JP2001245982A - Rotationally piercing type double injection needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily pierce an intravascular indwelling double injection needle by cutting discontinuous structure having a working side/face positioned slantingly to the needle piercing direction with uniformity on the outer needle (indwelling needle) surface though skill has been conventionally required for piercing of the indwelling double injection needle, and to cope with, to a certain degree, to insufficient strength of the outer needle or increase of frictional resistance in piercing by adjusting the dimension or the distribution density of the individual surface structure as the result of technical manufacturing easiness in comparison with a spiral structure cut continuously. SOLUTION: On the surface of the outer needle (indwelling needle) of the intravascular indwelling double injection needle, discontinuous structure having a working side/face slantingly positioned with uniformity toward the needle piercing direction is cut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double injection needle, and more particularly, to a double injection needle provided with an inner needle and an outer trocar supporting the inner needle.

[0002]

2. Description of the Related Art A double injection needle refers to a metal inner needle and a soft trocar attached thereto. Among them, the trocar refers to a soft indwelling portion in a blood vessel, while the inner needle is a metal needle inside the trocar and serves as a support when the trocar is inserted. In modern medicine, inserting a flexible trocar into a blood vessel has become an extremely common medical practice in infusion, blood collection, blood pressure measurement (invasive), and the like. When the metal inner needle, which is the guide needle, reaches the blood vessel lumen, blood flows backward through the inner needle bore (reference numeral 4 in FIG. 2), so the technician confirms that the inner needle has reached the blood vessel lumen. it can. At that point, stop further insertion of the inner needle and insert only the flexible trocar to slide into the vessel lumen. A flexible trocar, unlike a metal injection needle, does not need to limit the limb movement of the patient, and thus has an excellent blood vessel securing force. However, the insertion requires experience and intuition, and has conventionally been considered as one of special techniques requiring skill. The reason for this is that a slight lack of the needle tip or excessive insertion causes damage to the blood vessel wall or the needle may fall out of the blood vessel. Therefore, it was necessary to take measures to prevent the contralateral vascular wall from being damaged by the inner needle due to excessive piercing and to prevent the inner needle from being pushed back and coming off the vascular wall. To solve this problem, the applicant filed on June 17, 1996, "a double injection needle characterized by forming a spiral groove or projection at the tip of the surface of a trocar".
Applying for a patent claiming another, October 29, 1999
Patent granted on a date basis (Patent No. 29955651)
issue).

[0003]

However, a continuous spiral structure is originally carved accurately on the surface of an extremely thin trocar, and furthermore, this does not lead to a decrease in the strength of the trocar or an insertion obstacle (increase in frictional resistance). To do so, very precise processing technology was required. The present invention further improves the above-mentioned invention, and provides a double injection needle having a function of converting the rotational force of the needle into propulsion by engraving a discontinuous and uniform trocar surface structure different from the spiral structure. It is intended to be provided. The present invention improves the difficulty in manufacturing of such a conventional example, and is technically easier to manufacture than the conventional example.
In addition, it has the feature that a decrease in the strength of the trocar and an increase in frictional resistance during insertion can be prevented.

[0004]

SUMMARY OF THE INVENTION The present invention has been devised so that anyone can easily insert a double injection needle, which has been conventionally required as skill and one of special techniques. In order to achieve this object, according to the first aspect of the present invention, in a dual injection needle including an inner needle and an outer trocar having the inner needle as a support, the force for rotating the outer trocar is reduced. A discontinuous structure that can be converted to a propulsion force is added to the surface tip of the trocar. Each basic structure has a configuration in which the working side or working surface is positioned obliquely with uniformity to the needle insertion direction.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, a discontinuous surface structure is formed in the distal end portion of the surface of the trocar 3, in which the working side or the working surface is positioned obliquely with uniformity in the insertion direction of the needle. When actually inserting a double injection needle, first, as shown in FIG. 2, the metal inner needle 1 serving as an induction needle is made to reach the blood vessel lumen 6. When the blood reaches the blood vessel lumen 6, blood flows backward through the inner needle inner hole (reference numeral 4 in FIG. 2), so that the operator can confirm that the inner needle 1 has reached the blood vessel lumen 6. Next, when the inner needle 1 and the outer trocar 3 are rotated together by half a turn, the tip cut surface of the inner needle 1 faces the direction of the blood vessel lumen 6 as shown in FIG. The contact with the trocar 3 is strengthened due to the linear contact. At this time, it is more convenient to rotate the outer needle 3 at the same time as the inner needle 1 is rotated. Therefore, a one-way engagement mechanism (lock mechanism) may be provided between the two needles. At this point, further insertion of the inner needle 1 is stopped and only the flexible trocar 3 is inserted into the vessel lumen 6. At this time, when only the outer trocar 3 is rotated, the outer trocar 3 is “only” as shown in FIG.
Slides into the blood vessel lumen 6. For this reason, the insertion of the inner needle 1 is minimized, and there is no need to insert the needle excessively enough to cause damage to the contralateral blood vessel wall 5. Also,
The surface structure 2 oblique to the insertion direction can prevent a situation in which the needle is pushed back and the inner needle 1 comes off the blood vessel wall 5. As shown in FIG. 5, a discontinuous trocar surface structure has a uniform working edge or surface.
Any structure may be used as long as it is positioned obliquely to the insertion direction, but the working side or working surface may be in any form such as straight line, curved line, continuous, discontinuous, raised, and depressed. If classified, FIG. 5 (a) projection type (membrane-like, scale-like, rod-like, protrusion, etc.), (b) depression type (depression, scratch, groove, depression, etc.), (c) mixed type (cut, Section, etc.), but the present invention is not limited to the above embodiment, and the discontinuous trocar surface structure is positioned obliquely with respect to the insertion direction with uniformity, so that the force for rotating the trocar is reduced. Any structure that can convert the driving force (insertion force) of the needle may be used.

[0006]

Since the present invention is constructed and functions as described above, according to this, when only the trocar is rotated, the trocar "only" is caused by a reaction to the working side of the oblique structure on the surface. It slides into the vessel lumen.
This reduces the risk of contralateral vascular wall damage from the inner needle,
Only the trocar is safely and easily inserted into the vessel lumen without damaging the vessel. That is, it is possible to provide an unprecedented superior double injection needle in which insertion of an indwelling needle, which has conventionally required skill, can be performed safely and easily, including for beginners. And furthermore, carving a discontinuous surface structure, compared to carving a continuous spiral structure,
Fabrication is technically easier because the need for strict continuous control is reduced. In addition, by adjusting the individual size of the discontinuous surface structure and the distribution density per unit area, it is possible to adjust to the insufficient strength of the trocar and the increase in frictional resistance during insertion. is there.

[Brief description of the drawings]

FIG. 1 is an external view (side view) of the present invention.

FIG. 2 is an explanatory diagram at the time when it is confirmed that the needle lumen at the distal end of the inner needle has communicated with the blood vessel lumen by blood backflow (4) in the inner needle at the time of blood vessel insertion.

[FIG. 3] When the inner needle and the outer trocar (indwelling needle) are rotated half a turn together on the spot, the side surface of the inner needle comes into linear contact with the blood vessel wall, and is firmly used as a support for guiding the outer trocar (indwelling needle). FIG.

FIG. 4 is a view for explaining that only the trocar is safely inserted into the lumen of the blood vessel by the action of the surface structure and the blood vessel wall by rotating the trocar.

FIG. 5 is a classification diagram for explaining types of discontinuous surface structures cut into the trocar. A surface pattern and a cross-sectional view of each classification are illustrated, and the insertion direction of the needle is on the left side of the paper (←), and the bold line indicates an operation side or an operation surface.

[Explanation of symbols]

 1 is an inner needle 2 is a surface structure in which a working side is obliquely added to the insertion direction 3 is a trocar (indwelling needle) 4 is a backflow of blood from the trailing edge of the inner needle lumen 5 is a blood vessel wall 6 is an intravascular Cavity

Claims (1)

[Claims] 1. A double injection needle comprising an inner needle and an outer trocar supporting the inner needle, wherein a discontinuous structure is added to a distal end portion of the outer trocar surface. Each basic structure has a structure in which the working side or working surface is positioned obliquely with uniformity to the needle insertion direction. For this purpose, the working side or the working surface has a function of converting a force for rotating the trocar into a propulsive force of the needle.