference point to the tail of the extension line (246) shows a gradually outwardly expanding oblique trend toward the tail of the extension line (246), or shows a trend of first gradually outwardly expanding and then maintaining a constant inclination; on the bevel plane (23), a connecting line segment between the reference points of the two second concave arc lines (244) is set as a reference line segment (27), and a closed area is formed between the reference line segment (27) and the first convex arc line (241) and the two multiple arc lines, and the injection port contour line (25) is located within the closed area.

2. The microneedle capable of achieving intradermal injection according to claim 1, characterized in that: In the needle blade projection line: the length of the reference line segment (27) is 110 micrometers to 130 micrometers.

3. The microneedle capable of intradermal injection according to claim 1 or 2, characterized in that: The needle blade (24) is on the projection contour line of the surface of the substrate (1): the radius of the first convex arc (241) is R1=30 microns~40 microns, and its corresponding central angle γ is 60°~65°; the radius of the second convex arc (243) is R2=118 microns~122 microns, and the second convex arc (243) smoothly transitions to the first convex arc (241) through the first concave arc (242); the radius of the second concave arc (244) is R3=150 microns~160 microns, and the second concave arc (244) smoothly transitions to the extension line (246) through the third convex arc (245), and an outward-expanded shoulder is formed at the third convex arc (245); the extension line (246) is a vertical line, and the two extension lines (246) are parallel; or, the extension line (246) is an oblique straight line or an oblique arc.

4. The microneedle capable of intradermal injection according to claim 1 or 2, characterized in that: The needle body (2) is provided with an injection channel (22), and the projection contour of the injection port contour line (25) on the surface of the substrate (1) is a non-circular closed contour line, and the distance between any point on the non-circular closed contour line and the corresponding position of the needle blade projection line is d, 35 micrometers ≤ d ≤ 45 micrometers.

5. The microneedle capable of achieving intradermal injection according to claim 4, characterized in that: The non-circular closed contour line is an elliptical contour line, and the major axis of the elliptical contour line coincides with the central symmetry line (247) of the first convex arc line (241); or, the non-circular closed contour line is a symmetrical polygonal contour line, and any corner position of the symmetrical polygonal contour line is provided with a rounded transition, and the symmetry axis of the symmetrical polygonal contour line coincides with the central symmetry line (247) of the first convex arc line (241).

6. The microneedle capable of achieving intradermal injection according to claim 5, characterized in that: The distance between the intersection point of the central symmetry line (247) and the first convex arc line (241) and the intersection point of one end of the non-circular closed contour line facing the first convex arc line (241) and the central symmetry line (247) is 35 microns to 45 microns.

7. The microneedle capable of intradermal injection according to claim 1 or 2, characterized in that: The side profile surface (21) protrudes vertically from the surface of the substrate (1) as a whole, and an included angle α between the chamfered plane (23) and the upright direction of the front edge vertical surface (211) is 35.2° to 36.2°.

8. The microneedle capable of intradermal injection according to claim 1 or 2, characterized in that: The side profile surface (21) comprises: an upright section (28) protruding vertically from the surface of the substrate (1); a contraction section (29), the large end of the contraction section (29) smoothly transitioningly connecting with the end of the upright section (28) away from the substrate (1); the beveled plane (23) is formed by beveling the small end of the contraction section (29) toward the substrate (1), and the two ends of the intersection line (210) between the contraction section (29) and the upright section (28) respectively intersect with two third convex arcs (245) of the beveled plane (23); the intersection line of the vertical section of the side profile surface (21) and the beveled plane (23) is a first oblique line (213); the central symmetry line (247) of the first convex arc (241) is located in the vertical section; the vertical section The intersection line of the vertical section and the front edge vertical surface (211) in the contraction section (29) is a second oblique line (214), and the angle β between the second oblique line (214) and the first oblique line (213) is 46°~61°; the intersection line of the vertical section and the front edge vertical surface (211) in the upright section (28) is a straight line (215), and the angle δ between the second oblique line (214) and the straight line (215) is 155°~170°; in the vertical section: the highest point of the projection line of the extraction port contour line (25) is at a vertical height of the hole height L1 from the surface of the substrate (1); the intersection point of the first oblique line (213) and the second oblique line (214) is at a vertical height of the needle height L2 from the surface of the substrate (1); and the value of L1 / L2 is 7 / 8~9 / 10.

9. The microneedle capable of intradermal injection according to claim 1 or 2, characterized in that: The front edge vertical surface (211) is arranged as a whole to be inclined toward the injection channel (22), and the two side vertical surfaces (212) are as a whole vertically protruding from the surface of the substrate (1); the intersection line of the vertical section of the side profile surface (21) and the oblique cutting plane (23) is a first oblique line (213); the central symmetry line (247) of the first outer convex arc line (241) is located in the vertical section; the intersection line of the vertical section and the front edge vertical surface (211) is a second oblique line. line (214), the angle β between the second oblique line (214) and the first oblique line (213) is 36°~39°; in the vertical section: the highest point of the projection line of the extraction port contour line (25) is at a vertical height of the hole height L1 from the surface of the substrate (1); the intersection of the first oblique line (213) and the second oblique line (214) is at a vertical height of the needle height L2 from the surface of the substrate (1); and the value of L1 / L2 is 7 / 8~9 / 10.

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