[0001] The present invention relates to a puncturing 5 tool for small animals
used for collecting blood from small animals or the like.
BACKGROUND ART
[0002] Conventionally, when a small animal such as a mouse is subjected to
10 percutaneous blood collection or other treatment, a puncturing tool for small animals,
which is different from that for human bodies, has been used. This is because for
small animals, unlike the case of targeting the human bodies, the amount of blood
collected is very small, and it is necessary to puncture a narrow tail vein of the mouse
or the like.
15 [0003] A puncturing tool for small animals having a conventional structure is
disclosed in US Pat. No. US 4,393,882 (Patent Document 1). Specifically, a round
tubular elastic tube is provided on the proximal end side of the small-diameter hollow
needle, and a small-diameter capillary tube (a hematocrit capillary tube) can be
connected from the opening end of the elastic tube. Then, by puncturing a vein or
20 the like of a small animal with the hollow needle, a small amount of blood can be
collected in a capillary tube via the hollow needle due to a capillary phenomenon.
[0004] However, when the inventors examined such a puncturing tool for
small animals having a conventional structure, the inventors found that the said
puncturing tool has new and unknown problems.
25 [0005] For example, with the puncturing tool for small animals having a
conventional structure, it is difficult to know that the capillary tube is correctly
connected when the capillary tube is inserted into and connected to the elastic tube
provided on the proximal end side of the hollow needle. Therefore, the capillary
tube may be insufficiently inserted and fall off, while the excessive insertion of the
30 capillary tube may cause breakage.
[0006] In addition, when puncturing is performed with the capillary tube
inserted into the elastic tube and connected to the hollow needle, the capillary tube
that touches the operator's finger tends to incline at the connected site to the elastic
tube, thereby making it difficult to reliably obtain the stable sealing properties at the
35 connected site. Especially when puncturing a small animal, the puncture angle of the
hollow needle may be small, and it may be easier to operate if the capillary tube is
allowed to incline. However, with the puncturing tool for small animals having a
conventional structure, it is difficult to allow the inclination of the capillary tube and
to reliably obtain the stable sealing property in a compatible manner.
- 2 -
BACKGROUND ART DOCUMENT
PATENT DOCUMENT
[0007] Patent Document 1: US 4,393,882
5
SUMMARY OF THE INVENTION
PROBLEM THE INVENTION ATTEMPTS TO SOLVE
[0008] It is therefore an object of the present invention to provide a puncturing
tool for small animals with a novel structure which is able to make it easy to grasp the
connection status of the capillary tube and to prevent the capillary 10 tube from
accidentally falling off.
MEANS FOR SOLVING THE PROBLEM
[0009] A first preferred embodiment of the present invention provides a
puncturing tool for small animals including a hollow needle and a connecting part for
15 a capillary tube, the connecting part being provided on a proximal end side of the
hollow needle, wherein the connecting part has a tapered peripheral wall expanding
and extending in a direction away from the hollow needle, and the tapered peripheral
wall includes an elastic fitting part configured to allow the capillary tube to be
inserted, the elastic fitting part projecting inward from a lengthwise middle portion of
20 the tapered peripheral wall.
[0010] With the puncturing tool for small animals of the present preferred
embodiment, the insertion resistance of the capillary tube increases until the capillary
tube passes through the elastic fitting part. However, after the capillary tube passes
through the elastic fitting part, the insertion resistance of the capillary tube is
25 generally constant. Therefore, in comparison with the puncturing tool having the
conventional structure described in Patent Document 1 in which the insertion
resistance of the capillary tube just gradually increases, a tactile feeling can be
obtained in the insertion operation of the capillary tube, and the connection status of
the capillary tube can easily be grasped. Moreover, by passing through the elastic
30 fitting part, the retaining force due to the elasticity of the elastic fitting part is exerted
on the capillary tube, thereby exhibiting the effect of preventing the capillary tube
from accidentally falling off as well.
[0011] Moreover, since the connecting part has a tapered peripheral wall, the
insertion operation of the capillary tube is facilitated, and the inner diameter on the
35 opening end side of the connecting part, which is likely to come into abutment when
the capillary tube inclines, can be made large, thereby allowing the inclination of the
capillary tube.
[0012] Further, the internal volume of the connecting part on the distal end
side with respect to the elastic fitting part, where the distal end portion of the capillary
- 3 -
tube is to be inserted, is made small by the tapered peripheral wall. Thus, even if the
collected blood or the like leaks at the connected site of the puncture needle and the
capillary tube, the amount of leakage can be kept small.
[0013] A second preferred embodiment of the present invention provides a
puncturing tool for small animals including a hollow needle and a connecting 5 part for
a capillary tube, the connecting part being provided on a proximal end side of the
hollow needle, wherein the connecting part has a tubular peripheral wall extending in
a direction away from the hollow needle, and the tubular peripheral wall includes an
elastic fitting part projecting inward from a lengthwise middle portion of the tubular
10 peripheral wall, and a projecting distal end portion of the elastic fitting part that
projects inward is configured to be elastically deformed toward a distal end side in an
axial direction of the tubular peripheral wall while being expanded by the capillary
tube being inserted.
[0014] With the puncturing tool for small animals of the present preferred
15 embodiment, the projecting distal end portion of the elastic fitting part is elastically
deformed toward the distal end side in the axial direction due to the insertion of the
capillary tube. This suppresses operating resistance due to the insertion of the
capillary tube, thereby reducing damage to the capillary tube or the like. Moreover,
the projecting distal end portion of the elastic fitting part is elastically deformed while
20 being expanded due to the insertion of the capillary tube. This makes it possible to
achieve reduction in the insertion resistance of the capillary tube as described above
and good sealing properties between the elastic fitting part and the capillary tube in a
compatible manner.
[0015] A third preferred embodiment of the present invention provides the
25 puncturing tool for small animals according to the first or second preferred
embodiment, wherein the elastic fitting part inclines toward a hollow needle side and
projects inward.
[0016] With the puncturing tool for small animals of the present preferred
embodiment, since the inclination direction of the elastic fitting part is the insertion
30 direction of the capillary tube, the insertion resistance of the capillary tube through the
elastic fitting part can be reduced. In addition, by inclining the elastic fitting part, it
is also possible to increase the contact area with the capillary tube while reliably
obtaining the softness of the elastic fitting part, thereby improving the holding
performance and the sealing performance with respect to the capillary tube.
35 [0017] A fourth preferred embodiment of the present invention provides the
puncturing tool for small animals according to any of the first through third preferred
embodiments, wherein the elastic fitting part is tapered toward a projecting distal end
side.
[0018] With the puncturing tool for small animals of the present preferred
- 4 -
embodiment, the elastic fitting part is thinned especially in the vicinity of the contact
part with the capillary tube so as to be easily deformed. As a result, for example, it
becomes easy to deal with capillary tubes having different outer diameters. Further,
at the time of inclination or displacement of the capillary tube as well, the vicinity of
the contact part of the elastic fitting part with the capillary 5 tube easily follows to
deform, thereby making it possible to increase the allowable amount of movement of
the capillary tube.
[0019] A fifth preferred embodiment of the present invention provides the
puncturing tool for small animals according to any of the first through fourth preferred
10 embodiments, wherein the elastic fitting part has a slit configured to be pushed to
expand by the capillary tube being inserted.
[0020] With the puncturing tool for small animals of the present preferred
embodiment, the expanding deformation of the slit makes it possible to easily deal
with capillary tubes having different thicknesses, for example. Further, in the
15 non-connected state of the capillary tube, by closing the slit, the proximal end side of
the hollow needle can be closed or sufficiently narrowed at the connecting part. This
increases a degree of freedom in selecting operations, for example, preventing blood
leakage while connecting the capillary tube after puncturing with the hollow needle,
or the like.
20 [0021] A sixth preferred embodiment of the present invention provides the
puncturing tool for small animals according to any of the first through fifth preferred
embodiments, wherein an inside of the tapered peripheral wall or the tubular
peripheral wall on a hollow needle side with respect to the elastic fitting part
constitutes a deformation allowance space configured to allow entrance of the elastic
25 fitting part deformed by the capillary tube being inserted.
[0022] With the puncturing tool for small animals of the present preferred
embodiment, the mode of deformation of the elastic fitting part when the capillary
tube is inserted is stabilized by the deformation allowance space, thereby preventing
irregular deformation. As a result, during the insertion operation of the capillary
30 tube, it becomes possible to more stably obtain a tactile feeling due to the change in
the insertion resistance before and after the capillary tube passing through the elastic
fitting part as described above.
[0023] A seventh preferred embodiment of the present invention provides the
puncturing tool for small animals according to any of the first through sixth preferred
35 embodiments, wherein an internal volume of the tapered peripheral wall or the tubular
peripheral wall is configured such that an internal volume on a hollow needle side
with respect to the elastic fitting part is smaller than an internal volume on a proximal
end opening side with respect to the elastic fitting part.
[0024] With the puncturing tool for small animals of the present preferred
- 5 -
embodiment, the dead space inside the tapered peripheral wall or the tubular
peripheral wall can be minimized without excessively hindering the inclination of the
capillary tube. Further, even if the collected blood or the like leaks from the
connected portion between the hollow needle and the capillary tube inside the tapered
peripheral wall or the tubular peripheral wall, the volume of the 5 portion up to the
elastic fitting part is made small, so that it is also possible to minimize the amount of
leaked and wasted blood or the like.
[0025] An eighth preferred embodiment of the present invention provides the
puncturing tool for small animals according to any of the first through seventh
10 preferred embodiments, wherein a proximal end portion of the hollow needle is
provided with a needle hub, while a connecting member formed of a material softer
than that of the needle hub is attached to the needle hub, and the connecting member
extending from the needle hub to the proximal end side constitutes the connecting
part.
15 [0026] With the puncturing tool for small animals of the present preferred
embodiment, it is also possible to avoid damage to the capillary tube due to abutment
against the connecting part or the like while reliably obtaining the supporting
performance of the hollow needle by the needle hub.
[0027] A ninth preferred embodiment of the present invention provides the
20 puncturing tool for small animals according to the eighth preferred embodiment,
wherein a proximal end portion of the needle hub is provided with an abutting face
configured to define an insertion position of the capillary tube by being abutted by a
distal end face of the capillary tube inserted through the elastic fitting part.
[0028] With the puncturing tool for small animals of the present preferred
25 embodiment, when inserting the capillary tube, the position of the most distal end of
inserted tube can be more clearly grasped.
EFFECT OF THE INVENTION
[0029] According to the present invention, it is possible to provide a
puncturing tool for small animals with a novel structure which is able to make it easy
30 to grasp the connection status of the capillary tube and to prevent the capillary tube
from accidentally falling off.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a vertical cross-sectional view showing a puncturing tool for small
35 animals according to a first practical embodiment of the present invention, taken
along line 1-1 of FIG. 2.
FIG. 2 is a rear view of the puncturing tool for small animals shown in FIG. 1.
FIG. 3 is a vertical cross-sectional view of the puncturing tool for small
animals shown in FIG. 1 which shows the connected state of a capillary tube.
- 6 -
FIG. 4 is a vertical cross-sectional view of the puncturing tool for small
animals shown in FIG. 1, showing the connected state of a male luer.
FIG. 5 is a vertical cross-sectional view illustrating another embodiment of an
elastic fitting part adopted in the puncturing tool for small animals shown in FIG. 1.
FIG. 6 is a vertical cross-sectional view showing 5 a puncturing tool for small
animals according to a second practical embodiment of the present invention, taken
along line 6-6 of FIG. 7.
FIG. 7 is a rear view of the puncturing tool for small animals shown in FIG. 6.
FIG. 8 is a vertical cross-sectional view of the puncturing tool for small
10 animals shown in FIG. 6 which shows the connected state of a capillary tube, taken
along line 8-8 of FIG. 9.
FIG. 9 is a rear view of the puncturing tool for small animals in the connected
state of the capillary tube shown in FIG. 8.
FIG. 10 is a vertical cross-sectional view illustrating another embodiment of
15 an elastic fitting part adopted in the puncturing tool for small animals shown in FIG.
6.
EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0031] In order to clarify the present invention more specifically, practical
20 embodiments of the present invention will be described in detail below in reference to
the drawings.
[0032] First, FIGS. 1 and 2 show a puncturing tool 2 for small animals
according to a first practical embodiment of the present invention. The puncturing
tool 2 of the present practical embodiment includes a hollow needle 4 for puncturing,
25 and a connecting part 6 is provided on the proximal end side of the hollow needle 4.
As shown in FIG. 3, a capillary tube 8 is attachable and detachable with respect to the
connecting part 6. In the following description, the axial direction refers to the
needle axis direction of the hollow needle 4, and the distal end side and the proximal
end side refer to the distal end side and the proximal end side of the hollow needle 4
30 in the needle axis direction, respectively.
[0033] Described more specifically, the hollow needle 4 has a hollow structure
which is generally straight, and is provided with a sharp, pointed distal end 10. The
hollow needle 4 has a small diameter for puncturing a small animal, and for example,
a capillary phenomenon is also considered for blood collection. Preferably, a needle
35 having a small diameter of, for example, 23 gauge or higher and made of a rigid
material such as metal is used as the hollow needle 4.
[0034] A proximal end portion 12 of the hollow needle 4 is provided with a
needle hub 14. The needle hub 14 has a generally round tubular shape overall, and
the proximal end portion 12 of the hollow needle 4 is inserted into a central hole 16 of
- 7 -
the needle hub 14 in a fastened state. The fastening structure of the hollow needle 4
to the needle hub 14 is not limited. For example, the hollow needle 4 can be fixed
by press-fitting the hollow needle 4 into the central hole 16, but the hollow needle 4
can also be fastened by bonding, insert molding, or the like.
[0035] It is desirable that the proximal end portion 12 of 5 the hollow needle 4
is arranged so as to pass through the needle hub 14. In the present practical
embodiment, the proximal end face of the hollow needle 4 passes through so as to
reach and be generally flush with a proximal end face 34 of the needle hub 14. This
configuration avoids the occurrence of an unnecessary step in the central hole 16 of
10 the needle hub 14 and the occurrence of a stepped state due to the protrusion of the
hollow needle 4 from the needle hub 14.
[0036] In the present practical embodiment, the central hole 16 of the needle
hub 14 is expanded on the distal end side, which facilitates manufacturing by
press-fitting the hollow needle 4. Besides, the proximal end side of the central hole
15 16 has a small diameter over a predetermined length, and is fitted and fixed to the
outer circumferential surface of the hollow needle 4. On the other hand, on the distal
end side of the expanded central hole 16, an annular protrusion that protrudes on the
inner circumferential surface and abuts against the outer circumferential surface of the
hollow needle 4 is formed near the opening of the central hole 16, thereby improving
20 the bearing capacity of the hollow needle 4.
[0037] Besides, the needle hub 14 is provided with wing-like parts 20
projecting on the outer circumferential surface. In the present practical embodiment,
a pair of wing-like parts 20, 20 are provided so as to spread on both the left and right
sides of the needle hub 14 in FIG. 1. The needle hub 14 is preferably made of
25 synthetic resin, and the needle hub 14 is integrally molded with the pair of wing-like
parts 20, 20. A linking part 22 of each wing-like part 20 to the needle hub 14 is thin
and can be bent, and the pair of wing-like parts 20, 20 are configured to be gripped by
the user with the fingertips of one hand by being overlapped with each other.
[0038] Moreover, a connecting member 24, which is a tubular separate
30 member, is connected to the proximal end side of the needle hub 14. The connecting
member 24 includes a tapered peripheral wall 26 having a circular tapered shape and
serving as one type of a tubular peripheral wall. An attachment tube 28 having a
generally round tubular shape extends from the small-diameter side end of the tapered
peripheral wall 26 in the axial direction. The attachment tube 28 is fitted and fixed
35 to a proximal end portion 30 of the needle hub 14 in an externally fitted state, and is
bonded or the like as necessary. In the present practical embodiment, the proximal
end portion 30 of the needle hub 14 has a tapered tubular shape whose outer diameter
dimension gradually decreases toward the proximal end side.
[0039] With this configuration, the connecting member 24 extends outward
- 8 -
from the proximal end side of the needle hub 14 generally coaxially with the needle
hub 14, and a proximal end opening 32 having a large diameter constitutes an
insertion slot of the capillary tube 8. Besides, a proximal end face 34 of the needle
hub 14 is located within the small-diameter side end of the tapered peripheral wall 26.
The proximal end face 34 comprises a generally flat 5 surface extending in the
axis-perpendicular direction, and constitutes an abutting face that can define the
insertion end of the capillary tube 8 by being abutted by the distal end face of the
capillary tube 8 inserted into the tapered peripheral wall 26.
[0040] The connecting member 24 is preferably made softer than the needle
10 hub 14, and may be formed of, for example, polyvinyl chloride, isoprene rubber, or
the like having elasticity. Further, it is desirable that the proximal end portion 30 of
the needle hub 14 around which the attachment tube 28 of the connecting member 24
is externally fitted has a slightly tapered shape on its outer circumferential surface,
thereby making it easy to externally fit the attachment tube 28.
15 [0041] Furthermore, in the present practical embodiment, the portion of the
connecting member 24 extending from the needle hub 14 comprises the tapered
peripheral wall 26 having a tapered inner and outer circumferential surface across
generally the entire length. The tapered peripheral wall 26 includes an elastic fitting
part 36 projecting from the inner circumferential surface in the lengthwise middle
20 portion thereof.
[0042] The elastic fitting part 36 is made of an elastic material, and is
integrally formed with the tapered peripheral wall 26 of the connecting member 24 in
the present practical embodiment. Besides, the elastic fitting part 36 has a generally
tapered tubular shape that inclines and projects toward the distal end side in the axial
25 direction. Further, the elastic fitting part 36 has an inclination angle larger than that
of the tapered peripheral wall 26, and is formed with a length that does not reach the
small-diameter side end of the tapered peripheral wall 26.
[0043] In particular, the elastic fitting part 36 of the present practical
embodiment has a vertical cross-sectional shape that tapers toward the projecting
30 distal end side. That is, in the elastic fitting part 36, the thickness dimension of the
distal end portion is smaller than the thickness dimension of the proximal end portion
projecting from the tapered peripheral wall 26. Further, the minimum diameter of
the projecting distal end of the elastic fitting part 36 is smaller than the outer diameter
of the proximal end face 34 of the needle hub 14, which is the inner diameter of the
35 small-diameter side end of the tapered peripheral wall 26.
[0044] Furthermore, the position of the elastic fitting part 36 is not limited to
the lengthwise center of the tapered peripheral wall 26, but may be set to any
lengthwise middle position of the tapered peripheral wall 26 except for the lengthwise
opposite ends thereof. In the present practical embodiment, the elastic fitting part 36
- 9 -
is provided on the distal end side with respect to the lengthwise center of the tapered
peripheral wall 26. That is, the tapered peripheral wall 26 includes a distal side
tapered part 38 extending to the distal end side with respect to the elastic fitting part
36 and a proximal side tapered part 40 extending to the proximal end side with respect
to the elastic fitting part 36, and the proximal side tapered part 40 is 5 longer in the axial
direction than the distal side tapered part 38.
[0045] The taper angle, wall thickness, and the like of the tapered peripheral
wall 26 are not limited, but the taper angle, wall thickness, and the like may be
partially varied in the length direction. In the present practical embodiment, in
10 consideration of the strength of the peripheral wall, the guiding action of the capillary
tube 8, the connection of a male luer 54 described later, and the like, the wall
thickness of the proximal side tapered part 40 is made larger than that of the distal
side tapered part 38, and the taper angle of the inner circumferential surface of the
proximal side tapered part 40 is partially varied in the length direction.
15 [0046] Further, an internal space 42 of the tapered peripheral wall 26 includes
a distal side internal space 44 located on the distal end side with respect to the elastic
fitting part 36 and a proximal side internal space 46 located on the proximal end side
with respect to the elastic fitting part 36. Since the elastic fitting part 36 is provided
so as to be shifted to the distal end side, and in combination with the fact that the
20 peripheral wall has a tapered shape, the proximal side internal space 46 has an internal
volume smaller than that of the distal side internal space 44.
[0047] It is desirable that the volume of the distal side internal space 44 is set
to be equal to or larger than the volume of the elastic fitting part 36. With this
configuration, the distal side internal space 44 constitutes a deformation allowance
25 space that configured to allow entrance of the elastic fitting part 36 deformed toward
the distal end side due to insertion of the capillary tube 8, to reliably obtain a degree
of freedom of deformation of the elastic fitting part, and to suppress increase in the
insertion resistance of the capillary tube 8.
[0048] Further, it is desirable to set the shape and thickness of the elastic
30 fitting part 36, the inner diameter of the distal side tapered part 38, and the like such
that in the insertion state of the capillary tube 8 in which the elastic fitting part 36 is
elastically deformed so as to be pushed into the distal side internal space 44, a gap 48
remains between the radially outer side of the elastic fitting part 36 and the distal side
tapered part 38. With this configuration, even in the insertion state of the capillary
35 tube 8, elastic deformation of the elastic fitting part 36 is easily allowed, thereby
decreasing the insertion resistance of the capillary tube 8, increasing the allowable
amount of movement of the capillary tube 8 in the axis-perpendicular direction, and
the like.
[0049] The capillary tube 8 is configured to be connected to the puncturing
- 10 -
tool 2 having the above-mentioned structure, and with the capillary tube 8 inserted
and connected as illustrated in FIG. 3, the puncturing tool 2 is used, for example, as a
puncturing tool for collecting blood from a small animal. Through tail prick of a
mouse, the puncturing tool 2 is able to perform blood collection or the like from the
tail vein utilizing 5 capillary phenomenon.
[0050] In the puncturing tool 2, as shown in FIG. 3, the capillary tube 8
inserted in the axial direction from the proximal end opening 32 of the connecting
member 24 passes through the proximal side internal space 46 of the tapered
peripheral wall 26, and is further inserted in a state where the capillary tube 8 passes
10 through the elastic fitting part 36 and reaches so far as the distal side internal space 44.
By so doing, the distal end portion of the capillary tube 8 is inserted into the tapered
peripheral wall 26 of the connecting member 24, and the outer circumferential surface
thereof is elastically supported by the elastic fitting part 36, so as to be held in
communication with the central hole of hollow needle 4. As will be appreciated
15 from the above, in the present practical embodiment, the connecting part 6 of the
capillary tube 8 is constituted by the tapered peripheral wall 26 of the connecting
member 24 and the elastic fitting part 36.
[0051] Here, the outer diameter dimension of the capillary tube 8 is not
limited, but is preferably be set such that the capillary tube 8 to be used as a suitable
20 size is inserted so as to pass through the elastic fitting part 36, and the elastic fitting
part 36 comes into generally close contact with the outer circumferential surface of
the capillary tube 8 about the entire circumference. Specifically, it is desirable that
the inner diameter of the elastic fitting part 36 is set to be equal to or less than the
minimum outer diameter of the suitable capillary tube 8. Besides, it is desirable that
25 the inner diameter dimension of the tapered peripheral wall 26 at the formation site of
the elastic fitting part 36, which is the outer diameter dimension of the elastic fitting
part 36, is set to be equal to or larger than the maximum outer diameter of the suitable
capillary tube 8.
[0052] Then, the inserted capillary tube 8 is fitted and inserted through the
30 elastic fitting part 36 by elastically deforming a projecting distal end portion 36a,
which is especially decreased in diameter, so as to be bent or extended toward the
distal end side in the axial direction while being pushed to expand radially outward.
By so doing, due to the elastic recovering action of the elastic fitting part 36, the
elastic fitting part 36 is pressed against the outer circumferential surface of the
35 capillary tube 8 about the entire circumference so as to realize the sealed state. In
particular, in the present practical embodiment, the elastic fitting part 36 inclines
toward the distal end side with respect to the axis-perpendicular direction, and the
projecting distal end portion 36a is elastically deformed so that the said inclination
angle is larger. Therefore, in combination with the fact that the elastic fitting part 36
- 11 -
has a tapered cross-sectional shape, reduction in the insertion resistance of the
capillary tube 8 and improvement in the sealing performance with the capillary tube 8
can be achieved.
[0053] Further, even in the insertion state of the capillary tube 8, due to elastic
deformation of the elastic fitting part 36, inclination and 5 movement of the capillary
tube 8 are allowed while maintaining the sealed state. In addition, at the proximal
end portion where the amount of movement of the capillary tube 8 in the
axis-perpendicular direction increases during inclination of the capillary tube 8, the
inner diameter of the proximal side tapered part 40 of the tapered peripheral wall 26 is
10 made large. This will avoid an excessive limitation of the inclination of the capillary
tube 8 due to abutment of the capillary tube 8 against the connecting member 24.
Therefore, for example, when puncturing a small animal using the puncturing tool 2 to
which the capillary tube 8 is inserted and connected, even if the finger touches the
capillary tube 8 and the hollow needle 4 and the capillary tube 8 incline relative to
15 each other, damage to the capillary tube 8 will be prevented.
[0054] In particular, in the present practical embodiment, the elastic fitting
part 36 inclines toward the distal end side in the axial direction while decreasing in
diameter. Thus, in the insertion state of the capillary tube 8, not only the minimum
inner diameter portion in the elastic fitting part 36 but also the wide area of the
20 tapered inner circumferential surface of the projecting distal end portion 36a bent or
extended in the axial direction tends to come into close contact with the outer
circumferential surface of the capillary tube 8. As a result, a large sealing area can
be reliably obtained at the insertion site of the capillary tube 8 into the elastic fitting
part 36, thereby further improving the sealing properties with a small abutting force.
25 [0055] Moreover, in the present practical embodiment, the minimum inner
diameter portion of the elastic fitting part 36 is a generally circular inner hole smaller
than the outer diameter of the capillary tube 8. Therefore, the shape of the inner
circumferential surface of the elastic fitting part 36 easily conform to the outer
circumferential surface of the capillary tube 8 inserted so as to expand the inner hole
30 of the elastic fitting part 36. Accordingly, the elastic fitting part 36 comes into
intimate contact against the outer circumference of the capillary tube 8 about the
entire circumference with a generally uniform abutting force, thereby further
improving and stabilizing the sealing performance.
[0056] Furthermore, when connecting the capillary tube 8, first, the distal end
35 face of the capillary tube 8 comes into contact with the proximal end side face of the
elastic fitting part 36, and pushes the elastic fitting part 36 to the distal end side while
being accompanied by bending deformation to the distal end side and/or extending
deformation in the axial direction of the elastic fitting part 36. Besides, due to
increase in the insertion amount of the capillary tube 8, the inner hole of the elastic
- 12 -
fitting part 36 is gradually pushed open and deformed to expand. Then, when the
amount of expanding deformation of the inner hole of the elastic fitting part 36
becomes large and the capillary tube 8 passes through the elastic fitting part 36, the
increase in the insertion amount of the capillary tube 8 is allowed while increase in the
amount of elastic deformation of the elastic fitting part 3 5 6 is generally stopped.
[0057] Therefore, until the capillary tube 8 passes through the elastic fitting
part 36, the insertion resistance of the capillary tube 8 gradually increases due to
increase in the amount of elastic deformation of extension and expansion of the elastic
fitting part 36. Meanwhile, from the moment of passing through the elastic fitting
10 part 36, the insertion resistance is suppressed to a generally constant, small one due to
frictional resistance of the elastic fitting part 36 abutting against the outer
circumferential surface of the capillary tube 8. Therefore, when the capillary tube 8
is inserted, the user can tell that the capillary tube 8 passes through the elastic fitting
part 36 and the supporting and sealing state of the capillary tube 8 by the connecting
15 member 24 is realized, through a tactile feeling due to the change in the operating
resistance.
[0058] This facilitates the connection work of the capillary tube 8 to the
puncturing tool 2, and effectively prevents problems such as damage caused by
excessively pushing the capillary tube 8 and leakage of collected blood due to
20 insufficient insertion of the capillary tube 8. In particular, in the present practical
embodiment, since the maximum insertion end of the capillary tube 8 is clearly
defined by the abutment against the proximal end face 34 of the needle hub 14 and
can be felt by the user, the reliability of the connection operation of the capillary tube
8 is further improved. Further, since the proximal end portion of the hollow needle 4
25 does not protrude from the proximal end face 34 of the needle hub 14, damage due to
contact of the capillary tube 8 with the hollow needle 4 can be avoided. However,
the capillary tube 8 does not need to be pushed until it comes into abutment against
the proximal end face 34.
[0059] Furthermore, in the puncturing tool 2 of the present practical
30 embodiment, as shown in FIG. 4, the taper angle of the inner surface on the proximal
end side of the tapered peripheral wall 26 is set corresponding to the taper angle of the
male luer 54, making it also possible to connect the male luer 54 instead of the
capillary tube 8. With this configuration, the puncturing tool 2 can also be used to
connect a syringe, an external line, or the like to the central hole of the hollow needle
35 4, so as to perform fluid transfusion on small animals and the like in addition to blood
collection from small animals.
[0060] In the puncturing tool 2 of the present practical embodiment, the
specific shape of the elastic fitting part 36 may be appropriately changed in
consideration of the characteristics of the elastic fitting part 36 such as the elasticity,
- 13 -
the suitable size of the capillary tube 8, the required sealing performance, and the
tactile feeling of insertion of the capillary tube 8. For example, like a puncturing
tool 56 shown in FIG. 5, it is also possible to adopt an elastic fitting part 58 whose
thickness dimension is generally constant in the direction of projection from the
tapered peripheral 5 wall 26, or the like.
[0061] Next, FIGS. 6 and 7 show a puncturing tool 70 for small animals
according to a second practical embodiment of the present invention. This practical
embodiment exemplifies another mode of the connecting member, particularly the
elastic fitting part, with respect to the preceding first practical embodiment. In the
10 following description, the members and parts substantially the same as those in the
first practical embodiment are designated by the same reference numerals as those in
the first practical embodiment in the drawings, and detailed description thereof will be
omitted.
[0062] An elastic fitting part 72 of the present practical embodiment has a
15 circular disk shape with a generally constant thickness, and extends in the
axis-perpendicular direction so as to partition the internal space 42 of the tapered
peripheral wall 26.
[0063] The elastic fitting part 72 includes a slit 76 penetrating the central
portion thereof in the thickness direction, which is the direction of insertion of the
20 capillary tube 8. In the present practical embodiment, the slit 76 has a straight line
shape extending linearly in the diametrical direction. Further, a small-diameter
circular hole 78 is formed in the center of the elastic fitting part 72 so as to penetrate
in the thickness direction. The inner diameter of the circular hole 78 is made smaller
than the outer diameter dimension of the suitable capillary tube 8.
25 [0064] The slit 76 is formed in a mode extending from the circular hole 78 on
the opposite sides in the diametrical direction. The slit 76 is held in a closed state
based on the elasticity of the elastic fitting part 72, while the circular hole 78 is in an
open state.
[0065] FIGS. 8 and 9 show the connection state of the capillary tube 8 to the
30 puncturing tool 70 of the present practical embodiment. In the present practical
embodiment as well, as in the first practical embodiment, when the capillary tube 8 is
inserted, the distal end face of the capillary tube 8 abuts against the proximal end side
face of the elastic fitting part 72, and the elastic fitting part 72 is elastically deformed
so as to be pushed to expand to the distal end side. Then, after the slit 76 is opened
35 and the capillary tube 8 passes through, the capillary tube 8 is inserted toward the
distal end side while sliding in contact with the elastic fitting part 72. Therefore,
similarly to the first practical embodiment, all of the tactile feeling at the time of the
connection operation of the capillary tube 8, the sealing properties and the allowance
performance with respect to inclination of the capillary tube 8 in the connection state,
- 14 -
and the like can be effectively exhibited.
[0066] Additionally, in the present practical embodiment, since the circular
hole 78 is provided in the center of the slit 76, the elastic fitting part 72 is pushed open
and the capillary tube 8 is easily inserted. Furthermore, since the slit 76 is closed in
the non-insertion state of the capillary tube 8, by making the 5 circular hole 78
sufficiently small in diameter, the internal space 42 of the capillary tube 8 can be kept
in the substantially closed state. Therefore, for example, it would also be possible to
insert and connect the capillary tube 8 after puncturing a small animal with the hollow
needle 4 of the puncturing tool 70, to detach or exchange the capillary tube 8 with
10 respect to the puncturing tool 70 while puncturing is kept with the capillary tube 8
connected, and the like.
[0067] Meanwhile, the elastic fitting part 72 of the present practical
embodiment may also have a tapered cross-sectional shape whose thickness
dimension decreases from the outer peripheral portion toward the central portion or
15 from the outer peripheral portion toward the slit 76. Besides, the number and shape
of the slit formed in the elastic fitting part 72 are not limited. For example, like a
puncturing tool 80 shown in FIG. 10, three or more slits 84 extending from the center
in a spoke-wise fashion in the radial direction may also be adopted. Furthermore,
the size and shape of the central through hole formed in the elastic fitting part 72, such
20 as the circular hole 78, are not limited. It would also be acceptable to adopt a
through hole having a tapered shape in which the diameter dimension changes in the
axial direction, a through hole having a cross-sectional shape in which the diameter
dimension varies in the circumferential direction, for example, the diameter
dimension is made larger in the slit direction than in other diametrical directions, or
25 the like. Alternatively, such a through hole need not be formed in the center of the
elastic fitting part 72.
[0068] Although the practical embodiments of the present invention have been
described above, the present invention is not limitedly interpreted based on the
specific or restrictive description in the practical embodiments and in the summary
30 section, but may be embodied with various changes, modifications and improvements
which may occur to those skilled in the art.
[0069] For example, the structure in which the male luer 54 can be connected
to the proximal end side of the tapered peripheral wall 26 as shown in FIG. 4 need not
be adopted in the present invention. Besides, the proximal end face 34 of the needle
35 hub 14 and the proximal end face of the hollow needle 4 may be set at different
positions in the axial direction. Furthermore, a needle tip cover that covers the
needle tip after removal of the hollow needle 4 can also be adopted as needed.
Further, regarding the wing-like part of the needle hub 14, various shapes, sizes, and
numbers can be adopted, and the wing-like part may be formed separately from the
- 15 -
needle hub 14. It would also be possible not to provide the wing-like part.
[0070] Additionally, the elastic fitting part may be made of a different material
from that of the tapered peripheral wall, and for example, an elastic fitting part which
is softer or has a higher elasticity than the tapered peripheral wall may be adopted.
The elastic fitting part made of a different material from that of 5 the tapered peripheral
wall can be realized by, for example, integrally molding with the tapered peripheral
wall through multicolor molding or insert molding, or incorporating the elastic fitting
part formed as a separate member into the tapered peripheral wall by post-fastening.
Furthermore, it would also be possible to integrally mold the needle hub 14 and the
10 connecting member 24.
[0071] Moreover, in the preceding practical embodiment, the connecting part
6 is constituted by including the tapered peripheral wall 26, but the tubular peripheral
wall constituting the connecting part need not be tapered. For example, the tubular
peripheral wall constituting the connecting part may be a tubular peripheral wall of
15 round tubular shape having a constant inner diameter dimension and extending in the
axial direction. Even when such a tubular peripheral wall is adopted, the technical
effect exhibited without being based on the tapered peripheral wall is exhibited in the
same manner as in the preceding practical embodiment. Further, the deformation of
the elastic fitting part caused by the insertion of the capillary tube and the working
20 effects based on the said deformation can be exhibited regardless of the shape of the
peripheral wall of the connecting part.
[0072] Furthermore, the tubular peripheral wall may be divided into a distal
end side and a proximal end side in the axial direction regardless of its shape, and the
divided two sides may have different materials, softness, and the like from each other.
25 Further, the elastic fitting part may be integrally molded with the divided peripheral
wall of either or both of the distal end side and the proximal end side.
[0073] Besides, in the case where the peripheral wall of the connecting
member is tapered, the peripheral wall is not necessarily be tapered across the entire
length in the axial direction. For example, it would also be acceptable that only the
30 proximal end side with respect to the elastic fitting part is tapered, and the distal end
side attached to the needle hub may have, for example, a straight round tubular shape.
This can facilitate, for example, molding of the connecting member.
[0074] Additionally, the shape and structure of the externally fitted assembly
portion (the attachment tube) of the distal end portion of the connecting member with
35 respect to the proximal end portion of the needle hub are not limited. For example,
the externally fitted assembly portion may have a straight tubular shape, or a tapered
tubular shape opposite to that of the preceding practical embodiment. Further, in
order to prevent dislodgment or the like, a locking part comprising concave and
convex portions may be provided on the fitting surface of the externally fitted
- 16 -
assembly portion, and welding or bonding of at least a part thereof is also possible.
KEYS TO SYMBOLS
[0075] 2, 56, 70, 80: Puncturing tool for small animals, 4: hollow needle, 6:
connecting part, 8: capillary tube, 14: needle hub, 24: connecting 5 member, 26: tapered
peripheral wall, 32: proximal end opening, 34: proximal end face (abutting face), 36,
58, 72: elastic fitting part, 36a: projecting distal end portion, 44: distal side internal
space (deformation allowance space), 76, 84: slit

CLAIMS

1. A puncturing tool for small animals including a hollow needle and a
connecting part for a capillary tube, the connecting part being provided on a proximal
end side of the hollow 5 needle, wherein
the connecting part has a tapered peripheral wall expanding and extending in a
direction away from the hollow needle, and
the tapered peripheral wall includes an elastic fitting part configured to allow
the capillary tube to be inserted, the elastic fitting part projecting inward from a
10 lengthwise middle portion of the tapered peripheral wall.
2. A puncturing tool for small animals including a hollow needle and a
connecting part for a capillary tube, the connecting part being provided on a proximal
end side of the hollow needle, wherein
15 the connecting part has a tubular peripheral wall extending in a direction away
from the hollow needle, and
the tubular peripheral wall includes an elastic fitting part projecting inward
from a lengthwise middle portion of the tubular peripheral wall, and a projecting
distal end portion of the elastic fitting part that projects inward is configured to be
20 elastically deformed toward a distal end side in an axial direction of the tubular
peripheral wall while being expanded by the capillary tube being inserted.
3. The puncturing tool for small animals according to claim 1 or 2, wherein the
elastic fitting part inclines toward a hollow needle side and projects inward.
25
4. The puncturing tool for small animals according to any one of claims 1-3,
wherein the elastic fitting part is tapered toward a projecting distal end side.
5. The puncturing tool for small animals according to any one of claims 1-4,
30 wherein the elastic fitting part has a slit configured to be pushed to expand by the
capillary tube being inserted.
6. The puncturing tool for small animals according to any one of claims 1-5,
wherein an inside of the tapered peripheral wall or the tubular peripheral wall on a
35 hollow needle side with respect to the elastic fitting part constitutes a deformation
allowance space configured to allow entrance of the elastic fitting part deformed by
the capillary tube being inserted.
7. The puncturing tool for small animals according to any one of claims 1-6,
- 18 -
wherein an internal volume of the tapered peripheral wall or the tubular peripheral
wall is configured such that an internal volume on a hollow needle side with respect to
the elastic fitting part is smaller than an internal volume on a proximal end opening
side with respect to the elastic fitting part.
5
8. The puncturing tool for small animals according to any one of claims 1-7,
wherein a proximal end portion of the hollow needle is provided with a needle hub,
while a connecting member formed of a material softer than that of the needle hub is
attached to the needle hub, and the connecting member extending from the needle hub
to the proximal end side constitutes 10 the connecting part.
9. The puncturing tool for small animals according to claim 8, wherein a
proximal end portion of the needle hub is provided with an abutting face configured to
define an insertion position of the capillary tube by being abutted by a distal end face
15 of the capillary tube inserted through the elastic fitting part.