Tissue sampling needle

Abstract

[Problem] To provide a tissue sampling needle capable of suppressing the load on cells when the cells are sucked through an opening in a blade surface part. [Solution] A tissue sampling needle 1 comprises: a hollow body part 10 that extends in the axial direction; a blade surface part 20 that is provided at the tip of the body part and is formed in a tapered shape; and a reduction part 23 that is provided on at least a part of an edge of the blade surface part and reduces separation of the suction flow from the blade surface part.

Description

tissue collection needle

[0001] The present invention relates to a tissue collection needle.

[0002] BACKGROUND ART Conventionally, a procedure has been performed in which a tissue collection needle is inserted into biological tissue and cells are collected by suction from the blade surface of the tissue collection needle (for example, Patent Document 1 listed below).

[0003] Examples of the above-mentioned procedures include a procedure for transvaginally extracting eggs from the ovaries in infertility treatment, and a procedure for diagnosing a lesion by percutaneously aspirating and observing cells from the lesion.

[0004] Patent No. 5342554

[0005] A typical tissue collection needle has a tapered blade surface formed by cutting a hollow member at an angle. Therefore, the medium aspirated through the opening of the blade surface forms a flow field that is largely separated from the base end of the opening of the blade surface. Cells aspirated along with the medium may collide with the inner wall on the opposite side of the blade surface, potentially placing stress on the cells. Furthermore, cells aspirated through the opening of the blade surface may come into contact with a sharp point at the base end of the opening of the blade surface, potentially placing stress on the cells.

[0006] The present invention is intended to solve the above-mentioned problems, and aims to provide a tissue collection needle that can reduce the load on cells when cells are aspirated through an opening in the blade surface.

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) A tissue sampling needle having: a hollow main body extending in the axial direction; a tapered blade surface provided at the tip of the main body; and a reduction portion provided on at least a portion of the edge of the blade surface, which reduces separation of the suction flow from the blade surface.

[0009] (2) The tissue sampling needle according to (1), further comprising a suction port provided on the opposite side of the body portion from the blade surface portion in the radial direction.

[0010] (3) The tissue sampling needle according to (1) or (2), wherein the reduced portion has a fillet shape.

[0011] (4) The tissue sampling needle according to (3), wherein the radius of the fillet shape is 20% or more of the thickness of the main body portion.

[0012] (5) The tissue sampling needle according to (3) or (4), wherein the fillet shape is formed from a position 50% from the tip of the blade surface portion toward the base end of the opening of the blade surface portion.

[0013] (6) The tissue collection needle according to any one of (2) to (5), wherein the suction port is positioned in a position where the entire suction port can be seen when viewed from the blade surface portion.

[0014] (7) The tissue collection needle according to any one of (2) to (6), wherein, when the suction port is viewed from the blade surface, the base end of the suction port is positioned at a location that coincides with the base end of the opening of the blade surface.

[0015] (8) The tissue collection needle according to any one of (2) to (7), wherein, when the suction port is viewed from the blade surface, the projected area of ​​the suction port is 30% or more of the projected area of ​​the blade surface.

[0016] The tissue collection needle configured as described above is provided with a reduction section that can reduce the separation of the suction flow from the blade surface, so that when cells are aspirated through the opening in the blade surface, separation from the blade surface is reduced, thereby suppressing the load on the cells.

[0017] FIG. 1 is a front view showing a tissue collecting needle according to an embodiment of the present invention. FIG. 2 is a perspective view showing the vicinity of the tip of the tissue collecting needle according to this embodiment. FIG. 3 is a front sectional view showing the vicinity of the tip of the tissue collecting needle according to this embodiment. FIG. 4 is a plan view showing the vicinity of the tip of the tissue collecting needle according to this embodiment, and is a view for explaining the positional relationship between the blade surface and the suction port. FIG. 5 is a perspective view showing the vicinity of the tip of the tissue collecting needle according to this embodiment, and is a view for explaining the projected area of ​​the suction port and the projected area of ​​the blade surface. FIG. 6 is a simulation result showing the flow lines of the suction flow of the tissue collecting needle according to this embodiment. FIG. 7 is a perspective view showing a tissue collecting needle according to a comparative example. FIG. 8 is a simulation result showing the flow lines of the suction flow of the tissue collecting needle according to the comparative example. FIG. 9 is a front sectional view showing the vicinity of the tip of the tissue collecting needle according to modified example 1. FIG. 10 is a graph showing the shear stress distribution near the inner wall surface of the tissue collecting needle according to the embodiment, modified example 1, and comparative example.

[0018] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0019] The configuration of a tissue collecting needle 1 according to an embodiment of the present invention will be described below with reference to Figures 1 to 5. Figure 1 is a front view showing the tissue collecting needle 1 according to an embodiment of the present invention. Figure 2 is a perspective view showing the tip vicinity 1A of the tissue collecting needle 1 according to this embodiment. Figure 3 is a front cross-sectional view showing the tip vicinity 1A of the tissue collecting needle 1 according to this embodiment. Figure 4 is a plan view showing the tip vicinity 1A of the tissue collecting needle 1 according to this embodiment, and is a diagram for explaining the positional relationship between the blade surface portion 20 and the suction port 30. Figure 5 is a perspective view showing the tip vicinity 1A of the tissue collecting needle 1 according to this embodiment, and is a diagram for explaining the blade surface projected area S1 and the suction port projected area S2.

[0020] In the description of this specification, the axial direction is defined as the direction in which the tissue sampling needle 1 extends. The side of the tissue sampling needle 1 that is inserted into a living body is defined as the distal end, and the side opposite the distal end that is operated by the hand is defined as the proximal end.

[0021] The tissue collection needle 1 according to this embodiment is inserted into biological tissue and collects cells by aspirating them through the opening 22 and the suction port 30 of the blade surface 20 of the tissue collection needle 1. The tissue collection needle 1 according to this embodiment is used, for example, in a procedure for transvaginally collecting eggs from ovaries in infertility treatment, or in a procedure for diagnosing a lesion by percutaneously aspirating and observing cells from the lesion.

[0022] As shown in Figures 1 to 4, the tissue sampling needle 1 according to this embodiment has a main body portion 10 extending in the axial direction, a blade surface portion 20 provided at the tip of the main body portion 10, and a suction port 30 provided 180 degrees opposite the blade surface portion 20 in the radial direction of the main body portion 10.

[0023] The main body 10 is configured in the shape of a hollow pipe. The axial length of the main body 10 is, for example, 30 to 400 mm. The outer diameter of the main body 10 is, for example, 0.3 to 5.2 mm. The inner diameter of the main body 10 is, for example, 0.1 to 5.0 mm.

[0024] The cutting edge 20 is tapered as shown in Figures 1 to 5. Specifically, as shown in Figure 1, the cutting edge 20 is tapered so as to slope downward and to the left toward the tip.

[0025] 2 , the blade surface portion 20 has an edge 21 formed along the circumferential direction, an opening 22 provided on the inner periphery of the edge 21, and a reduction portion 23 provided on at least a part of the edge 21. The reduction portion 23 is formed to reduce separation of the suction flow from the blade surface portion 20.

[0026] In this embodiment, the reduction portion 23 has a fillet shape. The radius of the fillet-shaped reduction portion 23 is not particularly limited, but is preferably 0.01 mm or greater. Furthermore, the radius of the fillet-shaped reduction portion 23 is preferably 20% or greater, and more preferably 45% or greater, of the thickness d (see FIG. 3 ) of the main body 10. This configuration can more effectively suppress detachment of the suction flow in the reduction portion 23, thereby reducing the load on the cells.

[0027] 2 , the fillet-shaped reduction portion 23 is preferably configured so that the fillet radius gradually increases from a position 75% from the distal end 20A of the blade surface 20 toward the proximal end 20B of the opening 22 of the blade surface 20. More preferably, the fillet radius gradually increases from a position P1 50% from the distal end 20A of the blade surface 20 toward the proximal end 20B of the opening 22 of the blade surface 20. Note that FIG. 2 illustrates a configuration in which the fillet radius gradually increases from a position 50% from the distal end 20A of the blade surface 20 toward the proximal end 20B of the opening 22 of the blade surface 20. With this configuration, the reduction portion 23 can more effectively reduce separation of the suction flow from the blade surface 20.

[0028] As shown in FIGS. 2 to 4, the suction port 30 has an elliptical shape with the major axis extending in the axial direction.

[0029] As shown in Figures 3 and 4, the suction port 30 is positioned so that the entire suction port 30 can be seen when viewed from the blade surface portion 20 (viewed vertically from above to below). Furthermore, when viewed from the blade surface portion 20, the basal end 30A of the suction port 30 coincides with the basal end 20B of the opening 22 of the blade surface portion 20. This configuration allows the position at which cells are suctioned through the opening 22 of the blade surface portion 20 and the position at which cells are suctioned through the suction port 30 to be aligned. This allows the flow of suctioned cells to pass through the central axis, more effectively preventing them from colliding with the inner wall of the main body portion 10.

[0030] Next, we will explain the preferred range of the area of ​​the suction port 30. As shown in Figure 5, the area of ​​the opening 22 of the blade surface 20 projected onto a horizontal plane is defined as the blade surface projected area S1, and the area of ​​the suction port 30 projected onto the horizontal plane is defined as the suction port projected area S2.

[0031] In this case, the suction port projected area S2 is, for example, 30% or more of the blade surface projected area S1. Furthermore, the suction port projected area S2 is preferably 40% or more of the blade surface projected area S1, and more preferably 50% or more of the blade surface projected area S1.

[0032] If the attraction port projection area S2 is too small, the effect of the flow of the attracted cells passing through the central axis is reduced. On the other hand, the upper limit of the attraction port projection area S2 is set from the viewpoint of providing a predetermined strength as a needle.

[0033] The side edge 31 (see FIG. 3 ) of the suction port 30 is, for example, rectangular in shape, but may also be fillet-shaped like the reduced portion 23 of the blade surface portion 20 .

[0034] There are no particular restrictions on the material that can be used to construct the main body 10, but examples of materials that can be used include metal materials such as stainless steel, aluminum, aluminum alloys, titanium, and titanium alloys, and resin materials such as polyethylene, polypropylene, polymethyl methacrylate, polycarbonate, polyamide, and polyethylene terephthalate.

[0035] Next, with reference to Figures 6 to 11, the effects of the tissue collecting needle 1 according to this embodiment will be described while describing the configurations of the tissue collecting needle 900 according to a comparative example and the tissue collecting needle 2 according to Modification 1. Figure 6 is a simulation result showing the flow lines of the suction flow in the tissue collecting needle 1 according to this embodiment. Figure 7 is a perspective view showing the vicinity of the tip of the tissue collecting needle 900 according to the comparative example. Figure 8 is a simulation result showing the flow lines of the suction flow in the tissue collecting needle 900 according to the comparative example. Figure 9 is a front cross-sectional view showing the vicinity of the tip of the tissue collecting needle 2 according to Modification 1. Figure 10 is a simulation result showing the flow lines of the suction flow in the tissue collecting needle 2 according to Modification 1. Figure 11 is a graph showing the shear stress distribution near the inner wall surfaces of the tissue collecting needles according to the embodiment, Modification 1, and Comparative Example.

[0036] As shown in Fig. 7, the tissue sampling needle 900 according to the comparative example has a blade surface 920 formed by cutting a pipe obliquely, and does not have a reduction portion 23. As shown in Fig. 9, the tissue sampling needle 2 according to the first modification does not have a suction port 30, unlike the tissue sampling needle 1 according to the embodiment.

[0037] As shown in Fig. 6 , in the tissue collecting needle 1 according to the embodiment, cells aspirated together with the medium through the opening 22 of the blade surface 20 are prevented from colliding with the lower inner wall of the main body 10 due to the flow of the medium aspirated through the suction port 30, and the flow of cells is directed along the central axis. Furthermore, in the tissue collecting needle 1 according to the embodiment, the provision of the reduction section 23 reduces separation of the aspirated flow from the blade surface 20. Furthermore, in the tissue collecting needle 1 according to the embodiment, the reduction section 23 has a fillet shape, eliminating any sharp edges and reducing the load on the cells. Therefore, as shown in Fig. 11 , the shear stress applied to cells in the tissue collecting needle 1 according to the embodiment is lowest compared to the tissue collecting needle 900 according to the comparative example and the tissue collecting needle 2 according to the first modification.

[0038] On the other hand, the tissue collection needle 900 according to the comparative example does not have a reduction section, and therefore the medium aspirated from the blade surface 920 is largely detached from the base end 920B of the blade surface 920, as shown in Fig. 8. This increases the shear stress in the flow field, as shown in Fig. 11, and as a result, a load is also applied to the cells. Furthermore, the cells aspirated together with the medium collide with the inner wall of the lower side of the main body 910, causing a load on the cells. Furthermore, in the tissue collection needle 900 according to the comparative example, the base end 920B of the blade surface 920 is sharp, and therefore, when cells are aspirated from the blade surface 920, the cells come into contact with the sharp base end 920B, causing a load on the cells.

[0039] The tissue collecting needle 2 according to the first modification does not have the suction port 30 but has the reduction section 23, and therefore, compared to the tissue collecting needle 900 according to the comparative example, separation of the suction flow from the blade surface section 20 can be reduced as shown in Fig. 10. Therefore, as shown in Fig. 11, the shear stress colliding with the lower inner wall of the main body section 10 is reduced compared to the tissue collecting needle 900 according to the comparative example.

[0040] The tissue sampling needles 1 and 2 according to the present invention have been described above through the embodiments and modified examples, but the present invention is not limited to the configurations described in the specification, and can be modified as appropriate based on the claims.

[0041] For example, in the above-described embodiment, the reduced portion 23 has a fillet shape, but the reduced portion is not limited to a fillet shape and may have a chamfered shape or a rectangular shape.

[0042] In the above-described embodiment, the suction port 30 is configured as an ellipse, but it may be configured as a perfect circle or an elongated hole, or may have a plurality of holes formed therein.

[0043] In the above-described embodiment, the suction port 30 is positioned so that the entire suction port 30 is visible when viewed from the blade surface portion 20, and the proximal end 30A of the suction port 30 coincides with the proximal end 20B of the opening 22 of the blade surface portion 20. However, the proximal end 30A of the suction port 30 and the proximal end 20B of the opening 22 of the blade surface portion 20 do not have to coincide. Furthermore, the suction port 30 may be positioned so that at least a portion of the suction port 30 overlaps with the opening 22 of the blade surface portion 20 when viewed from the blade surface portion 20.

[0044] This application is based on Japanese Patent Application No. 2024-42516, filed on March 10, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0045] 1, 2 tissue collection needle, 10 main body, 20 blade surface, 21 edge, 22 opening, 23, 123, 223 reduction section, 30 suction port, S1 blade surface projected area, S2 suction port projected area.

Claims

1. A tissue sampling needle having an axially extending hollow main body portion, a tapered blade surface portion provided at the tip of the main body portion, and a reduction portion provided on at least a portion of the edge of the blade surface portion to reduce separation of the suction flow from the blade surface portion.

2. The tissue sampling needle according to claim 1, further comprising a suction port provided on the radially opposite side of said main body portion from said blade surface portion.

3. The tissue sampling needle according to claim 1 or 2, wherein the reduced portion is fillet-shaped.

4. The tissue sampling needle according to claim 3, wherein the radius of the fillet shape is 20% or more of the wall thickness of the main body portion.

5. The tissue sampling needle according to claim 3, wherein the fillet shape is formed from a position 50% from the tip of the blade surface toward the base end of the opening of the blade surface.

6. The tissue sampling needle according to claim 2, wherein the suction port is positioned so that the entire suction port can be seen when viewed from the blade surface.

7. The tissue sampling needle according to claim 6, wherein, when the suction port is viewed from the blade surface, the base end of the suction port is positioned at a location that coincides with the base end of the opening of the blade surface.

8. The tissue sampling needle according to claim 2, wherein when the suction port is viewed from the blade surface, the projected area of ​​the suction port is 30% or more of the projected area of ​​the blade surface.

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