JP5500742B2 - Method for producing spinal subarachnoid anesthesia needle - Google Patents

Description

  The present invention relates to a method for producing a spinal anesthesia needle used for spinal subarachnoid anesthesia.

  Spinal subarachnoid anesthesia is frequently used as lower body local anesthesia. A normal subarachnoid anesthesia needle has a cutting edge at the tip, but a headache may occur due to a decrease in the cerebrospinal fluid pressure flowing out from the puncture mark after surgery called PDPH. This is generally interpreted as the outflow of cerebrospinal fluid does not stop easily after puncturing the arachnoid because the tip of the anesthetic needle is sharp. In order to avoid this, there is a current tendency to make the anesthetic needle thinner, but as another method, a non-cut needle (the tip of which is in a pencil shape) in which the tip of the anesthetic needle is not attached has been developed and used. (See Patent Document 1). This is a pencil point needle, generally named after the developer, called Whitcare / Sprotte.

  6 and 7 show an example of a conventional anesthetic needle 11 (pencil point needle) for subarachnoid anesthesia, FIG. 5 is a plan view of the vicinity of the tip, and FIG. 6 is a side view of the same. The anesthesia needle 11 is provided with a conical tapered (pencil-like) tip 13 at the tip of a straight tube portion 12 having a uniform outer diameter, and an elongated opening 14 for discharging a drug solution is formed. All or most of the opening 14 is provided in the straight pipe portion 12. The distance a from the tip of the anesthetic needle 11 to the tip of the opening 14 is about 2.0 mm to 4.0 mm, and the axial length b of the opening 14 is about 3.0 to 5.0 mm. Since the pencil point needle has no blade at the tip, there is a merit that the puncture mark of the arachnoid membrane is small and the decrease in cerebrospinal fluid pressure does not easily occur. In addition, it is generally said that the operator can easily understand the sense of penetrating the arachnoid membrane compared to an anesthetic needle with a blade edge.

FIG. 8 is an explanatory diagram of the process of forming the opening 14 in the anesthetic needle 11. As shown in the figure, the opening 14 is formed by cutting the tip portion of the anesthetic needle 11 with a disk-shaped grindstone 15 rotated by a cutting machine.
No. 7-30031

As described above, in the conventional pencil point needle, the opening is almost provided in the straight pipe portion. For this reason, after penetrating the arachnoid membrane, if the needle is not advanced sufficiently so that the entire opening reaches below the arachnoid, the cerebrospinal fluid return (recall back) indicating that the needle has reached the predetermined site cannot be confirmed. If the needle is advanced too much, the nerve may be punctured and the nerve tissue may be damaged.
Although the present invention is a pencil point needle, the needle can be slightly advanced after penetrating the arachnoid membrane, so that cerebrospinal fluid burr (recall back) indicating that the needle has reached a predetermined site can be confirmed. The purpose of the present invention is to make it possible to produce an anesthetic needle that does not cause the needle to be advanced too much and damage the nerve tissue.

  The present invention provides a method for producing an anesthesia needle comprising a tip portion tapered in a conical shape at the tip of a straight tube portion having a uniform outer diameter, and an entire opening for discharging a drug solution is provided at the tip portion. A spinal arachnoid membrane comprising a step of opening the opening by causing a discharge needle of an electric discharge machine to act on the distal end portion at an angle of 25 to 35 ° with respect to the axis of the anesthetic needle. It is a manufacturing method of a lower anesthetic needle.

Since the anesthesia needle manufactured by the method of the present invention is a pencil point needle, the puncture mark of the arachnoid membrane is small and the decrease in cerebrospinal fluid pressure does not easily occur, and the sense of penetrating the arachnoid membrane is easy to understand.
Further, since the entire opening is provided at the tip portion tapered in a conical shape, after the needle tip punctures the arachnoid, the entire opening immediately enters the subarachnoid with a small advance amount, and the cerebrospinal fluid is returned ( (Recall back) can be confirmed promptly, and there is no risk of puncturing the nerve tissue by advancing the needle too much.
The present invention provides a spinal subarachnoid anesthesia needle having the above-described effect by opening the opening by causing the discharge needle of the electric discharge machine to act on the tip at an angle of 20 to 40 ° with respect to the axis of the anesthetic needle. Can be easily manufactured.

  The thickness of the anesthesia needle in the present invention may be the same as that of a conventional pencil point needle, and the material may be the same as that of a conventional one, and may be made of, for example, stainless steel.

  In the anesthetic needle of the present invention, the length of the tip is suitably about 1.5 mm to 4.0 mm.

  In the anesthetic needle according to the present invention, the distance a from the needle tip to the tip of the opening is desirably 0.5 mm to 1.5 mm. Not only is it difficult to make it less than 0.5 mm, but the strength of the needle tip is weakened. When the diameter exceeds 1.5 mm, the opening immediately enters the subarachnoid with a small amount of puncture, and the effect that the cerebrospinal fluid bounce (recall back) can be quickly confirmed is reduced. The distance in this case is a distance measured in a direction parallel to the axis as shown in FIG.

  In the anesthetic needle according to the present invention, the axial length b of the opening (the length from the opening front end to the rear end) is suitably about 0.4 mm to 1.0 mm.

  In the case of forming the opening, conventionally, the disk-shaped grindstone 15 was used to cut from the direction perpendicular to the axis of the anesthetic needle. However, in the manufacturing method of the present invention, an electric discharge machine is used. A suitable angle for causing the discharge needle to act on the tip of the anesthetic needle is 20 to 40 ° with respect to the axis of the anesthetic needle. Outside this angular range, the shape of the opening tends to be irregular, making it difficult to control the discharge needle.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the vicinity of the tip of a spinal subarachnoid anesthetic needle 1 manufactured by the method of the present invention, FIG. 2 is a side view, and FIG. 3 is a central cross-sectional view in FIG.

  The anesthesia needle 1 includes a distal end portion 3 that is tapered conically at the distal end of a straight tube portion 2 having a uniform outer diameter. The opening 4 is entirely provided at the tip 3. The straight pipe 2 has an outer diameter of 0.72 ± 0.01 mm, an inner diameter of 0.49 ± 0.01 mm, a distance a from the needle tip to the opening tip of 0.78 mm, and a length b from the opening tip to the rear end. Is 0.62 mm, and the tip length is 2.18 mm. The width of the opening 4 was set to be substantially equal to the inner diameter of the anesthetic needle in this portion.

  FIG. 4 is an explanatory diagram of a method of opening an opening in the anesthetic needle 1. First, the tip of a stainless steel tube having an outer diameter of 0.72 ± 0.01 mm and an inner diameter of 0.49 ± 0.01 mm is processed into a pencil point shape, and a tip portion tapered in a conical shape is provided. The pencil point processing can be performed by a conventionally known method (for example, see Japanese Patent Application Laid-Open No. 11-207427). The needle 1 processed into a pencil point shape is fixed on the mounting plate 5 a of the support base 5. The mounting table 5a is inclined by 60 ° with respect to the horizontal plane. The discharge needle 6 of the electric discharge machine is lowered vertically with respect to the needle 1 fixed to the support base 5. As a result, the discharge needle 6 can act on the distal end portion 3 of the anesthetic needle 1 at an angle of 30 ° with respect to the axis of the needle 1 to form the opening 4.

The anesthetic needle 1 and the conventional anesthetic needle 11 (outer diameter 0.72 ± 0.01 mm, inner diameter 0.49 ± 0.01 mm, a = 2 mm, b = 3.1 mm) shown in FIG. 5 are recalled. This time was measured.
FIG. 5 shows a state where the rubber tube 8 is punctured with the inner needle 7 (stylet) inserted into the anesthetic needle 1.
Three drops of red ink were dropped in a beaker and diluted with 100 ml of purified water to prepare Test Solution 9. The test solution was filled so that a water pressure of 90 mm was applied to a rubber tube having an outer diameter of 10 mm and an inner diameter of 8 mm. The anesthesia needle is punctured at right angles to the rubber tube with the inner needle inserted, and the opening is completely inserted into the rubber tube. The anesthetic needle 1 of the embodiment may be inserted at least 1.4 mm into the rubber tube, but the conventional anesthetic needle 11 needs to be inserted at least 5.1 mm.
At the same time that the measurer A pulls out the inner needle of the anesthesia needle, the measurer B starts measuring time with a stopwatch. When the test liquid begins to flow out from the rear end of the anesthetic needle, the measurer B measures the detection time. The detection time for both the anesthetic needles 1 and 11 was about 2 seconds. It was demonstrated that the time required for recalling the anesthetic needle of the present invention is comparable to that of a conventional anesthetic needle.

It is a top view of the spinal subarachnoid anesthesia needle 1 manufactured by the method of the present invention. 1 is a side view of an anesthetic needle 1. FIG. It is a center cross-sectional view in FIG. It is explanatory drawing of the method of opening an opening in the anesthetic needle. It is explanatory drawing of the time measurement concerning a recall back. It is a top view of the conventional anesthesia needle 11. FIG. It is a side view of the conventional anesthetic needle 11. It is explanatory drawing of the process of forming the opening 14 in the conventional anesthesia needle 11. FIG.

DESCRIPTION OF SYMBOLS 1 Anesthetic needle 2 Straight pipe part 3 Tip part 4 Opening 5 Support stand 6 Discharge needle 7 Inner needle 8 Rubber tube 9 Test solution 11 Anesthetic needle 12 Straight pipe part 13 Tip part 14 Opening 15 Grinding stone

Claims (1)

  An anesthesia needle manufacturing method comprising a tip portion tapered in a conical shape at the tip of a straight tube portion having a uniform outer diameter, and an entire opening for discharging a drug solution provided in the tip portion, A spinal anesthesia needle comprising a step of opening the opening by causing a discharge needle of an electric discharge machine to act on the tip at an angle of 20 to 40 ° with respect to the axis of the anesthetic needle. Production method.

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