Puncture-depth-controllable uniform injection needle for local infiltration anesthesia

Abstract

The uniform injection needle comprises a needle stem (4) and a needle sleeve (5), the needle sleeve (5) with the adjustable length is arranged at the starting end of the needle stem (4) in a sleeving mode, and multiple layers of auxiliary holes used for uniformly injecting fluid are formed in the needle stem (4). Injection is carried out according to the depth L1 of the first layer of auxiliary holes inserted into the skin during injection, the flow Q of the multiple layers of auxiliary holes used for uniformly injecting fluid and the pressure P1 of the end, closest to the skin surface, of the first layer of auxiliary holes, wherein the depth L1 is obtained through calculation.

Description

Technical Field

[0001] The invention relates to a needle with controllable insertion depth for uniform injection of local infiltration anesthesia, belonging to the technical field of needles. Background Art

[0002] Local infiltration anesthesia requires injecting local anesthetics layer by layer into the tissues of the surgical area. Taking lumbar puncture as an example, researchers usually need to inject the syringe layer by layer multiple times to achieve the effect of even distribution and full infiltration of anesthetics. However, this injection method requires a long operation time and certain operating skills. Otherwise, the anesthesia is not sufficient, which will cause unnecessary pain to the patient. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a needle with controllable insertion depth for uniform injection of local infiltration anesthesia.

[0004] Preferably, the present invention provides a needle with controllable insertion depth for uniform injection of local infiltration anesthesia, comprising a needle stem and a needle sheath, wherein the needle sheath with adjustable length is sheathed on the starting end of the needle stem, and multiple layers of auxiliary holes for uniform injection of fluid are provided on the needle stem, wherein the depth of the first layer of auxiliary holes inserted into the skin during injection is L is the total length of the needle sleeve, n is the total number of the first layer of auxiliary holes; the pressure P1 at the end of the first layer of auxiliary holes closest to the skin surface is:

[0005] P1=P begin +ρgL1,

[0006] Where P begin is the vacuum internal pressure at the skin surface, ρ is the density of the fluid, g is the gravitational acceleration, and L1 is the vertical distance between the end of the first layer of accessory holes closest to the skin surface and the skin surface, that is, the depth of the first layer of accessory holes inserted into the skin during injection.

[0007] Prior to this, the flow rate Q of the multi-layer secondary orifices for uniform fluid injection is calculated:

[0008]

[0009] In the formula, C d is the flow coefficient, A is the surface area of ​​the auxiliary hole, ΔP=P2-P1 is the pressure difference, P2=P1+2r, r is the radius of the auxiliary hole.

[0010] Preferably, the first layer of n1 secondary holes with a radius of r1 has a total outflow of fluid

[0011] According to Poiseuille's law, the relationship between the pressure difference at both ends of the auxiliary hole and the fluid flow rate is obtained:

[0012] Will Bring in The pressure difference is calculated The pressure at the end of the first layer of auxiliary holes farthest from the skin surface is obtained as P2=P1+ΔP.

[0013] Preferably, the depth of the second layer of accessory orifice injection into the skin n2 is the total number of secondary holes in the second layer;

[0014] The pressure P3 at the end of the second layer of secondary holes closest to the skin surface is:

[0015] P3=P2+ρgL2,

[0016] Where P2 is the pressure at the end of the first layer of secondary pores farthest from the skin surface, ρ is the density of the fluid, g is the acceleration of gravity, and L2 is the distance between the end of the second layer of secondary pores closest to the skin surface and the end of the first layer of secondary pores farthest from the skin surface.

[0017] Preferably, the depth of the nth layer of accessory holes when injected into the skin is P 2n-1 for:

[0018] P 2n-1 =P 2n-2 +ρgL n ,

[0019] Where P 2n-2 is the pressure at the end of the n-1th layer of secondary pores farthest from the skin surface, ρ is the density of the fluid, g is the gravitational acceleration, L n It is the distance between the end of the nth layer of secondary pores closest to the skin surface and the end of the n-1th layer of secondary pores farthest from the skin surface.

[0020] Preferably, the invention comprises a syringe and a needle plug, wherein the needle barrel is installed on the syringe through the needle plug.

[0021] Preferably, the syringe comprises a push-pull rod, a piston and an empty barrel, wherein the piston is slidably mounted in the empty barrel, and the push-pull rod and the piston are detachably connected.

[0022] Preferably, the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any one of the methods described in the first aspect when executing the program.

[0023] Preferably, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods described in the first aspect.

[0024] The beneficial effects achieved by the present invention are:

[0025] The length of the needle sheath is evenly divided and can be cut to a specific length as needed. The diameter of the needle sheath is larger than the needle stem and is exposed outside the skin during injection. It presses against the skin to control the penetration depth of the needle, and the part of the needle sheath covering the needle stem blocks the auxiliary hole on the side of the needle stem to prevent anesthetic drugs from leaking from the side. Taking local infiltration anesthesia by abdominal puncture as an example, when using this device, the penetration depth is determined before insertion, and the corresponding needle sheath length is cut so that the leaked needle stem length is the penetration depth. Then the anesthetic drugs are injected, and the anesthetic drugs can enter the human tissue from the auxiliary hole. Only one injection is required to achieve uniform distribution and sufficient infiltration of the drugs in the tissues of the surgical area. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 are cross-sectional views of some embodiments of the present application;

[0028] Figure 2 It is a stereogram of some embodiments of the present application;

[0029] Figure 3 It is a stereogram of some embodiments of the present application;

[0030] Figure 4 is a perspective view of a hollow cylinder and a piston assembly in some embodiments of the present application;

[0031] Figure 5 is a stereoscopic diagram of a needle sleeve in some embodiments of the present application;

[0032] Figure 6 is a stereogram of a needle stem in some embodiments of the present application;

[0033] Meaning of the reference numerals: 1-piston assembly, 2-empty cylinder, 3-needle bolt, 4-needle stem, 5-needle sleeve, 5-first layer auxiliary hole; 6-second layer auxiliary hole. DETAILED DESCRIPTION

[0034] Embodiment 1

[0035] See also Figure 1 , an embodiment of the present invention provides a needle with controllable insertion depth for uniform injection of local infiltration anesthesia, the needle with controllable insertion depth for uniform injection of local infiltration anesthesia comprising:

[0036] A needle assembly mounted on the syringe, the needle assembly comprising a needle plug 3, a needle stem 4 and a needle cover 5, the needle stem 4 being mounted on the syringe through the needle plug 3, and a plurality of auxiliary holes being formed at the blind end of the needle stem 4, and the needle cover 5 being sleeved on the needle stem;

[0037] In an embodiment of the present invention, the length of the needle sheath 5 is evenly divided, and a specific length can be manually cut as needed. The diameter of the needle sheath 5 is larger than the needle stem 4, and is exposed outside the skin during injection, pressing against the skin to control the penetration depth of the needle, and the portion of the needle sheath 5 covering the needle stem 4 blocks the auxiliary holes on the side of the needle stem 4 to prevent anesthetic drugs from leaking from the side of the needle stem 4. Taking local infiltration anesthesia by abdominal puncture as an example, when used, the penetration depth is determined before penetration, and the corresponding length of the needle sheath 5 is cut so that the leaked length of the needle stem 4 is the penetration depth, and then the anesthetic drugs are injected. The anesthetic drugs can enter the human tissue from the auxiliary holes on the side of the needle stem 4, and only one injection is required to achieve uniform distribution and sufficient infiltration of the drugs in the tissues of the surgical area.

[0038] In one embodiment of the present invention, see Figure 1 The plurality of auxiliary holes are evenly distributed in the circumferential direction of the needle stem 4, and the diameter of each auxiliary hole in the vertical direction of the cross section is designed according to Poiseuille's law to achieve a consistent drug flow rate in each layer;

[0039] The needle stem 4 is made of steel; the needle plug 3 is made of wear-resistant material;

[0040] The wear-resistant material is polypropylene; polypropylene is a plastic material with excellent heat resistance, chemical corrosion resistance, wear resistance and impact resistance. Therefore, polypropylene is widely used in medical equipment, medical devices and other fields, including injection needles, infusion sets, etc.

[0041] In this embodiment, a plurality of evenly distributed secondary holes can achieve multi-directional even distribution of the drug in the tumor with only one injection.

[0042] In one embodiment of the present invention, see Figure 2 The syringe comprises an empty barrel 2 and a piston assembly 1 disposed in the empty barrel 2; the piston assembly 1 comprises a push-pull rod and a piston, the piston is fixedly installed in the empty barrel 2, and the push-pull rod and the piston are detachably connected;

[0043] The empty cylinder 2 is made of polypropylene material;

[0044] The piston is made of drug-resistant material;

[0045] The drug-resistant material is styrene-butadiene rubber.

[0046] In this embodiment, the push-pull rod drives the piston to move in the empty cylinder 2 to complete the absorption or injection of the liquid medicine.

[0047] Working principle: When in use, determine the insertion depth before insertion, cut the corresponding needle sleeve length so that the length of the leaking needle stem is the insertion depth, and then inject the anesthetic drug. The anesthetic drug can enter the human tissue through the secondary hole. Only one injection is required to achieve uniform distribution and sufficient infiltration of the drug in the tissue of the surgical area.

[0048] Embodiment 2

[0049] The present invention assumes that the length of the needle tube inserted into the skin is L, and the radius of the needle tube itself is R. Now the present invention assumes that some needle holes need to be opened at any two positions of the needle tube to achieve the effect of uniform distribution and sufficient infiltration of the anesthetic drug. Of course, if more needle hole positions need to be opened, only more parameters L need to be introduced. i ,n i ,r i Yes, the principle is the same.

[0050] The present invention assumes that n1 circular holes with a radius of r1 are evenly distributed at L1 on the needle tube that pierces the skin, and then n2 circular holes with a radius of r2 are evenly distributed at L2 below the circular hole. The present invention records that at the skin, the vacuum pressure is P begin , then the flow rate at this time is Q0, the flow rate is V0, which satisfies

[0051] First, in P begin At P1, it is a pipeline model with up and down flow and closed on both sides. The present invention can calculate the value of P1 according to the Bernoulli equation. The Bernoulli equation is:

[0052]

[0053] Since the width of the pipe remains unchanged and there are no holes around it, the fluid flow rate remains unchanged, that is, V1 = V0. The present invention takes the skin layer as the reference layer, that is, h0 = 0, and then P1 = P begin +ρgL1.

[0054] Then, the present invention wants to calculate the flow rate of the small hole on the side of the pipe, and can use the following formula, which is based on the classic flow calculation of the fluid flowing out of the orifice:

[0055]

[0056] Here C d is the flow coefficient, and its value is generally between 0.6 and 0.8. It is related to the shape of the hole and the properties of the fluid. In practice, it can be obtained through experimental measurement. A is the area of ​​the small hole, ΔP=P2-P1 is the pressure difference, and ρ is the density of the fluid.

[0057] Then the present invention can obtain that in this layer, there are n1 circular holes with a radius of r1, and the total outflow of fluid is According to Poiseuille's law, the relationship between the pressure difference at both ends and the fluid flow rate is: Then Substituting in, the present invention can calculate ΔP=ΔP(r1,n1), that is, when the present invention confirms the number and size of the circular holes given in the first layer, the pressure difference ΔP can be obtained. Then the present invention can obtain P2=P1+ΔP, and the flow rate at P2 is Q0-Q1, then repeating the above steps, the present invention can calculate the values ​​of P3 and P4. Here, the present invention has P1=P1(L1), P2=P2(L1,r1,n1), P3=P3(L1,r1,n1,L2), P4=P4(L1,r1,n1,L2,r2,n2), and there are a total of 6 parameters that need to be determined (L3 can be given by the formula L=L1+L2+L3+2r1+2r2).

[0058] Finally, the present invention considers P end , where the flow rate is Q3 = Q0-Q1-Q2, then in order to achieve the effect of uniform distribution and full infiltration of anesthetic drugs, the present invention requires Then the present invention gives the initial flow rate Q0, then because Q1 is given, the present invention can be based on The pressure difference ΔP=ΔP(r1,n1) is obtained, and thus the relationship between r1 and n1 is obtained. Here, you only need to select the number of n1 to get the size of the opening r1.

[0059] Theoretically, the more openings there are, the better the effect of achieving uniform distribution and sufficient infiltration of anesthetic drugs. However, if the influence of the number of openings of the material itself on its strength, folding resistance and other properties is taken into consideration, the present invention only needs to reasonably select n1. For the longitudinal distribution, that is, the values ​​of L1, L2, and L3, since the flow rate is only related to the pressure difference, the pinhole size and the fluid itself, and has nothing to do with the position of the openings, since the present invention requires Q1=Q2=Q3, the present invention only needs to require L1=L2=L3, so that in the y direction, the effect of uniform distribution and sufficient infiltration of anesthetic drugs can be achieved. If the present invention requires that Q1, Q2, and Q3 are not equal, then at this time, the present invention needs to reasonably arrange L1, L2, and L3 to achieve the same average flow rate in each section in the y direction.

[0060] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0061] Those skilled in the art will readily appreciate other embodiments of the invention after considering the specification and practicing the invention invented herein. This application is intended to cover any variations, uses or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art that are not invented by the present invention. The specification and examples are intended to be exemplary only, and the true scope and spirit of the invention are indicated by the claims.

[0062] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific implementation methods of the present application and are not used to limit the protection scope of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present application should be included in the protection scope of the present application.

Claims

1. A needle with controllable penetration depth for uniform injection of local infiltration anesthesia, characterized in that: The needle stem (4) comprises a needle stem (4) and a needle sheath (5), wherein the needle sheath (5) with adjustable length is sheathed on the starting end of the needle stem (4), and the needle stem (4) is provided with multiple layers of auxiliary holes for uniformly injecting fluid, wherein the depth of the first layer of auxiliary holes inserted into the skin during injection is L is the total length of the needle sleeve (5), and n is the total number of auxiliary holes in the first layer; The pressure P1 at the end of the first layer of secondary holes closest to the skin surface is: P1=P begin +ρgL1, Where P begin is the vacuum internal pressure at the skin surface, ρ is the density of the fluid, g is the gravitational acceleration, and L1 is the vertical distance between the end of the first layer of accessory holes closest to the skin surface and the skin surface, that is, the depth of the first layer of accessory holes inserted into the skin during injection.

2. A needle with controllable penetration depth for uniform injection of local infiltration anesthesia according to claim 1, characterized in that: The flow rate Q of the multi-layer auxiliary holes for uniform fluid injection is calculated: In the formula, C d is the flow coefficient, A is the surface area of ​​the auxiliary hole, ΔP=P2-P1 is the pressure difference, P2=P1+2r, r is the radius of the auxiliary hole.

3. A needle with controllable penetration depth for uniform injection of local infiltration anesthesia according to claim 2, characterized in that: The total outflow of fluid from the n1 secondary holes with a radius of r1 in the first layer is According to Poiseuille's law, the relationship between the pressure difference at both ends of the auxiliary hole and the fluid flow rate is obtained: Will Bring in The pressure difference is calculated The pressure at the end of the first layer of auxiliary holes farthest from the skin surface is obtained as P2=P1+ΔP.

4. A needle with controllable penetration depth for uniform injection of local infiltration anesthesia according to claim 1, characterized in that: The depth of the second layer of accessory hole injection into the skin ; n2 is the total number of secondary holes in the second layer The pressure P3 at the end of the second layer of secondary holes closest to the skin surface is: P3=P2+ρgL2, Where P2 is the pressure at the end of the first layer of secondary pores farthest from the skin surface, ρ is the density of the fluid, g is the acceleration of gravity, and L2 is the distance between the end of the second layer of secondary pores closest to the skin surface and the end of the first layer of secondary pores farthest from the skin surface.

5. The needle with controllable penetration depth for uniform injection of local infiltration anesthesia according to claim 1, characterized in that: The depth of the nth layer of accessory hole when injecting into the skin is P 2n-1 for: P 2n-1 =P 2n-2 +ρgL n , Where P 2n-2 is the pressure at the end of the n-1th layer of secondary pores farthest from the skin surface, ρ is the density of the fluid, g is the gravitational acceleration, L n It is the distance between the end of the nth layer of secondary pores closest to the skin surface and the end of the n-1th layer of secondary pores farthest from the skin surface.

6. A needle with controllable penetration depth for uniform injection of local infiltration anesthesia according to any one of claims 1 to 5, characterized in that: It comprises a syringe and a needle plug (3), wherein the needle stem (4) is mounted on the syringe via the needle plug (3).

7. A needle with controllable penetration depth for uniform injection of local infiltration anesthesia according to claim 6, characterized in that: The syringe comprises a push-pull rod, a piston and an empty barrel (2), wherein the piston is slidably installed in the empty barrel (2), and the push-pull rod and the piston are detachably connected.

Images