WO2025197379A1 - Tissue sampling needle - Google Patents

Abstract

[Problem] To provide a tissue sampling needle configured to prevent the application of load on the cells of biological tissue at a tapered portion. [Solution] A tissue sampling needle 100 has a needle body section 110 with a lumen 115 formed therein. The needle body section comprises: a distal end part 120 which includes a needle tip 121 that is formed at the leading end and is capable of penetrating biological tissues, the distal end part extending along the axial direction and having a substantially constant inner diameter di1; a proximal end part 130 which is positioned closer to the proximal side than the distal end part is and extends along the axial direction with a substantially constant inner diameter di2; and a tapered part 140 which is located between the distal end part and the proximal end part, and has a inner diameter di3 that increases from the distal side to the proximal side. The inner diameter of the distal end part is 0.5 mm or more and the average taper angle of the tapered part is 5° or less.

Description

tissue collection needle

The present invention relates to a tissue sampling needle.

Traditionally, a procedure has been performed using a tissue collection needle to collect biological tissue and various cells contained in the biological tissue.

Examples of the above procedures include transvaginal oocyte collection from the ovaries in infertility treatment, and percutaneous aspirating and observing cells from the lesion to diagnose the lesion.

It is desirable for tissue collection needles to have a smaller outer diameter to reduce the pain that patients experience when they are punctured. However, if the inner diameter (lumen diameter) of a tissue collection needle is also made thinner as the outer diameter is made thinner, excessive stress is placed on the cells of the collected biological tissue as they move through the lumen. On the other hand, if the thickness of the tissue collection needle is made thin in order to maintain the inner diameter while reducing the outer diameter, the bending strength of the tissue collection needle will decrease, making it more susceptible to bending and other problems during procedures using the tissue collection needle, reducing operability.

In order to solve the above problems, it is conceivable to adopt a tapered needle, such as the tissue collection needle described in Patent Document 1, in which the outer and inner diameters at the tip end are small, the outer and inner diameters at the base end are larger than those at the tip end, and a tapered section is provided between the tip and base ends in which the outer and inner diameters gradually increase from the tip end to the base end. By configuring the tissue collection needle as a tapered needle, the pain felt by the patient can be reduced by the thinner tip end, while the larger diameter base end can prevent the tissue collection needle from bending.

Special table number 2010-534332

However, if the tapered portion has a large taper angle and the inner diameter of the tissue collection needle changes abruptly at the tapered portion, the following problems may arise.

If the taper angle of the tapered section located between the tip and base of the tissue collection needle is extremely large and a step-like section is formed within the lumen, turbulence will occur in the flow of biological tissue from the tip to the base. This will result in excessive stress being placed on the cells of the biological tissue.

The present invention aims to solve the above problems by providing a tissue collection needle that prevents cells from being subjected to stress at the tapered portion.

The above-mentioned object of the present invention is achieved by the following means.

(1)
A needle body having a lumen formed therein,
The needle body portion is
a tip portion having a needle tip formed at its tip that can be inserted into biological tissue and extending with a substantially constant inner diameter along the axial direction;
a base end portion that is disposed closer to the base end than the tip end portion and extends with a substantially constant inner diameter along the axial direction;
a tapered portion located between the distal end portion and the proximal end portion, the tapered portion having an inner diameter increasing from the distal end side toward the proximal end side,
The inner diameter of the tip is 0.5 mm or more,
A tissue collection needle, wherein the average taper angle of the tapered portion is 5° or less.

(2)
The tissue collection needle according to (1), wherein the inner diameter of the base end is 1.0 mm or more.

(3)
the tip portion extends along the axial direction with a substantially constant outer diameter of 1.1 mm or less,
The tissue sampling needle according to (1) or (2), wherein the base end portion extends along the axial direction with a substantially constant outer diameter of 1.2 mm or more.

(4)
The length of the tip portion in the axial direction is 10 mm or more,
The length of the tapered portion in the axial direction is 5.7 mm or more,
The tissue sampling needle according to any one of (1) to (3), wherein the length of the base end in the axial direction is 10 mm or more.

(5)
The tapered portion is
a first tapered portion extending from a base end of the distal end portion toward the base end side;
a second tapered portion extending from a base end of the first tapered portion toward the base end side,
The tissue sampling needle according to any one of (1) to (4), wherein the average taper angle of the first tapered portion is greater than the average taper angle of the second tapered portion.

(6)
The tissue sampling needle according to any one of (1) to (5), wherein the tapered portion extends linearly or curvedly from the distal end side to the proximal end side.

The above-mentioned tissue collection needle has an inner diameter of 0.5 mm or more at the tip and an average taper angle of 5° or less at the tapered portion, preventing stress from being placed on the cells of the collected biological tissue as it moves within the tip and along the tapered portion.

1A and 1B are diagrams illustrating a tissue collection needle according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the axial direction of the needle body. 3 is a cross-sectional view of the needle body taken along the arrow 3-3 shown in FIG. 2. 4 is a cross-sectional view of the needle body taken along the arrow 4-4 shown in FIG. 2. 5 is a cross-sectional view of the needle body taken along the arrow 5-5 in FIG. 2. 1A and 1B are enlarged views showing a portion of the needle body of an example and a portion of the needle body of a comparative example. 1 is a graph showing the results (pressure loss simulation results) of an example and a comparative example. 1 is a graph showing the results (simulation results of shear stress) of an example and a comparative example. 10 is an enlarged view of a part of the needle main body according to Modification 1. FIG. 10 is an enlarged view of a part of a needle main body according to Modification 2. FIG.

Embodiments of the present invention will now be described with reference to the accompanying drawings. Please note that the following description does not limit the technical scope or meaning of the terms described in the claims. Also, the dimensional proportions in the drawings have been exaggerated for the sake of explanation and may differ from the actual proportions.

The tissue collection needle 100 according to an embodiment of the present invention will now be described with reference to Figures 1 to 5.

FIG. 1 shows a tissue collection needle 100 according to an embodiment and a tissue collection device 10 including the tissue collection needle 100 as a component. FIG. 2 is a partial cross-sectional view along the axial direction of the needle main body 110, and FIGS. 3 to 5 are cross-sectional views (cross-sectional views perpendicular to the axis) of the needle main body 110 at the positions indicated by arrows 3-3, 4-4, and 5-5 shown in FIG. 2.

In the description herein, the direction in which the needle body 110 extends is defined as the "axial direction," and is indicated by the arrows X1-X2 in each figure. Furthermore, in the tissue collection needle 100, the side that is inserted into the living body (the side indicated by the arrow X1) is defined as the tip side, and the side that is operated by the hand and located opposite the tip side (the side indicated by the arrow X2) is defined as the base side.

<Tissue harvesting device 10>
As shown in FIG. 1 , the tissue sampling device 10 includes a tissue sampling needle 100 and a suction unit 200 .

The tissue collection needle 100 comprises a needle body 110 that is inserted into biological tissue. A lumen 115 (see Figure 2) is formed inside the needle body 110, and biological tissue cells can be collected via the lumen 115. The base end 130 of the tissue collection needle 100 is provided with a hub portion 160 that can be connected via a tube or the like to a suction portion 200 that generates suction pressure (negative pressure) within the lumen 115 when collecting tissue.

The suction unit 200 used in the tissue harvesting device 10 can be configured, for example, with a known pump mechanism used for harvesting biological tissue.

<Tissue collection needle 100>
As shown in FIGS. 1 and 2, the tissue sampling needle 100 comprises a needle body 110 having a lumen 115 formed therein, and a hub portion 160 connected to the base end of the needle body 110.

The tissue collection needle 100 is configured as a medical instrument used to aspirate and collect cells through the tip opening 121a formed on the needle tip 121 of the tissue collection needle 100. When collecting cells, the needle tip 121 of the needle body 110 is inserted into the biological tissue of a specified biological organ. Furthermore, by operating the suction unit 200 while the needle tip 121 is inserted into the biological tissue, cells from the biological tissue can be extracted outside the living body through the lumen 115 of the tissue collection needle 100.

There are no particular limitations on the uses of the tissue collection needle 100 according to this embodiment, but it can be used, for example, in procedures for transvaginally collecting eggs from the ovaries in infertility treatment, or in procedures for diagnosing lesions by percutaneously aspirating and observing cells from the lesion.

<Needle main body 110>
As shown in Figures 1 to 5, the needle body 110 has a tip 121 formed at its tip that can be inserted into biological tissue, and has a tip portion 120 that extends along the axial direction with a substantially constant inner diameter di1, a base portion 130 that is located closer to the base end than the tip portion 120 and extends along the axial direction with a substantially constant inner diameter di2, and a tapered portion 140 that is located between the tip portion 120 and the base portion 130 and has an inner diameter di3 that increases from the tip side to the base side.

The needle tip 121 can be configured as, for example, a known bevel needle. However, there are no particular restrictions on the specific shape or structure of the needle tip 121, as long as it can puncture the biological organ to be punctured.

The needle tip 121 has a tip opening 121a that communicates with the lumen 115. When a certain area of the tip side, including the needle tip 121, of the tissue collection needle 100 is inserted into a biological organ, the suction unit 200 can be activated to draw (suction) biological tissue into the lumen 115 via the tip opening 121a.

The tip portion 120 extends linearly over a certain range from the tip, where the needle tip 121 is located, to the base end. The outer diameter Do1 of the tip portion 120 can be configured to be approximately constant in the axial direction.

The tapered portion 140 begins at the tapered portion tip 141 located at the base end of the distal end 120 and extends linearly to the tapered portion base end 142 located at the tip of the proximal end 130, with the inner diameter di3 increasing and decreasing. The outer diameter Do3 of the tapered portion 140 is configured to increase from the distal end toward the proximal end at approximately the same rate as the inner diameter di3 of the tapered portion 140.

The base end 130 extends linearly over a certain range from the tapered portion base end 142 toward the base end. The outer diameter Do1 of the base end 130 can be configured to be approximately constant in the axial direction.

The lumen 115 is continuously connected along the distal end 120, tapered end 140, and proximal end 130. The central axis c1 of the needle body 110 passes through the centers of the respective sections 120, 130, and 140 (the centers of the cross sections perpendicular to the axis).

There are no particular restrictions on the material that can be used to construct the needle body 110, but examples 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.

The following describes example dimensions of each part of the needle main body 110.

The inner diameter di1 of the tip portion 120 can be configured to be 0.5 mm or more. Furthermore, the average taper angle of the tapered portion 140 can be configured to be 5° or less.

The needle body 110 is configured with an inner diameter di1 of 0.5 mm or greater at the tip 120, which reduces pressure loss at the tip 120 when suction pressure is generated within the lumen 115 of the needle body 110. This reduces the suction pressure generated to move collected cells toward the base end within the lumen 115. This reduces the load on cells as they move within the tip 120.

From the perspective of reducing pressure loss as described above, the inner diameter di1 of the tip portion 120 is preferably 0.6 mm or more, and more preferably 0.7 mm or more.

The needle main body 110 is configured so that the average taper angle of the tapered portion 140 is 5° or less, and therefore the inner diameter di3 of the tapered portion 140 gradually increases from the tapered portion tip 141 to the tapered portion base end 142. As a result, the needle main body 110 can prevent the flow of fluid (fluid containing biological tissue generated by suction by the suction portion 200) flowing through the tapered portion 140 from becoming significantly turbulent in the tapered portion 140. Therefore, the needle main body 110 can reduce the load on the collected cells as they flow through the tapered portion 140.

From the perspective of suppressing the generation of turbulence as described above, the average taper angle of the tapered portion 140 is preferably 4° or less, and more preferably 3° or less.

In this embodiment, the "average taper angle" can be defined as twice the angle (see θ in Figure 2) between the central axis c1 and a line representing the rate of change of the inner radius calculated by (inner diameter [mm] of tapered portion base end 142 - inner diameter [mm] of tapered portion tip 141) / 2 / axial length L3 [mm] of tapered portion 140 (linear length in the axial direction between tapered portion tip 141 and tapered portion base end 142).

The inner diameter di2 of the base end 130 (see Figure 4) can be configured to be 1.0 mm or greater. By configuring the inner diameter di2 of the base end 130 to be 1.0 mm or greater, pressure loss at the base end 130 can be reduced when suction pressure is generated within the lumen 115 of the needle main body 110.

From the perspective of reducing pressure loss as described above, the inner diameter di2 of the base end 130 is preferably 1.1 mm or more, and more preferably 1.2 mm or more.

The tip portion 120 can be configured to extend along the axial direction at a substantially constant outer diameter Do1 of 1.1 mm or less. The base portion 130 can be configured to extend along the axial direction at a substantially constant outer diameter Do2 of 1.2 mm or more.

The needle body 110 has a tip end 120 with an outer diameter Do1 of 1.1 mm or less, making it thinner than conventional tissue collection needles. This reduces the pain felt by the patient during procedures using the tissue collection needle 100. Furthermore, the needle body 110 has a base end 130 with an outer diameter Do2 of 1.2 mm or more, increasing the rigidity of the base end 130. This prevents bending of the needle body 110 during procedures using the tissue collection needle 100, preventing a decrease in usability.

From the perspective of reducing the pain felt by the patient as described above, the outer diameter Do1 of the tip portion 120 is preferably 1.0 mm or less, and more preferably 0.9 mm or less.

The outer diameter Do2 of the base end 130 is preferably 1.3 mm or greater, and more preferably 1.4 mm or greater, in order to prevent the occurrence of deflection during the procedure as described above.

The outer diameter Do3 of the tapered portion 140 can be any size depending on the difference between the outer diameter Do1 of the distal end 120 and the outer diameter Do2 of the proximal end 130. Note that the tapered portion 140 of this embodiment only needs to have an average taper angle of the inner diameter di3 of 5° or less as described above, and for example, the outer diameter Do3 does not have to be configured with the same average taper angle as the inner diameter di3.

The axial length L1 of the tip portion 120 can be configured to be 10 mm or more. The axial length L3 of the tapered portion 140 can be configured to be 5.7 mm or more. The axial length L2 of the base end portion 130 can be configured to be 10 mm or more. In this embodiment, the axial length L2 of the base end portion 130 is defined as the linear distance from the tapered portion base end 142 to the exposed portion of the hub portion 160.

When each part of the needle main body 110 is configured with the lengths L1, L2, and L3 described above, the tissue collection needle 100 can be configured with an appropriate size that allows it to be used as an egg collection needle. Furthermore, by making the axial length L3 of the tapered portion 140 5.7 mm or more, it becomes easy to configure the average taper angle of the tapered portion 140 to the desired size (5° or less), making it possible to provide a needle main body 110 that prevents the generation of the turbulence described above.

The axial length L1 of the distal end 120 is preferably 20 mm or more, and more preferably 30 mm or more. The axial length L3 of the tapered portion 140 is preferably 7.1 mm or more, and more preferably 9.5 mm or more. The axial length L2 of the proximal end 130 is preferably 100 mm or more, and more preferably 130 mm or more.

When the axial lengths L1, L2, and L3 of each part of the needle main body 110 are configured as described above, the total axial length of the needle main body 110 is preferably 30 mm or more and 400 mm or less, and more preferably 200 mm or more and 350 mm or less.

The thickness t of the needle body 110 can be the same for each of the sections 120, 130, and 140 of the needle body 110, for example. There are no particular restrictions on the size of the thickness t, but from the perspective of ensuring the rigidity of the needle body 110, it can be configured to be, for example, 0.1 mm or more. Furthermore, the thickness t is preferably 0.12 mm or more, and more preferably 0.14 mm or more.

As described above, the tissue sampling needle 100 according to this embodiment has a needle body 110 with a lumen 115 formed therein, and the needle body 110 has a tip 121 formed at its distal end that can be inserted into biological tissue, a distal end 120 that extends axially with a substantially constant inner diameter di1, a proximal end 130 that is located proximal to the distal end 120 and extends axially with a substantially constant inner diameter di2, and a tapered portion 140 that is located between the distal end 120 and the proximal end 130 and has an inner diameter di3 that increases from the distal end to the proximal end, the inner diameter of the distal end 120 being 0.5 mm or greater, and the average taper angle of the tapered portion 140 being 5° or less.

With the tissue collection needle 100 configured as described above, the inner diameter of the tip portion 120 is 5 mm or more, and the average taper angle of the tapered portion 140 is 5° or less, preventing stress from being placed on the cells of the collected biological tissue as it moves within the tip portion 120 and along the tapered portion 140.

<Example>
Next, examples will be described. Note that the configuration of the present invention is not limited to the contents of the examples described below.

The following sample 1 was prepared as the needle main body 110 according to the example (see FIG. 6(A)).
<Sample 1>
Inner diameter di1 of tip portion 120 = 0.71 mm
Inner diameter di2 of base end 130 = 1.22 mm
Average taper angle = 0.17°
Axial length L1 of the tip portion 120 = 24 mm
The axial length L3 of the tapered portion 140 is 170 mm.

The following sample 2 was prepared as a needle main body 310 according to a comparative example (see FIG. 6(B)).
<Sample 2>
Inner diameter di1 of tip portion 320 = 0.67 mm
Inner diameter di2 of base end 330 = 1.20 mm
Average taper angle = 14.84°
Axial length L1 of the tip portion 120 = 50 mm
The axial length L3 of the tapered portion 140 is 2 mm.

Figure 7 shows the simulation results of the needle pressure for Sample 1 and Sample 2, performed at a volumetric flow rate of 50 mL/min.

In the graph in Figure 7, the vertical axis represents pressure, and the horizontal axis represents the position from the tip of each needle body 110, 310. The slope of the graph represents local pressure loss, and the absolute value of the pressure at a position 370 mm from the tip represents the pressure loss throughout the needle.

The results shown in Figure 7 show that the inner diameter of the tip 120 of Sample 2 is smaller than that of Sample 1, resulting in greater localized pressure loss. Furthermore, near the tapered portion 340 (approximately 50 mm from the tip), extreme pressure values are observed due to turbulence caused by the sudden increase in the inner diameter of the needle main body 310.

In Sample 1, the inner diameter di1 of the tip 120 is 0.71 mm, which is larger than the tip 320 of Sample 2. As a result, local pressure loss at the tip is small. Also, in Sample 1, the average taper angle of the tapered section 140 is 0.17°, which is sufficiently smaller than in Sample 2. As a result, no extreme pressure values are observed that would occur due to flow turbulence.

In order to reduce pressure loss, it is necessary to lengthen the section of the needle with a larger inner diameter. Compared to Sample 2, Sample 1 has a gradually increasing inner diameter, which is disadvantageous in terms of pressure loss. However, when comparing Sample 1 and Sample 2, the pressure loss across the needle is the same. This is thought to be due to the fact that the inner diameter of the tip 120 of Sample 1 is larger than that of Sample 2.

Figure 8 shows the results of the shear stress simulation performed on Sample 1 and Sample 2.

In the graph of Figure 8, the vertical axis indicates the magnitude of shear stress at the central axis calculated from the velocity distribution of the flow field formed within the lumen, and the horizontal axis indicates the position from the tip of each needle main body 110, 310.

The results shown in Figure 8 show that the inner diameter of the needle main body 310 increases rapidly near the tapered section 340 of Sample 2 (approximately 50 mm from the tip), resulting in increased shear stress in the flow field. On the other hand, the inner diameter of the needle main body 310 also increases near the tapered section 140 of Sample 1 (approximately 24 mm from the tip), resulting in a tendency for the shear stress in the flow field to increase somewhat; however, because the average taper angle of the tapered section 140 of Sample 1 is sufficiently smaller than that of Sample 2, the shear stress is significantly reduced compared to Sample 2.

The results of the examples and comparative examples confirm that the needle body 110 of sample 1 has a larger inner diameter at the tip 120 than the needle body 310 of sample 2, and a smaller average taper angle, which enables pressure loss to be kept at a similar level to sample 2, and that the shear stress applied to biological tissue by the tapered portion 140 can be significantly reduced compared to sample 2.

Next, we will explain a modified version of the above-mentioned embodiment. In explaining the modified version, we will omit detailed explanations of the content already explained in the above-mentioned embodiment.

Figure 9 shows a portion of the needle main body 110A according to variant example 1.

As shown in FIG. 9, the tapered portion 140 can also be configured to have multiple tapered portions. For example, as shown in FIG. 9, the tapered portion 140 can be configured to have two tapered portions 140A and 140B.

The tapered portion 140 of variant 1 has a first tapered portion 140A extending from the base end of the tip portion 120 toward the base end, and a second tapered portion 140B extending from the base end of the first tapered portion 140A toward the base end.

The average taper angle of the first tapered portion 140A can be configured to be larger than the average taper angle of the second tapered portion 140B. In this modified example, the average taper angle of each tapered portion 140A, 140B is 5° or less. Furthermore, the average taper angle of the first tapered portion 140A can be, for example, 5° or less, and the average taper angle of the second tapered portion 140B can be, for example, 4° or less.

As shown in this modified example, there is no particular limit to the number of tapered portions that can be provided on the needle body 110A, as long as the average taper angle is 5° or less. For example, it is possible to provide three or more tapered portions on the needle body 110A.

Figure 9 shows a portion of the needle main body 110C according to variant example 2.

As shown in FIG. 9, the tapered portion 140C may extend in a curved line, for example, from the distal end toward the proximal end. The tapered portion 140C according to variant 2 has a shape that widens away from the central axis c1 from the distal end toward the proximal end. Even when configured in this manner, the same effect as in the previously described embodiment can be achieved as long as the average taper angle of the tapered portion 140C is 5° or less. As explained above in this variant, the shape of the tapered portion 140C (the cross-sectional shape of the lumen 115 along the axial direction) is not limited to a linear shape.

The tissue collection needle according to the present invention has been described through embodiments and modifications, but the present invention is not limited to the configurations described in the specification and can be modified as appropriate based on the claims.

This application is based on Japanese Patent Application No. 2024-042524, filed on March 18, 2024, the disclosure of which is incorporated herein by reference in its entirety.

10 Tissue sampling device 100 Tissue sampling needle 110 Needle body 110A Needle body 110C Needle body 115 Lumen 120 Tip 121 Needle tip 121a Tip opening 130 Base end 140 Tapered portion 140A First tapered portion 140B Second tapered portion 140C Tapered portion 141 Tapered portion tip 142 Tapered portion base end 160 Hub portion 200 Suction portion di1 Inner diameter di2 of tip Inner diameter di3 of base Inner diameter Do1 of tapered portion Outer diameter Do2 of tip Outer diameter Do3 of base Outer diameter c1 of tapered portion Central axis t Wall thickness

Claims (6)

A needle body having a lumen formed therein,
The needle body portion is
a tip portion having a needle tip formed at its tip that can be inserted into biological tissue and extending with a substantially constant inner diameter along the axial direction;
a base end portion that is disposed closer to the base end than the tip end portion and extends with a substantially constant inner diameter along the axial direction;
a tapered portion located between the distal end portion and the proximal end portion, the tapered portion having an inner diameter increasing from the distal end side toward the proximal end side,
The inner diameter of the tip is 0.5 mm or more,
A tissue collection needle, wherein the average taper angle of the tapered portion is 5° or less. The tissue collection needle of claim 1, wherein the inner diameter of the base end is 1.0 mm or greater. the tip portion extends along the axial direction with a substantially constant outer diameter of 1.1 mm or less,
The tissue sampling needle according to claim 1 , wherein the proximal end portion extends along the axial direction with a substantially constant outer diameter of 1.2 mm or more. The length of the tip portion in the axial direction is 10 mm or more,
The length of the tapered portion in the axial direction is 5.7 mm or more,
The tissue sampling needle according to claim 1 , wherein the axial length of the base end is 10 mm or more. The tapered portion is
a first tapered portion extending from a base end of the distal end portion toward the base end side;
a second tapered portion extending from a base end of the first tapered portion toward the base end side,
The tissue sampling needle of claim 1 , wherein the first tapered section has an average taper angle greater than the second tapered section. The tissue collection needle according to claim 1, wherein the tapered portion extends linearly or curvedly from the tip end to the base end.