JP6220119B2 - Needle - Google Patents

Description

  The present invention relates to an injection needle, and more particularly to an injection needle suitable for medical use.

  One ocular disease is retinal vein occlusion. Retinal vein occlusion is a disease that causes bleeding due to clogging of the veins of the retina due to high blood pressure and arteriosclerosis. This disease damages the retina and causes symptoms such as vision loss. In addition to internal treatment such as anticoagulant therapy, retinal vein occlusion can be treated by irradiating the retinal hemorrhage site or swelled area with laser light to cause bleeding or swelling to occur on the choroid side of the subretinal tissue. Methods of absorption are known. Retinal vein occlusion includes central vein occlusion and branch vein occlusion. Among these, arteriovenous cross section vascular sheath incision is performed for branch vein occlusion. However, any treatment is only symptomatic.

  Therefore, with the aim of regenerating venous blood flow in the retina, a treatment method has been proposed in which a thrombolytic agent (t-PA) used in the treatment of cerebral infarction patients is directly injected into the retinal vein (occluded blood vessel). This treatment can also be called a causal treatment that eliminates clogging of blood vessels that cause retinal vein occlusion. In particular, in an aging society with a large number of patients with retinal vein occlusion, the treatment method is an early treatment method. The establishment of is strongly desired. Incidentally, as a medical injection needle, what was described in the following patent documents 1 and patent documents 2 is known, for example.

JP 2006-280503 A JP 2004-290542 A

  The above-described treatment method is a method in which an injection needle is inserted into a vein of the retina, and a therapeutic liquid (hereinafter referred to as “treatment solution”) is injected into the vein through the injection needle. For this reason, it is necessary to prepare an injection needle that can pierce the vein of the retina. However, since the thickness of the vein (blood vessel) of the retina is very thin with a diameter of about 100 μm, it is necessary to make the injection needle to pierce it thinner. Such an ultra-fine injection needle can be made with a glass capillary tube, but in order to use a capillary tube for an injection needle that pierces a thin blood vessel such as a retinal vein, There are difficulties in terms.

  Since the capillary tube is made of glass which is a hard brittle material, it has a property of being easily broken. Therefore, for example, if the capillary tube is broken or chipped while the capillary tube is pierced into the blood vessel, a glass piece may remain in the blood vessel. For this reason, the capillary tube was unsuitable for said use.

Therefore, the present inventor has tried to realize an injection needle that can be pierced even by a thin blood vessel such as a vein of the retina by using a “metal injection needle”. However, at first, I couldn't make a needle that seemed like a series of failures. In particular, the obstacle to realization was that the following three requirements had to be satisfied at the same time.
(1) To reduce the outer diameter of the injection needle.
(2) Ensure the length of the injection needle.
(3) To ensure the circulation of the treatment solution.

  The requirement (1) is because it is necessary to pierce the retinal vein with the injection needle as described above. The requirement of (2) above is that the retinal vein to be inserted through the injection needle is near the fundus, whereas the injection needle must be inserted into the eyeball through the trocar near the cornea of the eyeball, and from there This is because it is necessary to reach the needle tip. The requirement (3) is because when the syringe needle is attached to the syringe and the plunger is pressed, the treatment liquid in the syringe needs to be discharged from the needle tip.

  The inventor actually made several prototypes of needles with different dimensions and structures, asked the ophthalmologist to confirm the usability of each prototype, and based on the results, considered the problem and cause and improved it. Repeated that.

  In such trial and error, the present inventor has known the fact that the length of the ultrafine tube attached to the needle tip has a greater influence on the flowability (ease of passage) of the treatment solution than expected. The present invention has been conceived.

  A main object of the present invention is to provide an injection needle that can pierce a needle tube even in a very thin blood vessel and inject a treatment liquid into the blood vessel through the needle tube.

The first aspect of the present invention is:
An injection needle provided with a needle tube having a treatment liquid discharge port at the needle tip,
The needle tube has a piercing tube in which the discharge port is formed and a main needle tube that is thicker than the piercing tube, and the piercing tube is provided at the tip of the main needle tube,
The piercing tube has a length condition of less than 7.0 mm (excluding zero), an outer diameter of 70 μm or less (not including zero), and an inner diameter of 40 μm or less (not including zero). It is an injection needle.

The second aspect of the present invention is:
The piercing tube has a length of 5.0 mm or less (excluding zero). The injection needle according to the first aspect described above, wherein

The third aspect of the present invention is:
The piercing tube has a length of 3.0 mm or less (excluding zero). The injection needle according to the first aspect described above, wherein

The fourth aspect of the present invention is:
The piercing tube has an outer diameter of not less than 40 μm and not more than 60 μm.

According to a fifth aspect of the present invention,
The piercing tube has an inner diameter of 20 μm or more and 30 μm or less. The injection needle according to any one of the first to fourth aspects.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a very thin blood vessel, a needle tube can be pierced, and the injection needle which can inject | pour therapeutic liquid into a blood vessel through the needle tube can be provided. As a result, it is possible to contribute early and reliably to an effective treatment method for regenerating venous blood flow in the retina of patients with retinal vein occlusion.

It is a figure which shows the structural example of the injection needle which concerns on embodiment of this invention. It is principal part sectional drawing which shows the attachment state of a piercing tube. It is a figure explaining the structure of a piercing tube. It is a figure explaining an example of the preparation methods of a piercing tube. It is a figure which shows the image obtained by observing the cross-section of a piercing tube with an electron microscope. It is a figure (the 1) which shows the structural example of the injection needle which concerns on other embodiment of this invention. It is FIG. (2) which shows the structural example of the injection needle which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the embodiment of the present invention, description will be given in the following order.
1. 1. Structure of injection needle 2. Manufacturing method of injection needle Examples and Comparative Examples 4. 4. Effects according to the embodiment Other Embodiments 6. Modifications etc.

<1. Structure of injection needle>
FIG. 1 is a diagram showing a configuration example of an injection needle according to an embodiment of the present invention. The illustrated injection needle 1 is mainly composed of a needle base 2 and a needle tube 3. The needle base 2 is a part that is detachably attached to the syringe tip of the syringe when the injection needle 1 is attached to a syringe (not shown). The needle base 2 is formed using, for example, a thermoplastic resin such as polypropylene, polyethylene, or polyvinyl chloride. The needle base 2 is formed in a stepped cylindrical shape as a whole.

  The needle tube 3 is attached to the distal end portion of the needle base 2. The needle tube 3 is formed into a thin tubular shape using a metal such as stainless steel, for example. The needle tube 3 has a multistage structure in which a plurality of tubes having different dimensions (outer diameter, inner diameter, length) are combined. In the present embodiment, as an example, a three-stage structure in which the main needle tube 31, the piercing tube 32, and the reinforcing tube 33 are combined. In addition, when the needle tube 3 is made of metal, for example, nickel chrome steel can be used in addition to stainless steel.

  The main needle tube 31 is the longest tube among the three tubes. The length L1 of the main needle tube 31 is defined by a protruding dimension from the distal end portion of the needle base 2. The base portion of the main needle tube 31 is fixed to the tip portion of the needle base 2 by adhesion or the like. The outer diameter d1 of the main needle tube 31 is set to be larger than the outer diameter d2 (see FIG. 3) of the piercing tube 32 and smaller than the outer diameter d3 of the reinforcing tube 33, for example, 0.3 mm. The length L1 of the main needle tube 31 is set to a size suitable for the use of the injection needle 1. By the way, in this embodiment, an injection needle used for the purpose of piercing the veins of the retina through the needle tube 3 in the eyeball, especially in ophthalmic medicine, is assumed among medical uses. For this reason, the length L1 of the main needle tube 31 is set so as to ensure a length of 25 mm or more (preferably around 27 mm) from the distal end portion of the needle base 2 in consideration of the size of the eyeball, for example. .

  FIG. 2 is a cross-sectional view of a main part showing an attached state of the piercing tube, and FIG. 3 is a view for explaining the structure of the piercing tube. In addition, (B) of FIG. 3 is an enlarged view which shows the P section cross section of (A). The piercing tube 32 is the shortest and thinnest tube among the three tubes. The piercing tube 32 is provided at the distal end portion of the main needle tube 31. The base portion of the piercing tube 32 is concentrically fixed to the distal end portion of the main needle tube 31. The distal end portion (needle tip) of the piercing tube 32 is inclined obliquely with respect to the central axis of the needle tube 3 in order to reduce resistance during piercing (hereinafter referred to as “piercing resistance”), thereby sharpening. A large blade surface 32C is formed.

  The piercing tube 32 has a part 32 </ b> A protruding from the tip of the main needle tube 31 and the other part 32 </ b> B inserted into the main needle tube 31. In the following description, a part 32A of the piercing tube 32 is referred to as a “projection 32A” and the other part 32B is referred to as an “insertion part 32B”. The length (full length) L2 of the piercing tube 32 is set so as to satisfy the condition of less than 7 mm (not including zero). The reason for applying this condition will be described later. The protrusion dimension L21 of the protrusion 32A is set to 0.3 mm or greater and 1.0 mm or less. The reason why the projecting dimension L21 of the projecting part 32A is 0.3 mm or more is that if it is shorter than this, the projecting part 32A is hidden behind the stepped part due to the outer diameter difference between the main needle tube 31 and the piercing tube 32. This is because it is difficult to confirm the position of the needle tip portion of the piercing tube 32. However, when the tip portion of the main needle tube 31 is tapered, the projecting dimension L21 of the projecting portion 32A can be set to 0.15 mm in consideration of the inclination of the tip of the piercing tube 32. Further, the reason why the projecting dimension L21 of the projecting portion 32A is set to 1.0 mm or less is that if it is longer than this, (1) the piercing tube 32 is easily bent by piercing resistance, and (2) the piercing tube 32. This may cause the blood vessel and the subvascular tissue to be damaged by being deeply stuck in the blood vessel. The insertion dimension L22 of the insertion part 32B depends on the length L2 of the piercing tube 32, the processing method of the tip part, and the projection dimension L21 of the projection part 32A, but is preferably set to 0.5 mm or more and 3.0 mm or less. The

  The above-described blade surface 32C is formed at the tip of the protrusion 32A. A discharge port 32D is opened in the same plane as the blade surface 32C. The discharge port 32D is a portion from which the treatment liquid is discharged in response to the pressing force when a plunger of a syringe (not shown) is pressed. The treatment liquid is not particularly limited as long as it is a liquid used for treatment, and examples thereof include a drug solution, physiological saline, and pure water. The discharge port 32D is formed in the most downstream portion of the flow path 32E (see FIG. 3) along the central axis of the piercing tube 32. The outer diameter d2 of the piercing tube 32 is set so as to satisfy the condition of 70 μm or less (not including zero). The reason for applying this condition is that when the outer diameter d2 of the piercing tube 32 exceeds 70 μm, it is extremely difficult to pierce the piercing tube 32 into a target blood vessel (such as a vein) having a thickness of about 100 μm. It is to become. Considering the ease of the procedure when the piercing tube 32 is pierced into the blood vessel, the outer diameter d2 of the piercing tube 32 is preferably 60 μm or less. However, if the outer diameter d2 of the piercing tube 32 is excessively reduced, (1) it becomes difficult to secure the inner diameter d4 of the piercing tube 32, and (2) the piercing tube 32 is easily bent by piercing resistance. It becomes easy to cause the malfunction. For this reason, the outer diameter d2 of the piercing tube 32 is preferably 40 μm or more.

  The inner diameter (diameter of the flow path 32E) d4 of the piercing tube 32 is set so as to satisfy the condition of 40 μm or less (not including zero). The reason for applying this condition is that in the drawing process employed in the manufacturing method of the injection needle 1 described later (particularly, the method for producing the piercing tube 32), the inner diameter d4 of the piercing tube 32 is the outer diameter of the piercing tube 32. This is because the dimension is about 60% of d2 or slightly less than d2. The inner diameter d4 of the piercing tube 32 is preferably larger if only the fluidity of the liquid is taken into consideration, but considering the outer diameter d2 of the piercing tube 32 described above, it is preferably 20 μm or more and 30 μm or less.

  The reinforcing pipe 33 is the thickest pipe among the three pipes. The reinforcing tube 33 is attached to the base side of the needle tube 3 so as to insert the main needle tube 31 therein. The reinforcing tube 33 is provided for the purpose of reinforcing the needle tube 3, particularly for increasing the rigidity of the entire needle tube 3. The base portion of the reinforcing tube 33 is fixed to the tip portion of the needle base 2 together with the main needle tube 31 described above by adhesion or the like. The length L3 of the reinforcing tube 33 may be set to, for example, a dimension that is 1/5 or more and 2/3 or less of the length L1 of the main needle tube 31, and more preferably a dimension that is 1/3 or more and 1/2 or less. The length L3 of the reinforcing tube 33 is defined by a protruding dimension from the distal end portion of the needle base 2.

  The outer diameter d3 of the reinforcing tube 33 is set to 0.5 mm, for example, although it depends on the outer diameter d1 of the main needle tube 31. The inner diameter of the reinforcing tube 33 is set to be at least larger than the outer diameter d1 of the main needle tube 31 so that the main needle tube 31 can be passed through the reinforcing tube 33. The reinforcing tube 33 is attached to the outside of the main needle tube 31 so as to form a double tube structure concentrically. The reinforcing pipe 33 is not an essential element in the present invention, and is provided as necessary depending on the length and thickness of the main needle pipe 31.

<2. Manufacturing method of injection needle>
Next, a method for manufacturing the injection needle 1 will be described. First, a needle base 2, a main needle tube 31, a piercing tube 32, and a reinforcing tube 33 that are components of the injection needle 1 are prepared. Among these, the parts excluding the piercing tube 32 can be manufactured by the same method as that of a general medical injection needle (however, the blade surface is not formed). For this reason, the manufacturing method of the piercing pipe | tube 32 is demonstrated in detail here.

  When the piercing tube 32 is manufactured, first, a metal tube having a circular cross section having an outer diameter larger than the target outer diameter d2 is manufactured. Specifically, for example, a thin plate of stainless steel such as SUS304 is rolled and the joint portion is welded. At this time, the joint portion is polished as necessary.

  Next, the metal tube is thinned by drawing. Specifically, as shown in FIG. 4, a conical plug 12 is inserted into the metal tube 11, and a metal is inserted into a tapered hole 14 provided in the die 13 along the conical surface of the plug 12. Pass tube 11 through. Then, the metal tube 11 is pulled out from the large diameter side of the hole 14 toward the small diameter side. Thereby, the outer diameter of the metal tube 11 drawn through the hole 14 of the die 13 is narrowed down to a size equivalent to the opening size of the small diameter side of the hole 14. Such a drawing process is repeated a plurality of times until, for example, the outer diameter of the metal tube 11 is reduced to about 0.5 mm. After that, the outer diameter of the metal tube 11 is reduced to a desired dimension (for example, 50 μm) by repeating the drawing process a plurality of times without inserting the plug 12.

Next, the metal tube 11 is cut into a desired length. Next, the tip of the metal tube 11 is processed into a sharp blade surface by wire cut electric discharge machining, grinding, or the like. The piercing tube 32 is obtained by the above procedure.
As a modified example of the manufacturing method of the injection needle 1, it is possible to further pull out a predetermined portion of the main needle tube 31 to manufacture a needle in which the main needle tube 31 and the piercing tube 32 are integrated.

Next, the assembly procedure of the components of the injection needle 1 will be described.
First, the main needle tube 31 is attached to the needle base 2. Specifically, after inserting the end portion of the main needle tube 31 into a through hole (not shown) formed on the distal end side of the needle base 2, an appropriate amount of adhesive is applied to the distal end portion of the needle base 2 using a dispenser or the like. Supply. As the adhesive, for example, a thermosetting resin or a photocurable resin can be used. However, at this stage, the adhesive is left in an uncured state.

  Next, the reinforcing tube 33 is fitted from the distal end side of the main needle tube 31, and the end portion of the reinforcing tube 33 is abutted against the distal end portion of the needle base 2 in a state of being in contact with the adhesive. Thereafter, the adhesive is cured by heating or irradiation with light (such as ultraviolet rays), and the main needle tube 31 and the reinforcing tube 33 are fixed together at the distal end portion of the needle base 2.

  Next, the end of the piercing tube 32 (the portion that becomes the insertion portion 32B) is inserted into the distal end of the main needle tube 31. At this time, the end portion of the piercing tube 32 is inserted into the main needle tube 31 so that the protruding portion 32A of the piercing tube 32 protrudes from the distal end portion of the main needle tube 31 by about 0.5 mm, for example. Thereafter, the piercing tube 32 is fixed to the main needle tube 31 by, for example, laser welding or an adhesive. In the case of laser welding, the inner peripheral surface of the main needle tube 31 and the outer peripheral surface of the reinforcing tube 33 are melted by irradiating the outer peripheral surface of the main needle tube 31 surrounding the insertion portion 32B of the piercing tube 32 with laser light. Join by. The number of laser light irradiation locations may be a plurality of locations in the circumferential direction of the main needle tube 31 (for example, three locations at equal intervals of 120 °).

<3. Examples and Comparative Examples>
Here, examples and comparative examples of the injection needle according to the present invention will be described. In this embodiment and the comparative example, the injection needle having the same size and structure is adopted except for the length of the piercing tube 32 and the like. Specifically, the dimensions of the main needle tube 31 are the outer diameter (d1) = 0.3 mm, the inner diameter = 0.08 mm, the length (L1) = 26 mm, and the dimensions of the reinforcing tube 33 are the outer diameter (d3) = 0.5 mm and length (L3) = 13 mm. The dimensions of the piercing tube 32 were set to an outer diameter (d2) = 50 μm and an inner diameter (d4) = 20 μm. In the injection needle according to the example, the length (L2) of the piercing tube 32 is 5 mm or 3 mm, the protrusion dimension L21 of the protrusion 32A is 0.5 mm, and the insertion dimension L22 of the insertion part 32B is 2.5 mm. . On the other hand, in the injection needle according to the comparative example, the length (L2) of the piercing tube 32 is 7 mm, the protrusion dimension (L21) of the protrusion 32A is 0.5 mm, and the insertion dimension (L22) of the insertion part 32B is. It was set to 6.5 mm.

As a result, when the injection needle according to the example and the injection needle according to the comparative example were respectively attached to the syringe and the condition of the liquid was confirmed, the following difference was recognized.
First, in the injection needle according to the comparative example, out of 100 injection needles prototyped with the length of the piercing tube 32 being 7 mm, the number of liquid discharges from the discharge port 32D of the piercing tube 32 could be confirmed. At this level, the discharge state was insufficient for all of them.
On the other hand, in the injection needle according to the embodiment, the liquid is discharged from the discharge port 32D of the puncture tube 32 by about half of the 50 injection needles prototyped with the length of the puncture tube 32 being 5 mm. The discharge state was particularly good in about 5 of them. Moreover, about 50 injection needles made with a length of the piercing tube 32 of 3 mm, all of them can confirm the liquid discharge from the discharge port 32D of the piercing tube 32, and about 20 of them are very In a good discharge state.

  Here, the injection needle according to the comparative example is one of the specific modes that the inventor made experimentally in the process of conceiving the present invention. The present inventor initially worried about the following points in addition to making the handling tube 32 difficult when the piercing tube 32 is shortened. That is, if the insertion dimension L22 when the piercing tube 32 is inserted into the distal end portion of the main needle tube 31 is not secured to some extent, even if the piercing tube 32 is fixed by laser welding or the like, the joining allowance is insufficient and I was concerned that the strength would not be sufficiently secured and the piercing tube 32 would be easily pulled out. In addition, if the insertion dimension L22 of the piercing tube 32 is short, there is a concern that the posture of the piercing tube 32 may not be stable when the piercing tube 32 is inserted into the main needle tube 31. In particular, since the piercing tube 32 is supposed to pierce a thin blood vessel, if the piercing tube 32 comes out of the main needle tube 31, does the piercing tube 32 remain stuck in the blood vessel? In some cases, the piercing tube 32 may be left behind in the blood vessel. For this reason, the inventor initially set the length of the piercing tube 32 to 7 mm.

  However, when this prototype (injection needle according to the comparative example) was mounted on a syringe and used, liquids did not come out from the piercing tube 32 in many prototypes, that is, clogging occurred in the piercing tube 32. . The present inventor considered that the cause is “clogging due to polishing litter” and tried to improve the manufacturing method (devise polishing method, improvement of cleaning method after polishing, etc.). The effect was not obtained. Therefore, while anxious about the above-mentioned points, when the length of the piercing tube 32 was set to half or less (3 mm) as a trial and the injection needle 1 was prototyped, the liquid in the piercing tube 32 was measured. The appearance (distribution) has improved dramatically. Further, it was found that the strength of the joint needle between the main needle tube 31 and the piercing tube 32 could be secured to a practically satisfactory level.

  Based on the result of the trial production, the present inventor has observed the cross-sectional structure of the piercing tube 32 with an electron microscope in order to investigate the cause of the clogging of the piercing tube 32. As a result, an image (secondary electron image) as shown in FIG. 5 was obtained. As can be seen from this image, a large number of fine irregularities (drawing rods by drawing) exist on the inner peripheral surface of the piercing tube 32. For this reason, although it is speculated, even if the inner diameter d4 of the piercing tube 32 is secured, the flow of the liquid inside the piercing tube 32 is obstructed by the unevenness, and the piercing tube 32 becomes a certain length or longer. It is considered that the liquid appearance is extremely deteriorated. Incidentally, it is assumed that the inner diameter d2 of the piercing tube 32 is defined by an average diameter that is intermediate between the peak portion and the valley portion due to the unevenness.

  From the result of the trial production described above, it can be seen that the length of the piercing tube 32 is more largely related to the flowability of the liquid in the piercing tube 32 than expected. In the needle used for normal blood vessel injection, even if it does not become a problem because a certain degree of thickness is secured, when it becomes a piercing tube 32 assuming a thin blood vessel of about 100 μm in thickness, because of its thinness, The liquid flow is obstructed by the irregularities on the inner diameter side. In particular, as a result of trial manufacture by the present inventor, it has been found that when the length L2 of the piercing tube 32 is 7.0 mm or more, the yield is extremely reduced. For this reason, the length L2 of the piercing tube 32 needs to be at least less than 7.0 mm, preferably in the range of 5.0 mm or less, and more preferably in the range of 3.0 mm or less ( However, L2> 0).

<4. Effect of Embodiment>
In the injection needle 1 according to the embodiment of the present invention, there is provided the injection needle 1 in which a needle tube 3 is pierced through a thin blood vessel having a thickness of about 100 μm, and a treatment liquid can be injected into the blood vessel through the needle tube 3. be able to. Further, as the configuration of the needle tube 3, an extremely fine piercing tube 32 is attached to the distal end portion of the main needle tube 31, and the needle base 2 side of the main needle tube 31 is reinforced by the reinforcing tube 33. Stiffness can be given. For this reason, the treatment liquid can be injected by inserting the piercing tube 32 of the needle tube 3 into the retinal vein in the fundus. Therefore, it is possible to remove the cause of retinal vein occlusion (eg, clogging of blood vessels), which has been treated only by symptomatic therapy so far, by directly injecting a therapeutic solution into the vein. The establishment of such causal therapy is extremely beneficial from the public interest viewpoint, especially in an aging society with a large number of patients with retinal vein occlusion, and is also meaningful from the viewpoint of advancement and development of ophthalmic medicine. It will be a thing.

<5. Other embodiments>
FIG. 6 is a diagram showing a configuration example of an injection needle according to another embodiment of the present invention. The illustrated injection needle 1 is different in the shape of the needle tube 3 as compared to the above-described embodiment. That is, in the embodiment described above, the needle tube 3 has a shape extending straight along the central axis of the needle base 2. On the other hand, in another embodiment, the needle tube 3 is bent with respect to the central axis of the needle base 2 (indicated by a one-dot chain line in the figure). The specific bending method may be a structure in which the main needle tube 31 is bent at an inclination angle θ from the middle of the main needle tube 31 as shown in the figure, or the entire needle tube 3 is bent into an arcuate shape as shown in FIG. It may be a structure.

  When the needle tube 3 is bent as described above, the following advantages are obtained. That is, as shown in FIG. 7, when the needle tube 3 is inserted into the eye through a cannula (not shown) fixed near the cornea 22 of the eyeball 21 and the puncture tube 32 is to be inserted into the vein of the retina, By manipulating the direction of a syringe (not shown) that supports the base 2, the piercing tube 32 at the tip of the needle tube 3 can be arranged along the vein. For this reason, it is easy to pierce the retinal vein with the piercing tube 32, and when the piercing tube 32 is actually pierced, the needle tip is easily retained in the vein. Moreover, when the shape which bent the whole needle tube 3 in the shape of a bow as shown in the figure is employ | adopted, the advantage that it becomes easy to let the main needle tube 31 pass to a cannula is acquired.

  Moreover, in the said embodiment, when manufacturing the injection needle 1, after cut | disconnecting the metal tube which has a desired outer diameter to desired length, when the needle-tip part is wire-cut electrical discharge machining or grinding, However, the present invention is not limited to this, and the following method can also be adopted.

  First, a metal tube thinned to a desired dimension (outer diameter) by the above-described drawing process is cut into a length corresponding to two piercing tubes 32 finally obtained. Next, an intermediate portion in the length direction of the metal tube is cut obliquely by laser processing. Thereby, the two piercing pipes 32 are obtained simultaneously by the cutting | disconnection by one laser irradiation. At that time, as the laser processing, it is desirable to employ pulse laser processing capable of non-thermal processing, more preferably femtosecond laser processing or picosecond laser processing. The reason for this is that when pulse laser processing or the like is employed, the edge portion of the cut surface of the metal tube that is the base of the piercing tube 32 is sharply formed without being sagted by heat, and the piercing resistance is reduced. Because. In addition, when polishing the tip of the piercing tube 32 whose diameter is narrowed assuming a thin blood vessel with a thickness of about 100 μm, there is a concern about the generation of clogging and clogging due to the thinness. Such a concern does not occur when pulse laser processing or the like is employed.

  In the above laser processing, for example, a plurality of metal tubes having a length of two are arranged on a support (not shown), and the metal tubes are sequentially cut by laser processing, thereby performing work efficiently. Can proceed. In addition, by using the above-described support tool, the cutting target portion of the metal tube is supported in a floating state, and the laser beam is condensed and cut to reduce contamination of the cut surface of the metal tube. it can. The reason for this is that when the planned cutting part of the metal tube is in a floating state and the laser beam is focused on the metal tube, evaporation and scattering of materials other than the metal tube can be suppressed, and other materials are present on the cut surface of the metal tube. It is because it becomes difficult to adhere.

  Further, when employing pulse laser processing or the like, the following manufacturing procedure can be employed. First, a metal tube obtained by drawing is cut into a length (for example, 10 mm) that is easy to handle. Next, a part of the cut metal tube is inserted into the main needle tube 31 and fixed by laser welding or the like. Thereafter, the tip of the metal tube is cut obliquely at a desired length by pulse laser processing or the like. By adopting this procedure, the protruding portion can be set short even for an injection needle having a piercing tube 32 having an outer diameter of 70 μm or less.

<6. Modified example>
The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications and improvements as long as the specific effects obtained by the constituent elements of the invention and combinations thereof can be derived.

  For example, in the above embodiment, the structure of the needle tube 3 attached to the needle base 2 is a three-stage structure using the main needle tube 31, the piercing tube 32 and the reinforcing tube 33, but the present invention is not limited to this. Specifically, the needle tube 3 has a tapered needle structure in which the diameter (outer diameter, inner diameter) continuously changes from the needle base side toward the needle tip side, and the needle tip portion is a needle structure that satisfies the above dimensional conditions. It may be configured as a through pipe.

  Further, a configuration may be adopted in which a clogging in the needle tube 3 (particularly, in the piercing tube 32) can be avoided by incorporating a filter in the needle base 2 and capturing fine foreign matters or the like with this filter. .

  In addition, the above-described injection needle 1 is suitable for use when piercing a very thin blood vessel, but the present invention is not limited to this, and can be widely used for general medical use or other uses. Is possible.

Hereinafter, preferred embodiments of the present invention will be additionally described.
[Appendix 1]
An injection needle provided with a needle tube having a treatment liquid discharge port at the needle tip,
The needle tube has a piercing tube in which the discharge port is formed and a main needle tube that is thicker than the piercing tube, and the piercing tube is provided at the tip of the main needle tube,
The piercing tube satisfies the dimensional conditions of a length of less than 7.0 mm (excluding zero), an outer diameter of 70 μm or less (not including zero), and an inner diameter of 40 μm or less (not including zero),
A needle tip portion of the piercing tube is cut obliquely by pulse laser processing, femtosecond laser processing, or picosecond laser processing.

DESCRIPTION OF SYMBOLS 1 ... Injection needle 2 ... Needle base 3 ... Needle tube 31 ... Main needle tube 32 ... Puncture tube 32A ... Projection part 32B ... Insertion part 32C ... Blade surface 32D ... Discharge port 33 ... Reinforcement tube

Claims (5)

An injection needle provided with a needle tube having a treatment liquid discharge port at the needle tip,
The needle tube is made of metal, has a piercing tube in which the discharge port is formed, and a main needle tube that is thicker than the piercing tube, and the piercing tube is provided at a distal end portion of the main needle tube. Is,
The piercing tube has a length condition of less than 7.0 mm (excluding zero), an outer diameter of 70 μm or less (not including zero), and an inner diameter of 40 μm or less (not including zero). And needle. The injection needle according to claim 1, wherein the piercing tube has a length of 5.0 mm or less (excluding zero). The injection needle according to claim 1, wherein the piercing tube has a length of 3.0 mm or less (excluding zero). The injection needle according to any one of claims 1 to 3, wherein the piercing tube has an outer diameter of 40 µm or more and 60 µm or less. The injection needle according to any one of claims 1 to 4, wherein the piercing tube has an inner diameter of 20 µm or more and 30 µm or less.