Patent ID: 12233237

DETAILED DESCRIPTION

Set forth below, with reference to the accompanying drawings, is a detailed description of several embodiments of an indwelling needle assembly and method of use representing examples of the indwelling needle assembly and method disclosed here.

In the following example, description will be made by referring to the left side inFIGS.1to5as the “proximal (end)” or rear end, the right side as the “distal (end)” or front end, the upper side as the “upper” and the lower side as the “lower.”

As shown inFIG.1, the indwelling needle assembly1includes a hollow outer needle2, an outer needle hub3fixed to a proximal portion of the outer needle2, an inner needle4inserted in the outer needle2, an inner needle hub5fixed to a proximal portion of the inner needle4, and a pressing member6connected to the outer needle hub3.

By way of example, the outer needle2has a certain degree of flexibility. For example, the material constituting the outer needle2is a resin material, such as a flexible resin material. Examples of the resin material include fluoro-resins such as PTFE, ETFE, PFA, etc., olefin reins such as polyethylene, polypropylene, etc. or mixtures thereof, polyurethane, polyesters, polyamides, polyether-nylon resins, mixtures of the olefin resin with an ethylene-vinyl acetate copolymer, and the like.

An outer needle2as disclosed may have inside visibility at the whole part or a part thereof. Besides, the material forming the outer needle2may be admixed with a radiopaque material, e.g., barium sulfate, barium carbonate, bismuth carbonate, or tungstic acid, whereby a radiopaque contrast function can be imparted to the material.

In addition, the length L1 of the outer needle2is not limited and can be set appropriately according to the use or various conditions. By way of example, the length L1 of the outer needle2can be set in the range of about 2.0 to 50.0 cm, for example, about 3.0 to 40.0 cm, and for example, about 10.0 to 30.0 cm.

The length L1 of the outer needle2helps ensure that the outer needle2can be used as a catheter which is longer than peripheral vein catheters, such as, for example, a central vein catheter, a PICC, or a midline catheter. Incidentally, the outer needle2may naturally be used as a peripheral vein catheter.

To a proximal portion of the outer needle2, the outer needle hub3is attachable, for example, firmly attached or fixed, in a liquid-tight manner by such a method as caulking, welding (heat welding, microwave welding, etc.), or adhesion with an adhesive.

The outer needle hub3is composed of a substantially tubular member, and the inside thereof communicates with a lumen21of the outer needle2. Besides, the outer needle hub3is formed with a flange31at an outer circumferential part of a proximal portion of the outer needle hub3.

In the outer needle2is inserted the inner needle4which has a sharp needlepoint41at its distal end. The indwelling needle assembly1is used in the state in which the inner needle4is inserted in the outer needle2and an inner needle hub5to be disclosed later is fitted to the outer needle hub3(the state in which the needlepoint41protrudes from a distal opening22of the outer needle2), namely, in the state as shown inFIGS.1and2. By way of example, this state will be referred to as “the assembled state”

The length of the inner needle4is so set that, in the assembled state, at least the needlepoint41protrudes from the distal opening22of the outer needle2.

The inner needle4may be a hollow needle, and may also be a solid needle. Where the inner needle4is a solid needle, relatively sufficient strength can be secured while setting the outside diameter of the inner needle4small. In addition, where the inner needle4is a solid needle, the solid needle helps ensure that in discarding the inner needle4after an operation is finished, such a risk as remaining of blood inside the inner needle4or flowing-out of the remaining blood is relatively absent, so that relatively high safety is secured.

By way of example, where the inner needle4is a hollow needle, upon puncture of a blood vessel by the inner needle4blood flows into the hollow part of the inner needle4and the flashback of the blood is confirmed by the user. In this connection, where the inner needle4is a solid needle, blood flows into the gap between the inner needle4and the outer needle2, so that the flashback of the blood can be confirmed more swiftly.

For example, while the inner needle4may have a configuration in which it has both a hollow part and a solid part (e.g., a configuration in which the lumen of a hollow needle is partly filled so that the needle is hollow on the distal side and solid on the proximal side), a configuration in which the whole body of the inner needle4is composed of a single member helps reduce the cost of the inner needle4.

In addition, the inner needle4may be constant in outside diameter, or may have plural (in this embodiment, three) parts which are different in outside diameter.

Examples of the material constituting such an inner needle4as above-mentioned include metallic materials such as stainless steel, aluminum or aluminum alloys, and titanium or titanium alloys.

By way of example, the inner needle4is such that when its part corresponding to a pressing section64of the pressing member6to be disclosed later (its part to be pressed by the pressing section64) is fixed and a force of about N in a direction perpendicular to the axis of the inner needle4is exerted on its distal portion, the displacement of the distal portion in the direction perpendicular to the axis of the inner needle4will be not more than about 3.0 mm, for example not more than about 2.0 mm.

The inner needle hub5can be fixed to a proximal portion of the inner needle4.

The inner needle hub5is composed of a substantially tubular member, and a flange51is formed at an outer circumferential part of a proximal portion thereof. In the assembled state, that part of the inner needle hub5which is on the distal side relative to the flange51is inserted in the inside of the outer needle hub3, and is fitted and fixed there.

For example, at a proximal-side opening of the inner needle hub5, a vent filter52is disposed so as to cover the opening. The vent filter52has such a property as to permit gas to pass therethrough, and block the passage of liquid therethrough.

Examples of the vent filter52include various sintered porous bodies, hydrophobic non-woven fabrics, and other porous bodies. For example, the sintered porous bodies are those obtained by sintering a material containing a polymer material (powder) such as polyethylene and a hydrophilic (water-soluble, or water-swellable) polymer. When the sintered porous body is used, its contact with liquid (blood) blocks ventilation as well, which helps prevent the external intrusion of air. For example, where the inner needle4is a solid needle, it is unnecessary to provide the vent filter52.

Examples of the method for fixing the inner needle4to the inner needle hub include such method as fitting, caulking, welding, or adhesion with an adhesive, and combinations of these methods.

By way of example, an inner needle hub5and the above-disclosed mentioned outer needle hub3can be formed respectively from transparent (colorless transparent), colored transparent or semi-transparent resins, whereby visibility of the inside thereof is secured. This helps ensure that when the outer needle2has securely reached the inside of a blood vessel, the flashback of blood flowing in can be confirmed by visual observation.

Materials constituting the outer needle hub3and the inner needle hub5are not restricted. Examples of the materials include various resin materials such as polyolefins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc., polyurethane, polyamides, polyesters, polycarbonate, polybutadiene, polyvinyl chloride, and polyacetal.

The pressing member6has the pressing section64which is pressed by a finger against that part (intermediate part) of the outer needle2between the proximal end and the distal end of the outer needle2, at the time of a puncturing operation of causing the needlepoint41of the inner needle4and a distal portion of the outer needle2in the assembled state to puncture a blood vessel, in a process for setting the outer needle2indwelling in the blood vessel. By the pressing section64, that part of the outer needle2between the proximal end and the distal end is pressed.

For example, the pressing member6includes an elongate main body section61disposed along the axis (center axis) of the outer needle2and located on the outer needle2, a finger hook projection62which is provided in the main body section61and on which a finger is placed, and the pressing section64composed of that part of the main body section61which is on the opposite side in the vertical direction from the finger hook projection62. The finger hook projection62is formed at a distal portion of the main body section61so as to project upward. Those parts of the finger hook projection62and the main body section61which are to be contacted by a finger are, for example, flat surfaces, or curved recessed surfaces, or curved protuberant surfaces. An upper-side part of the pressing member6constitutes a finger contact section on which a finger is placed.

By way of example, while the pressing section64is provided by utilizing the distal portion of the main body section61of the present embodiment. For example, the pressing section64may be composed of a projection formed at that part of the main body section61which is on the opposite side in the vertical direction from the finger hook projection62.

In addition, a proximal portion of the pressing member6, or a proximal portion of the main body section61, is connected to the outer needle hub3. This structure helps enable the finger hook projection62to serve also as a part to be pressed by a finger at the time of moving the outer needle2in the distal direction relative to the inner needle4, in the process of putting the outer needle2indwelling in a blood vessel. For example, the pressing member6naturally may be connected to other member, such as the inner needle hub5.

The pressing member6can be connected to the outer needle hub3in such a manner as to be turnable (displaceable) relative to the outer needle hub3. For example, a hinge structure section is composed of a shaft63provided at a proximal portion of the main body section61, and a bearing32provided on the upper portion of the outer surface of the outer needle hub3for supporting the shaft63, and, owing to the hinge structure section, the pressing member6can be turned relative to the outer needle hub3, with the proximal portion of the main body section61as a center of turning.

In addition, the pressing member6is configured to be displaceable into a first position shown inFIG.1where it is disposed along the axis of the outer needle2and a second position shown inFIG.5(a)where it is retracted from the outer needle2.

When the pressing member6is situated in the first position, the pressing member6is located on the outer needle2. In addition, the distal portion of the pressing member6, or the finger hook projection62and the pressing section64are located on the distal side relative to the proximal portion of the outer needle2and on the proximal side relative to the distal portion of the outer needle2. This configuration helps ensure that even in the case where the inner needle4and the outer needle2are comparatively large in length, at the time of a puncturing operation, by pressing down that part of the outer needle2between the proximal end and the distal end (that part of the outer needle2corresponding to the pressing section64of the pressing member6) through the pressing section64, to restrain the inner needle4and the outer needle2from deflection and to carry out the puncturing operation relatively easily and assuredly.

By way of example, since the puncturing operation can be performed by putting the finger on the finger hook projection62of the pressing member6that is located nearer to the distal portions of the inner needle4and the outer needle2than the inner needle hub5and the outer needle hub3, the needlepoint41of the inner needle4can be controlled relatively easily during the puncturing operation.

In addition, when the pressing member6is situated in the second position, the pressing member6is located on the proximal side relative to the outer needle2. The pressing member6can be moved into this second position, in the case where the pressing member6would otherwise be an obstacle to the operator (user) or the patient (the person for which the assembly is used) during the process of putting the outer needle2indwelling in a blood vessel or after the outer needle2is put indwelling in the blood vessel or in other similar situation.

For example, the pressing member6is configured to be attachable to and detachable from the outer needle hub3. The shaft63is provided at a proximal portion of the main body section61and can be detachably attached to the bearing32provided in the outer needle hub3. This configuration helps enable the pressing member6to be detached in the case where the pressing member6would otherwise be an obstacle to the operator or the patient during the process of putting the outer needle2indwelling in a blood vessel or after the outer needle2is put indwelling in the blood vessel or in other similar situation. In addition, when the pressing member6becomes necessary, the pressing member6can be attached.

By way of example, the dimensions of the pressing member6are not limited, insofar as that part of the outer needle2between the proximal end and the distal end can be pressed by the pressing section64of the pressing member6.

In addition, the pressing member6can be sized that when the pressing member6is pressed by a finger, the finger does not touch the outer needle2, which enhances safety. For example, the outer needle2as well as the parts to be brought into contact with the outer needle2, such as a back surface of the pressing member6, is in a sterilized state.

The material constituting the pressing member6is not restricted, and for example, the same or similar materials to those mentioned as examples of the materials for forming the outer needle hub3and the inner needle hub5above can be used.

According to an aspect, a method of using the indwelling needle assembly1(in the case of puncturing a blood vessel) (operation) is disclosed below.

As shown inFIG.2, the indwelling needle assembly1is put into the assembled state, and the pressing member6is positioned in the first position. The inner needle hub5is gripped by one hand, and an index finger is put on the finger hook projection62of the pressing member6. While pressing down the vicinity of a base part of the finger hook projection62by the index finger, a distal portion of the indwelling needle assembly1(the united distal portion of the outer needle2and the inner needle4) is made to puncture a skin of a patient toward a blood vessel, in the manner of pressing the united distal portion against the patient. In this instance, as above-mentioned, the pressing section64presses down that part of the outer needle2between the proximal end and the distal end, whereby the inner needle4and the outer needle2can be restrained from deflection. Incidentally, the inner needle hub5naturally may be gripped by the left hand.

When the needlepoint41of the inner needle4has punctured the blood vessel, the blood pressure causes blood to flow back in the proximal direction through the inner needle4, to be introduced into the inner needle hub5, and this flashback can be visually confirmed through the inner needle hub5having visibility. As a result, one can know that the needlepoint41of the inner needle4has relatively securely punctured the blood vessel.

Incidentally, attendant on the inflow of the blood, air in the inner needle hub is discharged via the vent filter52. However, since the blood does not pass through the vent filter52, this helps ensure that the blood does not leak to the exterior.

As shown inFIG.3, the outer needle2is advanced further by a minute distance in the distal direction along the inner needle4, with the inner needle4as a guide. For example, the finger hook projection62is pushed in the distal direction by the index finger, to move the outer needle2in the distal direction.

Subsequently, as shown inFIG.4, while fixing the position of the inner needle hub5with the other hand, the outer needle hub3is gripped, and the outer needle2is advanced further in the distal direction along the inner needle4, with the inner needle4as a guide. In this manner, a distal portion of the outer needle2is inserted to a target position in the blood vessel.

Next, while holding down by the left hand the outer needle hub3and the pressing member6on the side of the outer needle2kept indwelling in the blood vessel, the inner needle hub5is gripped by the right hand and is pulled in the proximal direction. This results in that the inner needle4is pulled out of the outer needle2. After the inner needle4is thus pulled out of the outer needle2, if necessary, as shown inFIG.5(a), the pressing member6may be positioned into the second position by turning. Alternatively, as shown inFIG.5(b), the pressing member6may be detached from the outer needle hub3. Further, as shown in FIG. the pressing member6may be left as it is.

To the outer needle hub3from which the inner needle4has been pulled out, a connector of an infusion set (not shown) is relatively quickly connected, and dispensing of an infusion liquid is started following the normal procedure.

After the inner needle4is pulled out of the outer needle2in accordance with this embodiment, the inner needle4and the inner needle hub5are unnecessary and can be disposed of.

As disclosed above, according to the indwelling needle assembly1, in the embodiment where the inner needle4and the outer needle2are comparatively large in length, by pressing down that part of the outer needle2between the proximal end and the distal end through the pressing section64of the pressing member6at the time of a puncturing operation, to relatively restrain the inner needle4and the outer needle2from deflection and to carry out the puncturing operation relatively easily and assuredly.

In addition, since the puncturing operation can be conducted by putting a finger on the finger hook projection62of the pressing member6that is nearer to the distal portions of the inner needle4and the outer needle2than the inner needle hub and the outer needle hub3, the needlepoint41of the inner needle4can be controlled during the puncturing operation relatively easily.

By way of example, by putting a finger on the finger hook projection62and pushing the finger hook projection62in the distal direction, the outer needle2can be moved in the distal direction relative to the inner needle4relatively easily and assuredly.

In the following exemplary embodiment, description will be made by referring to the left side inFIGS.6to11as “distal (end),” the right side as “proximal (end) (rear end),” the upper side as “upper” and the lower side as “lower.” In addition, inFIGS.6to11, a blood vessel is omitted from drawing.

According to a second embodiment will be disclosed below referring mainly to differences from the above-disclosed first embodiment, and descriptions of the same items as above will be omitted.

As shown inFIGS.6and7, in the indwelling needle assembly1according to the second embodiment, a plurality of finger hook projections62of a pressing member6are provided in a main body section61along the axis of an outer needle2. By way of example, in the configuration shown, the finger hook projections62are disposed at regular intervals. The finger hook projections62have the function as graduations indicative of the length of insertion of the outer needle2into a blood vessel, in addition to the function described in the first embodiment.

In addition, a pressing section64in this embodiment is composed of that part of the main body section61which is located on the opposite side in the vertical direction from the finger hook projection62at the distal-most end.

By way of example, those parts of the main body section61which are located on the opposite side in the vertical direction from the finger hook projections62may constitute pressing sections, respectively. For example, a predetermined part of a plurality of parts of the outer needle2between the proximal end and the distal end can be selectively pressed.

The indwelling needle assembly1has a grip member7which has a proximal portion connected (fixed) to an inner needle hub5and which protrudes from the inner needle hub5in the distal direction. This helps ensure that at the time of an operation of putting the outer needle2indwelling in a blood vessel, the grip member7can be gripped by hand and the operation can be carried out relatively easily and assuredly.

The grip member7is elongated in shape, and is composed of a bottom plate71and two wall sections72and73rising up from the bottom plate71. An inner needle4is disposed in a space on the inside of the grip member7.

In addition, in the assembled state, the pressing member6is contained in the space on the inside of the grip member7so as to be movable in the longitudinal direction thereof. The grip member7has a function as a guide member which, when the pressing member6is moved in the distal direction, relatively restricts the moving direction of the pressing member6. This helps ensures that when the pressing member6is moved in the distal direction, the pressing member6can be prevented from coming out of position in the transverse direction.

By way of example, at outside surfaces of distal portions of the side walls72and73, a plurality of ribs721and731extending in the vertical direction are respectively arrayed as hand slip preventive means. This helps ensures that when the grip member7is gripped with a hand, the hand can be prevented from slipping.

As shown inFIG.6, in the assembled state, the pressing member6is stored in the space on the inside of the grip member7.

In addition, in the assembled state, a distal portion of the grip member7is located on the distal side relative to a proximal portion of the outer needle2, and is located on the proximal side relative to a distal portion of the inner needle4.

By way of example, in the assembled state, when the pressing member6is positioned in the first position, the distal portion of the grip member7is located on the proximal side relative to the distal portion of the pressing member6.

This helps ensure that a puncturing operation and an operation of moving the outer needle2in the distal direction relative to the inner needle4can be carried out easily and assuredly.

By way of example, the material constituting the grip member7is not restricted. For example, the same or similar materials as those mentioned as examples of the materials for forming the outer needle hub3and the inner needle hub5above can be used.

An example of the method of using the indwelling needle assembly1(in the case of puncturing a blood vessel) (operation) will be described below.

As shown inFIG.6, the indwelling needle assembly1is put into the assembled state, and the pressing member6is positioned in the first position. Then, a distal portion of the grip member7provided at the inner needle hub5is gripped with the right hand (one hand), and an index finger of the right hand is put on the distal-most finger hook projection62of the pressing member6. While pressing down the vicinity of a base portion of the finger hook projection62by the index finger, a distal portion of the indwelling needle assembly1is made to puncture a skin of a patient toward a blood vessel, in such a manner as to press the distal portion against the patient. By way of example, the pressing section64presses down that portion of the outer needle2between the proximal end and the distal end, whereby the inner needle4and the outer needle2can be restrained from deflection.

When a needlepoint41of the inner needle4has punctured a blood vessel, the internal pressure of the blood vessel causes blood to flow back in the proximal direction through the inner needle4, to be introduced into the inner needle hub5, so that this flashback can be visually confirmed through the inner needle hub5having visibility. As a result, it can be known that the needlepoint41of the inner needle4has relatively securely punctured the blood vessel.

Next, as shown inFIG.8, the outer needle2is further advanced by a minute distance in the distal direction along the inner needle4, with the inner needle4as a guide. By way of example, the distal-most finger hook projection62is pushed in the distal direction by the index finger, to move the outer needle2in the distal direction.

Subsequently, as shown inFIG.9, the second distal-most finger hook projection62is pushed in the distal direction by the index finger, to move the outer needle2by a minute distance in the distal direction, and such an operation is sequentially repeated to insert a distal portion of the outer needle2to a target position in the blood vessel.

Next, as shown inFIG.10, while holding down by the left hand the pressing member6on the side of the outer needle2kept indwelling in the blood vessel, a proximal portion of the grip member7and the inner needle hub5are gripped by the right hand and pulled in the proximal direction. As a result, the inner needle4is pulled out of the outer needle2. After the inner needle4is pulled out of the outer needle2, if necessary, as shown inFIG.11(a), the pressing member6may be detached from the outer needle hub3. Alternatively, as shown inFIG.11(b), the pressing member may be positioned into the second position by turning. Further, the pressing member6may be kept as it is. By way of example, the subsequent operations are the same as in the first embodiment, and, therefore, descriptions of the subsequent operations are omitted.

According to this indwelling needle assembly1, the same effects as those of the above-described first embodiment can be obtained.

For example, since the plurality of finger hook projections62are provided along the axis of the outer needle2in this indwelling needle assembly1, by sequentially pushing the finger hook projections62in the distal direction, to move the outer needle2in the distal direction relative to the inner needle4relatively easily and assuredly.

In addition, since the grip member7is provided, the operation of putting the outer needle2indwelling in a blood vessel can be carried out relatively easily and assuredly.

In the following example, description will be made by referring to the left side inFIGS.12to14andFIGS.16to22as “distal (end),” the right side as “proximal (end) (rear end),” the upper side as “upper” and the lower side as “lower.” In addition, inFIGS.18to22, a blood vessel is omitted from drawing.

A third embodiment will be disclosed below referring mainly to differences from the above-described second embodiment, and descriptions of the same items as above will be omitted.

As shown inFIGS.12,13,19and20, in the indwelling needle assembly1according to the third embodiment, the pressing member6is configured to be curved or bent in a direction for coming away from the outer needle2, at an intermediate portion in the longitudinal direction thereof. For example, a small material thickness section611is formed at an intermediate portion in the longitudinal direction of a main body section61of the pressing member6, and the pressing member6is curved or bent through bending deformation of the small material thickness section611. In addition, the small material thickness section611is formed at a plurality of locations (in the configuration shown, two locations) along the longitudinal direction of the main body section61. Incidentally, the number of the location(s) at which the small material thickness section611is formed may naturally be one.

By way of example, this helps ensure that at the time of moving the outer needle2in the distal direction in putting the outer needle2indwelling in a blood vessel, it is relatively ensured that even if the distal portion of the pressing member6abuts on a predetermined part of the patient, the pressing member6is curved or bent at its intermediate portion, whereby interference between the pressing member6and the patient's predetermined part can be avoided. As a result, the outer needle2can be moved relatively easily and smoothly. For example, in the case of puncturing a patient's skin from the inside of an upper arm part and inserting the distal end of the outer needle2to a position immediately on the operator's side of the patient's side part, a gradual movement of the pressing member6in the distal direction may cause a distal portion of the pressing member6to abut on a knot of muscle corresponding to the biceps muscle of arm. By way of example, in such a situation, the pressing member6would not be an obstacle, since it is curved or bent at its intermediate portion.

In addition, the layout of the two small material thickness sections611is not limited. By way of example, in this embodiment, a setting of L1<L2 is adopted, where L1 (seeFIG.21) is the length in the longitudinal direction between the distal end of the pressing member6and the small material thickness section611on the distal side, and L2 (seeFIG.21) is the length in the longitudinal direction between the small material thickness section611on the distal side and the small material thickness section611on the proximal side.

The lengths L1 and L2 are not restricted, respectively, and may be appropriately set according to various conditions. By way of example, the length L1 can be about 10 to 30 mm, for example, about 15 to 20 mm. In addition, the length L2 can be about 20 to 90 mm, for example about 30 to 70 mm.

As shown inFIG.14, a distal portion of the pressing member6is so provided as to be directed upward (in such a direction as to come away from the outer needle2in a radial direction of the outer needle2). For example, the distal portion of the pressing member6can be warped so as to come away from the outer needle2, which helps ensure that in the case of moving the outer needle2in the distal direction in putting the outer needle2indwelling in a blood vessel. In addition, it also helps ensure that even if the distal portion of the pressing member6comes into contact with on a predetermined part of the patient, the distal portion of the pressing member6can ride over the predetermined part relatively easily and smoothly, whereby the outer needle2can be moved.

As shown inFIG.15, the indwelling needle assembly1has a groove (recess)65formed in the pressing member6, and a groove (recess)74formed in a grip member7, as slip-off preventive means for helping prevent the outer needle2from coming out of position in a direction perpendicular to the axis of the outer needle2, for example, in a transverse direction inFIG.15.

The groove65is formed in a lower surface of the main body section61of the pressing member6, and extends along the longitudinal direction of the pressing member6. By way of example, while the groove65is formed over the whole length, from the distal end to the proximal end, of the main body section61in the configuration shown, this configuration is not restrictive. For example, the groove65may be formed only in a distal portion of the main body section61.

In addition, the groove74is formed in an upper surface of a bottom plate71of the grip member7at a position corresponding to the groove65, and extends along the longitudinal direction of the grip member7. For example, while the groove74is formed over the whole length, from the distal end to the proximal end, of the bottom plate71in the configuration shown, this configuration is not restrictive. For example, the groove74may be formed only in a distal portion of the bottom plate71.

The outer needle2is held in the grooves65and74, which helps prevent the outer needle2from coming out of position in a transverse direction inFIG.15.

For example, the groove may be formed in only one of the pressing member6and the grip member7.

In addition, as shown inFIG.16, ribs (engaging sections)722and732projecting sideways to engage with the pressing member6can be formed respectively at inner surfaces of distal portions of wall sections72and73of the grip member7. The ribs722and732are so formed as to extend along the longitudinal direction of the grip member7and be parallel to each other, which helps ensures that, in the assembled state, the pressing member6can be prevented from being displaced in such a direction as to come away from the outer needle2in a radial direction of the outer needle2. For example, the pressing member6can be prevented from being lifted to the upper side. As a result, the state in which the outer needle2is inserted in the grooves65and74is held, so that the outer needle2can be prevented from coming out of position in a transverse direction inFIG.15, as above-mentioned.

By way of example, the grip member7has a cover section75which is formed at upper portions of the wall sections72and73and which covers the space on the inside of the grip member7. In the configuration shown, the cover section75is provided to extend from the proximal end to the distal side relative to a middle portion, of each of the wall sections72and73.

In addition, as shown inFIG.17, the pressing member6can be configured to be attachable to and detachable from the outer needle hub3. For example, a shaft63provided at a proximal portion of the main body section61of the pressing member6can be detachably attached to a bearing32provided in the outer needle hub3. The bearing32is composed of a pair of C-shaped support sections321and322. By way of example, the part of the proximal portion of the main body section61which is on the distal side of the shaft63can protrude in the axial direction, which helps ensure that when the pressing member6is positioned in the first position shown where it is disposed along the axis of the outer needle2, the pressing member6cannot be detached. For example, the pressing member6can be prevented from being disengaged from the outer needle hub3.

According to another embodiment, when the pressing member6is turned clockwise in the figure to a predetermined position relative to the outer needle2, the pressing member6can be detached.

The pressing member6has a pair of stepped sections661and662formed at that part of the main body section61which is on the distal side of the shaft63, as disengagement preventive means, which helps prevent the pressing member6from being disengaged from the outer needle hub3when the pressing member6is positioned in the first position shown inFIGS.12and17(a) where it is disposed along the axis of the outer needle2.

The bearing32can have a pair of C-shaped support sections321and322. The shaft63of the pressing member6is attached to and detached from the support sections321and322, from and to the right side inFIG.17.

When the pressing member6is positioned in the first position shown inFIG.17(a)where it is disposed along the axis of the outer needle2, an attempt to detach the shaft63from the support sections321and322by moving the pressing member6toward the right side inFIG.17fails. For example, the stepped sections661and662of the pressing member6come into contact with the support sections321,322, so that the shaft63cannot be detached from the support sections321,322. As a result, the pressing member6can be prevented from being disengaged from the outer needle hub3.

In addition, in the case where the pressing member6is turned clockwise inFIG.17from the first position, before the pressing member6becomes perpendicular to the outer needle2the shaft63of the pressing member6cannot be detached from the support sections321and322, since the stepped sections661and662of the pressing member6abut on the support sections321and322, in the same manner as above-mentioned, as shown inFIG.17(b).

When the pressing member6is turned further clockwise inFIG.17and the pressing member6is turned to a predetermined position relative to the outer needle2as shown inFIG.17(c), the shaft63of the pressing member6can be detached from the support sections321and322, as shown inFIG.17(d).

An example of the method of using the indwelling needle assembly1(in the case of puncturing a blood vessel) (operation) is disclosed below.

As shown inFIG.12, the indwelling needle assembly1is put into the assembled state, and the pressing member6is positioned in the first position. Then, a distal portion of the grip member7provided at the inner needle hub5is gripped by one hand, and an index finger is put on the distal-most finger hook projection62of the pressing member6. While pressing down the vicinity of a base portion of the finger hook projection62by the index finger, a distal portion of the indwelling needle assembly1is caused to puncture a skin of a patient toward a blood vessel, in such a manner as to press the distal portion against the patient. By way of example, the pressing section64presses down that part of the outer needle2between the proximal end and the distal end, whereby the inner needle4and the outer needle2can be restrained from deflection.

When the needlepoint41of the inner needle4has punctured the blood vessel, the internal pressure of the blood vessel causes blood to flow back in the proximal direction through the inner needle4, to be introduced into the inner needle hub5. This flashback can be visually confirmed through the inner needle hub5having visibility. As a result, it can be known that the needlepoint41of the inner needle4has securely punctured the blood vessel.

Next, as shown inFIG.18, the outer needle2is advanced further in the distal direction along the inner needle4, with the inner needle4as a guide. In this instance, the distal-most finger hook projection62is pushed in the distal direction by an index finger, to move the outer needle2in the distal direction. By way of example, when the distal portion of the pressing member6comes into contact with a predetermined part of the patient, the pressing member6is curved or bent at its intermediate portion, as shown inFIG.19, which helps ensure that the pressing member6would not be an obstacle, and the outer needle2can be moved relatively easily and smoothly.

Subsequently, as shown inFIG.20, the second distal-most finger hook projection62is pushed in the distal direction by the index finger, to move the outer needle2in the distal direction, and such an operation is sequentially repeated to insert a distal portion of the outer needle2to a target position in the blood vessel. For example, when the pressing member comes into contact with the patient's predetermined part, the pressing member6is curved or bent at its intermediate portion, as above-mentioned. As a result, the pressing member6would not be an obstacle, and the outer needle2can be moved relatively easily and smoothly.

Next, as shown inFIG.21, while holding down by the other hand the pressing member6on the side of the outer needle2kept indwelling in the blood vessel, a proximal portion of the grip member7and the inner needle hub5are gripped and pulled in the proximal direction, which can result in the inner needle4pulling out of the outer needle2. After the inner needle4is pulled out of the outer needle2, if necessary, as shown inFIG.22, the pressing member6may be detached from the outer needle hub3. Alternatively, the pressing member6may be positioned into the second position by turning. Further, the pressing member6may be kept as it is. Incidentally, the subsequent operations are the same as in the second embodiment, and, therefore, descriptions of the subsequent operations are omitted.

According to this indwelling needle assembly1, the same effects as those of the above-described second embodiment can be obtained.

Incidentally, while the main body section61of the pressing member6is formed with the small material thickness section611so that the pressing member6can be curved or bent in this embodiment, this configuration is not restrictive; for example, a hinge structure section including a shaft and a bearing for supporting the shaft may be provided at an intermediate portion in the longitudinal direction of the main body section61of the pressing member6.

By way of example, in other examples, the pressing member6is configured to have a shape of being curved or bent at its intermediate portion in the longitudinal direction in a natural state in which no external force is exerted on the pressing member6, and the pressing member6is contained in a rectilinearly stretched state in a space on the inside of the grip member7, which helps ensures that when the restraint by the grip member7is released, the pressing member6returns into its original shape before the curving or bending, so that its interference with a predetermined part of the patient can be obviated.

In addition, while the width of the pressing member6has been constant in this embodiment, this is not restrictive; for example, a configuration may be adopted in which the width of the pressing member6is enlarged only at a distal portion, and only the distal portion of the pressing member6engages with the ribs722and732. By way of example, when the distal portion of the pressing member6is located in a position corresponding to the ribs722and732, the distal portion of the pressing member6engages with the ribs722and732whereby the distal portion is prevented from being lifted to the upper side. Then, when the pressing member6is moved in the distal direction and the distal portion of the pressing member6is located on the distal side relative to the position corresponding to the ribs722and732, the pressing member6and the ribs722and732are disengaged from each other, so that the pressing member6can be moved upward. For example, the pressing member6can move upward before that part of the pressing member6on the proximal side relative to the distal portion is disengaged from the distal end of the grip member7.

While the indwelling needle assembly disclosed here has been described above based on the embodiments shown in the drawings, the disclosure is not restricted to the embodiments, and the configuration of each component can be replaced by one of an arbitrary configuration that has the same or equivalent function to the original. Besides, an arbitrary structure or structures may be added to the configuration of the present disclosure.

In addition, the present disclosure may be embodied by a combination of arbitrary two or more of the above-described embodiments.

By way of example, the indwelling needle assembly according to the present disclosure is not limited to the one that is used in the state of being inserted into a blood vessel. The present disclosure is also applicable, for example, to those to be used in the state of being inserted into abdominal cavity, thoracic cavity, lymphatic vessel, vertebral canal or the like.

According to the present disclosure, even in the case where an inner needle and an outer needle are large in length, by pressing down that part of the outer needle between the proximal end and the distal end through a pressing member, during a puncturing operation, to restrain the inner needle and the outer needle from deflection. As a result, the puncturing operation can be carried out easily and assuredly.

In addition, the puncturing operation can be performed while putting a finger on a predetermined part of the pressing member that is nearer to the distal portions of the inner needle and the outer needle than the inner needle hub and the outer needle hub. Therefore, during the puncturing operation, the needlepoint of the inner needle can be controlled relatively easily.

The foregoing embodiments are not intended to restrict the scope of the present invention. Various changes, modifications and equivalents could be effected by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. It is expressly intended that all such changes, modifications and equivalents, which fall within the scope of the claims are embraced by the claims.