JP7408113B2 - Puncture needle and puncture device - Google Patents

Description

The present invention relates to a puncture needle.

Conventionally, puncture needles used for treatment and testing include injection needles, blood sampling needles, and indwelling needles. It is desirable that the puncture needle causes less pain when puncturing a target part of a living body or the like. For this reason, proposals have been made to reduce the diameter of the puncture needle and to shape the blade surface to reduce resistance during puncturing.

For example, Non-Patent Document 1 discloses an injection needle whose tip has a diameter of 180 μm to reduce pain.

Further, Patent Document 1 discloses an injection needle in which a tapered tip is formed by cutting a tip of a cylindrical body obliquely from either side, and the injection needle is connected from the outer periphery of the cylindrical body. a first inclined surface formed at a predetermined angle with respect to the axial direction of the main body; a second inclined surface formed at a large angle; and a second inclined surface connected to the second inclined surface and connected to the cutting edge, and whose angle with respect to the axial direction of the cylindrical body is larger than that of the second inclined surface. An injection needle has been proposed that includes a third inclined surface formed by.

Japanese Patent Application Publication No. 2000-262615

Terumo Corporation, Top/Press Release/2012, [Retrieved September 8, 2017], Internet <http://www.terumo.co.jp/pressrelease/detail/20120830/37>

As mentioned above, the pain during puncture can be suppressed by reducing the diameter (outer diameter) of the puncture needle, but for example, the inner diameter required for injecting a drug solution or collecting body fluids, and the strength required for puncturing can be reduced. There is a limit to how small the diameter of the puncture needle can be in order to meet required conditions such as processing accuracy. For example, the smallest diameter of puncture needles currently available on the market is 180 μm.

On the other hand, the injection needle of Patent Document 1 is intended for thick injection needles, such as diameters of 1.4 mm or more, used in artificial dialysis, and is designed to reduce resistance during puncture to reduce pain during puncture. ing.

The inventor of the present application has discovered that with very thin puncture needles, such as 200 μm or less, it is effective to suppress pain by not only lowering the puncture resistance but also by increasing the sharpness when the blade surface enters the puncture target site. I found out.

Therefore, an object of the present invention is to provide a puncture needle that suppresses pain during puncture.

In order to solve the above problems, the puncture needle of the present invention is a minimally invasive or non-invasive puncture needle that punctures a target site of a living body, and includes a main body that is elongated in the puncturing direction, and a tip of the main body that has a plurality of shapes. and a tapered cutting edge portion formed by branching into two.

With this configuration, the puncture needle according to the present invention can accurately cut the puncture target site with the plurality of cutting edge portions and reduce the required outer diameter, thereby suppressing pain during puncture. Furthermore, since it has multiple cutting edges, it is more likely to cut capillaries and cause bleeding than conventional puncture needles.

The tip of the main body may have a blade surface formed from the outer circumferential surface of the main body to the apex of the plurality of branched cutting edge parts, so that the cutting edge part has a tapered shape. With this configuration, the puncture needle according to the present invention can easily tear apart the puncture target site.

Each of the blade surfaces of the puncture needle may be arranged rotationally symmetrically with respect to a central axis in the longitudinal direction of the main body. With this configuration, by arranging multiple blade surfaces in a well-balanced manner in the cross section of the tip of the main body, stress is dispersed not only at the cutting edge but also between the cutting edge and the valley between the cutting edges, thereby preventing excessive load during puncturing. Since it becomes difficult to concentrate in one part, strength, rigidity, etc. can be ensured without forming an excessively fragile part.

In the puncture needle, each of the blade surfaces has a different inclination with respect to the central axis in the longitudinal direction of the main body in a distal region and a proximal region, and the inclination is greater than the inclination in the distal region. The inclination of the region on the proximal end side may be small. With this configuration, the puncture needle according to the present invention suppresses the slope of the blade surface in the distal region to ensure rigidity of the blade tip, and increases the slope of the blade surface in the proximal region to reduce puncture resistance. , it is possible to suppress pain while ensuring the rigidity of the cutting edge.

The tip of the main body of the puncture needle punctures the living body by cutting the epidermis of the living body, and the living body contact area that comes into contact with the living body out of the surface area of the part inserted into the living body is It may be less than 0.897 mm ² . With this configuration, the puncture needle of the present invention can reduce puncture resistance and sufficiently suppress pain during puncture. Moreover, with this configuration, the puncture needle of the present invention can reduce the possibility of coming into contact with a painful point during puncture, and can suppress pain during puncture.

The puncture needle is provided with a groove that opens on the outer circumferential surface at the tip of the main body and extends along the longitudinal direction of the main body between the plurality of cutting edge parts, and the The blade edge portions may be spaced apart from each other. Note that the width of the groove may be smaller than the width of the epidermal cells. With this configuration, the puncture needle of the present invention has edges formed on both sides of the cutting edge, which increases the blade surface and makes it easier to cut the skin.Furthermore, by forming the groove, the contact area with the living body can be reduced. , it is possible to achieve both ease of cutting the skin and pain reduction. In addition, a puncture needle whose groove width is smaller than the width of the epidermal cells can reduce the possibility of destroying the epidermal cells by puncturing, thereby reducing the pain caused by the destruction of the epidermal cells. In addition, since the grooves are formed in the cylindrical material by laser processing, it is possible to relatively easily process the puncture needle into a puncture needle having a plurality of cutting edge portions.

Moreover, in the puncture needle according to the present invention, an outer diameter of the main body in a cross section perpendicular to the puncturing direction may be 95 μm or more and less than 100 μm. Thereby, it is possible to suitably provide a non-invasive needle that is hardly subjected to pain stress caused by puncturing a target site of a living body.

Furthermore, in the puncture needle according to the present invention, an outer diameter of the main body in a cross section perpendicular to the puncturing direction may be 100 μm or more and less than 180 μm. Thereby, it is possible to suitably provide a minimally invasive needle in which the stress of pain caused by puncturing a target site in a living body is suppressed to a sufficiently low level.

Moreover, in the puncture needle according to the present invention, an outer diameter of the main body in a cross section perpendicular to the puncturing direction may be 160 μm or more and 210 μm or less. Thereby, it is possible to suitably provide a minimally invasive needle in which the stress of pain caused by puncturing a target site in a living body is suppressed to a sufficiently low level.

Furthermore, the puncture needle according to the present invention may have a hollow portion that penetrates from the distal end to the proximal end in the puncturing direction and allows collection of body fluids or injection of medicine. With this configuration, the puncture needle of the present invention can be used as an injection needle or a blood collection needle.

Further, the puncture needle has a hollow portion penetrating from the distal end to the proximal end in the puncturing direction, and the outer diameter of the main body in a cross section perpendicular to the puncturing direction is 95 μm or more and 180 μm or less, and the wall thickness is It may be 45 μm or more and 65 μm or less. This ensures the rigidity of the tip of the puncture needle, making it easier to puncture the living body, suppressing pain during puncturing, and increasing the possibility of bleeding from the living body.

According to the present invention, it is possible to provide a puncture needle that suppresses pain during puncture.

FIG. 1 is a side view of the tip portion of the puncture needle in the first embodiment. FIG. 2 is a front view of the puncture needle of the first embodiment viewed from the tip side. FIG. 3 is a diagram showing changes in stress in mice due to differences in the outer diameter of puncture needles. FIG. 4 is a diagram showing changes in stress in mice due to differences in the living body contact area of the puncture needle. FIG. 5 is a perspective view of the tip portion of the puncture needle in the second embodiment. FIG. 6 is a front view of the puncture needle of the second embodiment viewed from the tip side. FIG. 7 is a side view showing the tip portion of the puncture needle according to the second embodiment. FIG. 8 is a diagram showing, as Example 1, the results of comparing the stress when the puncture needle of FIG. 5 and a conventional puncture needle (comparison needle 1) were punctured into the palm of a mouse. FIG. 9 is a diagram showing, as Example 2, the results of comparing the stress when the puncture needle of FIG. 5 and a conventional puncture needle (comparison needle 2) were punctured into the thigh of a mouse. FIG. 10 is an external perspective view of the puncture device. FIG. 11 is a schematic cross-sectional view showing the states of the puncture device before, during and after operation. FIG. 12 is a graph showing the evaluation results of evaluation test 1 in which stress changes in mice were evaluated due to differences in the outer diameter of the puncture needle. FIG. 13 is a graph showing the evaluation results of evaluation test 2 in which stress changes in mice due to differences in the outer diameter of the puncture needle were evaluated by excluding outliers from the evaluation results. FIG. 14 is a diagram showing (a) the state of the conventional puncture needle tip before puncturing, and (b) the state of the puncture needle tip of the third embodiment before puncturing. Figure 15 shows (c) the state of the conventional puncture needle tip after puncture (the puncture needle protrudes outward from the outer circumferential surface), and (d) the state of the conventional puncture needle tip after puncture (the puncture needle protrudes inward from the outer circumferential surface). (e) is a diagram showing the state of the tip of the puncture needle of the third embodiment after puncturing; FIG. 16 is a diagram showing the shape of the puncture needle tip before puncturing. FIG. 17 is a diagram showing the shape of the puncture needle tip after puncturing.

<First embodiment>
Hereinafter, embodiments of the puncture needle will be described with reference to the drawings. The puncture needle of this embodiment is a so-called lancet that is used for blood tests and self-medication, for example, by once puncturing the skin of a living body and then pulling it out, allowing blood to ooze out from the punctured part and examining blood components. It's a needle.

FIG. 1 is a side view of the tip portion of the puncture needle in the first embodiment. FIG. 2 is a front view of the puncture needle of the first embodiment viewed from the tip side. The puncture needle 10 of the present embodiment has a cylindrical main body 9 that is elongated in the puncturing direction (Z-axis direction), and has a tapered blade surface 1 and a tapered blade surface 1 on the distal end portion 8 of the main body 9. It has grooves 3a to 3c that divide it. The grooves 3a to 3c extend along the longitudinal direction of the main body 9 so as to open on the outer peripheral surface of the distal end portion 8 of the main body 9 of the puncture needle 10.

In the puncture needle 10, the blade surface 1 is divided by the grooves 3a to 3c, so that a plurality of sharp cutting edge parts 4a to 4c are formed at the tip end of the distal end portion 8, which are branched into a plurality of parts in the puncturing direction. A plurality of grooves 3a to 3c are provided between the plurality of cutting edge portions 4a to 4c of the puncture needle 10. In other words, the cutting edge portions 4a to 4c are spaced apart from each other via the plurality of grooves 3a to 3c. Although not shown in FIGS. 1 and 2, the puncture needle 10 may include a grip portion at the proximal end of the main body 9 for the user to grip the puncture needle 10.

The blade surface 1 is formed in a tapered shape from the outer circumferential surface of the main body 9 to the tips of the cutting edges 4a to 4c, and the angle of this taper (inclination with respect to the central axis 1X) is different between the tip side and the base end side. It is formed. In FIGS. 1 and 2, the portions of the blade surface 1 having different taper angles and the portions divided in the circumferential direction by the grooves 3a to 3c are designated with symbols 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc, respectively. There is. In the following description, when these are to be distinguished, the symbols 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc are used, and when they are collectively referred to, only the symbol 1 is used.

For example, the blade surfaces 1aa to 1ac on the distal end side have a larger taper angle than the blade surfaces 1ba to 1bc on the proximal end side. Further, the blade surfaces 1ba to 1bc are formed with a larger taper angle than the blade surfaces 1ca to 1cc on the proximal end side. In the example shown in FIG. 1, when the puncture needle 10 is viewed from the side (Y-axis direction), the shape of the outline of the puncture needle 10 formed by the blade surfaces 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc is a straight line. However, there is no particular limitation. For example, when the puncture needle 10 is viewed from the side (Y-axis direction), the shape of the outline of the puncture needle 10 formed by the blade surface 1 is a curved shape in which the slope of the proximal end side is smaller than that of the distal end side, that is, the outer side. It may have a curved shape with a bulge.

As shown in FIG. 1, the grooves 3a to 3c in the puncture needle 10 are provided on the side surface of the main body 9 from the tip of the puncture needle 10, and are formed in a V-shape in a cross section perpendicular to the longitudinal direction. Further, as shown in FIG. 2, the grooves 3a to 3c are formed radially in three directions from the center of the tip of the puncture needle 10, dividing the blade surface 1 into three. The grooves 3a to 3c are each formed rotationally symmetrically with respect to the central axis 1X of the puncture needle 10, and the blade surfaces 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc divided by these grooves 3a to 3c are also formed with respect to the central axis 1X, respectively. It is formed rotationally symmetrically.

The tip of the puncture needle 10 is branched into a plurality of cutting edge parts 4a to 4c by the respective grooves 3a to 3c. More specifically, the cutting edge portion 4a of the puncture needle 10 has a wall surface 3aa on the side of the blade surfaces 1aa, 1ba, 1ca in the groove 3a, a wall surface 3ab on the side of the blade surfaces 1aa, 1ba, 1ca in the groove 3b, and a wall surface 3ab on the side of the blade surfaces 1aa, 1ba in the groove 3b. , 1ca, and has a substantially triangular prism shape. Similarly, the cutting edge portion 4b of the puncture needle 10 has a wall surface 3bb on the side of the blade surfaces 1ab, 1bb, 1bc in the groove 3b, a wall surface 3bc on the side of the blade surfaces 1ab, 1bb, 1bc in the groove 3c,
It has a substantially triangular prism shape with an outer shape defined by blade surfaces 1ab, 1bb, and 1bc. Furthermore, the cutting edge portion 4c of the puncture needle 10 has a wall surface 3cc on the side of the blade surfaces 1ac, 1bc, 1cc in the groove 3c, a wall surface 3ac on the side of the blade surfaces 1ac, 1bc, 1cc in the groove 3a, and a wall surface 3ac on the side of the blade surfaces 1ac, 1bc, 1cc in the groove 3a. It has an approximately triangular prism shape with an outer shape defined by.

As described above, the tip of the main body 9 of the puncture needle 10 of this embodiment includes the cutting edge parts 4a to 4c branched into a plurality of grooves 3a to 3c, and tapers from the outer peripheral surface to the apex of the cutting edge parts 4a to 4c. By providing the formed blade surfaces 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc, the blade edge portions 4a to 4c have a tapered shape.

In addition, in this embodiment, the tip of the puncture needle 10 has a structure that is branched into three cutting edge parts 4a to 4c, but the structure is not limited to this, and the tip of the puncture needle 10 has a structure in which the tip of the puncture needle 10 has a plurality of cutting edge parts. It suffices if the structure is branched into two. In addition, compared to the case where the tip of the puncture needle 10 is branched into an even number of cutting edges and each cutting edge is arranged line-symmetrically with respect to the central axis 1X, the tip of the puncture needle 10 is divided into an even number of cutting edges. It is easier to ensure the strength, rigidity, etc. of the tip end of the puncture needle 10 when the blades are branched into cutting edge portions and the cutting edge portions are not arranged line-symmetrically with respect to the central axis 1X. Therefore, it is more preferable for the puncture needle 10 to have its tip section branched into an odd number of cutting edge sections, from the viewpoint of ensuring the strength, rigidity, etc. of the tip section.

The material of the puncture needle 10 is not particularly limited, but for example, metal materials such as stainless steel, aluminum or aluminum alloy, titanium or titanium alloy, or synthetic resin (plastic) may be used. Note that in this embodiment, SUS304 is used as the material for the puncture needle 10.

Further, as a method for forming the blade surface 1 and the grooves 3a to 3c on the tip portion 8 of the puncture needle 10, for example, cutting, polishing, laser machining, electric discharge machining, etc. can be used. In this embodiment, the ends of the cylindrical material are polished to form tapered surfaces, and the grooves 3a to 3c are formed by laser processing. In this embodiment, the blade surface 1 is formed by a tapered surface divided by grooves 3a to 3c.

The puncture needle 10 in this embodiment has a plurality of sharp cutting edge parts 4a to 4c in which the distal end portion 8 is branched into a plurality of parts. Blood vessels can be cut open more easily. More specifically, in the puncture needle 10, the cutting edge portion 4a has a pair of edge portions 5aa, 5ab, the cutting edge portion 4b has a pair of edge portions 5bb, 5bc, and the cutting edge portion 4c has a pair of edge portions 5ac, 5cc. have. In this way, the puncture needle 10 adopts a structure in which the tip portion 8 branches into a plurality of cutting edge parts 4a to 4c, thereby increasing the number of edge parts that cut capillaries during puncture. It can increase the chances of cutting capillaries. As a result, according to the puncture needle 10, even if the outer diameter of the puncture needle 10 is kept small, the capillary can be suitably cut at the time of puncturing, and the amount of blood required for, for example, a test can be more easily removed from the capillary. It can be exuded. That is, according to the puncture needle 10 in this embodiment, it is possible to suppress pain during puncturing.

Furthermore, in the puncture needle 10 of this embodiment, the width GW of each of the grooves 3a to 3c in a cross section perpendicular to the central axis 1X is defined to be 50 μm or less. The width GW of each groove 3a to 3c here is defined as the arc length of the area in which each groove 3a to 3c is formed in the outer circumference of the tip portion 8 of the puncture needle 10, as shown in FIG. Good too. In this way, by setting the width GW of each groove 3a to 3c to 50 μm or less, it is possible to make it difficult for skin cells and the like to enter the grooves 3a to 3c when puncturing with the puncture needle 10. Therefore, the portions of the grooves 3a to 3c are less likely to come into contact with the skin, and the contact area with the living body (living body contact area) can be substantially reduced. As a result, it becomes possible to suppress pain during puncturing with the puncturing needle 10 more suitably. Note that the width GW of each groove 3a to 3c is not limited to 50 μm or less, but may be set to a predetermined dimension smaller than the width of an epidermal cell, for example. A puncture needle in which the width of the groove is smaller than the width of the epidermal cells can reduce the possibility of destroying the epidermal cells by puncturing, thereby reducing the pain caused by the destruction of the epidermal cells.

Here, FIG. 3 is a diagram showing changes in stress in mice due to differences in the outer diameter of the puncture needle. FIG. 4 is a diagram showing changes in stress in mice due to differences in the living body contact area of the puncture needle. Particularly preferable sizes of each part of the puncture needle 10 will be described below based on the results of quantitative pain evaluation based on FIGS. 3 and 4.

In order to quantitatively evaluate pain during puncture with puncture needles, the inventor of the present application punctured mice with puncture needles with different outer diameters and living body contact areas, and measured α-amylase contained in mouse saliva immediately after puncture. By measuring the changes, stress changes in mice were investigated. The puncture needle was inserted into the mouse at the outer side of the thigh, where the puncture was easy and where nerves were concentrated, and the puncture depth was 3 mm to sufficiently reach the capillaries. Furthermore, the puncture time was 3 seconds. As a puncture needle with an outer diameter of 200 μm, Nanopass (registered trademark) 33G manufactured by Terumo Corporation was used. Other puncture needles include hollow tubes with outer diameters of 35 μm, 70 μm, and 95 μm manufactured by Luss.com Co., Ltd., and hollow tubes with outer diameters of 100 μm and 150 μm manufactured by Ohba Kiko Co., Ltd., whose tips are polished diagonally. A blade having a blade surface inclined at 12 degrees with respect to the puncturing direction (axial direction) was used. Note that other conditions are the same as those in the following document.
Kazuyoshi Tsuchiya: The Painless Injection Tube: From Bio-mimetic Technology to Medical Engineering, Thought-Evoking Approaches in Engineering Problems(Editors: Ito, Yoshimi (Ed.)), p71-94, Springer(2014). DOI 10.1007/978- 3-319-04120-9

In FIG. 3, the horizontal axis shows the outer diameter of the puncture needle, and the vertical axis shows the concentration of α-amylase. The outer diameter of the puncture needle is set to six levels: 35 μm, 70 μm, 95 μm, 100 μm, 150 μm, and 200 μm, and the relationship between the stress state of the mouse when punctured with the puncture needle and the outer diameter of the puncture needle is illustrated. . Note that Control in FIG. 3 indicates the stress state (α-amylase concentration) of the mouse when the puncture needle was not inserted.

In FIG. 4, the horizontal axis shows the living body contact area of the puncture needle, and the vertical axis shows the concentration of α-amylase. The living body contact area of the puncture needle was set at six levels: 0.324 mm ² , 0.639 mm ² , 0.842 mm ² , 0.900 mm ² , 1.314 mm ² , and 1.703 mm ^{2 ,} and The relationship between the stress state of the patient and the living body contact area of the puncture needle is shown. Note that the value of 0.000 mm ² indicates the stress state of the mouse when no puncture needle was inserted as a control. Note that the living body contact area here is defined as the contact area with a living body when a mouse is punctured with a puncture needle.

As shown in FIG. 3, when the outer diameter of the puncture needle was in the range of 95 μm or less, no significant difference from the control was observed, indicating that the mouse was hardly under stress. It can be seen that when the outer diameter of the puncture needle becomes 100 μm or more, the mouse is under greater stress as the outer diameter increases. Moreover, no significant difference in pain during puncture was observed between puncture needles with an outer diameter of less than 100 μm. That is, according to FIG. 3, the puncture needle slits capillaries without destroying skin cells when puncturing, and the state in which the puncture needle does not cause any pain to the living body or only gives a slight sensation that is not recognized as pain (in this embodiment) It can be said that the maximum permissible outer diameter for making the material (also referred to as "non-invasive") is in the range of 95 μm or more and less than 100 μm. In other words, when the puncture needle is non-invasive, the outer diameter is preferably less than 100 μm, more preferably 95 μm or less.

Moreover, as shown in FIG. 4, no significant difference from the control was observed until the living body contact area of the puncture needle was 0.842 mm ² , indicating that the mouse was hardly under stress.
It has been confirmed that the concentration of α-amylase in saliva increases when the puncture needle has a living body contact area of 0.842 mm ² to 0.897 mm ² when puncturing a mouse. Therefore, when the puncture needle is non-invasive, it is preferable that the living body contact area of the puncture needle be less than 0.897 mm ² , and more preferably 0.842 mm ² or less.

From the above, when the puncture needle 10 in this embodiment is designed as a non-invasive needle, the outer diameter of the puncture needle 10 is preferably less than 100 μm, and preferably 95 μm or less, from the viewpoint of suppressing pain during puncture. More preferred. By reducing the outer diameter of the puncture needle 10 in this way, it is possible to create a configuration in which the blood vessel can be cut without destroying cell nuclei on the skin surface during puncturing. This prevents pain transmitters from being released from cell nuclei during puncture, making it non-invasive. Note that from the viewpoint of suppressing pain during puncture with the puncture needle 10, the lower limit of the outer diameter is not particularly limited, but as shown in FIG. Since no significant difference was observed in terms of pain caused by the puncture, the outer diameter of the puncture needle 10 was determined to be 95 μm when judged comprehensively, including the rigidity and strength of the puncture needle 10, the processing accuracy for forming the tip portion 8, and the ease of manufacturing. It can be said that a particularly preferable embodiment is that the thickness is less than 100 μm. By setting the outer diameter of the puncture needle 10 to 95 μm or more and less than 100 μm, it is possible to provide a non-invasive needle with excellent rigidity and strength of the tip portion 8, processing accuracy, and ease of manufacture.

In the example shown in FIGS. 1 and 2 of this embodiment, the outer diameter of the main body 9 of the puncture needle 10 is 95 μm. Further, the outer diameter of the main body 9 here may be defined, for example, as the diameter of the virtual outer circumferential circle of the cross section when it is assumed that the main body 9 of the puncture needle 10 is not formed with the grooves 3a to 3c. .

Furthermore, when the puncture needle 10 in this embodiment is designed as a non-invasive needle, the living body contact area is preferably less than 0.897 mm ² from the viewpoint of suppressing pain during puncture, and is 0.842 mm ² or less. It can be said that this is more preferable. Note that the puncture needle 10 in this embodiment has grooves 3a to 3c formed on its outer circumference. Therefore, the living body contact area of the puncture needle 10 is calculated by subtracting the total surface area within each groove 3a to 3c that does not come into contact with the living body from the total surface area from the tip of the puncture needle 10 to the puncture depth at which the puncture target site is punctured. It may also be defined as the area.

Note that, similar to the outer diameter of the puncture needle 10, from the viewpoint of suppressing pain during puncture, there is no particular restriction on the lower limit of the living body contact area, but as shown in FIG. 4, the living body contact area is 0.842 mm ² or less. In the range of , there is no significant difference in the living body contact area and pain during puncture, so the judgment should be made comprehensively, taking into account the rigidity and strength of the puncture needle 10, the processing accuracy for forming the tip portion 8, and the ease of manufacturing. Therefore, it can be said that it is a particularly preferable embodiment that the living body contact area of the puncture needle 10 is 0.842 mm ² or more and less than 0.897 mm ² .

In addition, the puncture needle 10 in this embodiment has grooves 3a to 3a, which are open to the outer circumferential surface at the tip of the main body 9 and extend along the longitudinal direction of the main body 9, between the plurality of cutting edge parts 4a to 4c. 3c is provided, and a structure is adopted in which the cutting edge portions 4a to 4c are spaced apart from each other via the grooves 3a to 3c. With this configuration, the puncture needle 10 according to the present embodiment has an advantage in that it can easily tear the skin because edges are formed on both sides in the circumferential direction of the cutting edge portions 4a to 4c. Furthermore, by forming the grooves 3a to 3c on the outer circumference of the puncture needle 10, the contact area with the living body can be reduced, making it possible to achieve both ease of cutting the skin and reduction of pain.

Furthermore, although the puncture needle 10 in this embodiment is not a non-invasive needle, it may be applied as a minimally invasive needle that can sufficiently suppress the pain given to a living body during puncturing. In this case, in consideration of the effect of reducing pain during puncture and the productivity of the puncture needle 10, it is preferable that the outer diameter of the puncture needle 10 is, for example, 100 μm or more and 180 μm or less. In particular, the puncture needle 10
From the viewpoint of automating production, it is preferable that the outer diameter of the puncture needle 10 is 160 μm or more and 180 μm or less. As described above, by setting the outer diameter of the puncture needle 10 to 100 μm or more and 180 μm or less, it is possible to realize machine manufacturing of the puncture needle 10 and provide a minimally invasive needle that minimizes pain during puncture. can.

Further, in the puncture needle 10 of the present embodiment, the inclination angle θa of the blade surfaces 1aa to 1ac with respect to the central axis 1X is 45 degrees, the inclination angle θb of the blade surfaces 1ba to 1bc with respect to the central axis 1X is 25 degrees, and the blade surfaces 1ca to 1cc. The inclination angle θc with respect to the central axis 1X is 15 degrees. In FIG. 1, each of the inclination angles θa to θc is shown as an angle with respect to an auxiliary line 1XA drawn on the outer peripheral surface of the main body 9 parallel to the central axis 1X. According to the puncture needle 10 in this embodiment, the inclination of the blade surface 1 with respect to the central axis 1X in the longitudinal direction of the main body 9 is different between the distal region and the proximal region, and The inclination of the region on the proximal end side is set to a relatively smaller angle than the inclination of . Thereby, puncture resistance can be reduced while ensuring the strength and rigidity of the tip portion 8 of the puncture needle 10. However, the inclination angles of the blade surfaces 1aa to 1ac, blade surfaces 1ba to 1bc, and blade surfaces 1ca to 1cc with respect to the central axis 1X are not limited to the above example.

For example, if the tip blade surfaces 1aa to 1ac are formed with the same 15 degree inclination as the proximal blade surfaces 1ca to 1cc, the blade edge portion 4a is defined by the blade surfaces 1aa to 1ac and the side surfaces of the grooves 3a to 3c. It is conceivable that the tip of ~4c becomes too thin, making it difficult to secure the rigidity necessary for puncturing. On the other hand, if the blade surfaces 1aa to 1ac are tilted at 45 degrees in order to ensure the rigidity of the tip, and the proximal blade surfaces 1ba to 1bc and 1ca to 1cc are also formed at the same 45 degrees, the puncture resistance will be large. It is conceivable that if the needle becomes too tight, the pain during puncturing may increase. Therefore, in the puncture needle 10 of this embodiment, the inclination of the blade surface 1 is gradually increased along the longitudinal direction of the main body 9 with respect to the central axis 1X from the proximal region to the distal region. By doing so, it is possible to reduce puncture resistance while ensuring the strength and rigidity of the tip portion 8 of the puncture needle 10. Thereby, the puncture needle 10 in this embodiment can suitably balance ensuring the strength and rigidity of the tip portion 8 and suppressing pain during puncturing. However, in the puncture needle 10 of this embodiment, the inclination of the blade surface 1 is not limited to a specific aspect. Further, in the present embodiment, the inclination of the blade surface 1 is varied in three stages from the distal end side to the proximal end side, but the invention is not limited to this.If both the rigidity of the distal end portion 8 and the suppression of pain during puncture can be achieved , the number of stages may be four or more or two or less.

In the example shown in FIG. 1, the length of the tip portion 8 of the puncture needle 10 in the puncturing direction (direction along the central axis 1X), that is, the length of the portion where the blade surfaces 1a to 1c and 2a to 2c are formed. Although the length is 100 μm, the length of the tip portion 8 of the puncture needle 10 in the puncturing direction is not limited to the above example.

Further, as shown in FIG. 1, in the puncture needle 10 of this embodiment, the spacing between the tips of each of the cutting edge portions 4a to 4c is 10 μm, but it is not limited to this. For example, an embodiment may be mentioned in which the gap between the respective cutting edge portions 4a to 4c is set in a range of about 2 μm or more and about 40 μm. By defining the gaps (intervals) between the blade edges 4a to 4c within the above range, it is possible to sufficiently suppress the pain caused by puncturing the puncture needle 10 while ensuring the probability of cutting capillaries.

In the example shown in FIGS. 1 and 2, the puncture needle 10 does not have a hollow part, but the puncture needle 10 may have a hollow part through which body fluid can be collected or medicine can be injected. For example, the puncture needle 10 may have a hollow portion penetrating from the branch portion 7 at the distal end to the proximal end. In this case, the diameter (inner diameter) of the hollow portion of the puncture needle 10 may be, for example, 20 μm or more and 50 μm or less.

In addition, in the puncture needle 10 according to the present embodiment, a structure is adopted in which the tip portion 8 is divided into a plurality of cutting edge parts 4a to 4c by the grooves 3a to 3c, so that the puncture needle 10 with a small living body contact area can be easily manufactured. be able to. For example, even if the outer diameter of the puncture needle 10 is 100 μm, the surface area of the grooves 3a to 3c does not come into contact with the living body during puncturing, so the living body contact area is suitably adjusted to a range of 0.842 mm ² to 0.897 mm ² It is also easy. The puncture needle 10 in this embodiment is designed to have a living body contact area of less than 0.897 mm ² so that pain during puncture can be suitably suppressed.

Furthermore, the puncture needle 10 in this embodiment has a structure in which each of the blade surfaces 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc is arranged rotationally symmetrically with respect to the central axis 1X in the longitudinal direction of the main body 9. As a result, the plurality of blade surfaces 1aa to 1ac, 1ba to 1bc, and 1ca to 1cc are arranged in a well-balanced manner in the cross section of the tip portion 8, and the strength, rigidity, etc. are optimized without forming an excessively fragile part. can be secured.

<Second embodiment>
The puncture needle of this embodiment has a hollow portion that allows collection of body fluids or injection of medicine, and is used, for example, as a blood collection needle or injection needle.

FIG. 5 is a perspective view of the tip portion of the puncture needle in the second embodiment. FIG. 6 is a front view of the puncture needle of the second embodiment viewed from the tip side. FIG. 7 is a side view showing the tip portion of the puncture needle according to the second embodiment. The puncture needle 10A of this embodiment has a cylindrical main body 19 that is elongated in the puncturing direction (Z-axis direction), and has a sharp cutting edge that branches into a plurality of parts in the puncturing direction at the distal end portion 18 of the main body 19. It includes sections 14a to 14c. Although not shown in FIGS. 5 and 6, the puncture needle 10A is provided with a hub (needle base) at the proximal end of the main body 19 for connecting to a syringe or the tip of the syringe. It may be.

The tip portion 18 of the puncture needle 10A has a cylindrical main body 19 whose tip in the puncturing direction is cut obliquely from three sides to form tapered surfaces (blade surfaces) 11a to 11c rotationally symmetrical with respect to the central axis 11X. Further, the blade surfaces 11a to 11c of the puncture needle 10A are each cut into a planar shape inclined with respect to the central axis 11X, and the proximal end side is connected to the side surface of the main body 19, and the distal end side is connected to the inner wall surface 19a of the main body 19. ing. Therefore, the ridge lines 17a to 17c formed by the contact between the tips of the blade surfaces 11a to 11c and the inner wall surface 19a are formed in a parabolic shape. FIG. 7 shows that the blade surface 11a is cut at an angle (tip grinding angle) θ1 with respect to the outer peripheral surface of the main body 19 parallel to the central axis 11X. Note that the tip grinding angle θ1 is, for example, 15 degrees. However, the tip grinding angle θ1 can be arbitrarily set according to the required puncture resistance and strength.

One side of the blade surface 11a in the circumferential direction of the puncture needle 10A contacts the blade surface 11b to form a ridgeline 16a, and the other side contacts the blade surface 11c to form a ridgeline 16c. Similarly, the side of the blade surface 11b opposite to the ridgeline 16a in the circumferential direction of the puncture needle 10A is in contact with the blade surface 11c to form a ridgeline 16b.

The tip of the puncture needle 10A is branched into a plurality of cutting edge parts 14a to 14c by the blade surfaces 11a to 11c and the inner wall surface 19a. The cutting edge portion 14a of the puncture needle 10A has a substantially triangular prism shape with the blade surfaces 11a, 11b and the inner wall surface 19a as side surfaces and the ridgelines 16a, 17a, and 17b as sides. Similarly, the blade edge portion 14b has a substantially triangular prism shape with the blade surfaces 11b, 11c and the inner wall surface 19a as side surfaces and the ridgelines 16b, 17b, and 17c as sides. Further, the blade edge portion 14c has a substantially triangular prism shape with the blade surfaces 11a, 11c and the inner wall surface 19a as side surfaces and the ridgelines 16c, 17a, and 17c as sides. That is, the cutting edge portions 14a to 14c of the puncture needle 10A are branched by cutting the blade surfaces 11a to 11c into a tapered shape, and have a tapered shape from the branching portion 17 to the tip in the puncturing direction (direction along the central axis 1X). It becomes. In this embodiment, the tip of the puncture needle 10A has a structure in which it branches into three cutting edge parts 14a to 14c, but the structure is not limited to this. good.

The material of the puncture needle 10A is not particularly limited, but for example, metal materials such as stainless steel, aluminum or aluminum alloy, titanium or titanium alloy, or synthetic resin (plastic) may be used. In this embodiment, SUS304 is used as the material for the puncture needle 10A. Further, cutting, polishing, laser machining, electric discharge machining, etc. can be used as a method for forming the blade surfaces 11a to 11c on the tip portion 8 of the puncture needle 10A. In this embodiment, the blade surfaces 11a to 11c are formed by cutting the ends of a cylindrical material.

Here, the size of each part of the puncture needle 10A, for example, the outer diameter of the puncture needle 10A, the living body contact area, etc., may be the same as the puncture needle 10 according to the first embodiment. That is, the sizes of the respective parts of the puncture needle 10 described in the first embodiment can also be suitably applied to the puncture needle 10A in the second embodiment. However, the puncture needle 10A according to this embodiment includes a hollow portion 19b that penetrates the main body 19 from the distal end to the proximal end. Here, among the blood components, white blood cells, which are relatively large in size, are about 13 μm. Therefore, it is preferable that the diameter of the hollow part 19b is 20 μm or more, and by doing so, blood components can be smoothly transferred through the hollow part 19b, and it can be suitably used as a blood collection needle. Further, the upper limit of the diameter of the hollow portion 19b may be appropriately set based on the diameter and wall thickness of the puncture needle 10A, and may be, for example, about 50 μm. As described above, in the puncture needle 10A of this embodiment, the diameter (inner diameter) of the hollow portion 19b is 20 μm to 50 μm. In this case, for example, if the puncture needle 10A is a blood collection needle, the diameter (inner diameter) of the hollow portion 19b may be set to 25 μm to 30 μm, and in this embodiment, blood cells in the blood can be aspirated. Furthermore, if you can tolerate the pain caused by the increase in the outer diameter as the inner diameter increases, the diameter (inner diameter) of the hollow part 19b may be increased to about 50 μm. In this embodiment, the puncture needle 10A It is suitably used for administration, etc.

Furthermore, in the puncture needle 10A of the present embodiment, the tip portion 18 is provided with sharp cutting edge portions 14a to 14c that are branched into a plurality of parts in the puncture direction, so that the puncture needle 10A according to the first embodiment It has the same effect as the needle 10. According to the puncture needle 10A, even though it is an extremely thin needle, it is possible to easily cut the puncture target site, and it is possible to collect blood and inject a medicinal solution.

<Example>
Below, using the puncture needle 10A of this embodiment and a commercially available puncture needle, a pain comparison evaluation test and a bleeding determination were performed in a mouse experiment.

《Example 1》
In Example 1, the puncture needle 10A shown in FIG. 5 was used with an outer diameter of 120 μm, an inner diameter of 50 μm, and a tip grinding angle of 15 degrees. Further, as Comparative Needle 1, a 30 gauge needle (diameter: 310 μm) manufactured by BD was used.

In the comparative pain evaluation test, the amount of α-amylase secreted into the mouth of a mouse is measured when a needle is punctured into the palm of the mouse (the sole of the forelimb). Since α-amylase is secreted in proportion to stress, the higher the amount of α-amylase, the more stressed the person is due to pain, and the lower the amount of α-amylase, the less stressed the person is.

Bleeding was determined by puncturing the palm of a mouse with a needle, then removing the puncture needle, and photographing the needle puncture position with a camera without actively squeezing or the like to confirm the presence or absence of bleeding.

FIG. 8 is a diagram showing the results of comparing stress when puncturing the palm of a mouse with the puncture needle 10A of FIG. 5 and a conventional puncture needle (comparison needle 1) as Example 1. In FIG. 8, the vertical axis shows the concentration of α-amylase, and the horizontal axis shows the type of puncture needle.

Prepare 15 C57BL/6 mice (female) as living organisms to be punctured, collect saliva from 13 of the 15 mice without puncturing with a needle, and measure the amount of α-amylase in the saliva. did. In FIG. 8, a state in which there is no pain due to this puncture is taken as a control.

One week after the control measurement, comparative needle 1 was punctured into the palms of the 13 mice to a depth of 1.5 mm, saliva from the mice was collected, and the amount of α-amylase in the saliva was measured.

Furthermore, one week later, the palms of 13 mice (11 of the 13 mice plus 2 new mice) were punctured to a depth of 1.5 mm with the puncture needle 10A shown in FIG. 5, and the saliva of the mice was collected. The amount of α-amylase in saliva was measured. Note that the same jig as the comparison needle 1 was used to hold the puncture needle 10A so that the puncture needle 10A and the comparison needle 1 were under the same experimental conditions. Puncture needle 10A had a smaller diameter than comparative needle 1, and since the needle could not be fixed as it was, this part was fixed to the jig with resin.

As shown in the comparison results in FIG. 8, the control with no pain due to puncture with the puncture needle had the lowest α-amylase value. It can be seen that the subjects felt more stress when puncturing with puncture needle 10A than the control, but felt less stress than when puncturing with comparison needle 1. As a result of the significance test, there was a significant difference between the control and comparison needle 1, and it is considered that the patient felt pain due to the puncture of comparison needle 1. Moreover, there was no significant difference between the control and the puncture needle 10A, and it is considered that the subjects felt almost no pain due to the puncture with the puncture needle 10A.

Regarding bleeding determination, bleeding was confirmed in 40% of the mice using puncture needle 10A and in 58% of mice using comparison needle 1. When actually collecting blood, the puncture needle 10A is considered to have practically the same blood collection performance as the comparison needle 1 because blood is collected by actively squeezing the needle after the puncture. It will be done.

《Example 2》
In Example 2, the puncture needle 10A shown in FIG. 5 had an outer diameter of 120 μm, an inner diameter of 50 μm, and a tip grinding angle of 15 degrees. Further, as the comparison needle 2, a 21 gauge needle (diameter: 810 μm) manufactured by BD was used. In the comparative pain evaluation test, a puncture needle is inserted into the thigh of a mouse, which is a region where nerves are concentrated and are particularly sensitive to pain, and the amount of α-amylase secreted into the mouth of the mouse is measured. I went by that.

The experimental conditions are the same as in Example 1 above, except that the site of puncturing the mouse with the needle is different, the comparative needle is different, and the puncturing depth is 1.8 mm, so there will be no redundant explanation. is omitted.

FIG. 9 is a diagram showing, as Example 2, the results of comparing the stress when puncturing the thigh of a mouse with the puncturing needle 10A of FIG. 5 and a conventional puncturing needle (comparison needle 2). In FIG. 9, the vertical axis shows the concentration of α-amylase, and the horizontal axis shows the type of puncture needle.

As shown in the comparison results in Figure 9, in the control with no needle puncture and almost no stress, α
Amylase shows the lowest value. Compared to FIG. 8, the α-amylase values after puncturing the needles are high for both comparative needle 2 (pink) and puncturing needle 10A. This is considered to be because the thigh where the needle was punctured has a concentration of nerves as described above, which makes it easy to feel pain, and the patient felt stress due to the pain, so the α-amylase value was higher than that shown in FIG. 8.

Although the patient felt stress due to pain after puncturing with the puncture needle 10A, he felt less stress than when puncturing with the comparison needle 2, confirming that the puncture needle 10A reduced pain. Furthermore, as a result of a significant difference test, there was a significant difference between the control and the comparison needle 2, and it is considered that the patient felt pain due to the puncture of the comparison needle 2. There was no significant difference between the control and the puncture needle 10A, and it is considered that the subjects felt almost no pain due to the puncture with the puncture needle 10A. Furthermore, there is a significant difference between comparison needle 2 and puncture needle 10A, and it is considered that puncture with comparison needle 2 is more painful than puncture with puncture needle 10A.

As mentioned above, as a result of the comparative evaluation of pain in two animal experiments, the puncture needle 10A reduces pain more than existing puncture needles, and depending on the individual mouse, the α-amylase value when punctured with the puncture needle 10A decreases. , the α-amylase value is not significantly different from the stress value when the puncture needle is not inserted, and it can be seen that statistically speaking, the puncture needle 10A reduces pain.

<Third embodiment>
In the third embodiment, an example of a puncturing device including the aforementioned puncturing needle is shown. FIG. 10 is an external perspective view of the puncture device, and FIG. 11 is a schematic cross-sectional view of the puncture device.

The puncture device 100 includes a puncture needle 10A within a housing 30, as shown in FIGS. 10 and 11. The housing 30 is made of plastic, and has a storage section 31 for storing the puncture needle 10A before operation at the rear of the internal space, and a passage 32 for the puncture needle 10 in front of the storage section 31. The distal end surface 30A of the housing 30 is provided with an opening 33 that communicates with the passage 32, and this opening serves as an exit port of the puncture needle 10A.

The puncture needle 10A before operation is connected to the holder 11 at the rear end, and is placed at the pre-operation position in the storage section 31 with the injection spring 12 compressed by the flange section 11A of the holder 11, and the trigger (operation section) 40 locking claws (locking portions) 41 lock the front end side surface of the flange portion 11A, and this locked state is maintained. That is, the injection spring 12 is held in a state in which the puncture needle 10A is biased toward the distal end.

During puncturing, when the user brings the distal end surface 30A of the housing 30 into contact with the skin 50 to be punctured and pushes the actuating piece 42 of the trigger 40 toward the housing 30, the puncturing device 100 moves the fulcrum 43. The trigger 40 swings about the shaft, the locking pawl 41 separates from the flange portion 11A of the holder 11, and the locked state is released. As a result, the holder 11 and the puncture needle 10A are ejected toward the distal end due to the urging force of the injection spring 12, and the front surface of the flange portion 11A advances toward the distal end while compressing the return spring 13, so that the tip of the puncture needle 10A moves toward the skin 50. Move to the puncture position where the needle will be punctured. At this time, the outer circumferential surface of the flange portion 11A is guided by the inner circumferential surface of the passage 32 and slides, thereby allowing the puncture needle 10A to move with high accuracy in the puncturing direction. That is, the passage portion of the housing 30 and the holder 11 constitute the puncturing mechanism in this embodiment.

After the puncture, the puncture needle 10A is pulled out from the skin 50 by the contraction of the fully extended injection spring 12 and the reaction of the compressed return spring 13, and the position where the forces of the injection spring 12 and the return spring 13 are balanced. move until it stops. As a result, after the operation, the tip of the puncture needle 10A is stored in the housing 30.

In this way, the puncture device 100 of this embodiment accommodates the fine puncture needle 10A in the housing 30 to facilitate handling, and with one action of pressing the trigger 40, the puncture needle 10A punctures with a constant force. However, after puncturing, the puncture needle 10A can be quickly pulled out and stored, making puncturing easier.

Next, evaluation of pain when puncturing is performed using the puncturing device 100 of this embodiment using puncturing needles 10A having different outer diameters will be described.

《Evaluation test 1》
FIG. 12 is a graph showing the evaluation results of evaluation test 1 in which stress changes in mice were evaluated due to differences in the outer diameter of the puncture needle. In this embodiment, the puncture needles 10A shown in FIGS. 5 to 7 were used with outer diameters of 120 μm, 160 μm, and 180 μm. Of these, the puncture needle 10A with outer diameters of 160 μm and 180 μm had an inner diameter of 87 μm. Other conditions are the same as those in the experiment shown in FIGS. 3 and 4 of the first embodiment. Note that Control in FIG. 12 indicates the stress state (α-amylase concentration) of the mouse when the puncture needle was not inserted.

In FIG. 12, the horizontal axis shows the outer diameter of the puncture needle 10A, and the vertical axis shows the concentration of α-amylase. As shown in Figure 12, the concentration of α-amylase is low at all outer diameters, indicating that the mice are under less stress, but as the outer diameter becomes smaller, there is a tendency for the mice to be under greater stress. . That is, it is thought that the smaller the outer diameter, the greater the pain.

According to the findings of the first embodiment and the second embodiment described above, it is thought that the smaller the outer diameter, the more pain is suppressed. Therefore, the results shown in FIG. 12 are contrary to the findings of the first embodiment and the second embodiment. It looks like there is. For this reason, evaluation test 2 was further conducted using conventional puncture needles 90 and 10A with outer diameters of 160 μm, 180 μm, and 210 μm.

《Evaluation test 2》
Evaluation test 2 differs from evaluation test 1 in that the inner diameters of the puncture needle 10A are 160 μm and 180 μm in outer diameter, and a new puncture needle 10A with an outer diameter of 210 μm is used, and the other conditions are as follows. , is the same as the evaluation test 1 above. In the evaluation test 1, the inner diameter of the puncture needle 10A having an outer diameter of 160 μm and 180 μm was 87 μm, but in the evaluation test 2, the inner diameter of the puncture needle 10A was 50 μm. That is, in Evaluation Test 2, the thickness of the puncture needle 10A having an outer diameter of 160 μm and 180 μm was set to be thicker than in Evaluation Test 1. Furthermore, in evaluation test 2, the test results included values that were considered to be abnormal, so an outlier test was performed to exclude the outliers for evaluation. In this example, the Smirnov-Grubbs test was used as the outlier test.

FIG. 13 is a graph showing the evaluation results of stress changes in mice due to differences in the outer diameter of the puncture needle, which were evaluated by excluding outliers from the evaluation results.

As shown in FIG. 13, there was no significant difference in the evaluation results when the outer diameter of the puncture needle 10A was 160 to 210 μm, and a significant difference test was performed for these, but no significant difference was found. That is, the smaller the outer diameter of the puncture needle 10A, the smaller the pain, but there was no difference due to the change in the outer diameter. As will be described later, among the conventional puncture needles 90, there are needles that can reliably puncture a mouse, and needles that cannot be measured because the tip of the conventional needle 90 deforms when puncturing a mouse and cannot penetrate the skin surface. There were multiple pieces of data. For this reason, it has not been possible to obtain evaluation results of stress changes in mice due to differences in the outer diameter when the needle 90 is conventionally punctured.

In addition, before and after performing the puncture in the evaluation test, the condition of the tip of the conventional puncture needle 90 was confirmed using a laser microscope (KEYENCE, VK-200 series), and the condition of the tip of the puncture needle 10A was confirmed using a tabletop scanning electron microscope. Confirmed with (JEOL, JCM-6000Plus). FIG. 14 shows (a) the state of the tip of the conventional puncture needle 90 before puncturing, (b) the state of the tip of the puncture needle 10A of this embodiment before puncturing, and FIG. 15 shows (c) the state of the conventional puncture needle 90 tip after puncturing. (d) State of the tip of the conventional puncture needle 90 after puncture (puncture needle protruding inward from the outer circumferential surface), (e) It is a figure showing the state of the tip of puncture needle 10A of this embodiment after puncture. Note that the conventional puncture needle 90 shown in FIGS. 14 and 15 has a diameter of 160 μm, and the outer diameter of the puncture needle 10A is 180 μm.

Comparing the shape of the tip of the puncture needle 10A before puncturing (FIG. 14(b)) and after puncturing (FIG. 15(e)) shown in FIGS. 14 and 15, it is found that the cutting edge of the puncturing needle 10A is crushed by puncturing, The puncture needle 10A was found to be deformed so as to be compressed from the distal end side to the rear end side. Not all puncture needles 10A have deformed blade tips like this, and regardless of the difference in the outer diameter of the puncture needles 10A, some puncture needles 10A have deformed blade tips, and some have deformed blade tips. There were puncture needles 10A that were not used. Furthermore, in Evaluation Test 2, more deformations of the tip of the puncture needle 10A were observed in the puncture needle 10A having an outer diameter of 180 μm than in the puncture needle 10A having an outer diameter of 160 μm. On the other hand, in the conventional puncture needles 90, there are puncture needles 90 whose tips hardly change depending on the puncture, and puncture needles 90 whose tip parts are crushed and deformed so that they are compressed outward from the outer peripheral surface ( 15(c)) and the puncture needle 90 (FIG. 15(d)) deformed so as to be compressed inward from the outer peripheral surface.

Next, the stress during puncturing due to the difference in the outer diameter of the puncturing needle 10A will be analyzed. A skin analysis model and a needle analysis model were created using general-purpose finite element method analysis software ANSYS Workbench (ANASYS 15.0).

The needle analysis model was a hollow tube with an inner diameter of 50 μm, and the tip was cut obliquely from three sides to form a blade surface, as in FIGS. 5 to 7. Further, the needle analysis model was set to have a total length (length in the Z-axis direction) of 5 mm, a Young's modulus of 200 GPa, a Poisson's ratio of 0.3, and a density of 7850 kg/m ³ with reference to the physical property values of SUS304.

In addition, in the skin analysis model, since it seems that there is little influence of areas far away from the puncture position in the X-axis and Y-axis directions, the skin analysis model in this example uses periodic boundary conditions to The length was defined as a sufficiently large value compared to the outer diameter of the puncture needle 10A. In addition, referring to the physical properties of polydimethylsiloxane (PDMS), a resin material often used as a simulated skin, we found that the total length (length in the Z-axis direction) is 3 mm, Young's modulus is 220 kPa, Poisson's ratio is 0.49, and density is 970 kg/ ^m3. was set.

Then, the stress applied to the skin analysis model when puncturing the skin analysis model vertically was analyzed by changing the outer diameter of the needle analysis model.

表１は、皮膚解析モデルにかかる応力の解析結果を示す表である。表１において応力（最大）は、皮膚解析モデルにかかる応力のうち、最大のもの（以下、最大応力とも称す）であり、針解析モデルの針先端が皮膚モデルの表面を貫き、皮膚モデルに穿刺されていくときに皮膚モデルが受ける力（＝針全体が皮膚から受ける力）に伴うものと考えられる。
また、応力（最小）は、皮膚解析モデルにかかる応力のうち、最小のもの（以下、最小応力とも称す）であり、針解析モデルの針先端が皮膚表面にあたり、皮膚表面を貫くときに針先端から受ける力（＝針先端が皮膚から受ける力）の変化に伴うものと考えられる。表１に示されるように、外径１６０μｍ，１８０μｍ，２１０μｍの場合と比べて、外径１２０μｍとした場合に最大応力及び最小応力がどちらも、外径１６０μｍや外径１８０μｍとした場合と比べて、最も大きくなっている。また、最大応力は外径２１０μｍの場合が最も小さく、最小応力は外径１６０μｍの場合が最も小さくなっている。

Table 1 is a table showing the analysis results of stress applied to the skin analysis model. In Table 1, stress (maximum) is the maximum stress (hereinafter also referred to as maximum stress) among the stresses applied to the skin analysis model, and the needle tip of the needle analysis model penetrates the surface of the skin model and punctures the skin model. This is thought to be due to the force that the skin model receives when the needle is moved (the force that the entire needle receives from the skin).
In addition, stress (minimum) is the minimum stress (hereinafter also referred to as minimum stress) among the stresses applied to the skin analysis model, and when the needle tip of the needle analysis model hits the skin surface and penetrates the skin surface. This is thought to be due to a change in the force received from the skin (=the force the needle tip receives from the skin). As shown in Table 1, when the outer diameter is 120 μm, the maximum stress and the minimum stress are both lower than when the outer diameter is 160 μm, 180 μm, and 210 μm. , is the largest. Further, the maximum stress is the smallest when the outer diameter is 210 μm, and the minimum stress is the smallest when the outer diameter is 160 μm.

The stiffness of the needle tip of the needle analysis model decreases as the wall thickness decreases, but the cutting edge of the needle tip becomes sharper. In the needle analysis model with an outer diameter of 120 μm, the cutting edge of the needle tip is sharp, but the rigidity is too small, so the needle tip is easily deformed, and it is thought that the minimum stress value was the largest. When comparing a needle analysis model with an outer diameter of 160 μm and a needle analysis model with an outer diameter of 180 μm, the needle analysis model with an outer diameter of 180 μm has a larger value of the minimum stress that the skin model receives. Compared to the needle analysis model with an outer diameter of 160 μm, the needle tip with an outer diameter of 180 μm has increased rigidity, but its sharpness has decreased, making it difficult to penetrate the surface of the skin model. It is thought that the value of the minimum stress received by the skin model became larger, and the maximum stress that penetrated the skin model thereafter also became larger. Compared to the needle analysis model with an outer diameter of 180 μm, the needle analysis model with an outer diameter of 210 μm has more rigidity and can receive force over a larger area due to the increased area of the needle tip, so both maximum stress and minimum stress are lower. It is thought that it has become smaller. However, the larger the area of the needle tip, the better. The maximum stress will be smaller, but when actually puncturing a living body, even if the stress value decreases, the contact area of the needle tip with the living body will increase, reducing pain. It tends to be easier to feel. Therefore, depending on the application, such as when you want to suppress pain as much as possible, or when you want to suppress pain and increase the probability of bleeding, it is necessary to adjust the balance between the sharpness and rigidity of the needle tip and the area of contact with the living body when puncturing the puncture needle. It is considered that what is necessary is to set the outer diameter and wall thickness of the puncture needle 10A.

In this embodiment, the puncture needle 10A is punctured with a constant biasing force by the injection spring, so as shown in Table 1, if the puncture needle 10A with a smaller outer diameter has a higher stress on the skin, The smaller puncture needle 10A is easier to puncture and penetrates deeper. Furthermore, since the smaller the outer diameter of the puncture needle 10A is, the resistance during puncturing is lower than that of the puncture needle 10A having a larger outer diameter, so it is thought that the smaller the outer diameter of the puncture needle 10A is, the deeper the puncture will be. As the puncture depth increases, the amount of skin to be cut increases, making the puncture more painful.

That is, if the puncture depth is the same, the smaller the outer diameter of the puncture needle 10A, the less pain there will be. In this case, since the puncture depth changes depending on the outer diameter of the puncture needle 10A, if the outer diameter of the puncture needle 10A is made too small, the puncture depth becomes too deep and the pain becomes large. Therefore, in the data in FIG. 13, two effects are mixed: the effect of reducing pain due to the smaller outer diameter of the puncture needle 10A, and the effect of increasing the pain due to the smaller outer diameter of the puncture needle 10A. As a result, the pain reduction effect was canceled out, and it is considered that no significant difference was obtained in the evaluation results depending on the outer diameter of the puncture needle 10A.

As a result of these considerations, it was found that in a configuration in which the puncture needle 10A is pushed out by an injection spring as in this embodiment, there is a lower limit to the allowable outer diameter in order to sufficiently suppress pain during puncture. .

Therefore, in this embodiment, the outer diameter of the puncture needle 10A employed in the puncture device 100 was set to 160 μm or more and 210 μm or less in consideration of Evaluation Tests 1 and 2. More preferably, the outer diameter of the puncture needle 10A employed in the puncture device 100 may be 180 μm or more and 210 μm or less. As a result, the puncturing device 100 of this embodiment can easily perform puncturing, and can perform puncturing in a minimally invasive manner while minimizing the pain imparted to the living body.

Further, as shown in FIG. 17, in the conventional puncture needle 90, the distal end portion 91 is formed on the outer peripheral surface 93 side, whereas in the puncture needle 10A of this embodiment, the distal end portion 18a is formed on the inner peripheral surface 19c side. formed on the side. Therefore, when the conventional puncture needle 90 receives resistance on the blade surface 92 during puncturing, an outward force is applied to the tip 91 as shown in FIG. Therefore, even if a puncture is made, the needle is repelled by the skin surface and cannot be punctured, or when the puncture needle 90 is pulled out from the skin after puncturing, the tip 91 may cut the skin to a size larger than its original outer diameter. There was a needle that caused more pain.

On the other hand, in the puncture needle 10A of the present embodiment, when the blade surface 11c receives resistance during puncturing, an inward force is applied to the tip 18a as shown in FIG. 18, and the tip 91 is deformed. As confirmed in FIG. 16, is compressed toward the inner peripheral surface. For this reason, when the puncture needle 10A is pulled out of the skin, the tip 91 does not cut the skin larger than its original outer diameter, and compared to the conventional puncture needle 90, when the puncture needle 10A is pulled out of the skin, can reduce pain.

Evaluation test 1 is an evaluation test in which the inner diameter of the puncture needle 10A is unified to 87 μm and the outer diameter is varied, and evaluation test 2 is an evaluation test in which the inner diameter of the puncture needle 10A is unified to 50 μm and the outer diameter is varied. It's a test. Thus, in evaluation test 2, the inner diameter of puncture needle 10A is made smaller than in evaluation test 1, thereby increasing the wall thickness of puncture needle 10A and increasing the rigidity of the tip of puncture needle 10A. Using the results of Evaluation Test 1 and Evaluation Test 2, the number of blood bleeds was confirmed and the pain was evaluated when the puncture needles 10A had the same outer diameter and different inner diameters. Table 2 shows the number of bleeding and the α-amylase value (average value) depending on the inner diameter. In Table 2, "bleeding was confirmed" means that blood was visible after the puncture without any treatment such as squeezing the puncture site.

As shown in Table 2, when the wall thickness of the puncture needle 10A is increased, the α-amylase value increases for both the puncture needles 10A with an outer diameter of 160 μm and 180 μm, indicating that the mouse feels stress. This is considered to be because the increased thickness of the puncture needle 10A increases the contact area with the living body at the tip of the puncture needle 10A, making it easier to feel pain.

Regarding the number of blood bleeds, when the puncture needle 10A had an outer diameter of 160 μm and an inner diameter of 87 μm, there were two, but this increased to nine when the inner diameter was 50 μm. It can be seen that with the puncture needle 10A having an outer diameter of 160 μm, the number of bleeding increases by decreasing the inner diameter and increasing the wall thickness of the puncture needle 10A. In addition, with the puncture needle 10A having an outer diameter of 180 μm, no significant change in the number of bleeding was observed due to a change in the inner diameter.

If the puncture needle 10A has an outer diameter of 160 μm and the inner diameter is large and the wall thickness of the puncture needle 10A is thin, the needle tip will be sharp, but the rigidity will be small, so the needle tip will be bent and there is a possibility that puncturing will not be successful. In this case, by reducing the inner diameter of the puncture needle 10A and increasing its wall thickness, the rigidity of the tip of the puncture needle 10A increases, making it easier to puncture the living body, and by making the puncture deeper than the outer diameter of 180 μm, It is thought that the probability of damaging blood vessels has increased and the number of bleeding has increased. In the case of a puncture needle 10A with an outer diameter of 180 μm, an inner diameter of 50 μm increases the rigidity of the tip of the puncture needle 10A compared to an inner diameter of 87 μm, but because the sharpness of the needle tip decreases, it becomes difficult to penetrate the living body surface, and at the same time the living body contact area decreases. Because of the increase, it is thought that the α-amylase value increased even though no major change was observed in the number of bleedings. Therefore, for example, in the puncture needle 10A having an outer diameter of 95 μm or more and 180 μm or less, the wall thickness may be set to 45 μm or more and 65 μm or less.

In this way, when a uniform force is applied to the puncture needle 10A as shown in FIGS. 10 and 11, the puncture needle 10A has a small outer diameter and cannot puncture the living body well, so the number of bleeding may be low. Also, by reducing the inner diameter and increasing the wall thickness of the puncture needle 10A, the rigidity of the tip of the puncture needle 10A is increased, making it easier to puncture the living body, suppressing pain during puncture, and reducing the possibility of bleeding from the living body. can be increased.

In this way, it was found that the trends of the results obtained in Evaluation Test 1 and Evaluation Test 2, and the results obtained by creating and analyzing a skin analysis model and a needle analysis model are consistent.

Note that in this embodiment, the hollow puncture needle 10A is employed, but the present invention is not limited to this, and the solid puncture needle 10 shown in the first embodiment may be employed.

"others"
The embodiments of the present invention described above are merely examples, and the present invention is not limited thereto. Furthermore, the characteristic configurations shown in the embodiments described above can naturally be combined without departing from the spirit of the present invention. For example, although the design of the puncture needle (using SUS304 material) was shown in the embodiment described above, any material of the puncture needle that can be used to manufacture the puncture needle can be used without departing from the spirit of the present invention. It is possible to design according to the puncture needle, and an appropriate outer diameter and wall thickness can be adopted depending on the material of the puncture needle.

1X: Central axis 1a to 1c: Blade surface 2a to 2c: Blade surface 3a to 3c: Groove 4a to 4c: Blade tip portion 8: Tip portion 9: Main body 10, 10A: Puncture needle 11X: Central axis 11a to 11c: Blade surface 14a to 14c: Blade edge portion 18: Tip portion 19: Main body 19a: Inner wall surface 19b: Hollow 100: Puncture device

Claims (9)

A minimally invasive or non-invasive puncture needle that is punctured into a target part of a living body,
a main body that is elongated in the puncturing direction;
a tapered cutting edge portion formed by having a plurality of shapes at the tip of the main body and branching into an odd number;
Equipped with
having a hollow portion penetrating from the distal end to the proximal end in the puncturing direction;
The outer diameter of the main body in a cross section perpendicular to the puncturing direction is 95 μm or more and 180 μm or less, and the wall thickness is 45 μm or more and 65 μm or less,
The tip of the main body punctures the living body by cutting the epidermis of the living body, and the living body contact area that comes into contact with the living body is less than 0.897 mm ² out of the surface area of the part penetrated into the living body. A puncture needle characterized by : 2. The tip of the main body has a blade surface formed from the outer peripheral surface of the main body to the apex of the plurality of branched cutting edge parts, thereby giving the cutting edge part a tapered shape. puncture needle. The puncture needle according to claim 2, wherein each of the blade surfaces is arranged rotationally symmetrically with respect to a central axis in the longitudinal direction of the main body. A minimally invasive or non-invasive puncture needle that is punctured into a target part of a living body,
a main body that is elongated in the puncturing direction;
a tapered cutting edge portion formed by having a plurality of shapes at the tip of the main body and branching into an odd number;
Equipped with
A groove is provided between the plurality of cutting edge parts, and the groove is open to the outer circumferential surface at the tip of the main body and extends along the longitudinal direction of the main body, and the cutting edge parts are connected to each other through the groove. are spaced apart , and the width of the groove in a plane perpendicular to the puncturing direction is 50 μm or less,
The tip of the main body punctures the living body by cutting the epidermis of the living body, and the living body contact area that comes into contact with the living body is less than 0.897 mm ² out of the surface area of the part penetrated into the living body. A puncture needle characterized by : 5. The tip of the main body has a blade surface formed from the outer circumferential surface of the main body to the apex of the plurality of branched cutting edge parts, thereby giving the cutting edge part a tapered shape. puncture needle . The puncture needle according to claim 5, wherein each of the blade surfaces is arranged rotationally symmetrically with respect to a central axis in the longitudinal direction of the main body . Each of the blade surfaces has a different inclination with respect to the central axis in the longitudinal direction of the main body between the distal end region and the proximal region, and the inclination of the proximal end region is greater than the inclination of the distal end region. The puncture needle according to claim 5 or 6, wherein the inclination of the region is small . The puncture needle according to any one of claims 1 to 7 ,
a housing that stores the puncture needle;
an ejection spring that is actuated to eject the tip of the puncture needle to a puncture position and puncture the target site;
A lancing device comprising: The puncturing device according to claim 8 , further comprising a return spring that returns the puncturing needle into the housing after puncturing.

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