JP4550161B1 - Compound needle with lock mechanism - Google Patents

Abstract

Develop a compound needle that does not move the inner needle forward when the cap is advanced to lock the inner needle.
A composite needle having an outer needle having a cylindrical base at the proximal end and an inner needle inserted from the rear end of the cylindrical base and protruding from the distal end of the outer needle, formed on the outer peripheral surface of the axially intermediate portion An insertion portion is formed in front of the flange portion, and the insertion portion of the lock member having a tapered surface having a smaller outer diameter toward the rear side and a slit in which the cylindrical wall is cut in the axial direction is formed at the cylindrical base portion. Insert from behind. When the cap is turned to advance toward the tip side, the taper surface of the lock member enters the taper concave portion of the cap, the diameter of the insertion hole of the portion where the taper surface is formed is reduced, and the inserted inner needle is tightened and locked. However, since the lock member does not move forward with the flange portion coming into contact with the rear end surface of the cylindrical base, the inner needle will not move forward unexpectedly.
[Selection] Figure 2

Description

  The present invention relates to a compound needle used for spinal anesthesia and the like.

  When performing spinal anesthesia, etc., the use of a thin needle reduces the headache after surgery, but if only the thin needle is inserted into the body, the needle may break. Therefore, the outer needle is first inserted into the body, and then the thin inner needle is inserted through the outer needle to a predetermined position in the body, and an anesthetic solution is injected from the proximal end side of the inner needle with a syringe. Initially, this type of compound needle did not have a means for fixing the inner needle to the outer needle.

  The original compound needle of this type does not have a means to fix the inner needle to the outer needle, so that even if the inner needle is inserted through the outer needle until the tip reaches an anesthetic position, the patient's Due to the movement of the body and the operation of connecting the syringe barrel to the proximal end of the inner needle, the position of the tip of the inner needle may shift, and anesthesia may not work as expected, or the anesthetic solution may be wasted. .

  In order to solve such a problem, a compound needle shown in Patent Document 1 below has been proposed. This is a compound needle that has a cylindrical base at the proximal end of the outer needle and inserts the inner needle inside from the rear end of the cylindrical base toward the distal direction. A cylindrical cap with a tapered end and a slit in the axial direction is attached to the inside of the cylindrical base of the outer needle base end with Then, when the cylindrical cap is advanced to the distal end side, the distal end portion of the cylindrical cap enters the tapered portion inside the cylindrical base portion to reduce the diameter, and the inserted inner needle is tightened and locked, and the cylindrical cap is retracted. If it does, a front-end | tip part will recede from the taper part inside a cylindrical base, and will expand in diameter, and the lock | rock of an inner needle will be cancelled | released.

JP 2001-178823 A

Compound needle of Patent Document 1, when advancing the tubular cap in order to lock the inner needle, the tip portion of the cylindrical cap is tightened to fix the inner needle reduced in diameter was clamped to the inner needle The needle further advances in the state, and as a result, the inner needle also advances. For example, in spinal anesthesia, when the inner needle is locked, the inner needle may move forward and damage nerve tissue.

  An object of the present invention is to develop a compound needle that does not cause the inner needle to move forward when the cap is moved forward to lock the inner needle.

The present invention relates to a compound needle having an outer needle having a cylindrical base at the proximal end and an inner needle that is inserted from the rear end of the cylindrical base and protrudes from the distal end of the outer needle.
An insertion hole through which the inner needle is inserted has a cylindrical shape formed in the axial direction, and an insertion portion in front of the flange portion formed on the outer peripheral surface of the axial intermediate portion is inserted into the cylindrical base portion from the rear, A locking member having a tapered surface whose outer diameter is reduced toward the rear side at the rear end, and a slit in which the cylindrical wall is cut in the axial direction;
It has a cylindrical shape, a screw thread is formed on the inner peripheral surface of the front end portion to be screwed with a screw thread formed on the outer peripheral surface of the rear end portion of the cylindrical base portion, and has an insertion hole through which the inner needle is inserted. A cap having a tapered recess formed with a tapered surface corresponding to the tapered surface of the lock member;
When the cap is rotated and advanced toward the front end side, the lock member does not move forward with the surface perpendicular to the axial direction of the flange portion coming into contact with the rear end surface of the cylindrical base portion, and the tapered surface of the lock member is When the diameter of the insertion hole of the taper recess is reduced and the inner needle inserted is tightened and locked, and the cap is rotated backward to retract, the taper recess of the cap The composite needle is characterized in that the lock member is retracted with respect to the taper surface of the lock member, the diameter of the insertion hole of the lock member is increased, and the lock of the inner needle is released. (Claim 1)

  When the cap is moved forward to lock the inner needle, the taper surface of the lock member shrinks and the inner needle is tightened and fixed. However, the lock member moves forward with the flange contacting the rear end surface of the cylindrical base. Because there is no, the inner needle will not advance unexpectedly.

In the present invention, both the outer peripheral surface of the insertion portion of the lock member and the inner peripheral surface of the cylindrical base portion into which the insertion portion is inserted can be tapered. (Claim 2)
By doing in this way, the insertion part of a lock member can be easily inserted in the rear-end part of a cylindrical base part.

In the present invention, the slit can also be formed in the flange portion. (Claim 3)
By doing so, when the cap is advanced to lock the inner needle, the taper surface of the lock member is easily reduced in diameter, and the inner needle can be securely tightened and fixed.

  In the compound needle of the present invention, the inner needle can be fixed (locked) to the outer needle at an arbitrary position, so that the distal end of the inner needle can be adjusted by the movement of the patient's body or the operation of connecting the syringe barrel to the proximal end of the inner needle. The position will not shift. Also, when the cap is advanced to lock the inner needle, the taper surface of the lock member shrinks and the inner needle is tightened and fixed. However, the lock member moves forward with the flange contacting the rear end surface of the cylindrical base. Therefore, the inner needle will not move forward unintentionally, so that there is no risk of damaging the nerve tissue and the like, and the drug solution can be reliably injected into a predetermined portion.

It is a top view of compound needle 1 of an example. It is principal part sectional drawing which cut | disconnected the compound needle | hook 1 to the axial direction. It is a rear view of the compound needle 1 which removed the inner needle. It is the side view and back view of the lock member 7. It is sectional explanatory drawing of the state which advanced the cap 4. FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings showing examples.
The compound needle 1 of the embodiment has an outer needle 2 and an inner needle 5. A cylindrical base 3 is fixed to the proximal end of the outer needle 2. The outer needle 2 and the cylindrical base 3 are formed with insertion holes through which the inner needle 5 is inserted over the entire axial direction. As shown in FIG. 2, the cylindrical base 3 has a thread 3 a on the outer peripheral surface of the cylindrical rear end, which is screwed with the screw 4 a on the inner peripheral surface of the tip of the cap 4. . The insertion portion 7a of the lock member 7 is inserted into the rear end portion. The inner peripheral surface 3b of the portion is tapered so that the inner diameter becomes smaller toward the front side. A blade 3c is fixed to the middle part of the cylindrical base 3 slightly forward. When the outer needle is punctured, when the cap is turned and the inner needle is fixed, the work can be easily and reliably performed by picking the blade.

  The lock member 7 is made of plastic and has a substantially cylindrical shape. An insertion hole 7e through which the inner needle is inserted is formed in the axial direction. A flange portion 7b bulging in an annular shape is formed in the intermediate portion in the axial direction, and an insertion portion 7a to be inserted into the rear end portion of the cylindrical base portion 3 is provided in front of the flange portion 7b. The outer peripheral surface of the insertion portion 7a has a taper shape corresponding to the inner peripheral surface 3b of the cylindrical base 3 and the outer diameter decreases toward the front side. When the insertion portion 7 a is inserted into the rear end portion of the cylindrical base portion 3, the flange portion 7 b comes into contact with the rear end surface of the cylindrical base portion 3 and the lock member 7 is positioned. At the rear end portion of the lock member 7, a tapered surface 7c having an outer diameter that decreases toward the rear side is formed, and further, three slits 7d in which the cylindrical wall is cut in the axial direction are formed. The slit 7d extends further forward and reaches a part of the flange portion 7b and the insertion portion 7a. The number and length of the slits are appropriately designed so that the insertion hole in the tapered surface 7c can be sufficiently reduced in diameter so that the inner needle can be securely fastened and fixed.

  The cap 4 is made of plastic and has a substantially cylindrical shape. On the inner peripheral surface of the front end portion, a screw thread 4a that is screwed with a screw thread 3a formed on the outer peripheral surface of the rear end portion of the cylindrical base 3 is formed. The rear end portion has an insertion hole 4c through which the inner needle 5 is inserted, and a tapered recess 4b in which a tapered surface whose inner diameter is reduced toward the rear side corresponding to the tapered surface 7c of the lock member 7 is formed.

When the cap 4 is rotated and advanced with respect to the cylindrical base 3, the taper surface of the taper recess 4b advances while sliding with respect to the taper surface 7c of the lock member 7, as shown in FIG. 7c moves inward so as to reduce the diameter, and the insertion hole 7e in the portion where the tapered surface 7c is formed is reduced accordingly.
FIG. 5 shows a state where the inner needle is not inserted. However, when the inner needle is inserted, the insertion hole 7e in the portion where the tapered surface 7c is formed is appropriately reduced in diameter, and the inner needle is contracted. It is fastened and fixed by the diameter of the insertion hole 7e and is locked.

  When the cap 4 is rotated backward in the locked state and retracted, the taper surface of the taper recess 4b retracts while sliding with respect to the taper surface 7c of the lock member 7, so that the taper surface 7c expands due to its elasticity. Thus, it moves outward and returns, the tightening and fixing by the insertion hole 7e is released, and the inner needle is unlocked.

Next, a method for using the compound needle 1 will be described. First, only the outer needle 2 (the lock member 7 and the cap 4 are already mounted) is inserted into the patient's body. In this case, if a stylet (not shown) that closes the hole at the tip of the needle is used, damage to the patient's tissue can be reduced as in the conventional case. Next (when the stylet is used, it is removed), the inner needle 5 is inserted through the insertion hole 4c on the rear end side of the cap 4, and the needle tip is advanced to a predetermined position in the patient's body. Even when the inner needle 5 is inserted, a stylet (not shown) that closes the hole at the tip of the inner needle can be used as in the prior art.
Next, the cap 4 is rotated to fix the inner needle 5 to the outer needle 2. At this time, there is no possibility that the inner needle 5 moves forward. When the stylet is used, it is removed, and a syringe (not shown) is connected to the inner needle base 6 on the proximal end side of the inner needle 5 to inject the drug solution into the body. When the injection is completed, the inner needle that is locked may be removed together with the outer needle, or the cap 4 is rotated to unlock the inner needle 5, the inner needle 5 is removed from the outer needle 2, and finally Alternatively, the outer needle 2 may be removed from the body.

  The compound needle of the present invention is not limited to the examples, and it is needless to say that various modifications can be made within the scope described in the claims.

DESCRIPTION OF SYMBOLS 1 Compound needle 2 Outer needle 3 Cylindrical base part 3a Screw 3b Inner peripheral surface 3c Blade | wing 4 Cap 4a Screw 4b Taper recessed part 4c Insertion hole 5 Inner needle 6 Inner needle base 7 Lock member 7a Insertion part 7b Flange part 7c Tapered surface 7d Slit 7e Insertion hole

Claims (3)

In a composite needle having an outer needle having a cylindrical base at the proximal end and an inner needle inserted from the rear end of the cylindrical base and protruding from the distal end of the outer needle,
An insertion hole through which the inner needle is inserted has a cylindrical shape formed in the axial direction, and an insertion portion in front of the flange portion formed on the outer peripheral surface of the axial intermediate portion is inserted into the cylindrical base portion from the rear, A locking member having a tapered surface whose outer diameter is reduced toward the rear side at the rear end, and a slit in which the cylindrical wall is cut in the axial direction;
It has a cylindrical shape, a thread that is screwed with a thread formed on the outer peripheral surface of the rear end portion of the cylindrical base is formed on the inner peripheral surface of the front end portion, and has an insertion hole through which the inner needle is inserted at the rear end portion. A cap having a tapered recess formed with a tapered surface corresponding to the tapered surface of the lock member;
When the cap is rotated and advanced toward the front end side, the locking member does not move forward with the surface perpendicular to the axial direction of the flange portion coming into contact with the rear end surface of the cylindrical base portion, and the tapered surface of the locking member is When the diameter of the insertion hole of the taper recess is reduced and the inner needle inserted is tightened and locked, and the cap is rotated backward to retract, the taper recess of the cap A compound needle characterized by retreating with respect to the tapered surface of the lock member and expanding the insertion hole of the lock member to release the lock of the inner needle.   2. The composite needle according to claim 1, wherein an outer peripheral surface of the insertion portion of the lock member and an inner peripheral surface into which the insertion portion of the cylindrical base portion is inserted are both tapered toward the front side. .   The compound needle according to claim 1 or 2, wherein the slit is also formed in the flange portion.

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