JP3226347U - Epidural needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive epidural needle which can use a water drop method which is highly reliable and safe and which is unlikely to cause erroneous puncture as a method for judging the position of a needle tip. An epidural needle including an inner needle and an outer needle, the outer needle including a metallic needle tube and an outer needle base. The needle tube has a distal end portion, a proximal end portion 22b, and a needle inner space 22c penetrating between the distal end portion and the proximal end portion. The outer needle base has one end, the other end, and a base internal space 24c that penetrates between the one end and the other end. The proximal end of the needle tube is attached to one end of the outer needle so that the internal space of the base communicates with the internal space of the needle of the needle tube. The outer needle base has a base body made of a material different from that of the needle tube, and a metal liner 27 provided so as to cover the base inner wall 24s facing the inner space of the base. [Selection diagram] Figure 1

Description

The present invention relates to a needle mainly used for epidural anesthesia, and more specifically to a needle that allows a practitioner to easily detect that the needle has penetrated a predetermined site.

Epidural anesthesia is currently used as a type of anesthesia method performed during surgery. Epidural anesthesia is a method of temporarily paralyzing the spinal nerve by injecting a local anesthetic into the spinal epidural space. When performing epidural anesthesia, puncture the epidural needle so that the needle tip reaches the epidural space, and directly administer an anesthetic to the epidural space through the epidural needle, or An anesthetic is administered to the epidural space through a catheter inserted through the epidural needle. Epidural anesthesia has advantages over other methods of spinal anesthesia, such as less risk of side effects and the possibility of anesthesia for a long time using a catheter.

FIG. 6 is a typical epidural needle used for epidural anesthesia. FIG. 5A shows the appearance of the epidural needle 1. The epidural needle 1 generally comprises an inner needle 10 and an outer needle 20. The inner needle 10 includes an inner needle main body 12 having a tip portion 12a and a proximal end portion 12b, and an inner needle base portion 14 attached to the proximal end portion 12b of the inner needle body 12. The outer needle 20 has a needle tube 22 and an outer needle base 24 attached to the needle tube 22. FIG. 5B is a cross-sectional view of a part of the needle tube 22 of the outer needle 20 and the outer needle base 24. The needle tube 22 has a distal end portion 22a and a proximal end portion 22b, and has a needle inner space 22c penetrating the inside between the distal end portion 22a and the proximal end portion 22b. An outer needle base 24 is attached to the base end 22b of the needle tube 22. A base end portion 22b of the needle tube 22 is attached to one end portion 24a of the outer needle base portion 24, and the outer needle base portion 24 has a base portion inner space 24c penetrating therethrough between the one end portion 24a and the other end portion 24b. Have. The needle inner space 22c and the base inner space 24c communicate with each other in a positional relationship in which they are coaxially arranged. The other end 24b of the outer needle base 24 has an opening 24d in the base internal space 24c, and a flange 24e is provided around the opening 24d. The tip portions 12a and 22a are curved in the direction of the needle hole (direction perpendicular to the paper surface of FIG. 5). The outer needle base portion 24 is provided with a grasping body (wing portion) 26 for allowing the practitioner to pinch and apply force to advance the needle.

When performing epidural anesthesia using the epidural needle shown in FIG. 5, it is necessary for the practitioner to determine that the tip of the epidural needle has reached the narrow epidural space. As a main method for determining that the needle tip has reached the epidural space, there are a tactile method, a resistance disappearance method, and a water drop method (also referred to as a hanging drop method). The tactile method is a method in which the practitioner determines that the tip of the needle has reached the epidural space from the sensation when the needle penetrates the ligamentum flavum with high puncture resistance. The loss-of-resistance method (loss-of-resistance method) is a method that uses the feeling of loss of resistance immediately after penetrating the ligamentum flavum with a syringe. In this method, when the needle tip reaches near the ligamentum flavum, a syringe containing air, an anesthetic, or physiological saline is connected to the outer needle base opening (opening 24d in FIG. 5) of the epidural needle, While advancing the needle while pressurizing the piston of the syringe, when the needle tip passed the ligamentum flavum and reached the epidural space, it felt that the resistance of the piston had disappeared, and the needle tip reached the epidural space. This is a method for the practitioner to judge what has been done. The water drop method (hanging drop method) is a method that utilizes negative pressure in the epidural space. In this method, when the needle tip reaches the vicinity of the ligamentum flavum, water or physiological saline is put in the inner space 24c of the base of the epidural needle, and the needle is further advanced, and the needle tip passes through the ligamentum flavum and the dura mater is reached. Upon reaching the outer space, the needle tip reached the epidural space by visually observing that water was sucked from the base inner space 24c into the needle inner space 22c by the action of the negative pressure of the epidural space. This is how the practitioner decides that.

The tactile and resistance loss methods can only detect that the needle tip has reached the epidural space, and in the case of an immature operator, the dura is punctured to the subarachnoid space. It may reach the end and can be a dangerous method depending on the skill of the practitioner. On the other hand, the water drop method is more reliable and immature because not only the practitioner can visually recognize that the needle tip has reached the epidural space and also the feeling of penetration of the ligamentum flavum. This is a method in which even a practitioner is unlikely to have a false puncture.

As an epidural needle for preventing erroneous puncture, for example, the techniques described in Patent Documents 1 to 3 have been proposed.
Patent Document 1 (Japanese Patent Laid-Open No. 52-132589) is a device capable of testing the depth of penetration of a needle into a patient's body by utilizing a water drop method. The hollow needle and the recess that receives the test solution are connected in the passageway, and when the needle tip reaches the negative pressure position in the patient's body, the test solution is drawn into the passageway so that the position of the needle tip is changed. You can judge.
Patent Document 2 (Japanese Patent Laid-Open No. 10-57481) discloses that by coating the outer surface of the needle tube of an outer needle to reduce sliding friction when the needle tube enters the tissue of a patient, the needle tip is at a target position. It is a hypodermic needle that allows a practitioner to easily identify the arrival.
Patent Document 3 (Japanese Patent Laid-Open No. 2013-9919) is a technique that uses an epidural needle in which a needle base and a gripping body are connected by magnetic force and a pressure sensor. In this technique, when the pressure sensor that detects the puncture pressure of the needle detects that the needle tip has reached the epidural space and the puncture pressure has dropped sharply, The magnetic force disappears and the gripping body is released from the needle base.

JP-A-52-132589 Japanese Patent Laid-Open No. 10-57481 JP, 2013-9919, A

Many disposable products are used in the medical field. As a factor that many disposable products are used, the risk of infection due to reuse is eliminated, cost reduction due to the mass production of products using synthetic resins with the development of industrial technology, synthetic resins It can be used to reduce the weight and improve the visibility of chemicals by using transparent resin. As for epidural needles, disposable products are now widespread.

In the disposable epidural needle, the needle tube 22 shown in FIG. 5 is generally made of metal, and the outer needle base 24 is entirely made of synthetic resin. However, the conventional disposable epidural needle having such a structure is more reliable as a method for the practitioner to judge that the needle tip of the epidural needle has reached the narrow epidural space, It is difficult for even an inexperienced operator to use the water drop method, which is a method in which erroneous puncture is unlikely to occur. It is considered that this is because the conventional disposable epidural needle is different in the material of the needle tube and the material of the outer needle base.

With epidural puncture using a conventional disposable epidural needle, it is difficult to clearly confirm the aspiration of water even using the water drop method, so the epidural needle with a narrow needle tip is used. It is not possible to make a reliable judgment that it has reached inside. Therefore, when performing epidural space puncture using a disposable epidural needle, the resistance disappearance method is often used for determination. However, in this method, as described above, only the practitioner can sense that the tip of the needle has reached the epidural space, and therefore an immature practitioner may cause an accident. This point is the same even when the hypodermic injection needle described in Patent Document 2 is used. The device of Patent Document 1 has a complicated structure and is difficult to handle, and the device of Patent Document 3 has a complicated structure, so that neither device can be implemented at low cost.

INDUSTRIAL APPLICABILITY The present invention makes it possible to use the water drop method, which is highly reliable and safe and does not easily cause erroneous puncture, as a method for determining the position of the needle tip, and uses a special device or employs a complicated structure. It is an object of the present invention to provide an epidural needle that can be manufactured at low cost because it does not occur.

The present invention provides an epidural needle having an inner needle and an outer needle. The outer needle includes a metal needle tube and an outer needle base. The needle tube has a distal end portion, a proximal end portion, and a needle inner space penetrating between the distal end portion and the proximal end portion. The outer needle base has one end, the other end, and a base internal space that penetrates between the one end and the other end. The proximal end of the needle tube is attached to one end of the outer needle so that the internal space of the base communicates with the internal space of the needle of the needle tube. The outer needle base has a base body made of a material different from that of the needle tube, and a metal liner provided so as to cover an inner wall of the base facing the inner space of the base. In one embodiment, the metal liner is preferably a liner made of the same material as the needle tube.

In one embodiment, the outer needle has an opening in the inner space of the base at the other end and a flange located around the opening, and the flange is provided with a metal liner at least around the opening. Preferably. The metal liner provided on the flange is preferably a liner made of the same material as the needle tube.

In one embodiment, the base body is preferably made of resin.

In one embodiment, the tip portion of the needle tube has a needle hole that is an opening in the needle inner space, and is curved toward the opening direction of the needle hole. The angle α between the opening plane of the needle hole and the side surface of the needle tube continuing inside the curved portion is preferably 12° to 13°, and the tangent line extending in the longitudinal direction of the needle tube at the upper end outside the curved portion and the curve. It is preferable that the angle β between the side surface of the needle tube continuous to the outside of the part is 20°.

In the outer needle of the epidural needle according to the present invention, the main body of the outer needle base is made of inexpensive and lightweight resin, and the wall surface facing the inner space penetrating the inside is covered with metal. Therefore, the water drop method, which could not be used with the conventional outer needle of the disposable epidural needle, can be reliably used, and even an inexperienced practitioner does not easily cause a false puncture during epidural anesthesia. The outer membrane needle can be provided at low cost.

FIG. 3 is a longitudinal sectional view of a part of an outer needle of an epidural needle according to an embodiment of the present invention. FIG. 6 is a longitudinal sectional view of a part of an outer needle in an epidural needle according to another embodiment of the present invention. FIG. 6 is a longitudinal sectional view of a part of an outer needle of an epidural needle according to another embodiment of the present invention. FIG. 3 is an enlarged perspective view of a portion including a tip portion of an outer needle in the epidural needle according to the present invention. It is a conventional epidural needle, (a) is a side view of an inner needle and an outer needle, (b) is a longitudinal cross-sectional view of a part of the outer needle.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a part of an outer needle 20 in an epidural needle 1 according to an embodiment of the present invention. The part shown in FIG. 1 is similar to the part shown in FIG. In FIG. 1, the same elements as those of the outer needle 20 of FIG. 5 are designated by the same reference numerals.

The outer needle 20 shown in FIG. 1 has a needle tube 22 and an outer needle base 24 attached to the needle tube 22. The needle tube 22 has a distal end portion 22a (see FIG. 5) and a proximal end portion 22b, and a cylindrical needle inner space 22c penetrating the interior between the distal end portion 22a and the proximal end portion 22b. An outer needle base portion 24 is attached to the base end portion 22b of the needle tube 22. A base end portion 22b of the needle tube 22 is attached to one end portion 24a of the outer needle base portion 24, and the outer needle base portion 24 has a cylindrical base portion that penetrates the inside between the one end portion 24a and the other end portion 24b. It has an inner space 24c. The needle inner space 22c and the base inner space 24c communicate with each other in a positional relationship in which the central axes of the columnar shapes are arranged coaxially with each other. The other end 24b of the outer needle base 24 has an opening 24d in the base internal space 24c, and a flange 24e is provided around the opening 24d. The outer needle base portion 24 is usually provided with a grasping body (wing portion) 26 provided for the purpose of allowing a practitioner to pinch and apply force to advance the needle.

The needle tube 22 is usually entirely made of metal. The metal forming the needle tube 22 is not particularly limited as long as it is a metal generally used as an injection needle, but stainless steel is preferable from the viewpoint of corrosion resistance and influence on the human body, and austenitic stainless steel. Is more preferable. On the other hand, the outer needle base was previously entirely made of metal, but with the recent trend of making disposable needles disposable, the outer needle base is now entirely made of synthetic resin. That is, the outer needle base portion 24 of the outer needle 20 (in this specification, a portion other than the metal liner 27 of the outer needle base portion 24 is also referred to as a base body) is made of a material different from that of the needle tube 22. The synthetic resin is not particularly limited, but it is preferable to use polycarbonate or polypropylene. When the grip body (wing portion) 26 is provided, the grip body (wing portion) 26 is preferably made of the same material as the outer needle base portion 24.

In the outer needle base 24 shown in FIG. 1, a metal liner 27 is provided so as to cover the entire surface of the base inner wall 24s facing the base internal space 24c. The metal liner 27 may be formed of a metal different from that of the needle tube 22 or the same metal, but it is more preferably formed of the same metal. Thus, by using the outer needle 20 in which the metal liner 27 of the same material as the needle tube 22 is preferably provided on the inner wall 24 s of the base portion, the practitioner uses the water drop method to remove the outer needle of the epidural needle 1. It can be accurately determined that the needle tip 22a of the needle 20 has reached the inside of the narrow epidural space. Further, since the outer needle 20 has the base inner space 24c having substantially the same size as the base inner space of the conventional outer needle base, the resistance vanishing method can also be used.

The method of providing the metal liner 27 on the base inner wall 24s is not particularly limited. For example, a method of attaching a film or a film to be the metal liner 27 to the inner wall 24 s of the base by any means, for example, a general surface treatment/decoration method such as attaching a metal thin film, plating, physical vapor deposition, etc. may be appropriately used. it can. Alternatively, a tubular body, which is separately formed according to the shape of the base inner wall 24s and has an opening corresponding to the needle inner space 22c of the needle tube 22 on the bottom surface, is fitted into the base inner space 24c, and the fitted cup is a metal liner. It is possible to use a method of setting the value to be 27.

FIG. 2 is a vertical cross-sectional view of a portion of the outer needle 20 according to another embodiment of the present invention. In this embodiment, the shape of the base internal space 24c is different from the shape according to the embodiment of FIG. Specifically, the base inner space 24c is formed such that its diameter gradually decreases toward the one end 24a direction of the outer needle base 24 and smoothly continues to the needle inner space 22c. In this way, by smoothly continuing the base inner space 24c and the needle inner space 22c, when the water drop method is used, the resistance when the water in the base inner space 24c is sucked in becomes small, and the sensitivity for sensing negative pressure is reduced. Can be further improved. The outer needle 20 of this embodiment also has an advantage that the catheter can be inserted smoothly.

FIG. 3 is a longitudinal sectional view of a part of the outer needle 20 of the epidural needle 1 according to still another embodiment of the present invention. The outer needle 20 of this embodiment is different from the outer needle of the embodiment shown in FIG. 2 in that a flange metal liner 29 is also provided on the surface of the flange 24e of the outer needle base 24. The flange metal liner 29 is preferably made of the same metal as the needle tube 22. The flange portion metal liner 29 may be provided only in the peripheral portion of the opening 24d instead of the entire surface of the flange 24e.

Incidentally, in addition to the fact that the epidural needle 1 used for epidural anesthesia allows the practitioner to easily judge that the needle tip has reached the epidural space as described above, It is necessary that the accidental puncture of the dura due to the needle tip reaching the outer cavity does not occur and that the catheter is not damaged even when the inserted catheter is pulled back. The inventor of the present invention has conducted research for many years on the shapes of the tip portion 22a and the needle hole 22d of the outer needle 20 for satisfying such conditions, and has concluded a desirable shape.

FIG. 4 is an enlarged perspective view of a portion including the tip portion 22a of the outer needle 20 according to the embodiment of the present invention, and shows the shapes of the tip portion 22a and the needle hole 22d that the inventor considers desirable. In addition, here, the needle hole 22d means a portion in which the opening of the tip portion 22a and the tube wall of the needle tube 22 located around the opening are combined. In this shape, the tip portion 22a is curved toward the opening direction of the needle hole 22d. As shown in FIG. 4, the angle between the opening plane of the needle hole 22d and the linear portion of the side surface of the needle tube 22 which is continuous inside the curved portion is α, and the tangent line extending in the length direction of the needle tube at the upper end outside the curved portion. When the angle between the straight portion on the side surface of the needle tube 22 continuous to the outside of the curved portion is β, there is a relation that the major axis DL of the needle hole 22d increases as the angle α or the angle β decreases. When the major axis DL of the needle hole 22d increases, the tip 22at of the tip 22a becomes sharp and the opening area of the needle hole 22d increases. It is desirable that the tip 22at is blunt and that the opening area of the needle hole 22d be small, from the viewpoint of preventing erroneous puncture and facilitating understanding of the feeling of penetration of the subcutaneous, muscle, and ligamentum flavum. As the angles α and β for that purpose, the angle α is preferably 12° to 13°, and the angle β is preferably 20°. Further, the major diameter DL of the needle hole 22d is preferably 3 mm or less, and the minor diameter DW is preferably equal to the outer diameter of the needle tube 22. For example, if the size is a 17 G (gauge) needle (material: SUS304), the outer diameter of the needle tube 22 is about 1.46 mm, and if the size is 20 G, the outer diameter is about 0.89 mm. .

If the minor diameter DW of the needle hole 22d is larger than the outer diameter of the needle tube 22, the portion 22as located on the side of the needle hole 22d becomes sharp, and there is a risk of damaging surrounding tissues during puncture. Therefore, it is more preferable to make the minor diameter DW of the needle hole 22d smaller than the outer diameter of the needle tube 22 and to make the portion 22as located laterally smooth. Further, in order to prevent damage when the catheter is pulled back, it is preferable to smoothly form the outer peripheral inner surface of the needle hole 22d, particularly the inner surface of the portion 22ae located behind the needle hole 22d.

1 Epidural Injection Needle 10 Inner Needle 12 Inner Needle Body 14 Inner Needle Base 20 Outer Needle 22 Needle Tube 22a Tip 22b Base End 22c Needle Space 22d Needle Hole 24 Outer Needle Base 24a One End 24b Other End 24c Inside Base Space 24d Opening 24e Flange 24s Base inner wall 27 Metal liner 27s Metal liner surface 29 Flange metal liner 29s Flange metal liner surface 26 Gripping body (wing portion)

Claims (6)

An epidural needle having an inner needle and an outer needle,
The outer needle is
A distal end, a proximal end, and a needle needle space having a needle inner space penetrating between the distal end and the proximal end, and a metallic needle tube,
It has one end, the other end, and a base internal space that penetrates between the one end and the other end, and the base end is connected to the one end so that the base internal space communicates with the needle internal space. An outer needle base to which the part is attached,
An epidural needle characterized in that the outer needle base has a base body made of a material different from that of the needle tube, and a metal liner provided so as to cover an inner wall of the base facing the inner space of the base. The epidural needle according to claim 1, wherein the metal liner is a liner made of the same material as the needle tube. The other end portion has an opening in the base internal space and a flange located around the opening, and the flange is provided with a metal liner at least in the peripheral portion of the opening,
The epidural needle according to claim 1 or 2, characterized in that. The epidural needle according to claim 3, wherein the metal liner provided on the flange is a liner made of the same material as the needle tube. The epidural needle according to any one of claims 1 to 4, wherein the base body is made of resin. The tip portion of the needle tube has a needle hole that is an opening of the needle inner space, is curved toward the opening direction of the needle hole, and is continuous with the opening plane of the needle hole and inside the curved portion. The angle α with the side surface of the needle tube is 12° to 13°, and the angle β between the tangent line extending in the length direction of the needle tube at the upper end outside the curved portion and the side surface of the needle tube continuous to the outside of the curved portion is The epidural needle according to any one of claims 1 to 5, which is 20°.

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