Patent Description:
In the related art, a catheter assembly is used at the time of performing infusion and the like to a patient. This kind of the catheter assembly includes a hollow catheter, a catheter hub fixed to a proximal end of the catheter, a hollow inner needle inserted into the catheter and having a sharp needlepoint at a distal end, and a needle hub fixed to a proximal end of the inner needle (refer to <CIT>).

Furthermore, in the catheter assembly disclosed in <CIT>, since the catheter is inserted deep into the patient's body, the long catheter and the inner needle are housed in an axial direction of the inside of the cylindrical-shape needle hub in a stacking manner. A user such as a doctor or a nurse punctures the patient with the catheter and the inner needle, and performs advancing operation of a catheter operation member connected to the catheter hub in this puncturing state, thereby making the long catheter advance relative to the inner needle and the needle hub and inserting the same into the body.

Meanwhile, an above-described type of a catheter assembly has a structure in which a distal end side of a needle hub is separated into upper and lower portions at the time inserting a catheter into the inside of a body, and a catheter, a catheter hub, and a catheter operation member are detached from an inner needle and the needle hub after insertion of the catheter. However, in the structure in which the needle hub is thus separated, the catheter and the inner needle extend relative to the needle hub in a non-supported (free) state at the time of inserting the catheter, the catheter is relatively easily warped when reaction force is received from a patient. Depending on the case, a needlepoint may retract (slip out) from an inserted portion of the patient and the patient may be punctured again with the needlepoint.

The present invention is made in view of the above-described situation, and directed to providing a catheter assembly in which a catheter is prevented from being warped by enabling support for the catheter at the time of inserting the catheter, and furthermore a catheter hub and a catheter operation member can be easily detached from a needle hub.

In order to achieve the above-described objects, a catheter assembly according to the present invention is a catheter assembly according to independent claim <NUM>.

According to above, the catheter assembly can support the catheter with the support member located at the first position on an opposite side of the catheter operation member. Therefore, at the time of advancing operation of the catheter operation member, the support member contacts and supports the catheter inside the needle hub and can prevent the catheter from being warped even in the case where the catheter receives reaction force from a patient. Consequently, an extending state of the catheter and the inner needle is maintained, and a user can smoothly insert the catheter into the patient. Furthermore, the support member is displaced from the first position to the second position, thereby making the catheter hub and the catheter operation member advance without interference and achieving easy detachment from the needle hub.

In this case, preferably, the catheter is supported by being interposed between the catheter operation member and the support member in an initial state in which the needlepoint projects from a distal end of the catheter.

Thus, since the catheter is supported by being interposed between the catheter operation member and the support member in the initial state, the catheter and the inner needle can be prevent from being warped at the time of puncturing the patient with the catheter and the inner needle. Therefore, the user can perform puncture with the catheter and the inner needle without any discomfort.

Furthermore, preferably, the support member has the support main body portion inhibited from being moved from the first position in an initial state, and the support main body portion is released from inhibition of movement from the first position along with advancement of the catheter operation member relative to the needle hub.

Thus, since the support member is inhibited from being moved from the first position in the initial state, the catheter can be stably supported. On the other hand, since the support main body portion is released from inhibition of movement at the time of advancement of the catheter operation member, the catheter hub and the catheter operation member can be smoothly exposed from the needle hub.

Moreover, preferably, the catheter operation member includes a holding portion adapted to directly hold the catheter in a detachable manner.

With this structure, since the holding portion directly holds the catheter, warping can be prevented by the catheter operation member at the time of puncture with the catheter and the inner needle and at the time of inserting the catheter. At this point, since the support member can support the catheter on the opposite side of the catheter operation member, the catheter can be prevented from slipping out from the holding portion.

As the support member is rotatably attached to the needle hub, the support main body portion can be displaced in a short distance between the first position and the second position, and the catheter assembly can be downsized.

Furthermore, preferably, the support member includes an axial rod portion rotatably attached to the needle hub, and the support main body portion projects in a direction orthogonal to an axial direction of the axial rod portion.

With this structure, the support main body portion is rotated around the axial rod portion attached to the needle hub and smoothly displaced between the first position and the second position, and it is possible to easily switch between a catheter supportable state and a detachable state of the catheter hub and the like.

In addition to the above-described components, preferably, the needle hub includes a groove-like rail portion, the axial rod portion includes a groove portion arranged in the rail portion, the catheter operation member includes: a side edge housed in the rail portion and the groove portion in a manner freely slidable and adapted to be guided at the time of relative movement; and a cut-out portion formed by cutting out the side edge at a position same as or near an attachment position to the catheter hub and adapted not to be housed in the rail portion and the groove portion.

With this structure, in the case where the side edge of the catheter operation member exists in the groove portion, the support member becomes unable to be rotated and the catheter supportable state can be continued by making the support main body portion stand by at the first position. On the other hand, in the case where the cut-out portion of the catheter operation member exists in the groove portion, the support member becomes able to be rotated, and the catheter hub and the catheter operation member can be allowed to pass by displacing the support main body portion to the second position.

Furthermore, preferably, the axial rod portion is provided with a cam portion, and the groove portion extends from one end of the cam portion to the other end of the cam portion.

Thus, since the groove portion is provided across the both ends of the cam portion, a non-rotatable state of the support member by the side edge of the catheter operation member can be more surely maintained. Furthermore, when the cam portion enters the rail portion in a state that the support main body portion is located at the second position, the side edge of the catheter operation member contacts at the time of retraction of the catheter operation member. Consequently, the support main body portion can be displaced from the second position to the first position. This enables the support main body portion to support the catheter again.

Moreover, preferably, the support main body portion includes a projection adapted to contact a proximal end portion of the catheter operation member and displace the support main body portion from the first position to the second position along with advancement of the catheter operation member.

With this structure, the catheter operation member largely rotates the support main body portion by contacting the projection at the time of advancement, and the support main body portion can be surely arranged from the first position to the second position. Therefore, unintended contact between the catheter operation member and the support member can be prevented at the time of retracting operation of the catheter operation member, and the catheter operation member can be made to smoothly retract.

Here, the support member may be a torsion spring including a coil portion formed by winding a wire member and a projecting portion formed as the support main body portion and projecting radially outward from the coil portion.

Thus, since the support member is formed of the torsion spring, the projecting portion can properly support the catheter on the opposite side of the catheter operation member. On the other hand, the projecting portion can easily allow the catheter hub and the catheter operation member to pass by elastic deformation of the coil portion caused by contact of the catheter operation member.

Furthermore, preferably, the support main body portion is elastically deformed in a direction orthogonal to a moving direction of the catheter.

Thus, since the support main body portion is elastically deformed in the direction orthogonal to the moving direction of the catheter, the support main body portion is actively warped even when, for example, the holding portion contacts the same at the time of advancing and retracting operation of the catheter operation member. Therefore, mobility of the catheter operation member can be sufficiently secured.

Additionally, preferably, the support main body portion is inclined downward and outward in a width direction of the needle hub from a portion capable of contacting and supporting the catheter in a state of being arranged at the first position.

Thus, since the support main body portion is inclined downward and outward in the width direction of the needle hub, the catheter detached from the catheter operation member can be received by an inclined upper surface at the time of retraction of the catheter operation member. Therefore, the catheter can be prevented from being deviated in the width direction. Furthermore, the inclined upper surface guides the catheter to an upper portion of the support member and makes the catheter operation member to hold the catheter again.

According to the present invention, in the catheter assembly, the catheter is prevented from being warped by enabling support for the catheter at the time of inserting the catheter and furthermore the catheter hub and the catheter operation member can be easily detached from the needle hub.

In the following, a catheter assembly according to the present invention will be described in details with reference to the drawings by exemplifying preferable embodiments (first and second embodiments).

In the case of performing transfusion, blood transfusion, and the like to a patient (living body), a catheter assembly <NUM> according to the present invention is used to construct an introducing portion for medicinal solution and the like by being tapped into the patient's body and indwelled. The catheter assembly <NUM> may be used as a catheter having a length longer than a peripheral intravenous catheter (such as a central intravenous catheter, a PICC, and a midline intravenous catheter). Note that the catheter assembly <NUM> may also be formed as a peripheral venous catheter. Furthermore, the catheter assembly <NUM> is not limited to a venous catheter and may also be formed as an artery catheter such as peripheral artery catheter.

As illustrated in <FIG> and <FIG>, a catheter assembly <NUM> according to a first embodiment includes a catheter <NUM>, a catheter hub <NUM> to fixe and hold the catheter <NUM>, a hollow inner needle <NUM> inserted into the catheter <NUM>, a needle hub <NUM> to fix and hold the inner needle <NUM>, a catheter operation member <NUM> attached to an upper side of the catheter hub <NUM>, a tube-like auxiliary member <NUM> inserted between the catheter <NUM> and the inner needle <NUM>, an auxiliary member hub <NUM> to fix and hold the auxiliary member <NUM>, and a needle protection member <NUM> connected to the catheter hub <NUM> and a proximal end of the auxiliary member hub <NUM>.

In an initial state before use, the catheter assembly <NUM> has a multiple tube structure (multiple tube unit <NUM>) in which the catheter <NUM>, auxiliary member <NUM>, and inner needle <NUM> are stacked sequentially from the outside. The catheter operation member <NUM> has a structure to directly hold the multiple tube unit <NUM>. Additionally, in the initial state, the catheter assembly <NUM> houses, inside the needle hub <NUM>, part of the multiple tube unit <NUM>, catheter hub <NUM>, catheter operation member <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> by suitably assembling these components.

A user such as a doctor or a nurse grips the needle hub <NUM> of the catheter assembly <NUM> in the initial state illustrated in <FIG> and punctures a blood vessel (venous or artery) of the patient with a distal end of the multiple tube unit <NUM>. The user performs advancing operation of the catheter operation member <NUM> relative to the needle hub <NUM> while keeping the puncturing state, thereby making the catheter <NUM> advance more to a distal end side (deeper inside the blood vessel) than the inner needle <NUM>.

The catheter assembly <NUM> also integrally moves the catheter hub <NUM> connected to the catheter operation member <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> as illustrated in <FIG> along with advancement of the catheter <NUM> or retraction of the needle hub <NUM> relative to the catheter <NUM>. At this point, since the inner needle <NUM> is fixed to the needle hub <NUM>, the multiple tube unit <NUM> is changed to have a double-stack structure of the catheter <NUM> and the auxiliary member <NUM>. Furthermore, the catheter operation member <NUM> releases the multiple tube unit <NUM> from being held at the time of performing advancing operation of the catheter <NUM>.

In the case of continuing advancement, a portion up to the needle protection member <NUM> slips out from the distal end of the needle hub <NUM>, and a needlepoint 16a of the inner needle <NUM> is housed inside the needle protection member <NUM> as illustrated in <FIG>. Then, as illustrated in <FIG>, the catheter <NUM> and the catheter hub <NUM> can be separated from the auxiliary member hub <NUM> and the needle protection member <NUM> which have slipped out from the needle hub <NUM>, and are detached from the auxiliary member <NUM> along with continuous advancement. Finally, the catheter operation member <NUM> is detached from the catheter hub <NUM> as illustrated in <FIG>, thereby indwelling the catheter <NUM> and the catheter hub <NUM> in the patient. In the following, a structure of the catheter assembly <NUM> will be specifically described.

As illustrated in <FIG>, the catheter <NUM> of the catheter assembly <NUM> has flexibility, and a cavity <NUM> is formed inside in a penetrating manner. The cavity <NUM> is formed to have a diameter capable of housing the inner needle <NUM> and the auxiliary member <NUM> and flowing medicinal solution, blood, and the like. A length of the catheter <NUM> is not particularly limited and can be suitably designed in accordance with usage, conditions, and the like, and for example, the length is set to about <NUM> to <NUM>, set to about <NUM> to <NUM>, or set to about <NUM> to <NUM>.

A constituent material of the catheter <NUM> is not limited but a soft resin material may be suitable, and for example, fluororesins such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), perfluoroalkoxy fluororesin (PFA), olefin resins such as polyethylene and polypropylene, or mixtures thereof, polyurethane, polyesters, polyamides, polyether nylon resins, and mixtures of the olefin resin and ethylene/vinyl acetate copolymer, and the like may be exemplified.

A proximal end of the catheter <NUM> is fixed to a distal end of the catheter hub <NUM> by a suitable fixing method (caulking, fusion, bonding, and the like). The catheter hub <NUM> is exposed on patient's skin with the catheter <NUM> being inserted into a blood vessel, and indwelled together with the catheter <NUM> by being pasted with a tape or the like.

The catheter hub <NUM> is formed in a cylindrical shape tapered in a distal end direction. A constituent material of the catheter hub <NUM> is not particularly limited, but for example, thermoplastic resins such as polypropylene, polycarbonate, polyamides, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer may be applied. A transfusion tube connector not illustrated is connected to a proximal end side of the catheter hub <NUM> after detachment of the inner needle <NUM>.

A hollow portion <NUM> that is in communication with the cavity <NUM> of the catheter <NUM> and allows transfusion solution to flow is provided inside the catheter hub <NUM>. The hollow portion <NUM> may house a hemostasis valve, a plug, and the like not illustrated adapted to prevent back-flow of blood at the time of puncture with the inner needle <NUM> and also enable transfusion along with insertion of the transfusion tube connector.

Furthermore, an annular projection <NUM> which projects radially outward and revolves in a circumferential direction of the catheter hub <NUM> is formed close to a distal end of an outer peripheral surface of the catheter hub <NUM>. Additionally, same as the annular projection <NUM>, a screw portion <NUM> that revolves in the circumferential direction of the catheter hub <NUM> is formed in a projecting manner at a proximal end of the outer peripheral surface of the catheter hub <NUM>.

On the other hand, the inner needle <NUM> of the catheter assembly <NUM> is formed as a hollow tube having rigidity capable of puncturing skin of a living body, and arranged in the cavity <NUM> of the catheter <NUM> and the hollow portion <NUM> of the catheter hub <NUM> in a penetrating manner. The inner needle <NUM> has an entire length longer than the catheter <NUM> and is formed to have a diameter gradually becoming larger in the distal end direction from the proximal end portion, and the distal end thereof is provided with a sharp needlepoint 16a. In the initial state illustrated in <FIG>, the multiple tube unit <NUM> exposes the needlepoint 16a from the catheter <NUM> and the auxiliary member <NUM>. A through-hole 16b is provided inside the inner needle <NUM> in an axial direction of the inner needle <NUM>. Meanwhile, a groove portion (not illustrated) may also be provided in the axial direction on an outer peripheral surface of the inner needle <NUM>. Additionally, the inner needle <NUM> may also be a solid needle.

As a constituent material of the inner needle <NUM>, for example, metallic materials such as stainless steel, aluminum or an aluminum alloy, or titanium or a titanium alloy, a hard resin, ceramics, and the like may be exemplified. The inner needle <NUM> is firmly fixed to the needle hub <NUM> by a suitable fixing method (fusion, bonding, insert molding, and the like).

As illustrated in <FIG>, the needle hub <NUM> is formed as a housing <NUM> including a lower wall <NUM>, a pair of side walls 34a, 34b projecting upward from a side portions 32a of the lower wall <NUM>. The housing <NUM> has an elongated cup-like shape extending shorter than an axial length of the inner needle <NUM>. A housing space <NUM> to house part of the multiple tube unit <NUM>, the catheter hub <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> is formed on an inner side surrounded by the lower wall <NUM> and the pair of side walls 34a, 34b.

A constituent material to form the needle hub <NUM> is not particularly limited and, for example, may be suitably selected from materials exemplified for the catheter hub <NUM>. Meanwhile, the catheter hub <NUM> and the needle protection member <NUM> are exposed on the upper side in order to enable the catheter assembly <NUM> to rotate the catheter <NUM> relative to the inner needle <NUM>. Alternatively, the catheter assembly <NUM> may also have a structure in which the catheter hub <NUM>, needle protection member <NUM>, and the like are covered by forming an upper wall or attaching a lid body to the housing <NUM>.

The lower wall <NUM> includes: a pair of the side portions 32a formed flat; and a guide groove portion 32b interposed between the pair of the side portions 32a and recessed downward in an arc shape. In the guide groove portion 32b, the catheter hub <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> are slidably arranged in a longitudinal direction of the housing <NUM>. On a proximal end side and in a center portion in a width direction of the lower wall <NUM> (guide groove portion 32b), a needle holding portion <NUM> projecting upward from an upper surface thereof and adapted to fix the proximal end portion of the inner needle <NUM> at a predetermined height is integrally formed. Meanwhile, the needle holding portion <NUM> may also be formed separately from the housing <NUM> and may be bonded and fixed to the housing <NUM>.

The pair of side walls 34a, 34b extends in parallel in a longitudinal direction together with the lower wall <NUM> and has a constant vertical width on the proximal end side and an intermediate side, and the vertical width on the distal end side is formed wider relative to the intermediate side. Groove-like rail portions <NUM> are provided on upper portions on the distal end sides of the respective side walls 34a, 34b. The pair of rail portions <NUM> linearly extends in the longitudinal direction on inner surfaces of the wide portions of the respective side walls 34a, 34b, and reaches upper surfaces on the intermediate sides. The respective rail portions <NUM> house side edges 46a, 46b of the catheter operation member <NUM>, and guide advancement and retraction of the catheter operation member <NUM>. A distal end of a groove wall constituting the rail portion <NUM> is formed to have a curved surface 42a to allow the catheter operation member <NUM> to be curved.

Furthermore, an arrangement recessed portion <NUM> to attach a support member <NUM> is provided on the side wall 34a. The arrangement recessed portion <NUM> is cut out in the proximal end direction from the distal end of the side wall 34a, and located between the lower wall <NUM> and the rail portion <NUM>. The lower wall <NUM> and the side wall 34a at a forming position of the arrangement recessed portion <NUM> are provided with a pair of bearing holes 43a, 43b to rotatably attach the support member <NUM>. A window 43c in which a cam projecting portion <NUM> (refer to <FIG>) of the support member <NUM> described later is housed is provided at a position overlapping with the rail portion <NUM> (between the upper bearing hole 43a and the arrangement recessed portion <NUM>), and an cavity to be arranged with an axial rod portion <NUM> is formed on a wall between the arrangement recessed portion <NUM> and the window 43c. Furthermore, a locking recessed portion 43d into which a locking projecting portion <NUM> is inserted is formed on the lower wall <NUM> when the support main body portion <NUM> of the support member <NUM> is rotated about <NUM> degrees.

Referring back to <FIG>, the auxiliary member <NUM> of the catheter assembly <NUM> supports the catheter <NUM> from the inside and has a function to assist insertion of the catheter <NUM> into a blood vessel. The auxiliary member <NUM> has an outer diameter smaller than an inner diameter of the catheter <NUM>, and is formed inside a hollow tube having an inner diameter larger than an outer diameter of the inner needle <NUM>. A proximal end portion of the auxiliary member <NUM> is fixed to and held by the auxiliary member hub <NUM> by a suitable fixing method (caulking, fusion, bonding, and the like).

The auxiliary member hub <NUM> has a distal end side thereof assembled to the catheter hub <NUM> in a freely detachable manner, and the needle protection member <NUM> is assembled to a proximal end side thereof in a freely detachable manner. The auxiliary member hub <NUM> connects the catheter hub <NUM> and the needle protection member <NUM> respectively in a manner integrally rotatable. Meanwhile, the auxiliary member hub <NUM> may also integrated to the needle protection member <NUM> (more specifically, the auxiliary member <NUM> may also be fixed to the needle protection member <NUM>). Furthermore, the catheter assembly <NUM> may not necessarily include the auxiliary member <NUM> and the auxiliary member hub <NUM>. In this case, the needle protection member <NUM> is directly attached to the proximal end of the catheter hub <NUM>.

In the initial state, the needle protection member <NUM> has the inner needle <NUM> arranged in a penetrating manner. Furthermore, the needlepoint 16a having moved due to detachment of the catheter <NUM> and the inner needle <NUM> is housed, and the needlepoint 16a is prevented from being exposed again. The needle protection member <NUM> houses a shutter <NUM> and a slip-out stop member <NUM> in order to prevent the needlepoint 16a from being exposed again. The shutter <NUM> is elastically deformed by contacting the outer peripheral surface of the inner needle <NUM> in a state that the inner needle <NUM> is arranged in a penetrating manner, and when the needlepoint 16a slips out, the shutter <NUM> is elastically restored and shuts a penetrating route of the inner needle <NUM>. The slip-out stop member <NUM> includes a hole having a diameter smaller than that of the needlepoint 16a of the inner needle <NUM>, thereby inhibiting the needlepoint 16a from slipping out in the proximal end direction.

The catheter operation member <NUM> directly holds the catheter <NUM> and also is attached to the catheter hub <NUM>, thereby making the catheter <NUM> and the catheter hub <NUM> advance and retract relative to the inner needle <NUM> and the housing <NUM>. As illustrated in <FIG> and <FIG>, the catheter operation member <NUM> includes an operation plate portion <NUM> (long portion) extending in the longitudinal direction of the housing <NUM>, and a hub attachment portion <NUM> integrally formed with a proximal end of the operation plate portion <NUM> and attached to the catheter hub <NUM> freely detachably manner.

The operation plate portion <NUM> is a portion where a user's finger is touched and advancing and retracting operation is performed. In the initial state, a pair of side edges 46a, 46b of the operation plate portion <NUM> is arranged at the pair of rail portions <NUM> and upper surfaces of the pair of side walls 34a, 34b on the proximal end sides of the rail portions <NUM>. The operation plate portion <NUM> is formed thin enough to have flexibility capable of being curved in a direction orthogonal to a surface direction of the operation plate portion <NUM>, more specifically, in a direction separating away from the inner needle <NUM>. A constituent material of the operation plate portion <NUM> (catheter operation member <NUM>) is not particularly limited and, for example, may be suitably selected from the materials exemplified for the catheter hub <NUM>.

As illustrated in <FIG>, the operation plate portion <NUM> is formed a substantially rectangular shape in a plan view, and a cut-out portion <NUM> is provided on a proximal end side of a side edge 46a (setting place side of the support member <NUM>). The cut-out portion <NUM> forms a level difference 47a at a boundary between a forming position thereof and the operation plate portion <NUM> by cutting off the operation plate portion <NUM> toward the inside in a width direction. Furthermore, an inclined edge 46c gradually inclined toward the inside in the width direction in the proximal end direction is formed at the side edge 46a located more on the distal end side than the level difference 47a.

Additionally, as illustrated in <FIG> and <FIG>, an upper side rib <NUM> and tabs <NUM>, <NUM> are provided on an upper surface of the operation plate portion <NUM>, a distal end camber portion <NUM> is provided at a distal end of the operation plate portion <NUM>, and a holding portion <NUM> and a lower side rib <NUM> are provided on a lower surface of the operation plate portion <NUM>.

A plurality of upper side ribs <NUM> and a plurality of lower side ribs <NUM> are provided in a longitudinal direction of the operation plate portion <NUM>. These upper and lower side ribs <NUM>, <NUM> project upward and downward respectively and linearly extend in a width direction of the operation plate portion <NUM>, thereby enhancing strength in the width direction of the operation plate portion <NUM>. With this structure, the operation plate portion <NUM> is prevented from being bent, warped, or the like inside the housing <NUM> even when external force is applied from the outside, and advancing and retracting is smoothly performed along the upper surfaces of the pair of side walls 34a, 34b and the rail portions <NUM>.

The tabs <NUM>, <NUM> are portions provided assuming that the user's finger directly touches the same, and the tabs project higher than the upper side rib <NUM>. The number of tabs <NUM>, <NUM> to be provided is not limited to two illustrated in <FIG>, and one tab or three or more tabs may be provided.

As illustrated in <FIG>, the distal end camber portion <NUM> includes a thick portion 56a projecting to the lower surface side of the operation plate portion <NUM>, and becomes gradually thinner from the thick portion 56a in the distal end direction while being curved upward. An insertion groove <NUM> through which the catheter <NUM> is made to pass in a non-contacting manner or with little friction is formed at a center portion in a width direction of the thick portion 56a. With advancement of the catheter operation member <NUM>, a cambered lower surface side of the distal end camber portion <NUM> contacts the patient or is gripped by the user, thereby guiding the operation plate portion <NUM> to be directed obliquely upward.

On the other hand, a plurality of holding portions <NUM> of the catheter operation member <NUM> is provided in the longitudinal direction of the operation plate portion <NUM> (five holding portions in <FIG>). The holding portions <NUM> are arranged at equal intervals in the longitudinal direction of the operation plate portion <NUM>, and hold the catheter <NUM> at the respective places by contacting the outer peripheral surface thereof. Meanwhile, the catheter operation member <NUM> may also have a structure in which one holding portion <NUM> is provided at one predetermined place to hold the catheter <NUM>.

The plurality of holding portions <NUM> each includes a pair of projecting pieces <NUM> (projecting portions) projecting downward from the lower surface of the operation plate portion <NUM>. The pair of projecting pieces <NUM> is symmetrically formed each other interposing an intermediate portion in the width direction of the operation plate portion <NUM> (in the following, a projecting piece <NUM> located on a near side in <FIG> will be also referred to as a first projecting piece <NUM> and a projecting piece <NUM> located on a far side in <FIG> will be also referred to as a second projecting piece <NUM>).

The first and second projecting pieces <NUM>, <NUM> are formed in a rectangular shape that is wide in the width direction of the operation plate portion <NUM>. An interval of respective inner edges of the first projecting piece <NUM> and the second projecting piece <NUM> is set slightly wider than the outer diameter of the catheter <NUM>. Nail portions <NUM>, <NUM> slightly projecting to an inner side in the width direction are formed on lower portion sides of the respective inner edges. An interval of respective projecting ends of the pair of the nail portions <NUM>, <NUM> is set slightly narrower than the outer diameter of the catheter <NUM> by coming close to each other.

When the catheter <NUM> is assembled to the catheter operation member <NUM>, the catheter <NUM> passes the pair of nail portion <NUM>, <NUM> and is easily nipped between the first and second projecting pieces <NUM>, <NUM>. Meanwhile, "nipped" in the present specification means a state that the holding portions <NUM> contact and hold the catheter <NUM> with weak engagement force. Needless to mention, the structure of the holding portion <NUM> is not limited to the above-described pair of the projecting pieces <NUM>, and various kinds of structures to hold the catheter <NUM> are applicable.

The first and second projecting pieces <NUM>, <NUM> are formed in a square shape having round corners at protruding ends (lower ends) in side sectional view. The round corners of the first and second projecting pieces <NUM>, <NUM> allow the support member <NUM> located on the lower side to easily climb over the first and second projecting pieces <NUM>, <NUM> (improves slidability) when the catheter operation member <NUM> advances and retracts.

Moreover, the first and second projecting pieces <NUM>, <NUM> are formed in a projecting manner such that phases (forming positions) are mutually deviated in the longitudinal direction of the operation plate portion <NUM>. In other words, the first projecting piece <NUM> and the second projecting piece <NUM> hold the catheter <NUM> with weak engagement force by not clamping the catheter <NUM> on the same axis. Therefore, when the operation plate portion <NUM> is curved, the catheter operation member <NUM> displaces and detaches hooked portions of the catheter <NUM> in the order of the first projecting piece <NUM> and the second projecting piece <NUM>.

On the other hand, the hub attachment portion <NUM> of the catheter operation member <NUM> is formed in a box shape by a pair of side plates <NUM> projecting downward from the operation plate portion <NUM> and a semi-cylindrical upper plate <NUM> slightly projecting upward from the operation plate portion <NUM>. In the case of viewing the hub attachment portion <NUM> from the lower direction, a proximal end side and an intermediate side of the pair of the side plates <NUM> extend in parallel and a distal end side continuous to the intermediate side is inclined inward in the distal end direction.

The catheter hub <NUM> is rotatably housed inside the pair of side plates <NUM> and the upper plate <NUM> while an attachment chamber <NUM> to inhibit axial movement of the catheter hub <NUM> relative to the hub attachment portion <NUM> is provided. The attachment chamber <NUM> is open to the outside at the lower portion and the proximal end of the hub attachment portion <NUM>.

An inner surface of the attachment chamber <NUM> is formed with: a locking groove <NUM> formed by overlaying a trapezoid hole on a round hole; a groove portion <NUM> adapted to arrange the pair of side plates <NUM> and the upper plate <NUM> extending in a U-shape; and a pair of projections <NUM> projecting inside the hub attachment portion <NUM>. The locking groove <NUM> allows the catheter <NUM> to pass through the trapezoid hole having a wide lower side and a narrow upper side and then be arranged in the round hole, and appropriately locks the catheter <NUM> by hooking the catheter at a boundary portion between the trapezoid hole and the round hole. The groove portion <NUM> rotatably houses the annular projection <NUM> of the catheter hub <NUM> in a manner inhibiting movement thereof in the distal end and proximal end directions. Furthermore, the pair of projections <NUM> hooks the outer peripheral surface on the proximal end side of the catheter hub <NUM> with light engagement force.

Furthermore, as illustrated in <FIG>, since the catheter assembly <NUM> supports the lower side of the catheter <NUM> held by the catheter operation member <NUM>, the support member <NUM> is provided at the distal end side of the housing <NUM>. The support member <NUM> includes the cylindrical axial rod portion <NUM> and the support main body portion <NUM> projecting in a lateral direction from the axial rod portion <NUM> (direction orthogonal to an axial center of the axial rod portion <NUM>).

As illustrated in <FIG>, <FIG>, the axial rod portion <NUM> extends short in upper and lower directions, and an upper end portion and a lower end portion are inserted in to the pair of upper and lower bearing holes 43a, 43b of the arrangement recessed portion <NUM> respectively. The support member <NUM> is assembled to the housing <NUM> in a manner rotatable around the axial rod portion <NUM> as a base point.

A connection reinforcing portion <NUM> corresponding to a vertical length of the arrangement recessed portion <NUM> is formed in a bulging manner on the lower side of the axial rod portion <NUM> in a state that the support member <NUM> is assembled to the housing <NUM>. The support main body portion <NUM> is connected to the connection reinforcing portion <NUM>. Furthermore, a pair of the cam projecting portions <NUM> (cam portions) functioning as a cam portion adapted to rotatably operate the support member <NUM> is integrally formed on an upper side of the axial rod portion <NUM>. The pair of cam projecting portions <NUM> is provided at a predetermined position (position housed in the window 43c in a state of being assembled to the housing <NUM>), and projects mutually in opposite directions to the same extent, interposing the axial rod portion <NUM>.

Furthermore, the support member <NUM> includes an operation member groove portion <NUM> at a position facing the axial rod portion <NUM> and the support main body portion <NUM> of the pair of cam projecting portions <NUM>. The operation member groove portion <NUM> linearly extends from a most distal end of the cam projecting portion <NUM> on the distal end side to a most proximal end of the cam projecting portion <NUM> on the proximal end side in the initial state. The operation member groove portion <NUM> is arranged at a position corresponding to the rail portion <NUM>, and houses the side edge 46a of the catheter operation member <NUM> in a slidable manner together with the rail portion <NUM>.

On the other hand, the support main body portion <NUM> of the support member <NUM> is a portion to be moved by rotation around the axial rod portion <NUM> as the base point in a state of being assembled to the housing <NUM>. More specifically, the support main body portion <NUM> is displaced to a first position P1 located inside the housing space <NUM> and capable of contacting and supporting the catheter <NUM> (refer to <FIG> and <FIG>) and a second position P2 located outside the housing <NUM> and in the arrangement recessed portion <NUM> different from the first position P1, and not contacting the catheter <NUM> (refer to <FIG>). An angle between the first position P1 and the second position P2 around the axial center of the axial rod portion <NUM> is preferably <NUM> degrees or more such that the catheter hub <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> can easily slip out. According to the present embodiment, the angle is set to <NUM> degrees such that the cam projecting portion <NUM> is located inside the rail portion <NUM> at the second position P2.

The support main body portion <NUM> is formed in an S shape having a size almost same as the vertical width of the arrangement recessed portion <NUM> in a front view, and has spring force capable of being elastically deformed in the vertical direction. A raised portion <NUM> slightly rising upward is formed on an upper surface of the support main body portion <NUM>. The raised portion <NUM> is the first position P1 of the support main body portion <NUM> and can contact the catheter <NUM>(multiple tube unit <NUM>) held by the catheter operation member <NUM>. Meanwhile, in the present embodiment, the support main body portion <NUM> faces the catheter <NUM> in a non-contacting manner in a state of being located in the first position P1, and is adapted to contact and support the same when pressed by the user. However, not limited thereto, the support main body portion <NUM> may be adapted to contact and support the catheter <NUM> when located in the first position P1.

Furthermore, a distal end inclined surface <NUM> inclined downward and in the distal end direction is formed on an upper distal end side of the support main body portion <NUM>, and a proximal end inclined surface <NUM> inclined downward and in the proximal end direction is formed on an upper proximal end side of the support main body portion <NUM>. Additionally, a wing <NUM> projecting and inclined downward and outward in a width direction separating from the axial rod portion <NUM> is integrally formed at an end portion continued to the raised portion <NUM> of the support main body portion <NUM>.

The locking projecting portion <NUM> is formed downward in a projecting manner on a lower surface of the support main body portion <NUM>. The locking projecting portion <NUM> is inserted into the locking recessed portion 43d of the housing <NUM> at the second position P2 of the support main body portion <NUM>. Furthermore, a contacting projection <NUM> projecting the proximal end direction is provided at a proximal end on a lower portion side of the support main body portion <NUM>. The contacting projection <NUM> contacts the side plates <NUM> (hub attachment portion <NUM>) at the time of advancement of the catheter operation member <NUM>, and induces the support main body portion <NUM> to be displaced to the second position P2 distant from the first position P1 by <NUM> degrees.

A constituent material of the support member <NUM> is not particularly limited and, for example, may be suitably selected from the materials exemplified for the catheter hub <NUM>. Meanwhile, the support member <NUM> may be provided not only as a separate body from the housing <NUM> but also formed integrally with the housing <NUM>. Furthermore, the support member <NUM> may not only provided at the side wall 34a of the housing <NUM> but also provided at the side wall 34b, and a pair thereof may be provided at both of the side walls 34a, 34b. Additionally, a rotational direction of the support main body portion <NUM> is not limited to the plane direction of the housing <NUM> but in a side surface direction including upward and downward.

The catheter assembly <NUM> according to the present embodiment has the basic structure as described above, and functions and effects thereof will be described below.

As described above, the catheter assembly <NUM> is used to construct an introducing portion for transfusion to a patient. In the initial state illustrated in <FIG>, the catheter hub <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> are connected, and the catheter hub <NUM> is housed in the attachment chamber <NUM> of the catheter operation member <NUM> (hub attachment portion <NUM>) and integrally housed in the housing space <NUM> of the housing <NUM>.

Furthermore, in the initial state, the support main body portion <NUM> of the support member <NUM> assembled to the distal end portion of the housing <NUM> stands by at the first position P1, and faces the multiple tube unit <NUM> held by the plurality of holding portions <NUM> of the catheter operation member <NUM> as illustrated in <FIG>. Each of the holding portions <NUM> nips the outer peripheral surface of the catheter <NUM> with weak engagement force in each place in the axial direction, and the catheter <NUM> is firmly held as the entire catheter operation member <NUM>.

At the time of using the catheter assembly <NUM>, the user grips and operates the housing <NUM>, and punctures a patient with the multiple tube unit <NUM>. At the time of puncture, the holding portions <NUM> hold the catheter <NUM>, thereby preventing the multiple tube unit <NUM> from being warped inside the housing <NUM> even when resistance force is received along with puncture. Furthermore, when the distal end side of the catheter operation member <NUM> is pressed downward by the user's finger at the time of puncture, the multiple tube unit <NUM> is contacted and supported by the support member <NUM> standing by at the first position P1. Therefore, the multiple tube unit <NUM> is more prevented from being warped by being fixed between the catheter operation member <NUM> (insertion groove <NUM> of the distal end camber portion <NUM>) and the support member <NUM> (raised portion <NUM>).

As a result, the extending state of the multiple tube unit <NUM> from the distal end of the housing <NUM> is properly maintained, and the user can puncture the patient with the multiple tube unit <NUM> without any discomfort. Furthermore, the catheter assembly <NUM> can be formed thinner by reducing strength of the inner needle <NUM>, and burden on the patient can be reduced.

As illustrated in <FIG>, in a puncture state with the multiple tube unit <NUM>, the user makes the catheter <NUM> advance relative to the inner needle <NUM> and inserts the same into a blood vessel. At this point, the user puts a finger on the upper side rib <NUM> or the tabs <NUM>, <NUM> of the catheter operation member <NUM> and makes the catheter operation member <NUM> advance in the distal end direction relative to the housing <NUM> (relative movement). In advancing operation of the catheter operation member <NUM>, the multiple tube unit <NUM> is kept being held by the holding portions <NUM>, and the catheter <NUM> smoothly advances.

At the time of advancing operation, since the side edge 46a of the operation plate portion <NUM> exists in the operation member groove portion <NUM> of the support member <NUM> as illustrated in <FIG>, the support member <NUM> is prevented from being rotated, and the support main body portion <NUM> continues standing by at the first position P1. Therefore, the support member <NUM> keeps the state capable of supporting the lower side of the multiple tube unit <NUM>, and the multiple tube unit <NUM> is prevented from slipping out from the holding portions <NUM> even in the case where the catheter <NUM> receives reaction force from the skin and the like at the time of inserting the catheter <NUM>. Therefore, for example, the needlepoint 16a of the inner needle <NUM> is prevented from retracting and slipping out from the skin by being warped, and inconvenience such as puncturing the skin again with the inner needle <NUM> can be avoided.

Furthermore, since the support main body portion <NUM> has elastic force in the vertical direction and includes the proximal end inclined surface <NUM>, the support main body portion <NUM> is suitably and elastically deformed to allow the holding portion <NUM> to pass when contacted by the holding portion <NUM> (pair of projecting pieces <NUM>) at the time of advancement. Consequently, the catheter operation member <NUM> makes the catheter <NUM> smoothly advance.

When the distal end camber portion <NUM> contacts the patient's skin along with advancement in the distal end direction or when the user grips the distal end camber portion <NUM> or the like, the operation plate portion <NUM> of the catheter operation member <NUM> is curved in a manner separating away from the axial direction of the multiple tube unit <NUM>. The operation plate portion <NUM> is curved from the distal end side of the operation plate portion <NUM>, and the holding portions <NUM> aligned in the longitudinal direction sequentially detach the multiple tube unit <NUM> from the distal end side against respective engagement force. Even in the case where holding by the holding portion <NUM> on the distal end side is released due to curving of the operation plate portion <NUM>, the holding portion <NUM> on the proximal end side where linearity is kept inside the housing <NUM> can continue holding the multiple tube unit <NUM>. Furthermore, the support main body portion <NUM> of the support member <NUM> keeps standing by at the first position P1 and continues supporting the multiple tube unit <NUM> together with the holding portions <NUM> holding the catheter <NUM> on the proximal end side.

Here, in the case where the user cannot insert the catheter <NUM> smoothly, the user can once perform retracting operation of the catheter operation member <NUM> and may make the catheter <NUM> retract relative to the inner needle <NUM> and the housing <NUM>. At the time of retraction, the operation plate portion <NUM> is housed again in the rail portions <NUM> of the housing <NUM> and the curved state is changed to the linear state (non-curved state). Furthermore, due to retraction of the catheter operation member <NUM>, the wing <NUM> and the raised portion <NUM> lift the catheter <NUM> toward the holding portions <NUM>, and make the plurality of holding portions <NUM> (pair of projecting pieces <NUM>) nip the catheter <NUM> again.

When the catheter operation member <NUM> advances to some extent, a state in which the side edge 46a illustrated in <FIG> is located in the operation member groove portion <NUM> is shifted to a state in which the inclined edge 46c of the operation plate portion <NUM> illustrated in <FIG> is located in the operation member groove portion <NUM>. At the same time, the side plates <NUM> of the hub attachment portion <NUM> contact the contacting projection <NUM> of the support main body portion <NUM>, thereby starting rotation of the support main body portion <NUM> from the first position P1.

When the level difference 47a of the operation plate portion <NUM> passes the cam projecting portion <NUM> on the distal end side of the support member <NUM>, the cam projecting portion <NUM> comes to be located at the cut-out portion <NUM> and the support member <NUM> becomes rotatable. The contacting projection <NUM> of the support main body portion <NUM> rotates the support main body portion <NUM> with the sufficient rotation angle (<NUM> degrees) by contact of the catheter operation member <NUM>. As a result, the support main body portion <NUM> is displaced from the first position P1 illustrated in <FIG> to the second position P2 illustrated in <FIG>, and largely open a distal end side of the housing space <NUM>. Consequently, the catheter hub <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> can pass in the distal end direction and can easily slip out from the housing <NUM>.

In the state that the support main body portion <NUM> is located at the second position P2, the locking projecting portion <NUM> is inserted into the locking recessed portion 43d, thereby making the support main body portion <NUM> stand by at the second position P2. Further, in this state, one of the cam projecting portions <NUM> is located inside the rail portion <NUM>. Therefore, when the user perform retracting operation of the catheter operation member <NUM>, the support member <NUM> is rotated by contact of the level difference 47a and the cam projecting portion <NUM>, and the support main body portion <NUM> is returned to the first position P1 from the second position P2 again. When the support main body portion <NUM> is rotated, the wing <NUM> extends obliquely downward. Therefore, the catheter <NUM> is guided to an upper portion of the support main body portion <NUM> while the catheter <NUM> is prevented from being deviated in the lateral direction. Therefore, the support member <NUM> can make the holding portions <NUM> nip the catheter <NUM> again along with retraction of the catheter operation member <NUM>.

With advancement of the catheter operation member <NUM> (or with retraction of the inner needle <NUM> and the housing <NUM>), the catheter hub <NUM> attached to the hub attachment portion <NUM> and the needle protection member <NUM> attached to the catheter hub <NUM> also advance. Furthermore, when the catheter hub <NUM> and the needle protection member <NUM> slip out from the housing <NUM> and advance to some extent, the needlepoint 16a of the inner needle <NUM> is housed inside the needle protection member <NUM>. The needle protection member <NUM> inhibits the needlepoint 16a from slipping out by the slip-out stop member <NUM>, and also prevents the needlepoint 16a from being exposed again by opening, in front of the needlepoint 16a, the shutter <NUM> that has been closed by the outer peripheral surface of the inner needle <NUM> inside the needle protection member <NUM>.

Furthermore, after the catheter hub <NUM> is detached from the housing <NUM>, engagement between the locking groove <NUM>, pair of projections <NUM> of the hub attachment portion <NUM>, and catheter hub <NUM> can be easily released. Therefore, the user separates the catheter operation member <NUM> from the catheter <NUM> and the catheter hub <NUM> at suitable timing, and the catheter <NUM> and the catheter hub <NUM> are properly indwelled in the patient.

As described above, the catheter assembly <NUM> according to the present embodiment can support the catheter <NUM> with the support member <NUM> located at the first position P1 on an opposite side of the catheter operation member <NUM>. Therefore, at the time of advancing operation of the catheter operation member <NUM>, the support member <NUM> contacts and supports the catheter <NUM> inside the housing <NUM> and can prevent the same from being warped even in the case where the catheter <NUM> receives reaction force from a patient. Consequently, the extending state of the multiple tube unit <NUM> is properly maintained, and the user can smoothly insert the catheter <NUM> into the patient. Furthermore, the support member <NUM> is displaced from the first position P1 to the second position P2, thereby making the catheter hub <NUM> and the catheter operation member <NUM> advance without interference and enabling easy detachment from the inner needle <NUM> and the housing <NUM>.

In the catheter assembly <NUM>, the catheter <NUM> is supported by being interposed between the catheter operation member <NUM> and the support member <NUM> in the initial state. Consequently, the multiple tube unit <NUM> can be prevented from being warped at the time of puncturing the patient with the multiple tube unit <NUM>. Therefore, the user can perform puncture with the multiple tube unit <NUM> without any discomfort. Furthermore, since the support main body portion <NUM> is inhibited from being moved from the first position P1 in the initial state, the catheter <NUM> can be stably supported. On the other hand, since the support main body portion <NUM> is released from inhibition of movement at the time of advancement of the catheter operation member <NUM>, the catheter hub <NUM> and the catheter operation member <NUM> can be smoothly exposed from the housing <NUM>. Furthermore, since the holding portions <NUM> directly hold the catheter <NUM>, warping can be prevented by the catheter operation member <NUM> at the time of puncture with the multiple tube unit <NUM> and the catheter <NUM> and at the time of inserting the catheter <NUM>. At this point, since the support member <NUM> can support the catheter <NUM> on the opposite side of the catheter operation member <NUM>, the catheter <NUM> can be prevented from slipping out from the holding portion <NUM>.

In this case, when the support member <NUM> is rotatably attached to the housing <NUM>, the support main body portion <NUM> can be displaced in a short distance between the first position P1 and the second position P2, and the catheter assembly <NUM> can be downsized. Furthermore, since the support main body portion <NUM> is provided in a manner rotatable to the housing <NUM> by the axial rod portion <NUM>, the support main body portion is smoothly displaced between the first position P1 and the second position P2. This enables easy switch between the supportable state for the catheter <NUM> and the detachable state for the catheter hub <NUM> and the like. Additionally, in the case where the side edge 46a of the catheter operation member <NUM> exists in the operation member groove portion <NUM>, the support member <NUM> becomes unable to be rotated, and it is possible to continue making the support main body portion <NUM> stand by at the first position P1 capable of supporting the catheter <NUM>. On the other hand, in the case where the cut-out portion <NUM> of the catheter operation member <NUM> exists in the operation member groove portion <NUM>, the support member <NUM> becomes rotatable and the support main body portion <NUM> can be displaced to the second position P2 at which the catheter hub <NUM> and the like are allowed to pass.

Furthermore, at the time of advancing and retracting operation of the catheter operation member <NUM>, the support main body portion <NUM> is elastically deformed and allows the holding portion <NUM> to pass even when the holding portion <NUM> holding the catheter <NUM> contact the same. Therefore, mobility of the catheter operation member <NUM> can be sufficiently secured. The catheter operation member <NUM> largely rotates the support main body portion <NUM> by contacting the contacting projection <NUM> at the time of advancement, and the support main body portion <NUM> can be surely arranged at the second position P2 from the first position P1. Therefore, unintended contact between the catheter operation member <NUM> and the support member <NUM> can be prevented at the time of retracting operation of the catheter operation member <NUM>, and the catheter operation member <NUM> can be made to smoothly retract.

Note that the catheter assembly <NUM> according to the present invention is not limited to the above-described embodiment, and various kinds of application examples and modified examples are applicable. For example, the catheter assembly <NUM> may have a structure in which a guide wire not illustrated is housed in the through-hole 16b of the inner needle <NUM>, and the guide wire is exposed from the needlepoint 16a to guide the catheter <NUM> by controlling a guide wire operation member not illustrated and connected to the guide wire.

Furthermore, the support member <NUM> capable of supporting the catheter <NUM> inside the housing <NUM> is not limited to the above-described component, and for example, a slider (not illustrated and not being part of the present invention) that slides between the first position P1 and the second position P2 may be applied instead of the support member <NUM>. In this case, the slider is adapted to advance and retract in a width direction of the housing <NUM> (direction orthogonal to the moving direction of the catheter <NUM>). With this structure, the slider can easily switch the position between the first position P1 capable of supporting the catheter <NUM> near the axial center of the housing <NUM> and the second position P2 at which the catheter hub <NUM> and the like are allowed to pass outside the housing <NUM>.

Next, a catheter assembly 10A according to a first modified example will be described. Note that a reference sign same as the one used in the above-described embodiment has the same structure or the same function in the following description, and a detailed description therefor will be omitted.

A catheter assembly 10A according to the first modified example differs from the catheter assembly <NUM> in that a torsion spring <NUM> is adopted as the support member to support the catheter <NUM> as illustrated in <FIG>. Furthermore, a needle hub 18A (housing 19A) of the catheter assembly 10A includes a housing portion <NUM> to arrange the torsion spring <NUM> instead of the above-described arrangement recessed portion <NUM>.

The housing portion <NUM> slightly bulges outward in the width direction from the side wall 34a of the housing 19A and includes a spring housing chamber inside thereof (not illustrated). Furthermore, the housing portion <NUM> includes, on the lower side of the rail portion <NUM>, a slit 132a capable of passing a support spring portion <NUM> when the support spring portion <NUM> of the later-described torsion spring <NUM> is displaced.

The torsion spring <NUM> includes: a coil portion <NUM> formed by winding a wire member made of a metallic material in a spiral form; and the support spring portion <NUM> (support main body portion, projecting portion) projecting from an upper end of the coil portion <NUM> in a lateral direction (direction orthogonal to an axial center of the coil portion <NUM>). The coil portion <NUM> is assembled to the housing 19A such that the axial direction thereof is formed along a vertical direction of the housing 19A. Furthermore, the coil portion <NUM> includes a pin 134a projecting from a lower end portion, and the pin 134a is fixed to the housing portion <NUM> in a non-rotatable manner.

The support spring portion <NUM> is formed in a U-shape in a plane view, and extends from the coil portion <NUM> to a position exceeding the multiple tube unit <NUM> and the holding portion <NUM> (first position P1) in the state that the torsion spring <NUM> is assembled to the housing 19A. With this structure, the support spring portion <NUM> can support the multiple tube unit <NUM> and prevents the multiple tube unit <NUM> from being warped when the user operates a catheter operation member 20A. Since the support spring portion <NUM> is elastically deformed in the vertical direction by the coil portion <NUM> and own spring force of the support spring portion <NUM> itself, the support spring portion <NUM> escapes downward when contacted by the holding portion <NUM>, and easily makes the holding portion <NUM> pass at the time of advancement and retraction of the catheter operation member 20A.

Furthermore, the hub attachment portion <NUM> of the catheter operation member 20A is formed of a pair of leg portions <NUM> adapted to clamp the outer peripheral surface of the catheter hub <NUM> as illustrated in <FIG>. Additionally, the catheter operation member 20A includes a block <NUM> projecting downward on a lower surface near the side edge 46a on a front side of the pair of leg portions <NUM>. The support spring portion <NUM> is rotated anticlockwise (elastically deformed) in a plane view by the block <NUM> contacting the support spring portion <NUM> along with advancement of the catheter operation member 20A. Therefore, the support spring portion <NUM> is displaced to a position (second position P2) at which the support spring portion <NUM> is inserted into the slit 132a on the distal end side, and allows the catheter hub <NUM>, catheter hub auxiliary member hub <NUM>, and needle protection member <NUM> to pass.

Furthermore, at the time of assembling the catheter operation member 20A to the housing 19A and when the catheter operation member 20A retracts again, the needle protection member <NUM> and the like contact the support spring portion <NUM> and rotates the support spring portion <NUM> in the proximal end direction as illustrated in <FIG>. Consequently, the support spring portion <NUM> is inserted into the slit 132a on the proximal end side, and allows the catheter hub <NUM>, catheter hub auxiliary member hub <NUM>, and needle protection member <NUM> to pass.

As described above, in the catheter assembly 10A according to the first modified example also, effects same as the catheter assemblies <NUM> can be obtained. Particularly, the torsion spring <NUM> can stably support the multiple tube unit <NUM> until the torsion spring <NUM> is pressed by the block <NUM>, and the multiple tube unit <NUM> is effectively prevented from being warped. On the other hand, the torsion spring <NUM> can easily allow the catheter hub <NUM>, auxiliary member hub <NUM>, and needle protection member <NUM> to pass along with pressing by the block <NUM>. Meanwhile, the above-described wing <NUM> and contacting projection <NUM> may be provided at the torsion spring <NUM>.

Next, a catheter assembly <NUM> according to a second embodiment of the present invention will be described. In the catheter assembly <NUM>, a shape of a needle hub <NUM> differs from a needle hub <NUM> of a catheter assembly <NUM> according to a first embodiment as illustrated in <FIG> and <FIG>. More specifically, the needle hub <NUM> includes a housing <NUM> and a pair of arms <NUM> projecting from the housing <NUM> in a distal end direction.

The housing <NUM> includes: a lower wall <NUM> having a pair of side portions 32a and a guide groove 32b; and a pair of side walls <NUM> projecting upward from both side portions of the lower wall <NUM>, and forms a housing space 204a on an inner side of the lower wall <NUM> and the pair of side walls <NUM>. A needle protection member <NUM> is housed in the housing space 204a of the housing <NUM> in the initial state. Meanwhile, the catheter assembly <NUM> does not include an auxiliary member <NUM> and an auxiliary member hub <NUM> described above, but needless to mention that the respective components may be also included.

Furthermore, as illustrated in <FIG>, a needle holding member <NUM> formed as a separate body from the housing <NUM> is fixed more on a proximal end side than the needle protection member <NUM> on the lower wall <NUM> of the housing <NUM>. The needle holding member <NUM> includes a holding base portion 210a at a center portion in a width direction, a horizontal plate 210b projecting outward in the width direction from the vicinity of a lower side of the holding base portion 210a and contacting the pair of side portions 32a, and a vertical plate 210c projecting upward from a projecting end of the horizontal plate 210b and contacting the pair of side walls <NUM>. The holding base portion 210a fixes and holds a proximal end portion of an inner needle <NUM> at an upper portion thereof. Furthermore, a hook-like connecting portion not illustrated but adapted to hook an attachment hole 206a (refer to <FIG>) of the lower wall <NUM> and firmly fix the needle holding member <NUM> to the housing <NUM> is provided at a lower portion of the holding base portion 210a.

As illustrated in <FIG> and <FIG>, the pair of arms <NUM> (first arm <NUM> and second arm <NUM>) is connected to the pair of side walls <NUM> of the housing <NUM>, and extend directly in a distal end direction. A rail portion <NUM> is provided at an inner surface of each of the pair of arms <NUM>, and a grip 212a to be held by a user is provided on an outer surface of each of the arms. Furthermore, same as the first embodiment, in the first arm <NUM>, an arrangement recessed portion <NUM>, a pair of bearing holes 43a, 43b, a window 43c, and a locking recessed portion 43d are formed, and a support member <NUM> is rotatably attached. Meanwhile, the pair of arms <NUM> may be formed of a metallic material in order to enhance rigidity (more specifically, to enhance an extending posture), or an enhancement member such as a metal bar (not illustrated) may be embedded in the inside made of a resin material.

In the catheter assembly <NUM> according to the second embodiment, effects same as the catheter assembly <NUM> can be obtained. More specifically, by supporting a lower side of the multiple tube unit <NUM> with the support member <NUM> attached to the needle hub <NUM>, a multiple tube unit <NUM> can be properly prevented from being warped at the time of puncture. On the other hand, since the needle hub <NUM> includes the pair of arms <NUM>, weight reduction of an entire assembly is achieved, and also mobility of a catheter operation member <NUM> is improved by reducing friction at the time of advancement and retraction of the catheter operation member <NUM>.

Furthermore, a catheter assembly <NUM> (needle hub <NUM>) according to a second modified example illustrated in <FIG> includes the pair of arms <NUM> same as the needle hub <NUM> according to the second embodiment but has a structure further including a connection bridge portion <NUM> to provide a bridge between the pair of the arms <NUM>. The connection bridge portion <NUM> is integrally formed with the pair of arms <NUM> on an inner surface at a lower position on a distal end sides of the pair of arms <NUM>. The connection bridge portion <NUM> has a length same as a width direction of the lower wall <NUM> of the housing <NUM> and includes a pair of side portions 32a and a groove portion 32b. Furthermore, an axial length of the connection bridge portion <NUM> corresponds to an installation area of the support member <NUM>, and the connection bridge portion is set so as not to expose a lower side of the support member <NUM>.

Thus, since the needle hub <NUM> includes the connection bridge portion <NUM> on the distal end sides of the pair of arms <NUM>, an interval on the distal end side and an entire portion of the pair of arms <NUM> can be set constant. Therefore, even when the user grips the vicinity of the grip 212a of the pair of the arms <NUM>, a shape of the needle hub <NUM> can be properly maintained and advancing and retracting operation of the catheter operation member <NUM> can be smoothly performed.

Furthermore, a catheter assembly <NUM> (needle hub <NUM>) according to a third modified example illustrated in <FIG> has a structure including a connection rod <NUM> to connect the distal end sides of the pair of arms <NUM> instead of the above-described connection bridge portion <NUM>. The connection rod <NUM> is a member made of, for example, a metallic material and formed a shape of a cylindrical rod. The connection rod <NUM> provides a bridge having a length same as a width direction of the lower wall <NUM> between the pair of arms <NUM> in the same manner as the connection bridge portion <NUM>, thereby making the interval between the pair of arms <NUM> constant.

Claim 1:
A catheter assembly (<NUM>, 10A, <NUM>, <NUM>, <NUM>) comprising:
a hollow catheter (<NUM>);
a catheter hub (<NUM>) configured to fix and hold the catheter (<NUM>);
an inner needle (<NUM>) including a needlepoint (16a) and configured to be detachably inserted through inside of the catheter (<NUM>);
a needle hub (<NUM>, 18A, <NUM>, <NUM>, <NUM>) configured to fix and hold the inner needle (<NUM>);
a catheter operation member (<NUM>, 20A) capable of moving the catheter (<NUM>) relative to the inner needle (<NUM>); a support member (<NUM>, <NUM>) being provided at the needle hub (<NUM>, 18A, <NUM>, <NUM>, <NUM>),
wherein the support member (<NUM>, <NUM>) includes a support main body portion (<NUM>, <NUM>) freely movable to a first position (P1) located on an opposite side of the catheter operation member (<NUM>, 20A) interposing the catheter (<NUM>), and capable of contacting and supporting the catheter (<NUM>), and a second position (P2) that is a position different from the first position (P1), and not contacting the catheter (<NUM>),
characterized in that
said support member (<NUM>, <NUM>) is rotatably attached to the needle hub (<NUM>, <NUM>, <NUM>, <NUM>).