JP7558484B2 - Needle Assembly - Google Patents

Description

The present invention relates to a needle assembly that includes a puncture needle body with a puncture needle that is inserted into a blood vessel or the like and left in place, and a needle tip protector that protects the tip of the puncture needle when the puncture needle body is removed after use.

Puncture needle bodies such as indwelling needles used for transfusions, blood sampling, hemodialysis, etc. have been known for some time. A puncture needle body has a structure in which a needle hub is fixed to the base end of a puncture needle with a sharp needle tip. The puncture needle body is then inserted into and retained in a lumen in the body, such as a patient's blood vessel, and an external conduit is connected to the needle hub, whereby transfusions, blood sampling, hemodialysis, etc. are performed through the lumen of the puncture needle body and the external conduit.

Some puncture needles are equipped with a needle tip protector that protects the tip of the puncture needle when it is removed from the body lumen, in order to prevent accidental punctures or repeated use after use, or to facilitate disposal. A needle tip protector and a needle assembly equipped with the same are disclosed, for example, in JP 2017-196060 A (Patent Document 1). That is, according to the medical needle with protector in Patent Document 1, when the needle tube is pulled out from a blood vessel or the like, the protector moves toward the needle tip relative to the needle tube, and the needle tube removed from the patient is housed inside the protector, so that the tip of the needle tube is not exposed to the outside.

JP 2017-196060 A

However, after the inventors of the present invention conducted a detailed study of Patent Document 1, they found that, for example, there was a risk that the base end portion of the needle hub could be damaged by an external force applied to the needle hub in order to release the engagement between the needle hub and the needle tip protector.

The problem to be solved by the present invention is to provide a needle assembly with a novel structure that can ensure the load-bearing strength of the needle hub against the action of external forces.

The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is merely an example, and may be combined with one another as appropriate. The multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various alternative embodiments may be realized.

The first aspect is a needle assembly comprising a puncture needle body with a needle hub fixed to the base end side of the puncture needle, a needle tip protector movable in the axial direction of the puncture needle, and an arm portion that releasably connects the needle tip protector to the needle hub, in which the outer dimensions of the needle hub are larger at the base end side than at the tip end side of the needle hub, and the base end portion of the needle hub is provided with a thickness change portion whose thickness dimension changes, and the minimum thickness dimension of the thickness change portion is equal to or greater than the thickness dimension of the cylindrical tip portion of the needle hub.

According to the puncture needle body of this embodiment, for example, a thickness change section whose thickness dimension changes is provided at the base end portion of the needle hub where damage may occur due to the action of external forces such as the operating force applied when separating the puncture needle body from the needle tip protector, and the minimum thickness dimension of the thickness change section is set to be equal to or greater than the thickness dimension of the cylindrical tip portion of the needle hub, thereby improving the load-bearing capacity of the base end portion of the needle hub by reinforcing it and dispersing stress.

The second aspect is a puncture needle body as described in the first aspect, in which the thickness-changing section has a portion whose thickness dimension changes in an axial cross section parallel to the needle axis direction and passing through the arm, and the minimum thickness dimension of the thickness-changing section in the axial cross section parallel to the needle axis direction and passing through the arm is equal to or greater than the thickness dimension of the needle hub on the tip side of the thickness-changing section.

In this needle assembly, the minimum thickness dimension of the thickness-changing portion is equal to or greater than the thickness dimension of the tip side of the needle hub, which reinforces the base end portion of the needle hub and improves the load-bearing capacity of the base end portion of the needle hub.

The third aspect is a needle assembly according to the second aspect, in which the needle hub has a needle fixing part at the tip end to which the puncture needle is fixed and a pipeline connection part at the base end to which an external pipeline is connected, the thickness changing part is located between the needle fixing part and the pipeline connection part in the needle hub, and the minimum thickness dimension of the thickness changing part is equal to or greater than the thickness dimension of the needle fixing part in an axial longitudinal section parallel to the needle axial direction and passing through the arm part.

In the needle assembly of this embodiment, the minimum thickness dimension of the thickness-changing portion is equal to or greater than the thickness dimension of the needle fixing portion of the needle hub in the axial longitudinal section passing through the arm portion, thereby reinforcing the base end portion of the needle hub and improving the load-bearing capacity of the base end portion of the needle hub.

The fourth aspect is a needle assembly according to any one of the first to third aspects, in which a restricting portion is provided on the needle hub, which restricts movement of the needle tip protector relative to the needle hub in the needle axis direction by contacting the needle tip protector, and the minimum thickness dimension of the thickness-changing portion is equal to or greater than the thickness dimension of the needle hub at the restricting portion.

In this needle assembly, the minimum thickness dimension of the thickness-changing portion is equal to or greater than the thickness dimension of the needle hub at the restricting portion, which reinforces the base end portion of the needle hub and improves the load-bearing capacity of the base end portion of the needle hub.

The fifth aspect is the needle assembly described in the fourth aspect, in which the restricting portion includes at least one of a protrusion and a recess.

According to the needle assembly of this aspect, for example, when the restricting portion is a protrusion, the protrusion is a portion of the needle hub that is likely to be thick and has a relatively high strength. Therefore, by configuring the thickness dimension of the base end portion of the needle hub to be even larger than the thickness dimension of the protrusion, the needle hub can be further reinforced. As a result, the load-bearing capacity of the base end portion of the needle hub is improved.

Furthermore, when the restricting portion is a recess, the recess is a portion of the needle hub that is likely to be thin-walled, but the strength of the portion where the recess is formed is ensured by fixing the puncture needle. The strength of the needle hub can be improved by configuring the base end portion of the needle hub so that the thickness dimension is greater than the thickness dimension at the recess. As a result, the load-bearing capacity of the base end portion of the needle hub is improved.

The sixth aspect is a needle assembly according to the fourth or fifth aspect, in which the minimum thickness dimension of the thickness-changing portion in an axial cross section parallel to the needle axis direction and passing through the arm portion is equal to or greater than the thickness dimension of the portion of the needle fixing portion of the needle hub that is not within the restricting portion.

According to the needle assembly of this aspect, the needle fixing portion of the needle hub to which the puncture needle is fixed is likely to be thinner than other portions of the needle hub in order to allow for the insertion of the puncture needle, but the strength of the fixed puncture needle can be ensured. On the other hand, the restricting portion may be thicker than necessary, for example, due to the required function of restricting the movement of the needle hub. Therefore, by making the minimum thickness dimension of the thickness-changing portion equal to or greater than the thickness dimension of the portion of the needle fixing portion of the needle hub that is not restricted by the restricting portion, it is possible to ensure the strength of the needle hub while avoiding setting the needle hub to a thickness greater than necessary, and also to improve the load-bearing performance of the base end portion of the needle hub.

The seventh aspect is a needle assembly comprising a puncture needle body with a needle hub fixed to the base end side of the puncture needle, a needle tip protector movable in the axial direction of the puncture needle, and an arm portion that releasably connects the needle tip protector to the needle hub, in which the outer dimensions of the needle hub are larger at the base end side than at the tip end side of the needle hub, the base end portion of the needle hub is provided with a thickness change portion whose thickness dimension changes and includes a portion that is equal to or smaller than the thickness dimension of the tip end portion of the needle hub, and the base end portion of the needle hub is provided with a shaft portion to which an external conduit is connected, located inside the thickness change portion.

According to the needle assembly of this aspect, even if the thickness change portion includes a portion that is equal to or smaller than the thickness dimension of the tip side of the needle hub, the base end portion of the needle hub can be reinforced by providing a shaft portion located inside the thickness change portion. In particular, when an external conduit is connected to the shaft portion in an externally inserted state, the base end portion of the needle hub can also be reinforced by the external conduit.

The eighth aspect is a needle assembly according to the seventh aspect, in which the thickness change section has a portion whose thickness dimension changes in an axial cross section parallel to the needle axis direction and passing through the arm, the minimum thickness dimension of the thickness change section in an axial cross section parallel to the needle axis direction and passing through the arm is equal to or smaller than the thickness dimension of the needle hub on the tip side of the thickness change section, and the needle hub has an outer dimension of at least a portion on the tip side of the thickness change section that is equal to or larger than the outer dimension of the thickness change section.

In the needle assembly of this embodiment, the outer dimensions of the needle hub in at least a portion of the tip side of the thickness change section are equal to or larger than the outer dimensions of the needle hub in the thickness change section, which can be understood from the fact that the section modulus, which is an index of strength, is expressed as a power of the outer dimensions, and therefore it is possible to efficiently achieve a reinforcing effect in the area that is equal to or smaller than the thickness dimension on the tip side of the needle hub.

In the ninth aspect, in the needle assembly described in the seventh aspect, the thickness change section has a portion whose thickness dimension changes in an axial longitudinal section parallel to the needle axis direction and passing through the arm, and in an axial longitudinal section parallel to the needle axis direction and passing through the arm, the minimum thickness dimension of the thickness change section is equal to or less than the thickness dimension of the needle hub on the distal side of the thickness change section, and the needle hub has an outer dimension of at least a portion on the proximal side of the thickness change section that is equal to or less than the outer dimension of the thickness change section.

With this needle assembly, the outer dimensions of at least a portion of the base end of the thickness change section are set to be less than the outer dimensions of the thickness change section, so that the area of the thickness change section that has the minimum thickness dimension can be reinforced.

In the tenth aspect, in the needle assembly described in any one of the seventh to ninth aspects, the thickness change section has a portion whose thickness dimension changes in an axial longitudinal section parallel to the needle axis direction and passing through the arm, the minimum thickness dimension of the thickness change section in the axial longitudinal section parallel to the needle axis direction and passing through the arm is equal to or less than the thickness dimension of the needle hub on the tip side of the thickness change section, and the thickness change section has at least one of a convex portion, a concave portion, and an inclined portion on the tip side of the minimum thickness dimension portion.

The eleventh aspect is a needle assembly according to any one of the seventh to tenth aspects, in which the thickness change section has a portion whose thickness dimension changes in an axial cross section parallel to the needle axis direction and passing through the arm, the minimum thickness dimension of the thickness change section in the axial cross section parallel to the needle axis direction and passing through the arm is equal to or less than the thickness dimension of the needle hub on the tip side of the thickness change section, and the thickness change section has at least one of a convex portion, a concave portion, and an inclined portion on the base side of the minimum thickness dimension portion.

In the twelfth aspect, in the needle assembly described in any one of the seventh to eleventh aspects, the thickness change section has a portion whose thickness dimension changes in an axial longitudinal section parallel to the needle axis direction and passing through the arm, and in an axial longitudinal section parallel to the needle axis direction and passing through the arm, the minimum thickness dimension of the thickness change section is equal to or less than the thickness dimension of the needle hub on the tip side of the thickness change section, and the thickness change section has a first inclined section on the tip side of the minimum thickness dimension portion and a second inclined section on the base end side, and the first inclined surface provided on the first inclined section and the second inclined surface provided on the second inclined section are inclined in different directions.

In the thickness change section, the area where the thickness is less than the tip end of the needle hub is prone to stress concentration and damage. Therefore, in the needle assemblies described in the tenth to twelfth aspects, at least one of a convex portion, a concave portion, and an inclined portion is provided on at least one of the tip end and base end of the above-mentioned area, reinforcing the needle hub.

In the thirteenth aspect, in the needle assembly described in any one of the first to twelfth aspects, the thickness change portion has a portion whose thickness dimension changes in an axial cross section parallel to the needle axis direction and not passing through the arm portion, and in the axial cross section parallel to the needle axis direction and not passing through the arm portion, the minimum thickness dimension of the thickness change portion is equal to or greater than the thickness dimension of the needle hub on the tip side of the thickness change portion.

The fourteenth aspect is the needle assembly described in the thirteenth aspect, in which the needle hub has a needle fixing part at the tip end to which the puncture needle is fixed and a conduit connection part at the base end to which an external conduit is connected, and the thickness change part is located between the needle fixing part and the conduit connection part in the needle hub in an axial longitudinal section parallel to the needle axial direction and not passing through the arm part.

In the needle assembly of this aspect, the thickness-changing portion is located between the needle fixing portion of the needle hub and the pipeline connection portion. As a result, the thickness-changing portion is provided between the needle fixing portion of the needle hub and the pipeline connection portion, which may be damaged by the action of external forces such as the operating force applied when separating the puncture needle body from the needle tip protector, thereby providing reinforcement and dispersing stress, thereby improving load-bearing performance.

The fifteenth aspect is the needle assembly described in the thirteenth aspect, in which the needle hub has a needle fixing portion on the tip side to which the puncture needle is fixed and a conduit connection portion on the base side to which an external conduit is connected, and the thickness changing portion is provided on the needle fixing portion.

The sixteenth aspect is a needle assembly according to any one of the thirteenth to fifteenth aspects, in which a restricting portion is provided on the needle hub, the restricting portion contacting the needle tip protector restricts movement of the needle tip protector relative to the needle hub in the needle axis direction, and the minimum thickness dimension of the thickness-changing portion is equal to or greater than the thickness dimension of the needle hub at the restricting portion.

The seventeenth aspect is the needle assembly described in the sixteenth aspect, in which the restricting portion includes at least one of a protrusion and a recess.

The eighteenth aspect is a needle assembly according to any one of the thirteenth to seventeenth aspects, in which the needle hub has a guide rib that protrudes outward, and the minimum thickness dimension of the thickness change portion is equal to or greater than the thickness dimension of the needle hub at the portion where the guide rib is formed.

The 19th aspect is a needle assembly according to any one of the first to eighteenth aspects, in which the needle hub has a needle fixing part on the tip side to which the puncture needle is fixed and a conduit connection part on the base side to which an external conduit is connected, and the outer dimensions of the conduit connection part are larger than the outer dimensions of the needle fixing part.

The twentieth aspect is a needle assembly according to any one of the first to nineteenth aspects, in which the thickness change portion includes at least one of an inclined portion, a concave portion, a convex portion, and a stepped portion.

The 21st aspect is a needle assembly according to any one of the 1st to 20th aspects, in which the part of the needle hub where the thickness dimension is smallest in an axial longitudinal section parallel to the needle axial direction and passing through the arm is located at a position away from the outer circumferential corner on the bottom side of the connection hole that opens on the base end side of the needle hub and into which an external conduit is inserted.

The 22nd aspect is a needle assembly according to any one of the 1st to 21st aspects, in which the needle hub has a needle fixing portion at the tip end to which the puncture needle is fixed and a conduit connection portion at the base end to which an external conduit is connected, and a portion in which the thickness dimension of the needle hub is minimum in an axial longitudinal section parallel to the needle axial direction and passing through the arm portion is provided in the conduit connection portion.

The 23rd aspect is a needle assembly according to any one of the first to 22nd aspects, in which the needle hub has a needle fixing part at the tip end to which the puncture needle is fixed and a pipeline connection part at the base end to which an external pipeline is connected, and a part in which the thickness dimension of the needle hub is minimum in an axial longitudinal section parallel to the needle axis direction and passing through the arm part is provided in the needle fixing part.

The 24th aspect is a needle assembly comprising a puncture needle body with a needle hub fixed to the base end side of the puncture needle, a needle tip protector movable in the needle axis direction of the puncture needle, and an arm portion that releasably connects the needle tip protector to the needle hub, wherein the needle hub comprises a needle fixing portion on the tip side to which the puncture needle is fixed and a pipeline connection portion on the base side to which an external pipeline is connected, and the needle fixing portion and the pipeline connection portion are provided in close proximity to each other.

With this needle assembly, it is possible to reduce the portion of the needle hub where the puncture needle and external conduit are not inserted. As a result, the needle hub is reinforced over a wide area by the puncture needle and external conduit, improving the strength of the needle hub.

The 25th aspect is a needle assembly according to the 24th aspect, in which the needle hub is provided with a thickness-changing portion whose thickness dimension changes, and the thickness-changing portion is provided on at least one of the needle fixing portion and the pipeline connection portion.

According to the needle assembly of this aspect, by providing the thickness changing portion in the needle fixing portion or the conduit connection portion, it is possible to utilize the reinforcing effect of the puncture needle and the external conduit in the thickness changing portion as well, and it is possible to more effectively improve the strength of the needle hub than if the thickness changing portion were provided in a portion of the needle hub in which the puncture needle and the external conduit are not inserted. In other words, in this aspect, the base end of the puncture needle and the insertion tip of the external conduit can be set to extend in the axial direction to a position close to or reaching the thickness changing portion.

In the twenty-fourth or twenty-fifth aspect, an intermediate portion may be provided between the needle fixing portion and the pipeline connection portion.

The 26th aspect is a needle assembly comprising a puncture needle body having a needle hub at the base end of the puncture needle, and a needle tip protector that is movable in the needle axial direction between a puncture position where the puncture needle is protruded toward the tip side relative to the puncture needle body and a protection position where the tip of the puncture needle is accommodated, and a locking piece that is engaged with the needle hub in the protection position of the needle tip protector and restricts the movement of the needle tip protector toward the base end side relative to the puncture needle body, thereby preventing the re-exposure of the needle tip of the puncture needle. is provided on the needle tip protector, and the needle hub has a tip portion that is inserted into the inner periphery of the locking piece at the puncture position of the needle tip protector and is located on the tip side of the locking surface of the locking piece that engages the needle hub, a base portion that is exposed from the needle tip protector toward the base end at the puncture position of the needle tip protector, and an intermediate portion that is located between the tip portion and the base portion and has an outer dimension larger than that of the tip portion, and the needle hub has a thickness changing portion whose thickness dimension changes.

According to the needle assembly of this aspect, the needle hub may be damaged by external forces such as the operating force applied when separating the puncture needle from the needle tip protector. However, by providing a thickness changing section whose thickness dimension changes, the load-bearing capacity is improved by reinforcing the base end portion of the needle hub and dispersing stress.

The needle hub is particularly susceptible to damage at the base and middle parts exposed from the needle tip protector at the puncture position of the needle tip protector, but by providing a thickness change section, stress concentration at the base and middle parts is alleviated, ensuring the load-bearing capacity of the needle hub, especially at the base and middle parts.

The 27th aspect is a needle assembly according to the 26th aspect, in which the needle hub has an arm that releasably connects the needle hub to the needle tip protector at the puncture position, and the thickness-changing portion has a portion whose thickness dimension changes in an axial cross section parallel to the needle axis direction and passing through the arm.

According to the needle assembly of this aspect, for example, when the arm is operated to separate the needle hub and the needle tip protector, the load-bearing capacity is improved by the change in thickness dimension in the thickness-changing portion in the axial cross section passing through the arm on which the external force that operates the arm acts. Therefore, the thickness-changing portion effectively prevents damage to the needle hub caused by the operating force of the arm.

The 28th aspect is a needle assembly according to the 26th or 27th aspect, in which the thickness change portion is provided in the base portion.

According to the needle assembly of this aspect, for example, in the base portion where the load-bearing strength is likely to decrease due to the provision of a connection structure for an external conduit, the provision of a thickness change portion improves the load-bearing performance.

The 29th aspect is a needle assembly according to any one of the 26th to 28th aspects, in which the thickness change portion is provided in the middle portion.

In this needle assembly, a thickness change section is provided between the tip section reinforced by the puncture needle and the base section reinforced by the external duct, improving the load-bearing strength in the intermediate section, which is not reinforced by the puncture needle or the external duct and is therefore susceptible to damage due to the action of external forces.

In addition, the tip section, which has external dimensions that are restricted for attachment to the needle tip protector, and the base section, which has internal dimensions that are restricted for connection to an external conduit, are both separated by a thickness-changing section, making it easier to change the thickness of the thickness-changing section, and in particular allowing for thickening of the thickness-changing section.

The 30th aspect is a needle assembly according to any one of the 26th to 29th aspects, in which the thickness change portion is provided at the tip.

According to the needle assembly of this embodiment, for example, stress applied to the base or middle part of the needle hub can be released to the tip part as necessary, thereby dispersing the stress and improving the load-bearing capacity of the needle hub.

The 31st aspect is a needle assembly according to any one of the 26th to 30th aspects, in which the thickness change portion has at least one of a tapered portion, a concave portion, a convex portion, and a stepped portion.

In this needle assembly, the thickness change in the thickness change section is achieved by any one or a combination of a tapered section, a concave section, a convex section, and a stepped section.

The 32nd aspect is a needle assembly according to any one of the 26th to 31st aspects, in which the outer dimensions of the thickness changing portion are larger at the base end side than at the tip end side, and the outer dimensions of the intermediate portion are equal to or larger than the outer dimensions of the base portion in at least a portion of the circumferential direction.

With this needle assembly, the outer dimensions of the middle part that is not reinforced by insertion into the needle tip protector or connection to an external conduit are equal to or greater than the outer dimensions of the base part that is reinforced by connection to an external conduit, making it easier to ensure the load-bearing capacity of the middle part.

The 33rd aspect is a needle assembly according to any one of the 26th to 32nd aspects, in which the needle hub has an arm that releasably connects the needle hub to the needle tip protector at the puncture position, and the thickness-changing portion has a portion whose thickness dimension changes in an axial cross section that is parallel to the needle axial direction and does not pass through the arm.

According to the needle assembly of this aspect, for example, when an external force acts on the needle hub in a longitudinal cross-sectional direction that does not pass through the arm portion, and the needle hub is bent, the load-bearing capacity is improved due to the change in thickness dimension at the thickness change portion in the axial longitudinal cross-sectional direction that does not pass through the arm portion on which the external force acts.

The 34th aspect is a needle assembly according to any one of the 26th to 33rd aspects, in which the thickness dimension of the thickness-changing portion in an axial longitudinal section parallel to the needle axial direction and passing through the arm portion is greater than the thickness dimension of the tip portion provided on at least one of the base portion and the intermediate portion.

In the needle assembly of this aspect, the thickness dimension of the thickness change portion provided in at least one of the base and middle portions in the axial longitudinal section passing through the arm portion is made larger than the thickness dimension of the tip portion, so that the base or middle portion, where the action of an external force is expected in the needle hub, is reinforced by the thickness change portion. Therefore, it is possible to obtain a high load-bearing strength in at least one of the base and middle portions provided with the thickness change portion.

The 35th aspect is a needle assembly comprising a puncture needle body having a needle hub fixed to the base end side of the puncture needle, a needle tip protector movable in the axial direction of the puncture needle, and an arm portion that releasably connects the needle tip protector to the needle hub, in which a conduit connection portion to which an external conduit is connected is provided at the base end portion of the needle hub, and a portion having a thickness dimension equal to or greater than that of the conduit connection portion is provided on the tip side of the conduit connection portion.

According to the needle assembly of this aspect, the needle hub has a portion that is thicker than the conduit connection portion and is located distal to the conduit connection portion, thereby ensuring the strength of the distal end of the needle hub. The conduit connection portion that constitutes the base end of the needle hub can also be reinforced by using the external conduit to which it is connected.

The present invention ensures the load-bearing strength of the needle hub against the action of external forces.

FIG. 1 is a perspective view of a needle assembly according to a first embodiment of the present invention; FIG. 2 is a longitudinal sectional view of the needle assembly shown in FIG. 1, which corresponds to the cross section II-II of FIG. 3 is a cross-sectional view taken along line III-III of FIG. IV-IV cross-sectional view of FIG. FIG. 2 is a vertical cross-sectional view showing a state in which the needle tip is protected by a needle tip protector in the needle assembly shown in FIG. FIG. 1 is a longitudinal sectional view showing a main portion of a needle assembly according to a second embodiment of the present invention. FIG. 13 is a longitudinal sectional view showing a main portion of a needle assembly according to a third embodiment of the present invention. FIG. 13 is a longitudinal sectional view showing a main portion of a needle assembly according to a fourth embodiment of the present invention. FIG. 9 is a perspective view of a needle hub constituting the needle assembly shown in FIG. FIG. 13 is a longitudinal sectional view showing a main portion of a needle assembly according to a fifth embodiment of the present invention. FIG. 1 is a longitudinal cross-sectional view of a needle assembly according to another embodiment of the present invention; FIG. 11 is a longitudinal sectional view showing a main portion of a needle assembly according to another embodiment of the present invention;

The following describes an embodiment of the present invention with reference to the drawings.

Figures 1 to 4 show a needle assembly 10 as a first embodiment. The needle assembly 10 has a structure in which the puncture needle body 12 is inserted into the needle tip protector 14 so as to be movable in the needle axial direction. The needle tip protector 14 can cover at least the needle tip of the puncture needle body 12. In the following description, unless otherwise specified, the tip side refers to the left side in Figure 2, which is the side of the needle tip 20 of the puncture needle body 12 described later, and the base side refers to the right side in Figure 2, which is the rear of the puncture needle body 12 in the puncture direction. In addition, as a general rule, the up-down direction refers to the vertical direction in Figure 3, which is the vertical direction, and the left-right direction refers to the horizontal direction in Figure 2, which is the vertical direction.

More specifically, the puncture needle body 12 has a structure in which a needle hub 18 is fixed to the base end side of the puncture needle 16. The puncture needle 16 is formed of a metal such as stainless steel, and one end is a needle tip 20 having a sharp tapered shape.

The needle hub 18 has a generally cylindrical shape, and the base end portion of the puncture needle 16 is inserted and fixed at the tip. This allows the inner cavity of the needle hub 18 to communicate with the inner cavity of the puncture needle 16 in the needle axial direction. The needle hub 18 also has a restricting portion that restricts the movement of the needle tip protector 14 in the needle axial direction. More specifically, the needle hub 18 has a tip portion 24 provided with a restricting portion such as a protrusion or recess.

The tip portion 24 is generally cylindrical and has a needle fixing portion 26 into which the base end portion of the puncture needle 16 is inserted and fixed from the tip side. At least one restricting portion is provided in the needle fixing portion 26. Specifically, tip locking portions 28, 28 are provided on the tip side of the needle fixing portion 26 as restricting portions that protrude on both sides in the vertical direction. In addition, a pair of locking projections 30, 30 are provided on the base end side of the tip locking portions 28, 28 in the needle fixing portion 26 as restricting portions that protrude on both sides in the horizontal direction. The locking projections 30 have a tip side surface that spreads in the direction perpendicular to the axis, and a base side surface that is an inclined surface, so that the protruding height decreases toward the base end side. The base end side of the needle fixing portion 26 in the tip portion 24 is a tip portion 31 that is located away from the puncture needle 16 on the base end side. The restricting portion is not limited to the tip locking portion 28, 28 and the locking protrusions 30, 30, but may be, for example, a recess, groove, or step that opens into the outer circumferential surface of the tip portion 24.

The tip portion 24 has a pair of guide ridges 32, 32 that protrude outward on both sides in the vertical direction. The guide ridges 32 are generally rectangular plate-shaped and extend linearly to the base end of the tip portion 24 on the base end side of the tip locking portion 28. The tip of the guide ridges 32 is connected to the tip locking portion 28, and the base end is connected to the base portion 34 described below.

A base end portion 34 is provided on the base end side of the tip portion 24 in the needle hub 18. In this embodiment, the base end portion 34 is integrally formed with the tip portion 24. However, the base end portion 34 may be formed separately from the tip portion 24 and fixed to the tip portion 24 by means of adhesion or the like. The base end portion 34 has an outer dimension in the axis-perpendicular direction larger than that of the tip portion 24, so that the needle hub 18 has an outer dimension in the axis-perpendicular direction larger on the base end side than on the tip side. Recesses 35 are open on the upper and lower outer surfaces of the base end portion 34. The recesses 35 have a substantially rectangular cross section and are provided across the pipeline connection portion 36 and the intermediate portion 51, which will be described later.

The base end portion 34 of the needle hub 18 has a conduit connection portion 36 as a base portion having a substantially cylindrical shape. The conduit connection portion 36 constitutes the base end side of the base end portion 34. The conduit connection portion 36 has an outer dimension in the axial direction perpendicular to the axis that is larger than that of the tip portion 24 of the needle hub 18. The conduit connection portion 36 has a connection hole 38 that opens on the base end surface. The connection hole 38 has a substantially circular cross section. The connection hole 38 has a bottom 40 on the tip side, which is opposite to the opening. The inner hole of the conduit connection portion 36 penetrates the bottom 40 in the axial direction and is connected to the inner hole of the connection port 44 described later. The base end side, which is the opening side, of the connection hole 38 has a larger diameter than the tip side, which is the bottom 40 side. The bottom 40 side of the connection hole 38 gradually becomes larger in diameter toward the opening end, which is the base end side, and the inner peripheral wall of the connection hole 38 is tapered cylindrical on the bottom 40 side.

The bottom 40 of the connection hole 38 is provided with a connection port 44 as an axis portion. The connection port 44 is cylindrical and protrudes from the bottom 40 toward the opening of the connection hole 38 toward the base end side. The inner peripheral surface of the connection port 44 is a cylindrical surface having a substantially constant diameter in the axial direction. The outer peripheral surface of the connection port 44 is a tapered outer peripheral surface whose diameter gradually decreases toward the base end side in the axial direction. The outer peripheral surface of the connection port 44 may be a cylindrical surface having a substantially constant diameter at the tip end side and a tapered outer peripheral surface at the base end side. The connection port 44 may be separate from the conduit connection portion 36, but in this embodiment, it is formed integrally with the conduit connection portion 36. The connection port 44 as an axis portion is provided inside the thickness change portion 52 described later. In this embodiment, the direction in which the connection port 44 extends is substantially the same as the needle axis direction, but may be inclined with respect to the needle axis direction.

The base end portion 34 of the needle hub 18 is provided with a pair of engaging arms 46, 46 as arms. The engaging arms 46 extend laterally (vertically in FIG. 2) from the base end of the conduit connection portion 36 on both sides, and are curved and extend toward the tip side, and are provided on both sides of the base end portion 34 in the lateral direction with a predetermined gap therebetween. The engaging arms 46, 46 have a curved and narrow connection portion with the conduit connection portion 36, and are allowed to elastically deform in a direction approaching each other due to the action of an external force. In addition, a hook 48 is formed on each tip portion of the engaging arms 46, 46.

The base end portion 34 has the tip of an external conduit 49 inserted into the connection hole 38 of the conduit connection part 36, and the tip of the external conduit 49 is attached in an externally inserted state to the connection port 44. The external conduit 49 is, for example, a tube made of synthetic resin. The external conduit 49 is glued or welded to the inner surface of the connection hole 38 and the connection port 44 as necessary.

By connecting the external pipeline 49 to the pipeline connection portion 36, the tip portion 24 and the external pipeline 49 are connected to both sides of the base portion 34, and the inner cavity of the puncture needle 16 and the inner cavity of the needle hub 18 are connected to the external pipeline 49. As a result, a fluid flow path 50 is provided in the puncture needle body 12, which runs from the tip opening of the puncture needle 16 to the external pipeline 49.

In addition, the external conduit 49 is connected to the connection port 44 in an externally inserted state, so that the conduit connection portion 36 of the needle hub 18 is reinforced by the external conduit 49. In particular, in this embodiment, the end of the external conduit 49 is arranged in a filled state so as to fill the gap between the connection port 44 and the peripheral wall of the connection hole 38, so that the conduit connection portion 36, which is likely to become thin-walled due to the formation of the connection hole 38, is effectively reinforced by the external conduit 49.

Between the tip portion 24 and the conduit connection portion 36 of the needle hub 18, an intermediate portion 51 is provided, which constitutes the tip side of the base end portion 34. The intermediate portion 51 has an outer dimension in the direction perpendicular to the axis that is larger than that of the tip portion 31 due to the provision of a thickness change portion 52, which will be described later.

The intermediate portion 51 and the conduit connection portion 36 constituting the base end portion 34 of the needle hub 18 are provided with a thickness change portion 52. In this thickness change portion 52, the thickness dimension in the direction perpendicular to the axis of the needle hub 18 changes in the axial direction. The thickness change portion 52 provided in the base end portion 34 of the needle hub 18 is located between the pair of engaging arms 46, 46 having hooks 48, 48, and the tip of the thickness change portion 52 is located on the base end side of the tips of the hooks 48, 48. The thickness change portion 52 is located on the base end side away from the tip portion 24 to which the puncture needle 16 is fixed, and is located at a position away from the tip side of the connection hole 38 in the conduit connection portion 36 into which the external conduit 49 is inserted. As a result, the puncture needle 16 and the external conduit 49 are not inserted or inserted into the thickness change portion 52.

The thickness changing portion 52 has a tapered portion 54 as an inclined portion whose thickness dimension gradually increases from the tip side to the base end side in an axial cross section parallel to the opposing direction of the pair of engaging arms 46, 46 passing through the pair of engaging arms 46, 46 shown in FIG. 2, and a concave portion 56, 56 located on the base end side of the tapered portion 54 and having a concave outer circumferential surface. The tapered portion 54 has a first inclined surface that inclines from the tip side to the base end side. By providing such a tapered portion 54 and a concave portion 56, 56, the thickness changing portion 52 has a changing thickness dimension in an axial cross section parallel to the opposing direction of the pair of engaging arms 46, 46 passing through the pair of engaging arms 46, 46. That is, the thickness changing portion 52 is gradually thicker from the tip side to the base end side in the tapered portion 54, and is gradually thinner from the tip side to the axial center in the concave portion 56, and is gradually thicker from the axial center to the base end side in the concave portion 56. The thickness changing portion 52 has an inner diameter dimension that is approximately constant in the axial direction. In this embodiment, the tapered portion 54 is provided in the intermediate portion 51, and the concave portion 56 is provided in the pipe connection portion 36, and the thickness changing portion 52 is provided across the intermediate portion 51 and the pipe connection portion 36.

The tapered portion 54 is generally shaped like a truncated cone and is provided between the pair of guide ridges 32, 32 in the circumferential direction. The concave portions 56 are provided on the surfaces of the thickness-changing portion 52 that face the pair of engaging arms 46, 46, and extend linearly with a generally constant cross-sectional shape in the axial direction (up-down direction) perpendicular to the direction in which the pair of engaging arms 46, 46 face each other.

In the axial longitudinal section parallel to the opposing direction of the pair of engaging arms 46, 46 shown in FIG. 2, the thickness dimension of the thickness-changing portion 52 is minimum at the end portion on the tip side of the tapered portion 54. The tapered portion 54 and the concave portions 56, 56 are provided on the base end side of the minimum thickness portion of the thickness-changing portion 52. As a result, the minimum thickness dimension of the thickness-changing portion 52 is greater than the thickness dimension of the cylindrical tip portion 24, the thickness dimension of which is approximately constant in the axial direction. As a result, the strength of the needle hub 18 is ensured. Note that the tip portion 24 of the needle hub 18 is a cylindrical portion extending in the axial direction, and does not include the tip locking portions 28, 28 and the locking projections 30, 30, and the tip locking portions 28, 28 and the locking projections 30, 30 are provided protruding from the tip portion 24 toward the outer periphery.

In an axial cross section parallel to the opposing direction of the pair of engagement arms 46, 46, the minimum thickness dimension of the thickness-changing portion 52 is equal to or greater than the thickness dimension of the portion of the needle fixing portion 26 of the needle hub 18 that is free from the tip locking portions 28, 28 and the locking protrusions 30, 30. In other words, in the cross section, the thickness-changing portion 52 does not have a thinner portion than the portion of the needle fixing portion 26 of the needle hub 18 that is free from the tip locking portions 28, 28 and the locking protrusions 30, 30. In this embodiment, in the cross section, the minimum thickness dimension of the thickness-changing portion 52 is approximately the same as the thickness dimension of the portion of the needle fixing portion 26 of the needle hub 18 that is free from the tip locking portions 28, 28 and the locking protrusions 30, 30. This ensures the thickness dimension of the thickness-changing portion 52, and ensures the strength of the base end portion 34 of the needle hub 18. In addition, the tip portion 24 of the needle hub 18, which is relatively thin, is the portion that is inserted into the needle tip protector 14, so damage from external forces is unlikely to be an issue. In particular, the needle fixing portion 26 is reinforced by the insertion of the puncture needle 16, so load-bearing capacity is easily ensured.

The outer dimensions (outer diameter dimensions) of the tip portion 24 of the needle hub 18 are approximately the same as the outer dimensions of the tip of the thickness changing portion 52. The outer dimensions of the tip portion 24 of the needle hub 18 may be larger or smaller than the outer dimensions of the thickness changing portion 52. If the outer dimensions of the tip portion 24 of the needle hub 18 are equal to or larger than the outer dimensions of the thickness changing portion 52, it becomes easier to ensure the strength of the tip portion 24 of the needle hub 18. If the outer dimensions of the tip portion 24 of the needle hub 18 are equal to or smaller than the outer dimensions of the thickness changing portion 52, it becomes easier to ensure the thickness of the thickness changing portion 52, and the thickness changing portion 52 can be reinforced.

3 perpendicular to the opposing direction of the pair of engaging arms 46, 46, the thickness dimension of the thickness-changing portion 52 changes stepwise in the axial direction due to the step-like portion 57 formed at the connection portion of the tip portion 24 and the base portion 34, and the recesses 35, 35 opening on the upper and lower outer surfaces of the base portion 34. In this way, the thickness-changing portion 52 of this embodiment has a different manner of change in thickness dimension in the vertical direction and the horizontal direction. The thickness-changing portion 52 has a change in thickness dimension in a portion including the intermediate portion 51 even in the axial vertical section perpendicular to the opposing direction of the pair of engaging arms 46, 46. Note that the change in thickness dimension of the thickness-changing portion 52 is not necessarily set throughout the entire thickness-changing portion 52, and the thickness-changing portion 52 may include a portion in which the thickness dimension does not change.

The thickness-changing section 52 has a stepped portion 57 in an axial cross section perpendicular to the opposing direction of the pair of engaging arms 46, 46, and therefore has a larger outer dimension (vertical axial dimension) at the base end side than at the tip end side relative to the stepped portion 57. The intermediate section 51 provided with the thickness-changing section 52 has approximately the same outer dimension as the pipeline connection section 36 in an axial cross section perpendicular to the opposing direction of the pair of engaging arms 46, 46. The outer dimension of the intermediate section 51 may be larger than the outer dimension of the pipeline connection section 36.

In an axial cross section perpendicular to the opposing direction of the pair of engagement arms 46, 46, the thickness dimension of the thickness-changing portion 52 is minimum at the inner peripheral end of the step portion 57. The step portion 57 and the recesses 35, 35 are provided on the base end side of the minimum thickness part of the thickness-changing portion 52.

In the axial longitudinal section perpendicular to the opposing direction of the pair of engagement arms 46, 46, the minimum thickness dimension of the thickness-changing portion 52 is equal to or greater than the thickness dimension of the tip portion 24 of the needle hub 18. In other words, the thickness-changing portion 52 does not have a portion thinner than the tip portion 24 of the needle hub 18 in the longitudinal section. In this embodiment, the minimum thickness dimension of the thickness-changing portion 52 in the cross section is approximately the same as the thickness dimension of the portion where the tip locking portions 28, 28 are formed in the tip portion 24 of the needle hub 18. This ensures the thickness dimension of the thickness-changing portion 52 and ensures the strength of the base end portion 34 of the needle hub 18. In addition, since the tip portion 24 of the needle hub 18, which is relatively thin, is the portion inserted into the needle tip protector 14, damage due to the action of external forces is unlikely to be a problem, and in particular, the needle fixing portion 26 is reinforced by the insertion of the puncture needle 16, and load-bearing performance is easily ensured.

The tip portion 24 of the needle hub 18 is provided with a pair of guide ridges 32, 32 that protrude outward in an axial longitudinal section perpendicular to the opposing direction of the pair of engagement arms 46, 46, and it is desirable that the minimum thickness dimension of the thickness-changing portion 52 in this section is equal to or greater than the thickness dimension including the pair of guide ridges 32, 32 in the tip portion 24 of the needle hub 18. This ensures the thickness dimension of the base end portion 34 that includes the thickness-changing portion 52, and ensures load-bearing performance. In this embodiment, the minimum thickness dimension of the thickness-changing portion 52 in this section is approximately the same as the thickness dimension of the portion of the tip portion 24 of the needle hub 18 where the pair of guide ridges 32, 32 are provided, but it may be greater than the thickness dimension of the portion of the tip portion 24 of the needle hub 18 where the pair of guide ridges 32, 32 are provided.

The axial length of the thickness change section 52 is preferably 3% or more, and more preferably 5% or more, of the axial length of the entire needle hub 18. In addition, the axial length of the thickness change section 52 is preferably smaller than the axial length of the pipeline connection section 36.

By providing the thickness change portion 52 on the distal side of the conduit connection portion 36 having the connection hole 38, the outer peripheral corner of the bottom 40 side of the connection hole 38 in the conduit connection portion 36 is relatively thick in the axial longitudinal section parallel to the opposing direction of the pair of engagement arms 46, 46 shown in FIG. 3. As a result, the outer peripheral corner on the bottom 40 side of the connection hole 38 is not the thinnest part of the needle hub 18. That is, the thinnest part of the needle hub 18 is provided at a position away from the outer peripheral corner on the bottom 40 side of the connection hole 38, and in this embodiment, is provided at the axial middle part of the peripheral wall of the connection hole 38 in the conduit connection portion 36. Note that the thinnest part of the needle hub 18 does not necessarily have to be provided at the base end portion 34 of the needle hub 18, and may be provided at the tip 31 of the distal end portion 24 of the needle hub 18, for example.

In the axial longitudinal section parallel to the opposing direction of the pair of engaging arms 46, 46 shown in FIG. 2, the thickness dimension of the thickness-changing portion 52 is larger than the thickness dimension of the tip portion 24 of the needle hub 18. In particular, in the longitudinal section, the minimum thickness dimension of the thickness-changing portion 52 is set to be equal to or larger than the thickness dimension of the tip portion 31 at the tip portion 24. As a result, the load-bearing strength is improved by the change in the thickness dimension of the thickness-changing portion 52 at the base end portion 34 of the needle hub 18, which is more susceptible to the influence of external forces than the tip portion 24. The thickness dimension of the thickness-changing portion 52 at the deepest part of the recessed portion 56 is larger than the thickness dimension of the tip portion 24 (the tip portion 24 excluding the locking protrusions 30, 30 as the restricting portion). It is also smaller than the thickness dimension of the needle hub 18 at the restricting portion. The thickness dimension of the thickness-changing portion 52 at the recessed portion 56 may be smaller than the thickness dimension of the tip portion 24 excluding the locking protrusions 30, 30 as the restricting portion, or may be larger than the thickness dimension of the needle hub 18 at the restricting portion. The outer dimensions of the thickness change section 52 in the direction perpendicular to the axis at the deepest part of the recessed section 56 are larger than the outer dimensions of the tip section 24.

In the axial cross section perpendicular to the opposing direction of the pair of engaging arms 46, 46 shown in FIG. 3, the thickness dimension of the thickness-changing portion 52 is made larger than the thickness dimension of the tip portion 24 of the needle hub 18, including the tip locking portion 28 as a restricting portion. In particular, in the cross section, the minimum thickness dimension of the thickness-changing portion 52 is made larger than the thickness dimension of the tip portion 31 at the tip portion 24. This improves the load-bearing strength by changing the thickness dimension of the thickness-changing portion 52 in the base end portion 34 of the needle hub 18, which is more susceptible to the influence of external forces than the tip portion 24. Note that in both the axial cross sections of FIG. 2 and FIG. 3, it is sufficient that at least a portion of the thickness-changing portion 52 is thicker than the tip portion 24, and it is not necessary that the entire thickness-changing portion 52 is thicker than the tip portion 24.

The thickness change section 52 has an outer dimension larger than that of the connection port 44. In other words, the outer peripheral surface of the connection port 44 is located inside the outer peripheral surface of the thickness change section 52. As shown in FIG. 2, the connection port 44 may be provided at a position offset in the axial direction from the thickness change section 52. The connection port 44 may be provided on the inner circumference of the thickness change section 52 so that at least a portion of the connection port 44 is in the same axial position as the thickness change section 52.

As shown in Figures 1 to 4, the needle tip protector 14 has a generally cylindrical shape extending in the needle axis direction as a whole, and is integrally molded from a hard synthetic resin such as polypropylene, polycarbonate, glycol-modified polyethylene terephthalate, ABS resin, or MBS resin. The needle tip protector 14 is preferably transparent or translucent to allow the transmission of visible light. The needle tip protector 14 has a cylindrical peripheral wall 58, and an inner hole 60 that penetrates in the needle axis direction is formed on the inner circumference of the peripheral wall 58.

The peripheral wall 58 has a cylindrical portion 62 at the tip end that has a cross section that is roughly a perfect ring shape, and an expanded diameter portion 64 at the base end that is larger in diameter than the cylindrical portion 62 and expands to the outer periphery, and the shape differs in the needle axial direction.

The enlarged diameter portion 64 is formed in a substantially elliptical cylindrical shape, and the width dimension of the outer peripheral surface in the large diameter direction (horizontal direction) in FIG. 4 is larger than the width dimension of the outer peripheral surface in the small diameter direction (vertical direction) in FIG. 4. The wall portion constituting the enlarged diameter portion 64 is made up of small diameter portions 66, 66 constituting the vertical wall portion, while the wall portion in the horizontal direction is made up of large diameter portions 68, 68. The opposing direction of the small diameter portions 66, 66 and the opposing direction of the large diameter portions 68, 68 are substantially perpendicular to each other. An internal space 70 having a flat cross section whose horizontal dimension is larger than its vertical dimension is formed on the inner circumference of the enlarged diameter portion 64 at the base end portion of the inner hole 60 penetrating the needle tip protector 14. The internal dimension of the internal space 70 in the horizontal direction gradually increases toward the base end side.

Through windows 72, 72 are formed in the large diameter portions 68, 68 as engagement portions that penetrate in the plate thickness direction. The circumferential dimension of the through windows 72, 72 is larger than the circumferential dimension of the hooks 48, 48.

The peripheral wall 58 is provided with a pair of locking pieces 74, 74 that protrude from the cylindrical portion 62 toward the base end side. The locking pieces 74, 74 are arranged at positions corresponding to the large diameter portions 68, 68, are provided facing each other in the horizontal direction, and are spaced apart from each other in the circumferential direction. The locking pieces 74, 74 have a tip portion connected to the cylindrical portion 62 that extends approximately parallel to the needle axial direction, and the base portion has a tapered shape that slopes inward in the horizontal direction, which is the opposing direction, toward the base end side. The locking pieces 74, 74 are each curved in the circumferential direction. The radial distance between the opposing surfaces at the protruding tips of the locking pieces 74, 74 is slightly larger than the outer diameter dimension of the tip portion 24.

The protruding tips (base ends in the needle axis direction) of the locking pieces 74, 74 are located on the tip side in the needle axis direction relative to the base end of the enlarged diameter section 64. Therefore, the entirety of the locking pieces 74, 74 is housed in the internal space 70 of the enlarged diameter section 64.

A pair of side walls 76, 76 are provided on the inner periphery of the expanded diameter portion 64. As shown in Figures 3 and 4, the side walls 76, 76 are flat plates that extend in a direction substantially perpendicular to the vertical direction, and are arranged facing each other at a predetermined distance in the vertical direction. Therefore, the facing direction of the pair of side walls 76, 76 is substantially perpendicular to the facing direction of the pair of locking pieces 74, 74.

The side walls 76, 76 are spaced apart from the enlarged diameter portion 64 of the peripheral wall 58 on the inner circumferential side. As a result, a gap 78, 78 is formed between the side walls 76, 76 and the small diameter portions 66, 66 of the enlarged diameter portion 64 at least in the circumferential center portion of the small diameter portions 66, 66. The side walls 76, 76 are located closer to the tip side than the base ends of the locking pieces 74, 74. In this embodiment, the distance between the side walls 76, 76 is approximately equal to the outer diameter dimension of the tip portion 24 of the needle hub 18.

Each side wall portion 76 is composed of a pair of leaf springs 80, 80, which are elastically deformable in the thickness direction. The leaf springs 80, 80 are integrally formed with the large diameter portions 68, 68 of the enlarged diameter portion 64, and protrude laterally inward from the large diameter portions 68, 68. The leaf springs 80, 80 have protruding tips spaced apart from each other in the lateral direction, and a slit 82 is formed between the protruding tips, extending in the axial direction. When the puncture needle body 12, which will be described later, is inserted into the needle tip protector 14, the guide rib 32 of the needle hub 18 is inserted into the slit 82, and the guide rib 32 moves within the slit 82, thereby guiding the puncture needle body 12 in the axial direction relative to the needle tip protector 14.

As shown in FIG. 1, the tip portion of the needle tip protector 14 is provided with a wing-like portion 84. The wing-like portion 84 is formed, for example, from a soft synthetic resin. The wing-like portion 84 is formed integrally with a cylindrical fitting tube portion 86, with plate-like connecting portions 88, 88 protruding in the tangential direction of the fitting tube portion 86, and a wing body 90 is formed integrally with each of the connecting portions 88, 88 on the protruding tip side from the fitting tube portion 86. The wing-like portion 84 is attached to the peripheral wall 58 of the needle tip protector 14 by fitting the fitting tube portion 86 onto the tip portion of the cylindrical portion 62.

The needle assembly 10 is constructed by inserting the puncture needle body 12 through the inner hole 60 of the needle tip protector 14 from the opening on the base end side, and the needle tip protector 14 is fitted onto the puncture needle body 12. In the initial state before use of the needle assembly 10 shown in FIG. 1, the needle tip protector 14 is located at a puncture position where the needle tip 20 of the puncture needle 16 is exposed on the tip side of the needle tip protector 14 relative to the puncture needle body 12. In the initial state where the needle tip protector 14 is located at the puncture position relative to the puncture needle body 12, the tip 31 of the needle hub 18 is housed in the needle tip protector 14, and the tip 31 is inserted between the locking pieces 74, 74 of the needle tip protector 14. Therefore, in the initial state, at least a part of the tip 31 is located on the tip side of the base end surface. The conduit connection part 36 is provided at a position protruding toward the base end side from the needle tip protector 14, and is exposed from the needle tip protector 14. The stepped parts 57, 57 of the conduit connection part 36 abut against the base end surface of the needle tip protector 14 in the axial direction, so that the puncture needle body 12 and the needle tip protector 14 are positioned relative to each other in the axial direction.

In this initial state, as shown in FIG. 2, the hooks 48, 48 on the engagement arms 46, 46 of the needle hub 18 are inserted into and engaged with the through windows 72, 72 provided in the enlarged diameter portion 64 of the needle tip protector 14. This connects the needle tip protector 14 and the needle hub 18, maintaining the needle tip 20 in a protruding state, and restricting the movement of the puncture needle 16 toward the base end in the needle axial direction due to resistance during puncture, for example, when holding the wing-like portion 84 to perform puncture.

In the initial state of the needle assembly 10, the protruding tip portions of the locking pieces 74, 74 of the needle tip protector 14 are slightly spaced apart from the outer circumferential surface of the tip portion 24. The locking pieces 74, 74 may be in contact with the outer circumferential surface of the tip portion 24, and may be pushed slightly outward thereby.

In the initial state of the needle assembly 10, the thickness change section 52 in the needle hub 18 of the puncture needle body 12 is provided on the base end side of the locking pieces 74, 74 of the needle tip protector 14 located at the puncture position. Therefore, the thickness change section 52 is provided in a part of the needle hub 18 that is not protected by the needle tip protector 14. Therefore, in the thickness change section 52, the load-bearing capacity is improved by dispersing stress due to the change in thickness dimension and by reinforcing the thickness change section 52, thereby effectively preventing damage such as breakage of the needle hub 18.

Moreover, the thickness-changing portion 52 is provided on the distal side of the connection hole 38 in the conduit connection portion 36 into which the external conduit 49 is inserted, and is not reinforced by the external conduit 49. Therefore, the thickness-changing portion 52 is provided in a portion of the needle hub 18 that is easily damaged, and the reinforcing and stress-dispersing effects of the thickness-changing portion 52 effectively improve the load-bearing strength of the needle hub 18.

By providing a thickness change section 52 in the intermediate section 51 that connects the small-diameter tip section 24 to the larger-diameter pipe connection section 36 and in the pipe connection section 36 exposed from the needle tip protector 14, stress concentration is reduced in areas of the needle hub 18 that are prone to damage, improving the load-bearing capacity of the needle hub 18.

The needle assembly 10 is used for infusion, blood sampling, and hemodialysis through the fluid flow path 50 by inserting the puncture needle 16 into the patient's blood vessel and leaving the puncture needle body 12 in place. In addition, since the needle assembly 10 of this embodiment is provided with a wing-like portion 84, it is possible to insert the puncture needle 16 of the puncture needle body 12 while pinching the wing-like portion 84, for example. When leaving the puncture needle body 12 in a punctured state, it can be fixed with tape at the position of the wing-like portion 84, allowing it to be fixed with a wide contact area against the skin.

When removing the puncture needle body 12, the engagement arms 46, 46 of the needle hub 18 are pressed inward with the fingers while the needle tip protector 14 is fixed with tape at the wing-like portion 84. This releases the hooks 48, 48 from the through windows 72, 72, allowing the puncture needle body 12 to be moved toward the base end relative to the needle tip protector 14. By moving the puncture needle body 12 toward the base end relative to the needle tip protector 14 and removing the puncture needle 16 from the skin, the needle tip protector 14 moves toward the needle tip 20 relative to the puncture needle body 12. In this way, the connection between the puncture needle body 12 and the needle tip protector 14 at the puncture position by the pair of engagement arms 46, 46 can be released by operating the pair of engagement arms 46, 46, and the release of the connection allows the puncture needle body 12 and the needle tip protector 14 to move relatively in the axial direction.

The needle hub 18 has a thickness-changing section 52 whose thickness dimension changes, and when an operating force is applied to release the pair of engagement arms 46, 46, the stress is dispersed due to the change in axial rigidity of the thickness-changing section 52. As a result, the load-bearing capacity of the needle hub 18 is improved, and damage to the needle hub 18 due to the action of the operating force is avoided.

The thickness change section 52 is located axially away from the tip section 24 to which the puncture needle 16 is fixed and the conduit connection section 36 of the base section 34 to which the external conduit 49 is connected, and is provided between the tip section 24 and the conduit connection section 36. This provides reinforcement and distributes stress by the thickness change section 52 in the easily damaged parts of the needle hub 18 that are not reinforced by either the puncture needle 16 or the external conduit 49, and efficiently improves the load-bearing strength of the needle hub 18.

The thickness-changing section 52 is provided at a location that is separate from the needle fixing section 26, which has a restricted outer diameter dimension to allow insertion into the needle tip protector 14, and the conduit connection section 36, which has a restricted inner diameter dimension to allow insertion of the external conduit 49. This allows the thickness dimension of the thickness-changing section 52 to be changed with a large degree of freedom, making it particularly easy to tolerate thickening.

The base end portion 34 of the needle hub 18 is formed with a connection hole 38, and stress tends to concentrate at the outer circumferential corners on the bottom 40 side of the connection hole 38, which are prone to damage when an external force is applied. Therefore, the needle hub 18 has the thinnest part in an axial longitudinal section parallel to the opposing direction of the pair of engagement arms 46, 46, located away from the outer circumferential corners on the bottom 40 side of the connection hole 38 and in the axial middle part of the peripheral wall of the connection hole 38. This distributes stress to the thinned axial middle part of the peripheral wall of the connection hole 38, mitigating stress concentration at the outer circumferential corners on the bottom 40 side of the connection hole 38, improving the load-bearing strength of the needle hub 18.

5, the needle tip 20 of the puncture needle 16 is accommodated and covered by the inner circumference of the needle tip protector 14 when the puncture needle 12 is moved backward relative to the needle tip protector 14 to a predetermined protective position (the needle tip protector 14 is moved forward toward the needle tip 20 of the puncture needle 12). Furthermore, when the needle tip protector 14 moves to the protective position relative to the puncture needle 12, the free ends of the locking pieces 74, 74 move over the pair of locking protrusions 30, 30 as restricting parts and toward the tip side, so that the locking pieces 74, 74 that have elastically restored their shape are positioned toward the tip side relative to the pair of locking protrusions 30, 30. Then, when the puncture needle 12 tries to move toward the tip side relative to the needle tip protector 14, the base end surfaces of the pair of locking pieces 74, 74 abut against the tip surfaces of the pair of locking protrusions 30, 30 and are locked. As a result, the movement of the puncture needle body 12 toward the tip side relative to the needle tip protector 14 is restricted by the engagement between the pair of locking pieces 74, 74 and the pair of locking projections 30, 30, preventing the needle tip 20 of the puncture needle body 12 from being exposed again.

When the puncture needle body 12 attempts to move further toward the base end relative to the needle tip protector 14 in the protection position, the tip locking portion 28 provided on the needle hub 18 of the puncture needle body 12 abuts and locks against the side walls 76, 76 of the needle tip protector 14 in the axial direction. This restricts the movement of the puncture needle body 12 toward the base end, preventing the puncture needle body 12 from being pulled out toward the base end relative to the needle tip protector 14. In this way, when the needle tip 20 of the puncture needle 16 is protected by the needle tip protector 14, the movement of the puncture needle body 12 relative to the needle tip protector 14 is restricted on both the tip and base end sides, and the protection of the needle tip 20 by the needle tip protector 14 is maintained.

In this embodiment, a pair of locking pieces 74, 74 are provided, and together with the fact that the locking pieces 74, 74 are integrally molded with the peripheral wall 58 of the needle tip protector 14, when the locking pieces 74, 74 and the locking projections 30, 30 are locked, problems such as the needle tip protector 14 rattling against the puncture needle body 12 can be effectively prevented. In this way, by providing two or more locking pieces 74, the needle tip protector 14 is more reliably prevented from retracting toward the base end side relative to the puncture needle body 12, and the effect of preventing re-exposure of the needle tip 20 can be more stably exerted. In this case, it is preferable that the multiple locking pieces 74 are arranged approximately symmetrically with respect to the central axis of the needle tip protector 14.

With the needle tip 20 of the puncture needle body 12 protected by the needle tip protector 14, the tape fixing of the wing-shaped portion 84 is released and the needle assembly 10 is removed from the patient. However, the procedure for protecting the needle tip 20 is not limited to the above procedure. Specifically, for example, the tape fixing of the wing-shaped portion 84 may be released, the entire needle assembly 10 is moved back to remove the puncture needle 16 from the blood vessel, and then the puncture needle body 12 may be moved back relative to the needle tip protector 14 to protect the needle tip 20 of the puncture needle 16.

Figure 6 shows the base end portion of the needle assembly 100 as a second embodiment. In the following description, the same components and parts as those in the first embodiment are denoted by the same reference numerals and will not be described.

The needle hub 103 of the puncture needle 102 constituting the needle assembly 100 has a thickness-changing portion 106 of the base end portion 104 that has a shape different from that of the first embodiment in an axial longitudinal section parallel to the opposing direction of the pair of engagement arms 46, 46. That is, the thickness-changing portion 106 has a tapered portion 54 at the tip end and a convex portion 108 at the base end that has a semicircular cross section that is convex toward the outer periphery. As a result, the thickness dimension of the thickness-changing portion 106 changes so that the tapered portion 54 becomes thicker from the tip end side to the base end side, and the convex portion 108 becomes thicker toward the axial center portion.

According to this embodiment, the thickness changing portion 106 is provided with a convex portion 108 instead of the concave portion 56, so that the thickness dimension of the thickness changing portion 106 is made larger, and the load-bearing strength of the needle hub 103 at the thickness changing portion 106 is further improved. As shown in this embodiment, the thickness changing portion can be configured to include a convex portion. Although an example has been shown in which the convex portion 108 is provided on the base end side of the tapered portion 54, it may also be provided on the tip side.

The thickness changing section 106 includes a convex portion 108, so that at least the outer dimensions of the portion where the convex portion 108 is formed are larger than the outer dimensions of the pipeline connection section 36. In other words, the outer dimensions of the pipeline connection section 36 are equal to or smaller than the outer dimensions of the portion where the convex portion 108 is formed in the thickness changing section 106.

Figure 7 shows the base end portion of a needle assembly 110 as a third embodiment. The needle hub 113 of the puncture needle 112 constituting the needle assembly 110 has a thickness change portion 116 at the base end portion 114. The thickness change portion 116 is a tapered portion 54 as a whole, and gradually becomes thicker from the tip side to the base end side. The thickness change portion 116 of this embodiment also improves the load-bearing strength of the needle hub 113 by distributing stress.

Figure 8 shows the base end portion of the needle assembly 120 as a fourth embodiment. The needle hub 123 of the puncture needle body 122 constituting the needle assembly 120 has a thickness change portion 126 of the base end portion 124. As shown in Figures 8 and 9, the thickness change portion 126 has a small diameter tip portion 128 at the tip side and a large diameter base end portion 130 at the base end side, and a step portion 132 is formed on the outer circumferential surface of the connection portion between the small diameter tip portion 128 and the large diameter base end portion 130. In short, the thickness change portion 126 of this embodiment has a thickness dimension that changes stepwise in the axial direction due to the step portion 132 provided at the boundary portion between the small diameter tip portion 128 and the large diameter base end portion 130. The thickness change portion 126 of this embodiment has a thickness dimension that changes in two steps in the axial direction, but for example, the thickness dimension may change only at one point in the axial direction, or may change in three or more steps in the axial direction.

According to this embodiment, the thickness dimension is secured to be larger at the large diameter base end 130, and the load-bearing strength of the needle hub 123 is further improved at the large diameter base end 130 of the thickness change portion 126. In particular, as shown in FIG. 8, in the initial state in which the puncture needle body 122 is connected to the needle tip protector 14, the small diameter tip portion 128 is inserted into the needle tip protector 14, and the large diameter base end 130 is exposed from the needle tip protector 14 to the base end side. Therefore, the large diameter base end 130, which is less likely to be protected by the needle tip protector 14, is made thick, so that the load-bearing strength can be secured at the thickness change portion 126. As shown in this embodiment, the thickness change portion can be configured to include a step portion.

10 shows the base end portion of the needle assembly 140 as the fifth embodiment. The puncture needle body 142 constituting the needle assembly 140 has a thickness change portion 146 at the tip portion 144 of the needle hub 143. The thickness change portion 146 is provided at the tip portion 31 that is off the puncture needle 16 to the base end side at the tip portion 144. The thickness change portion 146 has concave portions 148, 148 that open in the opposing direction of the pair of engagement arms 46, 46 on the outer circumferential surface of the tip portion 31, and convex portions 150, 150 that protrude in the opposing direction of the pair of engagement arms 46, 46. In this embodiment, in addition to the thickness change portion 146 of the tip portion 31, the thickness change portion 52 of the intermediate portion 51 and the pipe connection portion 36 is also provided. However, for example, only the thickness change portion 146 of the tip portion 31 may be provided, and the thickness change portion 52 may not be required. In addition, it is desirable that the thickness change portion 146 of the tip 31 includes at least one of a convex portion, a concave portion, a tapered portion, and a stepped portion, similar to the thickness change portion 52 provided in the base end portion 34 shown in the first embodiment. The thickness change portion 146 of this embodiment has a minimum thickness dimension at the portion where the concave portions 148, 148 are formed, and the minimum thickness portion of the thickness change portion 146 is provided in the tip portion 144 of the needle hub 143.

Even in the needle assembly 140 constructed according to this embodiment, the load-bearing performance of the needle hub 143 can be improved by distributing stress and reinforcing the needle hub 143. In addition, in this embodiment, the part where the thickness dimension of the needle hub 143 is smallest in an axial cross section passing through the pair of engaging arms 46, 46 and parallel to the opposing direction of the pair of engaging arms 46, 46 is the part where the concave parts 148, 148 of the tip 31 are provided. This allows for the distribution of stress to the tip 31 when an external force such as the operating force of the pair of engaging arms 46, 46 is applied to the base end portion 34.

In the axial cross section passing through the pair of engagement arms 46, 46, the minimum thickness dimension of the thickness change portion 52 may be equal to or less than the thickness dimension of the needle hub 18 on the tip side of the thickness change portion 52. In this case, the outer dimension of at least a part of the tip side of the thickness change portion 52 may be equal to or greater than the outer dimension of the thickness change portion 52. This allows the needle hub 18 to reinforce the above-mentioned part that is likely to become weak, improving the strength performance of the needle hub 18. In addition, when the thickness change portion 52 becomes thicker toward the base end side, the outer dimension of the needle hub 18 may be configured to be equal to or less than the outer dimension of the thickness change portion 52 on the base end side of the thickness change portion 52. By configuring in this way, the thickness change portion 52 is likely to become thicker than the base end of the needle hub 18, and the above-mentioned part that is likely to become weak can be reinforced, improving the strength performance of the needle hub 18.

The thickness changing section 52 has a portion where the thickness dimension changes in an axial longitudinal section parallel to the needle axis direction and passing through the arm portion, and in an axial longitudinal section parallel to the needle axis direction and passing through the engagement arms 46, 46, the minimum thickness dimension of the thickness changing section 52 is equal to or less than the thickness dimension of the needle hub 18 on the tip side of the thickness changing section 52, and the thickness changing section 52 may have at least one of a convex portion, a concave portion, and an inclined portion on the tip side of the minimum thickness dimension portion. By providing the thickness changing section 52 with a concave portion, in addition to the portion where the thickness dimension of the thickness changing section 52 is equal to or less than the thickness dimension on the tip side of the needle hub 18, further portions that tend to become thin can be provided, and the external forces acting on those portions that tend to become thin can be dispersed and reduced. As a result, the strength performance of the needle hub 18 is improved.

In the embodiment shown in FIG. 11, a recess 162 is formed on the outer peripheral surface of the tip portion of the needle hub 160. The recess 162 is, for example, a groove extending in the circumferential direction, and the inner surface of the groove on the base end side is a base end side locking surface 164 that expands in the axially perpendicular direction. When the puncture needle body 12 is pulled out from the needle tip protector 14 to the base end side and the needle tip 20 of the puncture needle 16 is protected by the needle tip protector 14, the locking pieces 74, 74 of the needle tip protector 14 enter the recess 162. As a result, even if the needle tip protector 14 is moved toward the base end side relative to the puncture needle body 12, the locking pieces 74, 74 abut against the base end side locking surface 164 of the recess 162, restricting the movement of the needle tip protector 14. As a result, the tip 20 of the puncture needle 16 is prevented from re-protruding beyond the tip protector 14, and the protected state of the tip 20 is maintained.

In the structure of FIG. 11, the minimum thickness dimension of the thickness-changing portion 52 is equal to or greater than the thickness dimension of the portion of the needle fixing portion 26 where the recess 162 is formed. This ensures that the thickness dimension of the base end portion 34 of the needle hub 160, which includes the thickness-changing portion 52, is sufficient, ensuring the strength of the base end portion 34 of the needle hub 160, which is susceptible to the action of external forces. Furthermore, since the needle fixing portion 26 is reinforced by inserting the puncture needle 16, sufficient strength is ensured even if the recess 162 is formed and the needle fixing portion 26 is partially thin-walled.

The needle hub 170 shown in FIG. 12 has a first inclined portion 174 and a second inclined portion 176 on the distal end side and proximal end side of the minimum thickness portion (here, the outer circumferential corner portion of the connection hole 38) that is likely to be thin-walled of the thickness change portion 172. The first inclined portion 174 has a first inclined surface 178 that gradually inclines outward toward the proximal end side. The second inclined portion 176 has a second inclined surface 180 that gradually inclines outward toward the proximal end side. The first inclined surface 178 and the second inclined surface 180 have different inclinations from each other. For example, in this embodiment, the inclination angle of the first inclined surface 178 on the distal end side is smaller than the inclination angle of the second inclined surface 180 on the proximal end side. This allows a valley-shaped portion that is likely to become thin to be provided at the boundary between the first inclined surface 178 and the second inclined surface 180, in addition to the minimum thickness dimension portion of the thickness change portion 172, improving strength performance by dispersing stress. In the structure of FIG. 12, the boundary between the first inclined surface 178 and the second inclined surface 180 is located on the tip side of the bottom surface of the connection hole 38.

The inclination angle of the first inclined surface 178 may be greater than the inclination angle of the second inclined surface 180. In that case, the mountain-shaped portion of the boundary between the first inclined surface 178 and the second inclined surface 180 is provided at the outer circumferential corner on the bottom 40 side of the connection hole 38. As a result, the portion that is likely to become thin due to the formation of the connection hole 38 is reinforced by being thickened on the outer circumferential side.

In the embodiment shown in FIG. 12, the needle fixing portion 26 to which the puncture needle 16 is fixed and the conduit connection portion 36 are provided close to each other in the needle axial direction. That is, in the structure shown in FIG. 12, either the puncture needle 16 or the external conduit 49 is inserted over the entire axial length of the needle hub 18, and there is no portion where neither the puncture needle 16 nor the external conduit 49 is inserted. In this way, a reinforcing effect can be obtained by the puncture needle 16 and the external conduit 49 over the entire axial length of the needle hub 18, improving the load-bearing capacity of the needle hub 18.

In FIG. 12, the thickness change portion 172 is provided in the needle fixing portion 26 and the conduit connection portion 36. According to this, when the thickness change portion 172 is thinner than the needle fixing portion 26 of the needle hub 18, the needle hub 18 can be reinforced, and when the thickness change portion 172 is thicker than the needle fixing portion 26 of the needle hub 18, the strength of the needle hub 18 is further improved. Even when the tip portion 31 and the intermediate portion 51 in which neither the puncture needle 16 nor the external conduit 49 is inserted are provided between the needle fixing portion 26 and the conduit connection portion 36 as in the above embodiment, the needle fixing portion 26 and the conduit connection portion 36 can be considered to be provided substantially close to each other, for example, when the axial length of the tip portion 31 and the intermediate portion 51 is sufficiently short.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the specific description. For example, the thickness changing portion 52 may be provided in a portion that is housed in the needle tip protector 14 in the initial state of the needle assembly 10 in which the puncture needle body 12 and the needle tip protector 14 are connected. At least a portion of the thickness changing portion 52 may be located on the tip side of the pair of engagement arms 46, 46. It is preferable that the thickness changing portion 52 is provided in the base end portion of the needle hub 18, but it may also be provided in the tip portion of the needle hub 18, such as the tip portion 24, for example.

In the above embodiment, the thickness changing portion 52 has a substantially constant inner diameter, and the thickness changes with the change in the outer diameter. However, the thickness of the thickness changing portion may change, for example, by changing the inner diameter in the axial direction. The change in thickness of the thickness changing portion 52 is not necessarily limited to a change to a thickness thicker than the tip portion 24, but may be a change to a thickness thinner than the tip portion 24. It is preferable that the thickness of the thickness changing portion 52 changes in the axial direction over the entire circumference. However, for example, the thickness changing portion 52 may be provided partially in the circumferential direction, and the thickness may be substantially constant in the axial direction in the portion outside the thickness changing portion 52 in the circumferential direction.

The axial length dimension of the thickness-changing portion 52 is not particularly limited, and the ratio to the axial length dimension of the needle hub 18 is also not particularly limited. For example, the axial length dimension of the thickness-changing portion 52 may be greater than the axial length dimension of the pipeline connection portion 36. The thickness-changing portion 52 may be provided at multiple locations in the axial direction. Specifically, for example, the thickness-changing portion 52 may be provided at each of the tip portion 31 and the pipeline connection portion 36 serving as the base, and the thickness-changing portion 52 of the tip portion 31 and the thickness-changing portion 52 of the pipeline connection portion 36 may be positioned apart from each other in the axial direction.

The thickness change section 52 desirably has at least one of the tapered section 54, the concave section 56, the convex section 108, and the stepped section 132, and the thickness change section 52 may be composed of one of these types or a combination of multiple types. The thickness dimension of the tapered section 54 may gradually increase from the base end side to the tip end side of the needle hub 18. Also, the base end side relative to the stepped section 132 may have a smaller diameter than the tip end side.

As mentioned above, the technical idea of the invention disclosed in the specification is to ensure the load-bearing strength of the needle hub against the action of external forces, and is particularly advantageous in a novel aspect that can improve the strength of the base end portion of the needle hub. From this perspective, in addition to the thickness-changing portion described in the claims, it is also possible to disperse the stress generated in response to an external force in the axial direction by changing the diameter dimension in the axial direction, for example, even if the thickness is the same, and thereby changing the section modulus that governs the strength characteristics.

10, 100, 110, 120, 140 Needle assembly 12, 102, 112, 122, 142 Puncture needle body 14 Needle tip protector 16 Puncture needle 18, 103, 113, 123, 143, 160, 170 Needle hub 20 Needle tip 24, 144 Tip portion 26 Needle fixing portion 28 Tip locking portion 30 Locking protrusion 31 Tip portion 32 Guide protrusion 34, 104, 114, 124 Base end portion 35 Recess (recessed portion)
36 Pipe connection part (base)
38 Connection hole 40 Bottom 44 Connection port (shaft)
46 Engagement arm (arm portion)
48 Hook 49 External conduit 50 Fluid flow path 51 Intermediate portion 52, 106, 116, 126, 146, 172 Thickness change portion 54 Tapered portion 56, 148 Concave portion 57, 132 Step portion 58 Peripheral wall 60 Inner hole 62 Cylinder shaped portion 64 , enlarged diameter portion 66 , small diameter portion 68 , large diameter portion 70 , internal space 72 , through window 74 , locking piece 76 , side wall portion 78 , gap 80 , leaf spring 82 , slit 84 , wing-shaped portion 86 , fitting tube portion 88 , connecting portion 90 , wing main body 108 , 150 Convex portion 128 Small diameter tip portion 130 Large diameter base end portion 162 Recess 164 Base end side locking surface 174 First inclined portion 176 Second inclined portion 178 First inclined surface 180 Second inclined surface

Claims (17)

a puncture needle body having a needle hub fixed to a base end side of the puncture needle;
a needle tip protector movable in the axial direction of the puncture needle;
A needle assembly comprising the needle tip protector and an arm portion releasably connecting the needle hub,
The outer dimensions of the needle hub are larger on the proximal side than on the distal side of the needle hub,
The base end portion of the needle hub is provided with a thickness change portion whose thickness dimension changes,
The minimum thickness dimension of the thickness change portion is equal to or greater than the thickness dimension of the cylindrical tip portion of the needle hub, and
The needle hub has the arm portion integrally formed from the base end side toward the tip end side of the needle hub, a connection hole for an external conduit opening at the base end side of the needle hub, and a connection port integrally formed protruding from the bottom of the connection hole toward the base end side,
The bottom of the connection hole is located closer to the base end of the needle hub than the thickness change portion,
A needle assembly in which the base end of the arm is located closer to the base end of the needle hub than the bottom of the connection hole . The thickness changing portion has a portion whose thickness dimension changes in an axial longitudinal section parallel to the needle axis direction and passing through the arm portion,
2. The needle assembly according to claim 1, wherein in an axial longitudinal section parallel to the needle axial direction and passing through the arm portion, the minimum thickness dimension of the thickness change portion is greater than or equal to the thickness dimension of the needle hub on the tip side of the thickness change portion. the needle hub includes a tip-side needle fixing portion to which the puncture needle is fixed, and a base-side pipeline connecting portion to which an external pipeline is connected,
the thickness change portion is located between the needle fixing portion and the pipeline connection portion in the needle hub,
3. The needle assembly according to claim 2, wherein in an axial longitudinal section parallel to the needle axial direction and passing through the arm portion, the minimum thickness dimension of the thickness varying portion is equal to or greater than the thickness dimension of the needle fixing portion. a restricting portion that restricts movement of the needle tip protector relative to the needle hub in the needle axis direction by contacting the needle tip protector is provided on the needle hub,
4. The needle assembly according to claim 1, wherein the minimum thickness dimension of the thickness changing portion is equal to or greater than the thickness dimension of the needle hub at the restricting portion. The needle assembly according to claim 4, wherein the restricting portion includes at least one of a protrusion and a recess. 6. The needle assembly according to claim 4, wherein the needle hub is provided with a needle fixing portion to which the puncture needle is fixed, and in an axial longitudinal section parallel to the needle axis direction and passing through the arm portion, the minimum thickness dimension of the thickness changing portion is equal to or greater than the thickness dimension of a portion of the needle fixing portion of the needle hub that is free from the restricting portion. The thickness changing portion has a portion in which a thickness dimension changes in an axial longitudinal section parallel to the needle axis direction and not passing through the arm portion,
7. The needle assembly according to claim 1, wherein in an axial longitudinal section parallel to the needle axial direction and not passing through the arm portion, the minimum thickness dimension of the thickness changing portion is equal to or greater than the thickness dimension of the needle hub on the tip side of the thickness changing portion. the needle hub includes a tip-side needle fixing portion to which the puncture needle is fixed, and a base-side pipeline connecting portion to which an external pipeline is connected,
8. The needle assembly according to claim 7 , wherein the thickness change portion is located between the needle fixing portion and the pipeline connection portion in the needle hub in an axial vertical section parallel to the needle axial direction and not passing through the arm portion. the needle hub includes a tip-side needle fixing portion to which the puncture needle is fixed, and a base-side pipeline connecting portion to which an external pipeline is connected,
8. The needle assembly according to claim 7, wherein the thickness change portion is provided on the needle fixing portion. a restricting portion that restricts movement of the needle tip protector relative to the needle hub in the needle axis direction by contacting the needle tip protector is provided on the needle hub,
10. The needle assembly according to claim 7 , wherein the minimum thickness dimension of the thickness changing portion is equal to or greater than the thickness dimension of the needle hub at the restricting portion. The needle assembly of claim 10 , wherein the restriction portion includes at least one of a protrusion and a recess. The needle hub has an outwardly protruding guide rib,
12. The needle assembly according to claim 7 , wherein the minimum thickness dimension of the thickness changing portion is equal to or greater than the thickness dimension of the needle hub at the portion where the guide rib is formed. the needle hub includes a tip-side needle fixing portion to which the puncture needle is fixed, and a base-side pipeline connecting portion to which an external pipeline is connected,
13. The needle assembly according to claim 1, wherein the outer dimensions of the pipeline connection part are larger than the outer dimensions of the needle fixing part. The needle assembly according to any one of claims 1 to 13 , wherein the thickness changing portion includes at least one of an inclined portion, a concave portion, a convex portion, and a stepped portion. 15. The needle assembly according to claim 1, wherein a portion of the needle hub where the thickness dimension is smallest in an axial longitudinal section parallel to the needle axis direction and passing through the arm portion is located at a position away from an outer peripheral corner on the bottom side of a connection hole which opens on the base end side of the needle hub and into which an external conduit is inserted. the needle hub includes a tip-side needle fixing portion to which the puncture needle is fixed, and a base-side pipeline connecting portion to which an external pipeline is connected,
The needle assembly according to any one of claims 1 to 15 , wherein a portion where the thickness dimension of the needle hub is minimum in an axial longitudinal section parallel to the needle axis direction and passing through the arm portion is provided in the pipeline connection portion. the needle hub includes a tip-side needle fixing portion to which the puncture needle is fixed, and a base-side pipeline connecting portion to which an external pipeline is connected,
A needle assembly according to any one of claims 1 to 16 , wherein a portion where the thickness dimension of the needle hub is minimum in an axial longitudinal section parallel to the needle axis direction and passing through the arm portion is provided in the needle fixing portion.

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