JP2008029575A - Injection needle for spinal anesthesia and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection needle for spinal anesthesia which reduces the width of cutting viable tissue open upon puncture. <P>SOLUTION: A first inclined surface 2 is formed by obliquely grinding the distal end part of a cylindrical needle tube 1, a second inclined surface 4 and a third inclined surface 5 forming a ridge line 6 in the center axial direction of the needle tube 1 are formed at the distal end part of the first inclined surface 2, and distal end blade parts 41 and 51 forming a sharp blade tip are formed of the distal end parts of the second inclined surface 4 and the third inclined surface 5 and the outer diameter surface of the needle tube. Then, a sliding surface is formed by removing the edge of the edge part 42 of the second inclined surface and the edge part 52 of the third inclined surface continued to the distal end blade parts 41 and 51 and formed of the second inclined surface 4, the third inclined surface 5 and the outer diameter surface of the needle tube 1 and the edge parts 21 and 22 of the first inclined surface continued to the edge part 42 of the second inclined surface and the edge part 52 of the third inclined surface and formed of the first inclined surface and the outer diameter surface of the needle tube 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an injection needle for spinal anesthesia and a method for manufacturing the same, and more particularly to an injection needle for spinal anesthesia with a blade at the tip and a method for manufacturing the same.

Spinal anesthesia needles used as conventional spinal anesthesia needles (vertebral subarachnoid anesthesia needles) include a cutting needle with a blade at the tip and a non-cutting needle (pencil point needle) with a conical tip. Exists.
Since this cutting needle cuts tissue of the human body when puncturing, cerebrospinal fluid may leak from the cut and cause headaches or damage nerves and cause severe pain. May be forced.

  On the other hand, the non-cutting needle pushes the tissue of the human body when puncturing, so the incision is small, but the opening for injecting the anesthetic into the body cavity is away from the tip, so it goes deep inside the body cavity. Need to puncture and may impose an excessive burden on the patient. In addition, since the injection needle is disposable and not reused to prevent infection, it is desired to be inexpensive, but it is expensive because the manufacturing process for forming the tip into a conical shape is complicated. .

In view of such problems, the applicant forms an inclined surface by obliquely grinding the distal end portion of the injection needle (needle tube), and further, the outer peripheral edge of the blade surface extending in the outer circumferential direction on both sides of the distal end of the inclined surface. A first blade portion having a sharp blade edge and a second blade portion formed by rounding the outer peripheral edge of the blade surface continuous to the blade edge, and cutting the living tissue with the first blade portion at the time of puncturing The inventors have invented an injection needle that has a reduced cut width, simplified structure as an injection needle, simplified manufacturing steps, and reduced manufacturing costs (see, for example, Patent Document 1).
Japanese Patent Laying-Open No. 2005-323898 (paragraphs “0013” to “0019”, FIG. 1)

However, in the above-described conventional technique, not only the second blade portion opposite to the first blade portion but also the outer peripheral edge (edge portion) of the inclined surface continuous with the blade portion, particularly the blade, at the time of puncturing In some cases, the living tissue may be widely cut from the end of the part to the outer peripheral edge near the center of the inclined surface, and the cerebrospinal fluid leaks from the cut end.
An object of the present invention is to solve such a problem.

  Therefore, the present invention provides a spinal anesthesia injection needle in which the tip portion of a cylindrical needle tube is obliquely ground to form a first inclined surface, and the tip portion of the first inclined surface is arranged in the direction of the central axis of the needle tube. A second inclined surface and a third inclined surface that form a ridge line, and the edges of the second inclined surface and the third inclined surface excluding the second inclined surface and the tip of the third inclined surface; The sliding surface is formed by dropping the edge and the edge of the first inclined surface.

  Thus, the present invention makes it easier to puncture a spinal anesthesia injection needle and can reduce the width of opening a living tissue at the time of puncture, and there is no leakage of cerebrospinal fluid in the epidural space, which is excessive for the patient. The effect of not forcing the burden of is obtained.

  Embodiments of a spinal anesthesia needle and a method for manufacturing the same according to the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view showing an injection needle for spinal anesthesia (hereinafter referred to as “injection needle”) in the embodiment, and FIG. 1B is a side view showing the injection needle in the embodiment.
In FIG. 1, reference numeral 1 denotes a needle tube, which is a cylindrical injection needle. The needle tube 1 is made of a metal, for example, a cylindrical pipe made of a cold-rolled stainless steel plate, and has an outer diameter of about 0.3 to 3 mm.

Reference numeral 2 denotes a first inclined surface, which is formed by grinding the tip of the needle tube 1 at a predetermined angle with respect to the axial direction. By forming the first inclined surface 2, a sharp blade-like edge is formed at the tip of the needle tube 1, and an elliptical opening 3 for injecting a drug solution into the body is formed. The predetermined angle is preferably 17 to 20 degrees.
Reference numerals 21 and 22 denote edges of the first inclined surface, which are formed on the outer peripheral edge of the needle tube 1 (first inclined surface 2) by providing the first inclined surface 2. The edge portions 21 and 22 of the first inclined surface are blade-like edge portions in which the angle formed by the outer diameter surface of the needle tube 1 and the first inclined surface 2 is an acute angle particularly on the distal end side from the center of the opening 3. A certain edge is formed, but it is formed on the edges 21 and 22 of the first inclined surface by spraying an abrasive material, which will be described later, in which the edge of the edge of the blade is formed into a round curved surface. A sharp edge is dropped and a sliding surface is formed.

Reference numeral 4 denotes a second inclined surface, and reference numeral 5 denotes a third inclined surface, which is formed by grinding on both sides of the front end portion of the first inclined surface 2. With the inclined surface 5, the first ridge line 6 is formed in the axial direction passing through the center 31 of the opening 3, that is, in the central axial direction of the needle tube 1.
41 and 51 are front-end | tip blade parts (the front-end | tip part of the 2nd inclined surface 4 and the 3rd inclined surface 5), and the 2nd inclination is provided by providing the 2nd inclined surface 4 and the 3rd inclined surface 5. It is the tip of the surface 4 and the third inclined surface 5, and is a sharp cutting edge formed on the outer peripheral edge of the needle tube 1.

The length of the first ridgeline 6 formed by the second inclined surface 4 and the third inclined surface 5 is formed to be 0.05 to 0.5 mm in consideration of the outer diameter of the needle tube 1. It is desirable.
When the length of the first ridge line 6 exceeds 0.5 mm, the width of opening the living tissue with the tip blade portion 41 and the tip blade portion 51 exceeds about 0.75 mm, which is about 1.5 times, and the width is large. This is because it is not preferable, and when it is less than 0.05 mm, the width for cutting the living tissue is less than about 0.075 mm, and the width becomes small and it is difficult to puncture.

Reference numeral 42 denotes a second inclined surface edge portion, which is a portion excluding the tip blade portion 41 formed on the outer peripheral edge of the needle tube 1 (second inclined surface 4) by providing the second inclined surface 4. .
Reference numeral 52 denotes a third inclined surface edge, and by providing the third inclined surface 5, a portion excluding the tip blade portion 51 formed on the outer peripheral edge of the needle tube 1 (third inclined surface 5). It is.
The second inclined surface edge portion 42 and the third inclined surface edge portion 52 are formed to have a curved shape with rounded corners by eliminating a sharp blade edge by spraying an abrasive that will be described later. The sharp edges formed on the inclined surface edge portion 42 and the third inclined surface edge portion 52 are dropped to form a sliding surface.

Reference numeral 43 denotes a second ridge line, which is formed by the first inclined surface 2 and the second inclined surface 4.
Reference numeral 53 denotes a third ridge line, which is formed by the first inclined surface 2 and the third inclined surface 5.
The first ridge line 6, the second ridge line 43, and the third ridge line 53 intersect at one point, and an angle formed by the second ridge line 43 and the third ridge line 53 (in the first inclined surface 2). The first inclined surface 2, the second inclined surface 4, and the third inclined surface 5 are formed so that the angle formed by the second inclined surface 4 and the third inclined surface 5 is approximately 75 degrees. It is desirable.

2 is a cross-sectional view showing the injection needle in the embodiment, FIG. 2 (a) is a cross-sectional view taken along line AA in FIG. 1, and FIG. 2 (b) is a cross-sectional view taken along line BB in FIG.
As shown in FIG. 2A, the edge portion 42 of the second inclined surface 4 and the edge portion 52 of the third inclined surface 5 are formed in a curved surface shape without a sharp blade edge. Therefore, the living tissue is not cut open during puncture.

In FIG. 2B, the edge portions 21 and 22 of the first inclined surface 2 are also formed in a curved surface shape by eliminating a sharp blade edge by spraying an abrasive material to be described later.
In particular, the edges 21 and 22 of the first inclined surface 2 at the tip of the needle tube 1 in the axial direction from the center of the opening 3 are formed in a curved surface shape without a sharp cutting edge.
Next, the manufacturing method of an injection needle is demonstrated.

FIG. 3 is an explanatory view of a method of manufacturing an injection needle in the embodiment, FIG. 3 (a) is a plan view showing the injection needle, and FIG. 3 (b) is a side view showing the injection needle.
First, the first inclined surface 2 is formed by grinding the distal end portion of the needle tube 1 formed of a cylindrical pipe at a predetermined angle (for example, 18 degrees) with respect to the axial direction.
When the first inclined surface 2 is formed, the first ridge line 6, the second ridge line 43, and the third ridge line 53 described above intersect at one point, and further, the second ridge line 43 and the third ridge line 53 form. The second inclined surface 4 and the third inclined surface 5 are formed so that the angle is 75 degrees.

At this time, the edge 42 and the edge 52 formed by the second inclined surface 4 and the third inclined surface 5 are formed with sharp cutting edges.
The plurality of needle tubes 1 formed in this way are arranged on the jig plate 8 and their positions are fixed by means such as taping.
When the needle tube 1 is fixed on the jig plate 8, the mask 7 having a width W in the axial direction is covered in the region of the distal end portion of the needle tube 1 where the second inclined surface 4 and the third inclined surface 5 are formed.

The mask 7 has a width W of 0.05 to 0.5 mm in order to set the length of the tip blade portions 41 and 51 in the axial direction, that is, the length of the first ridge line 6 to 0.05 to 0.5 mm. As described above, it is composed of a synthetic resin plate, a rubber plate, a metal plate, an adhesive tape or the like so as to cover the region.
The mask 7 may be moved with precision using a tool (not shown) so that a large number of needle tubes 1 can be processed at once and so as to accurately cover a minute length region.

  Next, as shown by the arrow in FIG. 3B, the second inclined surface 4 including the edge 42 which is the tip of the needle tube 1, the third inclined surface 5 including the edge 52, and the first inclined The edge 42 of the second inclined surface, the edge 52 of the third inclined surface, and the edge of the first inclined surface that are not covered with the mask 7 by spraying small particles of the abrasive 9 onto the surface 2 from above In the case of puncture, the sharp cutting edges 21 and 22 are formed into curved surfaces, that is, the sharp edges formed on the second inclined surface edge 42 and the third inclined surface edge 52 are dropped to form a sliding surface. Do not cut open the living tissue.

  Here, the abrasive 9 is commercially available for blasting, and glass-based, ceramic-based, and metal-based materials such as glass beads, sandblasting sand, and the like are used. The processing method for spraying the abrasive 9 is well known, and the edge 42 of the second inclined surface, the edge 52 of the third inclined surface, and the edges 21 and 22 of the first inclined surface are sharp. Forming a curved surface shape on the cutting edge can be easily performed.

  After the abrasive 9 is sprayed onto the edge 42 of the second inclined surface, the edge 52 of the third inclined surface, and the edges 21 and 22 of the first inclined surface that are not covered with the mask 7, the mask When the edge 7 is removed, the edge 42 of the second inclined surface, the edge 52 of the third inclined surface, and the edges 21 and 22 of the first inclined surface are formed into a curved surface shape, and the tip where the sharp cutting edge remains. The needle tube 1 having the blade portions 41 and 51 is formed.

In this way, since a plurality of injection needles are processed and manufactured collectively, the manufacturing cost can be reduced.
In addition, in order to remove the burr | flash which can be made in the jaw part 10 of the needle tube 1, the abrasive material 9 is sprayed toward the jaw part 10 from the direction of the front-end | tip of the needle tube 1 normally. Therefore, the abrasive 9 is sprayed from above or obliquely upward to the edge 42 of the second inclined surface, the edge 52 of the third inclined surface, and the edges 21 and 22 of the first inclined surface. Thus, a curved surface shape can be easily formed.

A form in which the thus produced injection needle is used as a spinal anesthesia needle will be described with reference to an explanatory view of a use form of the injection needle in the embodiment of FIG.
FIG. 4 shows a state in which an anesthetic solution 63 in a syringe barrel 62 of a syringe is injected into the human spine by using the injection needle of the present invention as the spinal anesthesia needle 61. The human body is shown in a cross-sectional view. The outermost side is skin 71, the next layer is ligament 72, the next is epidural space 73, and the inner side of the outer space is dura 74. The arachnoid membrane 75 is formed in a bag shape inside the dura 74, that is, between the two layers of the arachnoid membrane 75 is the subarachnoid space 76, in which cerebrospinal fluid circulates, and the cauda equina 77 runs.

The spinal anesthesia needle 61 is omitted in the middle, and the human body side is enlarged, but the anesthetic solution 63 is injected into the subarachnoid space 76 through the spinal anesthesia needle 61 and acts on the caudad nerve 77 to cause anesthesia. Take it.
At the time of injection, the spinal anesthesia needle 61 is punctured and reaches the dura 74 through the skin 71, the ligament 72, and the epidural space 73. The spinal anesthesia needle 61 is provided with tip blades 41 and 51 having small sharp edges. Since it is formed, it is easy to pierce, and the tip blades 41 and 51 can cut through the fibers of the dura 74 slightly and penetrate easily.

Further, since the second inclined surface edge portion 42, the third inclined surface edge portion 52, and the first inclined surface edges 21 and 22 following the leading edge blade portions 41 and 51 are formed rounded, The fibers of the dura 74 are pushed into each other without greatly opening.
Therefore, the cutting width by the tip blade portions 41 and 51 is small, there is no leakage of cerebrospinal fluid or anesthetic solution 63 to the epidural space 73, and there is little possibility of damaging the cauda equina 77 in the subarachnoid space 76, and repair of the cut. Becomes faster.

Further, the dura 74 is hard and has a large resistance to push the fibers of the dura 74 separately, and even if it penetrates, the penetration feeling when reaching the submembrane space 76, that is, the click feeling is large and can be easily detected. it can.
Therefore, the anesthetic solution 63 can be accurately injected into the subarachnoid space 76.
As described above, in the present embodiment, the distal end portions 41 and 51 are provided at the distal end portion of the needle tube 1 and the curved shape is eliminated, that is, the sharp edge is dropped to form the second sliding surface. By providing the edge portion 42 of the inclined surface 4, the edge portion 52 of the third inclined surface 5, and the edge portions 21 and 22 of the first inclined surface 2, it becomes easy to puncture the injection needle. In addition, it is possible to reduce the width of opening the living tissue.

Especially with spinal anesthesia needles, the width of opening the dura mater when puncturing is reduced, so that there is no leakage of cerebrospinal fluid or anesthetic into the epidural space, and there is less risk of damaging nerves in the subarachnoid space The effect is obtained.
Leakage of cerebrospinal fluid in the epidural space or injected anesthetic from the incision of the dura is considered to be a cause of headaches that occur after surgery. The effect is that the burden is not forced.

  Moreover, the edge part 42 of the 2nd inclined surface 4 formed in the curved surface shape (sliding surface), the edge part 52 of the 3rd inclined surface 5, and 1st of the front-end | tip blade parts 41 and 51 are made small. By increasing the width of the edges 21 and 22 of the inclined surface 2, the resistance increases when the dura is punctured, and the click feeling that the tip of the spinal anesthesia needle enters the subarachnoid space is greatly detected, that is, The effect that the dural penetration is easily obtained is obtained.

Thus, it is easy to obtain a sense of penetration of the dura mater, which means that it can be confirmed whether the tip of the spinal anesthesia needle penetrates the dura mater and enters the subarachnoid space. The effect that can be injected is obtained.
Furthermore, since the structure as a syringe needle is simple and a plurality of syringe needles can be processed in a lump, the manufacturing cost can be reduced. Particularly, in order to prevent infection, the injection needle is disposable, and the price of the injection needle is desired to be low. Therefore, it is possible to provide an inexpensive injection needle by keeping the manufacturing cost low. Is obtained.

The top view and side view which show the injection needle in an Example Sectional drawing which shows the injection needle in an Example Explanatory drawing of the manufacturing method of the injection needle in an Example Explanatory drawing of the usage form of the injection needle in an Example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Needle tube 2 1st inclined surface 3 Opening part 4 2nd inclined surface 5 3rd inclined surface 41,51 Tip blade part 21,22,42,52 Edge 6,43,53 Edge 7 Mask 8 Jig board 9 Abrasive material 10 Chin

Claims (5)

In the injection needle for spinal anesthesia in which the tip portion of the cylindrical needle tube is obliquely ground to form the first inclined surface,
The distal end portion of the first inclined surface includes a second inclined surface and a third inclined surface that form a ridge line in the direction of the central axis of the needle tube,
The sliding surface is formed by dropping the edge of the second inclined surface, the edge of the third inclined surface, and the edge of the first inclined surface excluding the second inclined surface and the tip of the third inclined surface. An injection needle for spinal anesthesia characterized by being formed. The injection needle for spinal anesthesia according to claim 1,
An injection needle for spinal anesthesia, characterized in that the end of the ridge line is formed on the first inclined surface. The injection needle for spinal anesthesia according to claim 1 or claim 2,
An injection needle for spinal anesthesia characterized in that the ridge line has a length of 0.05 to 0.5 mm. In the injection needle for spinal anesthesia according to claim 1, claim 2, or claim 3,
An injection needle for spinal anesthesia characterized in that an angle formed by the second inclined surface and the third inclined surface in the first inclined surface is 75 degrees. Forming the first inclined surface by obliquely grinding the tip of the cylindrical needle tube;
Forming a second inclined surface and a third inclined surface so as to form a ridge line in the central axis direction of the needle tube at the tip of the first inclined surface;
Masking the tip of the second inclined surface and the third inclined surface;
The edge of the second inclined surface excluding the tip of the second inclined surface and the third inclined surface by spraying abrasive on the first inclined surface, the second inclined surface, and the third inclined surface. And a step of forming a sliding surface by dropping the edge of the third inclined surface and forming the sliding surface by dropping the edge of the first inclined surface.