JP2022076674A - Medical needle - Google Patents

Abstract

To provide a medical needle that has a reduced level of pain given to a living body when penetrating the living body.SOLUTION: A medical needle has a rod-like body 2, a taper 3 that is in communication with one end side of the body and has a section with its cross-sectional area decreasing as the taper goes away from one end of the body along a longitudinal direction A of the body, and a needle tip 4 overlapping the taper. The needle tip has a first blade face 40 and a second blade face 41 crossing each other to form a peak 42. The peak has a ridge 43 to form an edge 44. The edge is inclined to be displaced in a radial direction of the body as the edge goes in the longitudinal direction. The edge extends to a point of the needle tip of in the longitudinal direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a medical needle.

It is preferable that the puncture needle can easily penetrate the living body and the degree of pain at the time of penetration is as small as possible. As such a puncture needle, for example, a needle in which the apex portion of a substantially conical shape is cut at a certain angle and a cut surface having an acute angle with respect to its own axial direction is formed at the tip has been proposed (for example,). See Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-194731

However, since the puncture needle has one cut surface, the tip is composed of a cut surface and a conical surface continuous with the cut surface in the circumferential direction. Further, the cutting edge is formed at the tip of the puncture needle and has a curved surface shape that is convex toward the tip side. Therefore, there is a problem in the sharpness of the cutting edge of the tip, and in particular, in Patent Document 1, it is said that it is difficult to incise a tissue, particularly a peritoneum, etc. without ultrasonic vibration by the puncture needle. (See paragraph (0012) of Patent Document 1).

In view of such circumstances, the present invention aims to provide a medical needle that minimizes damage to blood vessels when penetrating a living body and significantly suppresses the amount of bleeding.

The present invention has been made to solve the above problems, and the medical needle of the present invention is continuous with a rod-shaped main body portion and one end side of the main body portion, and is said to be continuous along the longitudinal direction of the main body portion. A tapered portion having a section in which the cross-sectional area decreases as the distance from the one end of the main body portion increases, and a needle tip portion superimposing on the tapered portion, the needle tip portions intersect with each other to form a peak portion. It has one blade surface and a second blade surface, and is characterized in that the cutting edge is formed by the ridge line of the peak portion.

The medical needle of the present invention is characterized in that the cutting edge is inclined so as to be displaced in the radial direction of the main body portion as it advances in the longitudinal direction.

In the medical needle of the present invention, the needle tip portion is characterized by having a portion having a triangular or fan-shaped cross-sectional shape orthogonal to the longitudinal direction.

The medical needle of the present invention is characterized in that the cutting edge extends to the tip of the needle tip in the longitudinal direction.

The medical needle of the present invention is characterized in that the maximum length of the cutting edge in the radial direction is 1/3 or less of the maximum length of the tapered portion in the radial direction.

The medical needle of the present invention is characterized in that the length of the cutting edge in the longitudinal direction is 1/4 or less of the length of the tapered portion and the needle tip portion in the longitudinal direction.

The inclination angle θ1 of the cutting edge with respect to the longitudinal direction is in the range of 15 degrees to 55 degrees.

In the medical needle of the present invention, when the needle tip portion is viewed in a plan view from the front side of the tip end of the needle tip portion in the longitudinal direction, the angle formed by the perpendiculars of the first blade surface and the second blade surface is formed. θ5 is characterized in that it is in the range of 90 degrees to 150 degrees.

In the medical needle of the present invention, the conical surface when the peripheral surface of the tapered portion, which is at least partially formed in a conical trapezoidal shape, is extended to the needle tip portion is formed by a virtual conical surface and the virtual conical surface. When the cone is defined as a virtual cone and the central axis of the virtual cone is defined as the virtual central axis, the inclination angle θ6 of the bus of the virtual cone with respect to the virtual central axis is within the range of 7.5 degrees to 15 degrees. It is characterized by being.

In the medical needle of the present invention, the conical surface when the peripheral surface of the tapered portion, which is at least partially formed in a conical trapezoidal shape, is extended to the needle tip portion is formed by a virtual conical surface and the virtual conical surface. When the cone is defined as a virtual cone and the central axis of the virtual cone is defined as the virtual central axis, the inclination angle θ3 with respect to the virtual central axis of the first blade surface and the second blade surface is the virtual central axis. It is characterized in that it is larger than the inclination angle θ6 of the bus of the virtual cone as a reference.

The medical needle of the present invention is characterized in that the friction coefficient on the surface of the tapered portion is 0.3 or less.

The medical needle of the present invention is characterized in that the cutting edge extends in parallel in a direction orthogonal to the longitudinal direction.

In the medical needle of the present invention, the needle tip portion intersects the first blade surface and the second blade surface, and further forms a third blade surface having two ridges having each ridge line as the blade edge. It is characterized by having.

The medical needle of the present invention is characterized in that at least one of the first blade surface and the second blade surface is a concave curved surface or a flat surface.

According to the medical needle of the present invention, it is possible to obtain an excellent effect that the damage of blood vessels when penetrating the living body can be minimized and the amount of bleeding can be significantly suppressed.

(A) is a perspective view of a medical needle according to the first embodiment of the present invention. (B) is an enlarged view of the tip end side of the medical needle in the first embodiment of the present invention. (A) is a plan view of a medical needle according to the first embodiment of the present invention. (B) is a bottom view of a medical needle according to the first embodiment of the present invention. (C) is a side view of a medical needle according to the first embodiment of the present invention. (A) is a cross-sectional view of a tapered portion of a medical needle according to the first embodiment of the present invention. (B) is a cross-sectional view of a needle tip portion of a medical needle in the first section of the first embodiment of the present invention. (C) is a cross-sectional view of a second section of a needle tip portion of a medical needle according to the first embodiment of the present invention. The upper figure is a front view of the medical needle in the first embodiment of the present invention. The lower figure is the B arrow view of the upper figure. (A) is a front view which changed the aspect of the cutting edge of the medical needle in 1st Embodiment of this invention. (B) is a plan view of a modified state of the cutting edge of a medical needle according to the first embodiment of the present invention. (A) is a front view which changed the aspect of the cutting edge of the medical needle in 1st Embodiment of this invention. (B) is a plan view of a modified state of the cutting edge of a medical needle according to the first embodiment of the present invention. (A) is a plan view of the first and second blade surfaces of the medical needle according to the first embodiment of the present invention. (B) is a side view of the first blade surface and the second blade surface of the medical needle in the first embodiment of the present invention changed. It is a table which shows each value of θ1 to θ6, α1, F1, F2, R1, R2 of 9 kinds of medical needles in 1st Embodiment of this invention. (A) to (J) are side views of nine types of medical needles in the first embodiment of the present invention corresponding to the table of FIG. 8, respectively. (A) is a perspective view of a medical needle in the second embodiment of the present invention. (B) is a plane (bottom) view of a medical needle according to the second embodiment of the present invention. (C) is a side view of a medical needle according to the second embodiment of the present invention. (A) is a front view of the medical needle in the second embodiment of the present invention. (B) is a cross-sectional view of a needle tip portion of a medical needle according to the second embodiment of the present invention. (A) is a perspective view of a medical needle in the third embodiment of the present invention. (B) is a plan view of a medical needle according to the third embodiment of the present invention. (C) is a bottom view of the medical needle according to the third embodiment of the present invention. (A) is a front view of the medical needle in the third embodiment of the present invention. (B) is a front view of the modified example of the medical needle in the third embodiment of the present invention. (A) is a sectional view in the first section of the needle tip portion of the medical needle in the third embodiment of the present invention. (B) is a cross-sectional view of a second section of a needle tip portion of a medical needle according to a third embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The medical needle of the present invention corresponds to, for example, a puncture needle or the like, but it can also be applied to other medical needles.

<First Embodiment>
The medical needle 1 in the first embodiment of the present invention will be described. Examples of the material of the medical needle 1 in the present embodiment include stainless steel such as SUS304, or other metals and alloys. As shown in FIG. 1A, the medical needle 1 in the present embodiment has a main body portion 2, a tapered portion 3, and a needle tip portion 4.

<Main body>
The main body 2 is formed in a rod shape. In the present embodiment, the main body portion 2 extends linearly. The main body portion 2 has a first large diameter portion 20, a small diameter portion 21, a second large diameter portion 22, and a connecting portion 23. The main body portion 2 is continuously formed in the order of the first large diameter portion 20, the small diameter portion 21, the second large diameter portion 22, and the connecting portion 23 in the longitudinal direction A of the main body portion 2. The longitudinal direction A of the main body 2 in the present embodiment coincides with the longitudinal direction of the medical needle 1, and hereinafter, they are simply referred to as the longitudinal direction A. In the medical needle 1, the side of the needle tip portion 4 in the longitudinal direction A is referred to as the tip end side, and the side opposite to the tip end side is referred to as the proximal end side.

The first large diameter portion 20 and the second large diameter portion 22 are coaxial with each other and are formed in a columnar shape having the same diameter. The small diameter portion 21 is provided between the first large diameter portion 20 and the second large diameter portion 22 so as to be continuous with the first large diameter portion 20 and the second large diameter portion 22, and the first large diameter portion 20 and the second large diameter portion 22 are provided. The diameter is smaller than the two large diameter portions 22. Specifically, the small diameter portion 21 is formed in a tapered shape in the both end side sections continuous to each of the first large diameter portion 20 and the second large diameter portion 22, and in the central section between the both end side sections. , It is formed in a columnar shape with a constant diameter. The small diameter portion 21 is also coaxial with the first large diameter portion 20 and the second large diameter portion 22. The radial direction R of the main body 2 in the present embodiment coincides with the radial direction of the medical needle 1, and hereinafter, they are simply referred to as the radial direction R.

In addition, for example, another small diameter portion (not shown) continuous with the second large diameter portion 22 on the proximal end side of the second large diameter portion 22 in the longitudinal direction A, and the proximal end side of the small diameter portion in the longitudinal direction A. In, a third large diameter portion (not shown) continuous with the small diameter portion may be provided. Further, similarly, a plurality of different small diameter portions and large diameter portions may be provided. When the main body 2 is bent, the main body 2 is bent at a small diameter portion. Therefore, if there are a plurality of small diameter portions, it is easy to shape the medical needle 1 into various shapes.

Further, as shown in FIG. 1A, at least one linear or strip-shaped groove 24 extending in the longitudinal direction A is provided on the surface of at least one of the first large diameter portion 20 and the second large diameter portion 22. It may be formed. This is because if the groove 24 is provided, the contact area between the main body 2 and the living body can be reduced when the medical needle 1 is inserted into the living body. In that sense, it is preferable that a plurality of the grooves 24 are provided.

The connecting portion 23 extends in the longitudinal direction A from the base end 22A of the second large diameter portion 22 distal to the small diameter portion 21, and has three annular steps 23A extending in the longitudinal direction A on the peripheral surface. Have. The annular step 23A goes around the circumferential direction of the connecting portion 23, respectively. By inserting the connecting portion 23 into the hole 61 of the pipe 60, the pipe 60 and the main body portion 2 are connected.

<Tapered part>
As shown in FIGS. 1 (B) and 2 (A) to (C), the tapered portion 3 is continuous with one end 2A side of the main body portion 2 and from one end 2A of the main body portion 2 along the longitudinal direction A. It has a section (hereinafter, referred to as a section for reducing the cross-sectional area) in which the cross-sectional area decreases as the distance progresses in the direction away (the tip side direction A1 in the longitudinal direction A). In the present embodiment, the entire section of the tapered portion 3 is a section where the cross-sectional area is reduced, but the present invention is not limited to this, and a part of the section of the tapered portion 3 may be a section where the cross-sectional area is reduced. Examples of the section other than the section where the cross-sectional area decreases include a section where the cross-sectional area is constant and a section where the cross-sectional area increases.

In the present embodiment, when the tapered portion 3 is divided into sections in the longitudinal direction A, the shape of the tapered portion 3 differs depending on the section. That is, as shown in FIGS. 2A to 2C, the tapered portion 3 in the present embodiment has a first section S1 on which the tapered portion 3 and the needle tip portion 4 are superimposed in order from the tip side, and the first section described later. It has a second section S2 in which an outer peripheral surface is formed by a blade surface 40, a second blade surface 41 and other curved surfaces, and a remaining third section S3 having a truncated cone shape. In the present embodiment, the cross-sectional shape of the tapered portion 3 orthogonal to the longitudinal direction A is fan-shaped (the side corresponding to the base is the needle tip) in the first section S1 (cross section 4S1) as shown in FIG. 3 (C). A triangle that is a convex curve on the outer side of the portion 4), and in the second section S2 (cross section 3S2), as shown in FIG. It becomes a trapezoid (quadrangle), and in the third section S3 (cross section 3S3), it becomes a circle as shown in FIG. 3 (A).

Further, it is preferable that the friction coefficient of the surface of the tapered portion 3 is small. This is to make the tapered portion 3 slippery with respect to the living body. When the taper portion 3 is made of SUS304, the coefficient of friction is usually about 0.6. In the present embodiment, the surface of the tapered portion 3 is subjected to a mirror finish treatment, a Teflon (registered trademark) coating, a PLL coating, or the like to reduce the friction coefficient to 0.3 or less.

<Needle tip>
As shown in FIGS. 1 (B) and 2 (A) to 2 (C), the needle tip portion 4 forms the needle tip of the medical needle 1, and is tapered in the first section S1 of the tapered portion 3. It is provided so as to be superimposed on the unit 3. Specifically, the needle tip portion 4 is continuous with the second section S2 of the tapered portion 3, and the cross-sectional area becomes smaller as it advances along the longitudinal direction A toward the tip 4A of the tapered portion 3 (the tip side direction A1 in the longitudinal direction A). Become. In the present embodiment, the entire section of the needle tip portion 4 (first section S1) is a section where the cross-sectional area is reduced, but the section is not limited to this, and a part section of the needle tip portion 4 (first section S1) is. It may be an embodiment in which the cross-sectional area is reduced. Examples of the section other than the section where the cross-sectional area decreases include a section where the cross-sectional area is constant and a section where the cross-sectional area increases. The above is the same in other embodiments. The tip 4A of the needle tip 4 is sharp. The boundary K2 between the second section S2 and the third section S3 of the tapered portion 3 shown in FIGS. 2A to 2C is the inner edge of the first blade surface 40 and the second blade surface 41 (for example,). , The innermost point 40B of the first blade surface 40, and the innermost point 41B of the second blade surface 41) are connected, and is orthogonal to the virtual central axis DA. Here, the conical surface formed when the peripheral surface of the third section S3 of the tapered portion 3 forming the conical trapezoidal shape is extended toward the needle tip portion 4 is formed by the virtual conical surface C and the virtual conical surface C. When the cone is defined as the virtual cone D, the virtual central axis DA refers to the central axis of the virtual cone D. Further, in the present embodiment, the generatrix of the virtual cone D is a straight line, but is not limited to this, a concave curve dented inward, a convex curve convex outward, a curve in which they are mixed, and other curves. It may be all curves or lines in which curves and straight lines are mixed.

Further, as shown in FIGS. 1B and 2A to 2C, the needle tip portion 4 has a first blade surface 40 and a second blade surface 41 on the peripheral surface of the needle tip portion 4. And have. The first blade surface 40 and the second blade surface 41 intersect with each other to form a peak portion 42. Further, the peak portion 42 extends to the tip 4A of the needle tip portion 4.

The ridge line 43 of the peak portion 42 constitutes the cutting edge 44. Therefore, the cutting edge 44 also extends to the tip 4A of the needle tip portion 4. Further, as shown in FIG. 2C, the cutting edge 44 is inclined with respect to the longitudinal direction A so as to be displaced in the radial direction R as it advances in the longitudinal direction A. The cutting edge 44 has an inclination angle θ1 (0 degree <θ1 <90 degree) with respect to the virtual central axis DA. The inclination angle θ1 is preferably in the range of, for example, 15 degrees to 55 degrees (28.19 degrees in this embodiment), more preferably in the range of 15 degrees to 30 degrees, and in the range of 20 degrees to 30 degrees. More preferred. Then, as shown in FIG. 2C, the cutting edge 44 intersects with the virtual central axis DA, passes through it, or extends so as to straddle it.

The maximum length R1 (see FIG. 2C) of the cutting edge 44 in the radial direction R is preferably 1/3 or less of the maximum length R2 in the radial direction R of the tapered portion 3, and the maximum length R2. It is more preferably 1/4 or less, and further preferably 1/5 or less of the maximum length R2. In the present embodiment, the maximum length R2 of the tapered portion 3 in the radial direction is the radial length of the tapered portion 3 at the boundary K1 between the main body portion 2 and the tapered portion 3 (see FIG. 2C). Point to. Further, the length F1 of the cutting edge 44 in the longitudinal direction A (see FIG. 2C) may be 1/3 or less of the length F2 of the tapered portion 3 in the longitudinal direction A (see FIG. 2C). It is more preferably 1/4 or less of the length F2, and further preferably 1/5 or less of the length F2. As described above, if the size of the cutting edge 44 is configured, the size of the cutting edge 44 can be reduced with respect to the tapered portion 3, so that the cutting edge 44 comes into contact with the skin when the cutting edge 44 cuts through the patient's skin. The length to be used can be reduced. As a result, damage to blood vessels can be minimized and the amount of bleeding can be significantly reduced.

Further, in the present embodiment, the section provided with the cutting edge 44 (peak portion 42) corresponds to the first section S1 (needle tip portion 4). Then, as shown in FIGS. 2A to 2C, in the first section S1, the peripheral surfaces of the needle tip portion 4 are the first blade surface 40, the second blade surface 41, and the first peripheral surface 45. And. In the present embodiment, the first blade surface 40 and the second blade surface 41 are flat surfaces, but the present invention is not limited to this, and the first blade surface 40 and the second blade surface 41 are on the outer side (diametrical outside) of the needle tip portion 4 (tapered portion 3). It may be a curved surface that is convex, a curved surface that is concave on the inner side (inward in the radial direction) of the needle tip portion 4 (tapered portion 3), or a surface that includes both the above flat surface and the curved surface. In particular, if either the first blade surface 40 or the second blade surface 41 is formed of a curved surface that is concave on the inner side (inward in the radial direction) of the needle tip portion 4 (tapered portion 3), the peak portion 42 is formed. The slope can be steep and the apex angle of the cutting edge 44 can be reduced. As a result, the cutting edge 44 is formed sharper than when it is composed of a flat surface. Further, in the present embodiment, the first peripheral surface 45 is a curved surface (for example, a part of the virtual conical surface C) that is convex toward the outer side (diameter outside) of the needle tip portion 4 (tapered portion 3). The present invention is not limited to this, but is a flat surface, a curved surface that is concave on the inner side (inward in the radial direction) of the needle tip portion 4 (tapered portion 3), or a surface that includes both the above flat surface and the curved surface. There may be.

The first blade surface 40, the second blade surface 41, and the first peripheral surface 45 are continuously connected in the circumferential direction of the needle tip portion 4 to form a conical surface in the first section S1. That is, in the first section S1 in the present embodiment, as shown in FIG. 3C, the shape of the cross section 4S1 of the needle tip portion 4 orthogonal to the longitudinal direction A is fan-shaped (the side corresponding to the bottom is the needle tip portion). It becomes a triangle that becomes a convex curve on the outer side of 4. The circumferential direction of the needle tip portion 4 refers to the direction around the central axis 4C of the needle tip portion 4 that coincides with the virtual central axis DA.

Further, the apex angle α1 of the cross section 4S1 of the needle tip portion 4 shown in FIG. 3C corresponds to the apex angle of the peak portion 42 on the projection plane when the peak portion 42 is projected in the longitudinal direction A. That is, the apex angle α1 shown in FIG. 3C corresponds to the apex angle of the peak portion 42 when the peak portion 42 is viewed in a plan view from the longitudinal direction A. The apex angle α1 of the cross section 4S1 of the needle tip portion 4 is preferably in the range of, for example, 30 degrees to 90 degrees (60 degrees in this embodiment), and more preferably in the range of 40 degrees to 80 degrees. .. The apex angle of the peak portion 42 is determined by an angle corresponding to the angles θ2 and θ3 described later.

Further, the second section S2 is a section from the end edge 441 on the inner side of the cutting edge 44 to the boundary K2. That is, the second section S2 refers to a section of the tapered portion 3 including the first blade surface 40 and the second blade surface 41, which does not include the cutting edge 44. In the second section S2 in the present embodiment, as shown in FIGS. 2A to 2C, the peripheral surfaces of the tapered portion 3 are the first blade surface 40, the second blade surface 41, and the second peripheral surface. It is composed of 46 and a third peripheral surface 47. The first blade surface 40, the second peripheral surface 46, the second blade surface 41, and the third peripheral surface 47 are continuously connected in the circumferential direction of the tapered portion 3 in order, and a partial conical surface is formed in the second section S2. To configure. The partial conical surface refers to a surface of a part of the conical surface excluding the section including the apex of the conical surface. That is, the second peripheral surface 46 and the third peripheral surface 47 are connected to the first blade surface 40 and the second blade surface 41 between the first blade surface 40 and the second blade surface 41, respectively. Then, in the second section S2 in the present embodiment, as shown in FIG. 3B, in the cross section 3S2 of the tapered portion 3 orthogonal to the longitudinal direction A, the sides corresponding to the upper base and the lower base are convex outward. It becomes a trapezoid (quadrangle) that becomes a curve. The sides corresponding to the upper base and the lower base correspond to the second peripheral surface 46 and the third peripheral surface 47. Further, in the present embodiment, the second peripheral surface 46 and / or the third peripheral surface 47 is a curved surface (for example, a part of the virtual conical surface C) that is convex toward the outer side (diametrically outer side) of the tapered portion 3. However, the present invention is not limited to this, and may be a flat surface, a curved surface that is concave on the inner side (inward in the radial direction) of the tapered portion 3, or a surface that includes both the above flat surface and the curved surface. ..

Next, for the explanation of the first blade surface 40 and the second blade surface 41, as shown in FIG. 2A, the virtual central axis DA and the ridge line 43 are completely overlapped with each other so as to be orthogonal to the longitudinal direction A. When the needle tip portion 4 is viewed in a plan view from the visible direction, the direction orthogonal to the longitudinal direction A is defined as the width direction W, and the direction orthogonal to the width direction W is defined as the height direction H (see FIG. 2C). do. The upper part of FIG. 4 is a plan view of the medical needle 1 in the present embodiment in the longitudinal direction A from the tip 4A side. As shown in the upper part of FIG. 4, when the medical needle 1 is viewed in a plan view from the tip 4A side in the longitudinal direction A, the first blade surface 40 and the second blade surface 41 intersecting the central axis 4C of the needle tip portion 4. The angle formed by the direction in which the respective perpendicular lines P (40) and P (41) are projected on the plane and the width line WA extending in the width direction W and intersecting the central axis 4C of the needle tip portion 4 is The angle θ2. That is, the angle formed by the direction in which the perpendicular line P (40) is projected on the plane and the direction in which the perpendicular line P (41) is projected on the plane is an angle θ5 (θ5 = 180-2θ2). The angle θ2 is preferably in the range of, for example, 20 degrees to 40 degrees (30 degrees in this embodiment). That is, the angle θ5 is preferably in the range of, for example, 100 degrees to 140 degrees (120 degrees in this embodiment).

Similarly, when the medical needle 1 is viewed in a plan view, it faces the central axis 4C of the needle tip portion 4 and counterclockwise with respect to the perpendicular line P (41) (at the end edge 441 on the back side of the cutting edge 44). The lower view of FIG. 4 shows a plan view of the medical needle 1 as viewed from the direction B forming an angle θ4 (90 degrees in this embodiment) in the direction of rotation on the approaching side. At this time, as shown in the lower diagram of FIG. 4, the second blade surface 41 appears to extend in the direction perpendicular to the paper surface, and is therefore drawn as a line L. The line L (second blade surface 41) extends along the longitudinal direction A toward the tip 4A of the needle tip portion 4 (the tip side direction A1 in the longitudinal direction A) so as to approach the virtual central axis DA. At this time, the inclination angle of the line L corresponding to the second blade surface 41 with respect to the virtual central axis DA (central axis 4C of the needle tip portion 4) is the angle θ3. The angle θ3 is preferably in the range of, for example, 12 degrees to 25 degrees (15 degrees in this embodiment), and more preferably in the range of 12 degrees to 15 degrees. The above is the same for the first blade surface 40.

When the virtual cone D is cut to provide the first blade surface 40 and the second blade surface 41, the virtual cone D is cut so as to satisfy the above conditions. That is, if the virtual cone D is cut so that the line L (second blade surface 41) is inclined by an angle θ3 with respect to the virtual center axis DA, the first blade surface 40 and the second blade surface 41 are formed. At this time, as a matter of course, as shown in the lower diagram of FIG. 4, the angle θ3 is larger than the inclination angle θ6 of the generatrix of the virtual cone D with respect to the virtual central axis DA of the virtual cone D (side CA). The inclination angle θ6 is preferably in the range of, for example, 7 degrees to 15 degrees (10 degrees in this embodiment), more preferably in the range of 7.5 degrees to 13 degrees, and more preferably 8 degrees to 13 degrees. It is more preferably in the range of 12 degrees.

When the medical needle 1 in the present embodiment penetrates the skin of a living body, first, the tip 440 of the cutting edge 44 of the needle tip portion 4 comes into contact with the skin and penetrates the skin. Then, subsequently, when the inclined cutting edge 44 in the first section S1 moves in the penetrating direction and passes through the skin, the cut end of the living body is cut open in the direction orthogonal to the penetrating direction. Further, subsequently, when the tapered portion 3 in the second section S2 and the third section S3 passes through the skin, the cut end of the living body is pushed around. In the present embodiment, since the size of the cutting edge 44 can be reduced with respect to the tapered portion 3, damage to blood vessels can be minimized and the amount of bleeding can be significantly suppressed.

In the above, as shown in FIG. 2A, the needle tip portion 4 is orthogonal to the longitudinal direction A and is seen to overlap the virtual central axis DA and the ridge line 43 (directly above the ridge line 43 (cutting edge 44)). When the ridge line 43 (blade edge 44) is viewed in a plan view, the ridge line 43 (blade edge 44) coincides with the virtual central axis DA. However, the present invention is not limited to this, and as shown in FIGS. 5 and 6, the ridge line 43 (blade edge 44) of the peak portion 42 is virtual in the first blade surface 40 and the second blade surface 41. It may be formed so as to deviate from the central axis DA.

For example, as shown in FIG. 5A, when the needle tip portion 4 is viewed in a plan view from the front side of the tip 4A of the needle tip portion 4 in the longitudinal direction A, the ridge line 43 (blade tip 44) has a width direction W and a height. It may also be inclined with respect to the vertical direction H. In this case, when the ridge line 43 (cutting edge 44) of the needle tip portion 4 is viewed in a plan view from directly above the ridge line 43 (cutting edge 44) in the same manner as described above, the ridge line 43 (cutting edge 44) is shown in FIG. Inclines and extends so as to intersect the virtual central axis DA. Further, as shown in FIG. 6A, the ridge line 43 (cutting edge 44) is formed so as to be in a posture parallel to the height direction H at a position deviated from the virtual central axis DA in the width direction W. May be good. In this case, when the needle tip portion 4 is viewed in a plan view from directly above the ridge line 43 (cutting edge 44) in the same manner as described above, the ridge line 43 (cutting edge 44) becomes the virtual central axis DA as shown in FIG. 6 (B). On the other hand, it is located at a position moved in parallel with the width direction W. Such things are also included in the scope of the present invention.

Further, as shown in FIGS. 7A and 7B, in the medical needle 1 in the present embodiment, the first blade surface 40 and the second blade surface 41 extend to the main body portion 2 in the tapered portion 3. May be good. In this case, the third section S3 disappears from the tapered portion 3, and only the first section S1 and the second section S2 are formed. The needle tip portion 4 is formed in the first section S1. Such things are also included in the scope of the present invention.

<Example>
The inventor of the present application created nine types of medical needles 1 by changing θ1 to θ6, α1, F1, F2, R1 and R2 described above. In the table shown in FIG. 8, each value of θ1 to θ6, α1, F1, F2, R1 and R2 corresponding to the medical needle 1 of Nos. 1 to 9 is described. The medical needles 1 of Nos. 1 to 9 created based on these are drawn in order in FIGS. 9A to 9I.

Looking at the medical needles 1 of Nos. 1 to 9 shown in FIGS. 9A to 9I, the size of the cutting edge 44 is smaller than that of the tapered portion 3, and all of them are preferable as the medical needle 1. Further, when the values of (F1 / F2) shown in FIG. 8 are compared from the viewpoint of reducing the size of the cutting edge 44 with respect to the tapered portion 3, the values of No. 1 to 7 and 9 are higher than the values of the medical needle 1 of No. 8. The value of the medical needle 1 is preferable, and among them, the value of the medical needle 1 of Nos. 1 to 7 is more preferable. Further, when comparing the values of (R1 / R2) shown in FIG. 8 from the same viewpoint, the values of the medical needles 1 of No. 1 to 8 are preferable to the values of the medical needle 1 of No. 9, and among them, No. 1 is particularly preferable. The value of the medical needle 1 of about 7 is more preferable. Further, when the inclination angle θ1 of the cutting edge 44 with respect to the virtual central axis DA is small, the cutting edge 44 becomes sharper and the burden on the living body can be suppressed. From this point of view, the medical needles 1 to 4, 6, 8 and 9 are preferable to the medical needles 1 of Nos. 5 and 7. Considering the above, it can be said that the medical needles 1 of Nos. 1 to 9 are all preferable embodiments, and among them, the medical needles 1 of Nos. 1 to 4 and 6 are more preferable than the other medical needles 1.

<Second embodiment>
The medical needle 1 in the second embodiment of the present invention will be described. As shown in FIG. 10A, the medical needle 1 in the present embodiment has a main body portion 2, a tapered portion 3, and a needle tip portion 4. Since the main body portion 2 and the tapered portion 3 in the present embodiment are the same as those in the first embodiment, the description thereof will be omitted.

<Needle tip>
As shown in FIGS. 10A to 10C, the needle tip portion 4 in the present embodiment forms the needle tip of the medical needle 1 and is provided so as to be superimposed on the tapered portion 3. Specifically, the needle tip portion 4 is superimposed on the tapered portion 3 at the tip of the medical needle 1. Further, the first blade surface 40 and the second blade surface 41 in the present embodiment intersect with each other to form the peak portion 42, as in the case of the first embodiment. This point is the same as that in the first embodiment.

However, the first blade surface 40 and the second blade surface 41 in the present embodiment intersect at the tip 4A of the needle tip portion 4 as shown in FIGS. 10 (A) to 10 (C) and FIG. 11 (A). The point is different from that in the first embodiment in that the ridge portion 42 in which the ridge line 43 extends parallel to the radial direction R or the ridge portion 42 in which the ridge line 43 is orthogonal to the virtual central axis DA is formed. Further, the peak portion 42 and its ridge line 43 (cutting edge 44) extend in parallel to the radial direction R at the tip 4A of the medical needle 1. Therefore, in the present embodiment, the first section S1 described in the first embodiment corresponds to the tip. When the virtual cone D is cut to provide the first blade surface 40 and the second blade surface 41, the virtual cone D is cut so as to satisfy the above conditions.

Further, the apex angle α2 of the peak portion 42 in the present embodiment is preferably in the range of, for example, 40 degrees to 80 degrees, as in the apex angle α1 in the first embodiment.

Further, the maximum length R3 of the cutting edge 44 in the radial direction R3 (see FIG. 10C) in the present embodiment is preferably 1/3 or less of the maximum length R4 in the radial direction R of the tapered portion 3. It is more preferably 1/4 or less of the maximum length R4, and further preferably 1/5 or less of the maximum length R4. In the present embodiment, the maximum length R4 of the tapered portion 3 in the radial direction is the radial length of the tapered portion 3 at the boundary K1 between the main body portion 2 and the tapered portion 3 (see FIG. 10C). Point to. As described above, if the size of the cutting edge 44 is configured, the size of the cutting edge 44 can be reduced with respect to the tapered portion 3, so that the cutting edge 44 comes into contact with the skin when the cutting edge 44 cuts through the patient's skin. The length to be used can be reduced. As a result, damage to blood vessels can be minimized and the amount of bleeding can be significantly reduced.

Further, in the present embodiment, the second section S2 is a section from immediately after the tip 4A of the medical needle 1 to the boundary K2. In the second section S2, the peripheral surface of the tapered portion 3 is composed of a first blade surface 40, a second blade surface 41, a first peripheral surface 48A, and a second peripheral surface 48B. In the present embodiment, the first blade surface 40 and the second blade surface 41 are flat surfaces, but the present invention is not limited to this, and the tapered portion 3 is a curved surface that is convex toward the outside (diameter outside) or a curved surface. , A curved surface that is concave on the inner side (inward in the radial direction) of the tapered portion 3, or a surface that includes the above planes and curved surfaces. In particular, if either the first blade surface 40 or the second blade surface 41 is formed of a curved surface that is concave on the inner side (inward in the radial direction) of the tapered portion 3, the peak portion 42 may have a steep slope. The apex angle of the cutting edge 44 can be reduced. As a result, the cutting edge 44 is formed sharper than when it is composed of a flat surface. Further, in the present embodiment, the first peripheral surface 48A and / or the second peripheral surface 48B is a curved surface that is convex toward the outer side (diametrically outer side) of the tapered portion 3, but is not limited to this, and is a flat surface. , Or a curved surface that is concave on the inner side (inward in the radial direction) of the tapered portion 3, or a surface that includes both the above flat surface and the curved surface.

The first blade surface 40, the second blade surface 41, the first peripheral surface 48A, and the second peripheral surface 48B are continuously connected in the circumferential direction of the tapered portion 3 to form a conical surface. That is, the first peripheral surface 48A and the second peripheral surface 48B are connected to the first blade surface 40 and the second blade surface 41 between the first blade surface 40 and the second blade surface 41, respectively. Then, as shown in FIG. 11B, in the cross section 3S2 in the second section S2 of the tapered portion 3 orthogonal to the longitudinal direction A, the pair of opposite sides becomes a curve convex to the outer side of the tapered portion 3, and the remaining opposite sides. Becomes a quadrangle with a straight line. The curve corresponds to the first peripheral surface 48A and the second peripheral surface 48B, and the straight line corresponds to the first blade surface 40 and the second blade surface 41.

When the medical needle 1 in the present embodiment penetrates the skin of a living body, first, the cutting edge 44 of the needle tip portion 4 comes into contact with the skin and penetrates the skin. Then, as the tapered portion 3 passes through the skin, the cut end of the living body is subsequently pushed around. In the present embodiment, since the size of the cutting edge 44 can be reduced with respect to the tapered portion 3, damage to blood vessels can be minimized when the skin is torn, and the amount of bleeding can be significantly suppressed.

<Third embodiment>
The medical needle 1 in the third embodiment of the present invention will be described. As shown in FIG. 12A, the medical needle 1 in the present embodiment has a main body portion 2, a tapered portion 3, and a needle tip portion 4. Since the main body portion 2 and the tapered portion 3 in the present embodiment are the same as those in the first embodiment, the description thereof will be omitted.

As shown in FIGS. 12A to 12C, the needle tip portion 4 in the present embodiment forms the needle tip of the medical needle 1 and is provided so as to be superimposed on the tapered portion 3. Specifically, the needle tip portion 4 is superimposed on the tapered portion 3 in the first section S1 of the tapered portion 3. .. This point is the same as that in the first embodiment.

As shown in FIGS. 12 (A) to 12 (C) and FIG. 13 (A), the needle tip portion 4 in the present embodiment includes not only the first blade surface 40 and the second blade surface 41 but also the third blade surface 49. Has. This point is different from other embodiments. The first blade surface 40 and the second blade surface 41 intersect with each other to form a peak portion 42A. The first blade surface 40 and the third blade surface 49 intersect with each other to form a peak portion 42B. The second blade surface 41 and the third blade surface 49 intersect with each other to form the peak portion 42C. As shown in FIGS. 12A to 12C, the peak portions 42A to 42C are convex toward the tip end side direction A1 in the longitudinal direction A and outward in the radial direction R. Further, the peak portions 42A to 42C extend to the tip 4A of the needle tip portion 4.

The ridges 43A to 43C of the peaks 42A to 42C form the cutting edges 44A to 44C. Therefore, the cutting edges 44A to 44C extend to the tip 4A of the needle tip portion 4 and intersect at the tip 4A of the needle tip portion 4. In the present embodiment, as shown in FIG. 13A, the cutting edges 44A to 44C intersect the virtual central axis DA at the tip 4A of the needle tip portion 4, respectively, but the present invention is not limited to this, and FIG. As shown in (B), the tip 4A of the needle tip portion 4 may not intersect the virtual central axis DA but may intersect at a position deviated from the virtual central axis DA.

Further, as shown in FIGS. 12 (B) and 12 (C), the cutting edges 44A to 44C are inclined with respect to the longitudinal direction A so as to be displaced in the radial direction R toward the longitudinal direction A. The cutting edges 44A to 44C each have an inclination angle with respect to the virtual central axis DA (length direction A). FIG. 12C shows the inclination angles θ1B and θ1C (0 degrees <θ1B <90 degrees, 0 degrees <θ1C <90 degrees) corresponding to the cutting edges 44B and 44C. The inclination angles corresponding to the cutting edges 44A to 44C may be the same or different. It is preferable that each inclination angle corresponding to the cutting edge 44A to 44C is in the same range as that in the first embodiment, for example.

The maximum lengths of the cutting edges 44A to 44C in the radial direction R may be the same or different. The maximum length of each of the radial edges R of the cutting edges 44A to 44C is preferably 1/3 or less of the maximum length of the tapered portion 3 in the radial direction R, and is 1/4 or less of the maximum length. It is more preferable, and it is further preferable that it is 1/5 or less of the maximum length. Further, the lengths of the cutting edges 44A to 44C in the longitudinal direction A may be the same or different. The length of each of the cutting edges 44A to 44C in the longitudinal direction A is preferably 1/3 or less of the length of the tapered portion 3 and the needle tip portion 4 in the longitudinal direction, and is 1/4 or less of the above length. It is more preferable that the length is 1/5 or less of the above length. As described above, if the sizes of the cutting edges 44A to 44C are configured, the size of the cutting edges 44A to 44C can be reduced with respect to the tapered portion 3, so that when the cutting edges 44A to 44C cut through the patient's skin, the cutting edges 44A to 44C can be reduced in size. The length of the cutting edge 44A to 44C in contact with the skin can be reduced. As a result, damage to blood vessels can be minimized and the amount of bleeding can be significantly reduced.

Also in the present embodiment, the tapered portion 3 can be divided into the first section S1 to the third section S3 as in the case of the first embodiment. As shown in FIG. 12B, in the first section S1 in the present embodiment, the peripheral surface of the needle tip portion 4 is composed of the first blade surface 40, the second blade surface 41, and the third blade surface 49. It is composed. In the present embodiment, the first blade surface 40, the second blade surface 41, and the third blade surface 49 are flat surfaces, but the present invention is not limited to these, and the outer side (radial outer side) of the needle tip portion 4 is not limited thereto. It may be a curved surface that is convex, a curved surface that is concave on the inner side (inward in the radial direction) of the needle tip portion 4, or a surface that includes the above planes and curved surfaces. In particular, if any of the first blade surface 40, the second blade surface 41, and the third blade surface 49 is formed of a curved surface that is concave on the inner side (inward in the radial direction) of the needle tip portion 4, the peak portion 42A Any of ~ 42C can be made steep, and the apex angle of any of the cutting edges 44A to 44C can be made small. As a result, any of the cutting edges 44A to 44C is formed sharper than when it is composed of a flat surface.

The first blade surface 40, the second blade surface 41, and the third blade surface 49 are sequentially continuously connected in the circumferential direction of the needle tip portion 4 to form a conical surface in the first section S1. Then, in the first section S1 in the present embodiment, as shown in FIG. 14A, the cross section 4S1 of the needle tip portion 4 orthogonal to the longitudinal direction A is a triangle.

Further, the apex angles α3 to α5 of the cross section 4S1 of the needle tip portion 4 correspond to the apex angle of the ridge portion 42 when the ridge portions 42A to 42C are projected in the longitudinal direction A. The apex angles α3 to α5 of the cross section 4S1 of the needle tip portion 4 are assumed to be, for example, 60 degrees, respectively, but the present invention is not limited to this, and the apex angles α3 to α5 may be different from each other. However, of the apex angles α3 to α5, two may have the same angle and the other one may have a different angle.

As shown in FIG. 12B, in the second section S2 in the present embodiment, the peripheral surfaces of the tapered portion 3 are the first blade surface 40, the second blade surface 41, the third blade surface 49, and the first. It is composed of a first peripheral surface 50A, a second peripheral surface 50B, and a third peripheral surface 50C. The first blade surface 40, the first peripheral surface 50A, the second blade surface 41, the second peripheral surface 50B, the third blade surface 49, and the third peripheral surface 50C are, in order, the circumference of the tapered portion 3. They are continuously connected in the direction to form a partial conical surface in the second section S2. That is, the first peripheral surface 50A is connected to the first blade surface 40 and the second blade surface 41 between the first blade surface 40 and the second blade surface 41. Further, the second peripheral surface 50B is connected to the first blade surface 40 and the third blade surface 49 between the first blade surface 40 and the third blade surface 49. The third peripheral surface 50C is connected to the second blade surface 41 and the third blade surface 49 between the second blade surface 41 and the third blade surface 49. Then, in the second section S2 in the present embodiment, as shown in FIG. 14B, the cross section 3S2 of the tapered portion 3 orthogonal to the longitudinal direction A has a curve and a straight line convex on the outer side of the tapered portion 3. Becomes a hexagon that is connected alternately. The convex curve corresponds to the first peripheral surface 50A, the second peripheral surface 50B and the third peripheral surface 50C, and the straight line corresponds to the first blade surface 40, the second blade surface 41 and the third blade surface 49. Further, in the present embodiment, the first peripheral surface 50A, the second peripheral surface 50B, and the third peripheral surface 50C are curved surfaces that are convex toward the outer side (diametrically outer side) of the tapered portion 3, but are limited thereto. Instead, it may be a flat surface, a curved surface that is concave on the inner side (radial outer side) of the tapered portion 3, or a surface that includes both the above flat surface and the curved surface.

When the medical needle 1 in the present embodiment penetrates the skin of a living body, first, the tip 440 of the cutting edge 44 of the needle tip portion 4 comes into contact with the skin and penetrates the skin. Then, subsequently, when the inclined cutting edges 44A to 44C in the first section S1 move in the penetrating direction and pass through the skin, the cut end of the living body is cut open in the direction orthogonal to the penetrating direction. Further, subsequently, when the tapered portion 3 in the second section S2 and the third section S3 passes through the skin, the cut end of the living body is pushed around. In the present embodiment, since the size of the cutting edges 44A to 44C can be reduced with respect to the tapered portion 3, damage to blood vessels can be minimized when the skin is torn, and the amount of bleeding can be significantly suppressed.

It should be noted that the scope of the present invention also includes those in which the number of blade surfaces in the medical needle 1 is further increased. In this case, each blade surface is formed so as to go around the circumferential direction of the needle tip portion 4 and form the peripheral surface of the needle tip portion 4. At this time, each blade surface is continuously connected to form a conical surface, or is alternately continuously connected to another peripheral surface in the circumferential direction to form a partial conical surface. Further, the adjacent blade surfaces intersect so as to form the peak portion 42. The ridge line 43 of the peak portion 42 constitutes the cutting edge 44. The cutting edge 44 extends toward the tip 4A of the needle tip portion 4. At this time, each cutting edge 44 is inclined with respect to the virtual center axis DA or the radial direction R. A medical needle 1 satisfying such a condition is included in the scope of the present invention.

It should be noted that the medical needle 1 of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

1 Medical needle 2 Main body 2A One end of main body 3 Tapered part 3A One end of tapered part 3S2, 3S3 Cross section of tapered part 4 Needle tip 4A Tip of needle tip 4C Central axis of needle tip 4S1 Cross section of needle tip 20 1st large diameter part 21 Small diameter part 22 2nd large diameter part 23 Connecting part 40 1st blade surface 40B Deepest point of 1st blade surface 41 2nd blade surface 41B Deepest point of 2nd blade surface 42, 42A, 42B, 42C Peak 43, 43A, 43B, 43C Ridge 44, 44A, 44B, 44C Cutting edge 45, 48A, 50A First peripheral surface 46, 48B, 50B Second peripheral surface 47, 50C Third peripheral surface 49 Third blade Surface 70 Straight line A Longitudinal direction C Virtual cone surface D Virtual cone DA Virtual center axis R Radial direction

Claims (14)

The rod-shaped body and
A tapered portion having a section continuous with one end side of the main body portion and having a section whose cross-sectional area decreases as the distance from the one end of the main body portion increases along the longitudinal direction of the main body portion.
The needle tip portion superimposed on the taper portion and the needle tip portion
Equipped with
The needle tip portion has a first blade surface and a second blade surface that intersect each other to form a peak portion, and the blade tip is formed by the ridge line of the peak portion.
Medical needle. The cutting edge is characterized in that it is inclined so as to be displaced in the radial direction of the main body portion as it advances in the longitudinal direction.
The medical needle according to claim 1. The needle tip portion is characterized by having a portion having a triangular or fan-shaped cross-sectional shape orthogonal to the longitudinal direction.
The medical needle according to claim 1 or 2. The cutting edge extends to the tip of the needle tip portion in the longitudinal direction.
The medical needle according to any one of claims 1 to 3. The maximum length of the cutting edge in the radial direction is 1/3 or less of the maximum length of the tapered portion in the radial direction.
The medical needle according to claim 2. The length of the cutting edge in the longitudinal direction is 1/4 or less of the length of the tapered portion in the longitudinal direction.
The medical needle according to claim 2. The inclination angle θ1 of the cutting edge with respect to the longitudinal direction is in the range of 15 degrees to 55 degrees.
The medical needle according to claim 2. When the needle tip is viewed in a plan view from the front side of the tip of the needle tip in the longitudinal direction, the angle θ5 formed by the perpendiculars of the first blade surface and the second blade surface is 90 degrees to 150 degrees. Characterized by being within the range of,
The medical needle according to claim 2. The conical surface when the peripheral surface of the tapered portion, which is at least partially formed in a conical trapezoidal shape, is extended to the needle tip portion is a virtual conical surface, and the conical formed by the virtual conical surface is a virtual cone, the virtual cone. When defining the central axis of is a virtual central axis,
The inclination angle θ6 of the generatrix of the virtual cone with respect to the virtual central axis is in the range of 7.5 degrees to 15 degrees.
The medical needle according to any one of claims 1 to 8. The conical surface when the peripheral surface of the tapered portion, which is at least partially formed in a conical trapezoidal shape, is extended to the needle tip portion is a virtual conical surface, and the conical formed by the virtual conical surface is a virtual cone, the virtual cone. When defining the central axis of is a virtual central axis,
The inclination angle θ3 of the first blade surface and the second blade surface with respect to the virtual central axis is larger than the inclination angle θ6 of the bus of the virtual cone with respect to the virtual central axis. ,
The medical needle according to any one of claims 1 to 8. The friction coefficient on the surface of the tapered portion is 0.3 or less.
The medical needle according to any one of claims 1 to 10. The cutting edge extends in parallel in a direction orthogonal to the longitudinal direction.
The medical needle according to claim 1. The needle tip portion is characterized by having a third blade surface that intersects the first blade surface and the second blade surface and further forms two peaks where each ridge line serves as a blade edge.
The medical needle according to any one of claims 1 to 11. At least one of the first blade surface and the second blade surface is a concave curved surface or a flat surface.
The medical needle according to any one of claims 1 to 13.

Images