Valve body and medical tool

A valve body is formed from an elastic member in the form of an elliptic or circular film (disk shape) having an upper face and a lower face. The valve body has an opening and closing section which is opened and closed in response to insertion and pulling out of a dilator and is formed from a first slit, a second slit, a second concave portion and two third concave portions. A pair of ribs and six projections are formed on the lower face side of the valve body. The ribs are disposed in opposing relationship to each other with the second slit interposed therebetween and extend along the lower face. Further, the projections are disposed such that they are positioned on the inner side of the ribs and are opposed to each other with the second slit interposed therebetween.

This application is a continuation of International Application No. PCT/JP2008/067328 filed on Sep. 25, 2008, and claims priority to Japanese Application No. 2007-252478 filed on Sep. 27, 2007 and Japanese Application No. 2007-252477 filed on Sep. 27, 2007, the entire content of all three of which is incorporated herein by reference.

TECHNICAL FIELD

This invention generally relates to a valve body. More specifically, the invention pertains to a valve body used in a medical tool, and a medical tool which incorporates the valve body, wherein the valve body includes an opening and closing section which is opened and closed in response to insertion and pulling off of an elongated medical member such as, for example, a catheter, a guide wire or a dilator.

BACKGROUND DISCUSSION

When an elongated member used for medical care, such as a catheter or a guide wire, is to be introduced into a living organism, an introducer (medical tool) is used. An example of one such introducer is disclosed in Japanese Patent Publication No. Hei 2-949.

This introducer is composed of a hub having a tubular shape, a sheath having a cap mounted at one end portion of the hub and a sheath tube connected to the other end portion of the hub, and a dilator which is inserted into and used together with the sheath in order to facilitate introduction of the sheath into a living organism. An opening is provided in the cap such that it is communicated with a hollow portion of the hub. A valve body having a disk shape covers the opening to maintain a liquid-tight state of the hollow portion of the hub.

The valve body is made of an elastic material such as silicone rubber and has two slits formed thereon that intersect crosswise with each other. The slits are placed into an open state when an elongated member (pipe body) is inserted into the sheath, but are placed into a closed state when the elongated member is pulled off from the sheath.

However, with such a valve body as just described, if an elongated member is kept inserted for a long period of time or insertion and pulling off of an elongated member are repeated frequently, a tear may occur with the slits, and there is the possibility that the tear may further advance.

If a tear occurs with the slits, when the elongated medical member is pulled off and the slits are closed, the liquid-tightness of the valve body (slits) may be deteriorated (damaged) by the tear. This may also be the case even when the elongated member is positioned in the valve body.

Further, even if a tear does not occur, for example, when coagulations or the like of the blood stick in the sheath are sucked and removed through the side port, since the inside of the sheath is placed into a negative pressure state, there is the possibility that a central portion of the valve body may be drawn into the inside of the sheath to open the slits thereby to allow air to be sucked into the inside of the sheath from the outside.

In this manner, the prior art valve body described above is not fully satisfactory with respect to sealability (sealing performance).

SUMMARY

A valve body and a medical tool embodying the valve body are disclosed which allow insertion and pulling off of an elongated member to be readily carried out while possessing superior sealability.

A valve body having upper and lower faces is made of an elastic material and has an opening and closing section which opens and closes in response to insertion and pulling out of an elongated member into and from the valve body. The opening and closing section includes a first slit extending to the upper face but not to the lower face, and a second slit extending to the lower face but not to the upper face and intersecting with the first slit in the inside of the valve body. The valve body further includes a pair of ribs on the lower face side. The ribs are disposed in opposing relationship to each other with the second slit interposed therebetween and extending along the lower face. In addition, projections are provided between the pair of ribs and the second slit.

This configuration of the valve body improves the sliding performance of the elongated member, insertion and pulling out of the elongated member can be carried out quite readily, and the sealability (sealing performance) of the opening and closing section is improved.

In particular, the valve body is reinforced by the ribs, and, for example, the ribs contact a mounting section for the valve body to suppress deformation of the valve body, whereby the sealing performance of the opening and closing section is improved.

The valve body is also reinforced by the projections, and consequently, deformation of the valve body is suppressed and the sealability of the opening and closing section is improved.

When the elongated member is pulled out from the valve body (opening and closing section), the valve body is deformed such that a central portion of the valve body is displaced in the direction of the movement of the elongated member and the projections contact (point-contact) an outer circumferential surface of the elongated member. Consequently, the contact area of the outer circumferential surface of the elongated member and the valve body decreases, and the resistance (sliding resistance) when the elongated member is pulled out from the valve body decreases. Consequently, the sliding performance of the elongated member is improved, and the elongated member can be relatively readily pulled out from the valve body.

Therefore, the valve body disclosed here has useful application in a sheath of an introducer for introducing an elongated medical member for use with medical care, such as for example a catheter or a guide wire, into a living organism.

Preferably, the ribs have an arcuate shape.

With this configuration, when the valve body is mounted on a tubular mounting section, the outer side of the ribs can contact the mounting section, and consequently, it is possible to inhibit or prevent the second slit from being opened, and so the sealability of the opening and closing section can be maintained.

In the embodiment of the valve body disclosed here, when the valve body is mounted on a mounting section, the outer side or outer surface of the ribs contacts the mounting section.

According to this configuration, it is possible to inhibit or prevent the second slit from being opened, and so the sealability of the opening and closing section can be maintained.

In the embodiment of the valve body disclosed here, the second slit preferably has a straight line shape as viewed in plan, and the ribs are disposed so as to be line-symmetrical with respect to the second slit and point-symmetrical with respect to an intersecting portion of the first slit and the second slit as viewed in plan.

It is thus possible to inhibit or prevent the second slit from being opened with a higher degree of certainty, and so the sealability of the opening and closing section can be maintained.

In the embodiment of the valve body disclosed here, the ribs are preferably not provided on an extension line of the second slit as viewed in plan.

Thus, when the valve body is deformed, a relief corresponding to the deformed portion is relatively assured. Consequently, the valve body can contact (closely contact) uniformly with the mounting section.

In the embodiment of the valve body disclosed here, the projections are radially disposed with respect to an intersecting portion of the first slit and the second slit.

When the elongated member is moved upwardly and pulled out from the valve body, the valve body is deformed such that a portion thereof in the proximity of the intersecting portion is displaced upwardly and the projections contact (point-contact) with the outer circumferential face of the elongated member. Consequently, the contact area of the outer circumferential face of the elongated member and the valve body decreases, and the sliding resistance when the elongated member is pulled out from the valve body decreases. Consequently, the sliding performance of the elongated member is improved, and the elongated member can be pulled out from the valve body readily.

Preferably, in the embodiment of the valve body disclosed here, the projections extend from the ribs to an intersecting portion of the first slit and the second slit as viewed in plan.

With this configuration, when the elongated member is moved upwardly and pulled out from the valve body, the projections contact (point-contact) the outer circumferential face of the elongated member with a higher degree of certainty. Consequently, the contact area of the outer circumferential face of the elongated member and the valve body decreases, and the sliding resistance when the elongated member is pulled out from the valve body decreases. Consequently, the sliding performance of the elongated member is improved, and the elongated member can be pulled out from the valve body relatively readily.

In the embodiment of the valve body disclosed here, the projections preferably do not extend to the second slit.

Thus, when the elongated member is moved downwardly and inserted into the valve body, the valve body becomes liable to be curved such that a portion thereof in the proximity of the intersecting portion is displaced downwardly by a suitable amount as viewed in plan.

Preferably, all of the gap distances between the ends of the projections on the second slit side and an intersecting portion of the first slit and the second slit are equal to each other.

With this arrangement, when the elongated member is moved upwardly and pulled off from the valve body, the projections and the outer circumferential face of the elongated member can contact uniformly with each other. Consequently, the elongated member can be pulled out from the valve body readily and stably.

In the embodiment of the valve body disclosed here, the second slit has a straight line shape as viewed in plan, and the projections are disposed so as to be line-symmetrical with respect to the second slit and point-symmetrical with respect to an intersecting portion of the first slit and the second slit as viewed in plan.

When the elongated member is moved upwardly and pulled out from the valve body, the valve body is deformed such that a portion thereof in the proximity of the intersecting portion is displaced upwardly and the projections contact (point-contact) with the outer circumferential face of the elongated member. Consequently, the contact area of the outer circumferential face of the elongated member and the valve body decreases, and the sliding resistance when the elongated member is pulled out from the valve body decreases. Consequently, the sliding performance of the elongated member is improved, and the elongated member can be pulled out from the valve body readily.

In the embodiment of the valve body disclosed here, the projections are preferably not provided on an extension line of the second slit as viewed in plan.

With this arrangement, the sliding resistance when the elongated member is moved (inserted and pulled out) with respect to the valve body can be inhibited or prevented from increasing unnecessarily. Consequently, the sliding performance of the elongated member is improved, and insertion and pulling out of the elongated member can be carried out readily.

Preferably, in the valve body disclosed here, the projections have a height which gradually decreases from the rib side toward the second slit side.

Accordingly, when the elongated member is moved downwardly and inserted into the valve body, the sliding resistance can be reduced to a comparatively low value.

In the embodiment of the valve body disclosed here, the projections preferably have a width which gradually decreases from the rib side toward the second slit side.

Thus, when the elongated member is moved downwardly and inserted into the valve body, increase of the sliding resistance of the same can be suppressed.

The projection preferably has a height which is lower than that of the ribs.

With this arrangement, the increasing amount of the volume of the valve body can be suppressed to a comparatively small amount, and the sliding resistance when the elongated member is moved (inserted and pulled off) with respect to the valve body can be set to a comparatively low value.

In the natural state of the valve body, the first slit is open, and the valve body is deformed, when the valve body is mounted on the mounting section, in such a manner as to be compressed toward the intersecting portion of the first slit and the second slit, and the first slit is closed thereby.

This helps provide quite good sliding performance and sealing performance.

In the natural state of the valve body disclosed here, the first slit and the second slit are open, and when the valve body is deformed upon being mounted on the mounting section in such a manner as to be compressed toward the intersecting portion of the first slit and the second slit, the first slit is closed.

With this configuration, superior sliding performance and sealing performance can be obtained.

In the state in which the valve body is mounted on the mounting section, at least part of the second slit is open.

This helps facilitate superior sliding performance and sealing performance.

Preferably, in the valve body disclosed here, the first slit has a shape of a straight line as viewed in plan.

This contributes to the first slit being opened and closed readily and with certainty.

In the embodiment of the valve body disclosed here, the second slit has a shape of a straight line as viewed in plan, and the first slit and the second slit intersect crosswise with each other.

Superior sealing performance can thus be obtained, and the opening and closing section can be opened and closed readily and with certainty.

The elongated medical member can be a dilator, a catheter or a guide wire.

The configuration of the valve body allows insertion and pulling out of the dilator, the catheter or the guide wire to be carried out readily.

In the natural state of the valve body, the first slit is open and a first space is formed by an inner face of the first slit while the second slit is open and a second space is formed from an inner face of the second slit, and the first space and the second space communicate with each other through the intersecting portion.

With this configuration, when the valve body wherein the first space and the second space are communicated with each other through the intersecting portion in the natural state is mounted on the mounting section, the first slit and the second slit are compressed (pressed) individually in a closing direction by the mounting section. Therefore, the first slit is placed into a closely contacting (closed) state wherein the inner faces thereof are pressed against each other. However, by the elastic force of the valve body itself (restoring force tending to open the first slit), the close contact is placed to such a degree that occurrence of blocking is suppressed (or prevented). Similarly, also the second slit is placed into a closely contacting state as the inner faces thereof are pressed against each other. However, by the elastic force of the valve body itself (restoring force tending to open the second slit), the close contact is placed to such a degree that occurrence of blocking is suppressed (or prevented).

If radiation sterilization is carried out in this state, then occurrence of excessive (excessively firm) blocking between the inner faces of the first slit or between the inner faces of the second slit is inhibited or prevented with relative certainty. Consequently, when the elongated medical member is inserted into the valve body for the first time after sterilization, the inner faces of the first slit (also the inner faces of the second slit) are exfoliated readily. Consequently, the penetration resistance of them is reduced, and an operation when the elongated member is inserted and pulled off can be carried out readily. Further, when the elongated member is inserted and pulled off, damage to the first slit or the second slit can be prevented with certainty.

When the valve body is in a state in which the valve body is mounted on the mounting section, the valve body is deformed in such a manner as to be compressed at the intersecting portion such that the first slit and/or the second slit are contacted closely at least at inner peripheral faces thereof in the proximity of the intersecting portion with each other so as to be closed.

With this configuration, if radiation sterilization is carried out in the state in which the valve body is mounted on the mounting section, occurrence of excessive (excessively firm) blocking between the inner faces of the first slit or between the inner faces of the second slit is inhibited or prevented with certainty. Consequently, when the elongated medical member is inserted into the valve body for the first time after sterilization, the inner faces of the first slit (also the inner faces of the second slit) are exfoliated readily. Consequently, the penetration resistance of them is reduced, and an operation when the elongated member is inserted and pulled off can be carried out readily. Further, when the elongated member is inserted and pulled out, damage to the first slit or the second slit can be inhibited or prevented with reliability.

In the embodiment of the valve body disclosed here, the first space and the second space preferably have a flattened shape.

According to this configuration, superior sealing performance is obtained, and the opening and closing section can be opened and closed readily and with certainty.

In the embodiment of the valve body disclosed here, the intersecting portion preferably has a shape of a hexahedron in the natural state, and the sum total in length of those eight sides from among the 12 sides forming the hexahedron which are nodal lines formed by intersection of the inner faces of the first slit and the second slit is 1.0 to 6.0 mm.

If the sum total is within such a numeral value range as given above, the elongated member can be inserted into and pulled out from the valve body suitably (smoothly without causing damage to any of the first slit and the second slit) without depending upon the outer diameter of a portion, which is inserted into a living organism, of the elongated member which is normally used (inserted) in a medical tool. Also, the sealing performance of the opening and closing section in the state wherein the elongated member is fitted in the valve body can be maintained appropriately.

The intersecting portion preferably is positioned at a central portion of the valve body as viewed in plan.

Accordingly, when the elongated member is inserted into and pulled out from the valve body, the operation can be carried out stably.

In the embodiment of the valve body disclosed here, the first space and/or the second space have a depth which gradually decreases from the intersecting portion toward a direction away from the intersecting portion.

Thus, when the elongated medical member is inserted into the first slit, the distal end portion of the elongated member is guided so as to be directed to the intersecting portion, and consequently, the insertion operation can be carried out with certainty. Further, the distal end portion of the elongated member is prevented from piercing (penetrating) a portion of the first slit other than the intersecting portion, and further prevented from extending to the second slit. Consequently, damage to the valve body can be inhibited or prevented.

Preferably, in the valve body disclosed here, the first space and/or the second space has a width which gradually decreases toward the intersecting portion.

With this arrangement, when the elongated member is inserted into the first slit, the distal end portion of the elongated member is guided so as to be directed to the intersecting portion, and consequently, the insertion operation can be carried out with relative certainty.

The first slit and the second slit preferably have a shape of a straight line as viewed in plan and intersect crosswise with each other.

Accordingly, a suitable sealing performance is obtained, and the opening and closing section can be opened and closed readily and with relative certainty.

Another aspect of the disclosure here involves a medical tool outfitted with the valve body disclosed here, with the valve body installed such that the upper face of the valve body is exposed to the outer side and the lower face is exposed to the inside of a flow path.

A medical tool outfitted with such valve body facilitates insertion and pulling out of the elongated member.

DETAILED DESCRIPTION

The following describes a valve body and a medical tool disclosed here. In this embodiment disclosed here, the medical tool is, by way of example, an introducer.

In the following description involvingFIGS. 1-3,5,6,8,10,11,13,15and16, the upper side is referred to as the “upper” or “proximal end” and the lower side is referred to as the “lower” or “distal end”. InFIG. 4, the upper side is referred to as the “lower” or “distal end” and the lower side is referred to as the “upper” or “proximal end”. Further, to facilitate illustration and an understanding of the illustrated features, the first slit and the second slit are shown inFIG. 11with other elements and features omitted.

As mentioned above, the medical tool1described and illustrated here by way of example is an introducer1. The introducer is used to introduce an elongated medical member used in medical care (medical procedure) such as, for example, a guide wire or a catheter into a living organism (for example, a blood vessel or the like).

This introducer1is composed of a sheath7having a hub2, a sheath tube (tube)4in the form of an elongated pipe having a proximal end secured to the distal end side of the hub2, sealing means5for effecting sealing of the interior of the hub2as discussed in more detail below, and a dilator (expanding tube)10positioned in and used together with the sheath7to facilitate introduction of the sheath7into a living organism.

The hub2is formed from a hollow pipe body or tubular body.

A side port (connecting portion)21extends outwardly away from the outer circumferential portion of the hub2so that is projects in a sideward manner (in a sideways direction). The side port21is in the form of a tubular member or pipe, and the hollow portion (interior)211of the side port21communicates with the interior of the hub2. One end of a preferably flexible tube8made of, for example, polyvinyl chloride is connected in a liquid-tight manner to the side port21.

The sheath tube4is a member (portion) to be introduced into a living organism and is formed from a thin pipe-shaped member. The proximal end portion of the sheath tube4is secured to the distal end portion of the hub2by fitting or another appropriate securing means for securing the sheath tube4to the hub2. Further, the interior of the sheath tube4communicates with the interior211of the hub2.

The sealing means5for sealing the inside of the hub2is provided at a proximal end portion of the hub2.

The sealing means5is composed of a valve body6through which the dilator (expanding pipe)10, a catheter or a guide wire can pass, and an annular (cylindrical) lid member51for fixedly supporting the valve body6on the hub2.

The lid member51is configured (sized and shaped) such that it can fit into the inner circumferential portion22at the proximal end of the hub2. When the lid member51is mounted on the hub2with the valve body6fixedly supported on the hub2, the distal end portion of the lid member51is positioned in the proximal end inner circumferential portion22.

The lid member51includes a projecting rib511on the inner circumferential face portion of the lid member51. In the illustrated embodiment, the rib is a cylindrical rib511on the inner circumferential face portion of the lid member51that projects in an oblique distal end direction. In particular, as shown inFIG. 1, the inner diameter and the outer diameter of the rib511gradually decrease from the proximal end toward the distal end.

The proximal end portion of the lid member51forms an insertion port to allow an elongated member such as the dilator10, a catheter or a guide wire to be inserted into the sheath7.

The dilator10is in the form of a flexible pipe body (tube). The dilator10is inserted into (positioned in) the sheath7and is inserted (introduced) into a living organism in a state wherein it is fixed to the sheath7. Further, to facilitate introduction of the dilator10, for example, into a blood vessel, the outer diameter of the distal end portion101of the dilator10narrows or decreases (gradually narrows or decreases) toward the distal end.

The dilator10having a configuration as described above is removed from the sheath7after the sheath tube4is inserted into a living organism (blood vessel). Thereafter, a catheter or a guide wire is inserted through the opening (proximal end opening)513at the proximal end of the lid member51.

As mentioned above, the sealing means5includes the valve body6.

As shown inFIGS. 1-4and8, the valve body6is comprised of a plate-shaped elastic body possessing a pair of end faces. In particular, the elastic body has an upper face (one face)601and a lower face (the other face)602, and is in the shape of an elliptic or circular film (disk form). This valve body6is secured in a liquid-tight manner to the hub2by virtue of being sandwiched between a stepped portion23at the proximal end portion of the hub2on the one hand and the distal end face514of the lid member51and the distal end face512of the rib511on the other hand as illustrated inFIGS. 1 and 2. In the introducer1(sheath7), the portion surrounded by the distal end face514of the lid member51and the distal end face512of the rib511functions as a “mounting section (installation section)” on which the valve body6is mounted (installed).

The shape of the valve body6in a natural state as viewed in plan, that is the shape of the valve body6before it is mounted on the hub2as viewed in plan, is an elliptical shape as shown inFIGS. 7 and 14. The shape of the valve body6in a mounted state in which it is mounted on the hub2(this state is hereinafter referred to simply as the “mounted state”) as viewed in plan, has a circular shape as shown inFIG. 12. When the valve body6is mounted on the hub2, the valve body6is deformed by virtue of being compressed toward an intersecting portion63(hereinafter described) along the major axis direction. Consequently, the valve body6takes on a circular shape as viewed in plan. Here, the “natural state” refers to a state in which no external force is applied to the valve body6.

Although the dimension of the valve body6is not specifically restricted, the major diameter of the valve body6in the natural state preferably is approximately 5 to 20 mm, more preferably approximately 8 to 12 mm. The major diameter of the valve body6in the natural state is preferably greater than the sum total of the inner diameter of the proximal end inner circumferential portion22of the hub2and the maximum width w1of a first slit61. With this relative configuration, sealability (sealing performance) of an opening and closing section60of the valve body in the mounted state is obtained.

The minor diameter of the valve body6is preferably approximately 4 to 16 mm, more preferably approximately 7 to 10 mm.

The thickness of the valve body6is preferably approximately 0.5 to 3 mm, more preferably approximately 0.8 to 1.5 mm.

The material forming the valve body6is not restricted to a specific material. Elastic materials such as, for example, natural rubber, various synthetic rubbers such as isoprene rubber, silicone rubber, urethane rubber, styrene-butadiene rubber, fluororubber and acrylic rubber, and various plastic elastomers of polyamide-based elastomer and polyester-based elastomer may be used.

The valve body6includes a first concave portion64whose bottom face is a curved concave face (curved concave face)641. The first concave portion64is on the upper face side601of the valve body6(i.e., the side facing away from the interior of the hub2). In particular, the first concave portion64is bowl-shaped. Further, the first concave portion64is elliptical or circular in shape as viewed in plan and is disposed such that a central portion (center) of the first concave portion64and the central portion (center) of the valve body6coincide with each other. The end face of the valve body6which is on the side opposite the concave face (bottom face)641is the lower face602. The valve body6is disposed relative to the hub2such that the concave face641(upper face601) is exposed (positioned) to the outer side of the sheath7while the lower face602is exposed in the flow path (in the interior of the hub2) of the sheath7.

When the dilator (elongated member)10is inserted into or positioned in the valve body6, the distal end portion101of the dilator10can be introduced to or inserted into a portion of the first slit61corresponding to the intersecting portion63hereinafter described by the first concave portion64. Consequently, damage to any portion other than the first slit61and a second slit62by the dilator10can be avoided or prevented. Further, it is possible to inhibit or prevent the distal end portion101of the dilator10from being crushed or deformed.

The dimension of the first concave portion64is not specifically limited. By way of example, the depth (maximum depth) of the central portion (center) of the first concave portion64is preferably greater than 0.3 mm, more preferably greater than 0.4 mm, and further preferably is approximately 0.4 to 0.7 mm.

As shown inFIGS. 3-8,11-14and16, the valve body6has an opening and closing section60which is opened or closed in response to insertion or removal of the dilator10(elongated member).

The opening and closing section60is composed of a first slit61, a second slit62, a second concave portion65and two third concave portions66.

The first slit61is formed such that it extends to the concave face641(upper face601) but does not extend to the lower face602. In other words, the first slit61is formed such that it extends only to the concave face641(upper face601) from the inside of the valve body6(i.e., the first slit61extends through only a portion of the thickness of the valve body or through less than the entirety of the valve body).

This first slit61is formed as a straight line which coincides with (or extends in parallel to) the minor axis of the valve body6as viewed in plan and is included in the first concave portion64as viewed in plan. In other words, the valve body6is formed in a straight line from one end portion to the other end portion of the first concave portion64. Consequently, in the mounted state, the first slit61(opening and closing section60) can be opened and closed readily and with relative certainty.

As shown inFIG. 5(also inFIGS. 3 and 7), the first slit61is opened (open) in the natural state. Consequently, in the first slit61, a first space611is formed by (bordered by) inner faces612of the first slit. This first space611has a semicircular disk shape (flattened shape). The first slit61is deformed in such a manner that it is compressed toward the intersecting portion63along the major axis direction when the valve body6is mounted on the hub2, and consequently is closed by the mounting. In other words, in the mounted state, the first slit61is closed.

Further, the second slit62is formed such that it extends to (opens to) the lower face602but does not extend to (open to) the concave face641(upper face601). In other words, the second slit62is formed such that it extends only to the lower face602from the inside of the valve body6(i.e., the second slit62extends through only a portion of the thickness of the valve body or through less than the entirety of the valve body thickness).

This second slit62is formed such that it coincides with (or extends in parallel to) the major axis of the valve body6as viewed in plan, that is, the shape of the second slit62is a straight line shape as viewed in plan (refer toFIG. 14). Consequently, in the mounted state, the opening and closing section60can be opened and closed readily and with certainty. The second slit62is elongated in a direction of elongation (i.e., the left-right direction as seen with reference toFIG. 14).

As shown inFIG. 5(also inFIGS. 4 and 14), the second slit62is opened (open) in the natural state in a manner similar to the first slit61. Consequently, in the second slit62, a second space621is formed by the inner faces612. This second space621is semicircular disk-shaped (flattened shape). In the mounted state, the second slit62is partly closed (partly open).

The first slit61and the second slit62configured in the manner described above and illustrated in the drawing figures partly intersect each other in the inside of the valve body6(at an interior portion of the valve body spaced inwardly from the opposite outermost faces of the valve body6). The first space611and the second space621communicate with each other, as seen for example inFIG. 5, through the intersecting portion63at which the slits intersect each other (the intersecting portion63between the first slit61and the second slit62).

When the valve body6, with the first slit61and the second slit62communicating with each other in this manner in the natural state, is mounted on the hub2, the first slit61and the second slit62are compressed (pressed) in their closing direction by the proximal end inner circumferential portion22of the hub2(refer toFIG. 11). Therefore, in the first slit61, the inner faces612are pressed against each other and placed into a closely contacting (closed) state. However, by the elastic force of the valve body6itself (restoring force by which the first slit61tends to be opened), the degree of the close contact is reduced to such a degree that the occurrence of blocking is suppressed (or prevented). Similarly, in the second slit62, inner faces622are pressed against each other and placed into a closely contacting state. However, by the elastic force of the valve body6itself (restoring force by which the second slit62tends to be opened), the degree of the close contact is reduced to such a degree that occurrence of blocking is suppressed (or prevented).

If radiation sterilization (for example, electron beam sterilization, γ ray sterilization, X-ray sterilization or the like) is carried out, the occurrence of excessive (excessively firm) blocking between the inner faces612of the first slit61or between the inner faces622of the second slit62is inhibited or prevented from occurring with relative certainty. Even with silicone rubber with which a sticking phenomenon of the inner faces is known to occur, the occurrence of blocking is inhibited or prevented with relative certainty. Consequently, when an elongated medical member such as the dilator10is inserted into the valve body6for the first time after the sterilization (hereinafter referred to simply as “upon first time insertion”), the inner faces612(also the inner faces622) exfoliate from each other readily, and consequently, the penetration resistance is reduced and the operation involving insertion and removal of the elongated medical member can be readily carried out. Further, when an elongated medical member is inserted and removed, damage to the first slit61or the second slit62can be prevented with relatively good certainty.

As shown inFIG. 5, the depth k1of the first space611gradually decreases toward the direction away from the intersecting portion63. In other words, a portion (bottom face613) of the first slit61which becomes the bottom of the inner faces612is curved in an arcuate manner. Consequently, when the dilator10is inserted into the first slit61, the distal end portion101of the dilator10is guided so as to be directed toward the intersecting portion63. This facilitates the insertion operation. Further, the distal end portion101of the dilator10is inhibited or prevented from piercing (penetrating) a portion of the first slit61other than the intersecting portion63until it comes to the second slit62, and consequently, damage to the valve body6can be inhibited or prevented.

Further, as shown inFIG. 5, the width w1of the first space611gradually decreases toward the bottom face613(intersecting portion63). Consequently, when the dilator10is inserted into the first slit61, the distal end portion101of the dilator10is guided so as to be directed to the intersecting portion63, and consequently, the insertion operation can be carried out with relatively good certainty.

The maximum depth k1of the first slit61is not restricted specifically, but is preferably, for example, approximately 35 to 90% of the thickness of the valve body6, more preferably approximately 40 to 80% of the thickness of the valve body6.

Although the bottom face613of the first slit61in the configuration shown inFIG. 5is a curved face curved in an arcuate manner, the shape of the bottom face613is not limited to this. For example, the bottom face613may have a V-shape whose apex (vertex) is the intersecting portion63.

As shown inFIG. 5, the depth k2of the second space621gradually decreases toward the direction away from the intersecting portion63similarly to the first space611. In other words, a portion (bottom face623) of the second slit62which is the bottom of the inner faces622is curved in an arcuate manner.

Further, the width w2(refer toFIG. 5) of the second space621gradually decreases toward the bottom face623(intersecting portion63).

The second slit62is pressed, in the mounted state, in the direction in which it is closed, that is in the minor axis direction, and is pressed also in its opening direction, that is in the major axis direction. Therefore, as shown inFIG. 11, in the second slit62in the mounted state, a portion at which the inner faces622closely contact each other (are closed) and another portion at which the inner faces622remain spaced away from each other are formed.

Consequently, the contact area of the inner faces622of the second slit62decreases, and therefore, the area of a portion at which blocking is likely to occur when radiation sterilization is carried out (area over which the inner faces622stick to each other) can be decreased. Consequently, since the inner faces622of the second slit62exfoliate readily from each other, occurrence of damage to the second slit62is inhibited or prevented, and the dilator10can be readily inserted into the valve body6.

In this manner, from a relative standpoint, the first slit61which is positioned on the insertion side of an elongated medical member exhibits a higher degree of close contact than the second slit62. Here, the “degree of close contact” signifies the close contact area and the close contacting force between the inner faces.

By adjusting the pressing force (close contacting force) between the inner faces612of the first slit61in the mounted state, blocking of the portion of the first slit61when radiation sterilization is carried out can be suppressed to the minimum while the sealing performance of the opening and closing section60is facilitated or assured.

Further, a portion at which the inner faces622are closed is formed in the second slit62in the mounted state as described above, and the sealability (sealing performance) of the opening and closing section60is obtained by cooperation with the first slit61closed in the mounted state. In other words, the liquid-tightness of the inside of the hub2is achieved or assured, and leakage of liquid (for example, blood) filled in the hub2can be inhibited or prevented with relatively good certainty.

It is to be understood that the second slit62may be entirely closed in the mounted state in a manner similar to the first slit61.

Further, the maximum depth k2of the second slit62is not specifically restricted and preferably is, for example, approximately 35 to 90% of the thickness of the valve body6, more preferably approximately 40 to 80% of the thickness of the valve body6.

The bottom face623of the second slit62in the configuration shown inFIG. 5is formed as a curved face that is curved in an arcuate manner, the shape of the bottom face623is not limited to this. For example, the bottom face623may have a V-shape whose apex (vertex) is the intersecting portion63.

As shown inFIG. 5, the first slit61and the second slit62intersect crosswise with each other at the portion at which the depth of them is in the maximum such that the intersecting angle is 90°. Naturally, the intersecting angle of these slits61and62is not limited to 90°.

The intersecting portion63between the first slit61(first space611) and the second slit62(second space621) is shared by both of the first slit61and the second slit62and is set to a middle portion (central portion) of the valve body6as viewed in plan. In other words, the intersecting portion63is positioned at a central portion of the first concave portion64as viewed in plan and is included within the first concave portion64. Consequently, when the dilator10is inserted into and removed from the valve body6(opening and closing section60), the operation can be carried out relatively stably.

Referring toFIG. 8, the length L of the intersecting portion63is not specifically restricted. By way of example, the length L is preferably approximately 10 to 50% of the thickness of the valve body6, more preferably approximately 15 to 35% of the thickness of the valve body6. The intersecting portion63is described in more detail below.

As shown inFIG. 6and also inFIG. 5, the intersecting portion63is a space having the shape of a hexahedron in the natural state of the valve body. This intersecting portion63(hexahedron) has 12 sides which form the same, and the sides include eight sides which are given as nodal lines formed by intersection of the inner faces612of the first slit61and the inner faces622of the second slit62(inFIG. 6, the sides631,632,633,634,635,636,637and638).

Though the sum total of the lengths of the sides631-638is not restricted, it is preferably 1.0 to 6.0 mm, more preferably 1.5 to 4.5 mm. If the sum total is within this numerical value range, an elongated medical member which is normally used (inserted) in the introducer1can be inserted into and pulled out from the valve body6in an appropriate manner (smoothly without damaging the first slit61and the second slit62) without relying upon the outer diameter φs (shown inFIG. 1) of a portion of the elongated member to be inserted into a living organism. Further, in a state in which the elongated medical member is fitted in the valve body6, the sealing performance of the opening and closing section60is also properly maintained.

Although the length L1of the sides632,634,636,638which extend parallel to the upper face601and the lower face602of the valve body6is not specifically limited, the length L1is preferably 0.1 to 0.5 mm. If the length L1is within this numerical value range, no edge exists at the intersecting portion63. Accordingly, even if the distal end portion101of the dilator10strikes the bottom face613, it is reliably inhibited or prevented from making a starting point of damage to the first slit61and the second slit62.

The length L2of the four sides other than the nodal lines (distance between the side634and the side638and distance between the side632and the side636) is not restricted specifically, but is preferably 0.1 to 0.7 mm.

The length L3of the intersecting portion63which extends perpendicularly to the upper face601and the lower face602of the valve body6is not limited to a specific value, but is preferably 0.2 to 0.6 mm.

Similarly, the angle θ defined by the direction of the length L3(a line parallel to the length L3) and the sides631,633,635and637which do not extend parallel to the upper face601and the lower face602of the valve body6is not specifically limited. However, the angle θ is preferably 5 to 40°. When the angle θ is within this numerical value range, when the valve body6is mounted on the hub2, the occurrence of excessive blocking between the inner faces612of the first slit61or between the inner faces622of the second slit62is inhibited or prevented with relatively good certainty. Further, the penetration resistance is reduced and an operation when an elongated medical member is inserted and pulled out can be carried out quite readily.

The outer diameter φs of the elongated medical member permitted to be fitted into the opening and closing section60of the valve body6is not limited to a specific size. By way of example, the maximum value of the outer diameter φs of the elongated medical member is 6 to 7 mm, more preferably 6.5 to 7 mm. Meanwhile, the minimum value is preferably 0.1 to 0.3 mm, more preferably 0.1 to 0.2 mm.

The manner of forming or fabricating the first slit61and the second slit62is not limited. By way of example, the valve body6is preferably molded by compression molding, LIM molding, transfer molding or the like, and during this formation the first slit61and the second slit62are preferably formed simultaneously.

As described above, the opening and closing section60(valve body6) has the second concave portion65and the third concave portions66. The second concave portion65and the third concave portions66are formed on the concave face641(upper face601) side.

Here, in order to facilitate recognition of the second concave portion65and the third concave portions66(in order that the first slit61and the second concave portion65and third concave portions66can be distinguished readily from each other), only the first slit61of the valve body6is shown inFIG. 9(a), and the first slit61, the second concave portion65and the third concave portions66of the valve body6are shown inFIG. 9(b). Further, inFIGS. 9(a) and9(b), the first slit61is indicated by a solid line and the second concave portion65and the third concave portions66are indicated by dotted lines (broken lines).

From a similar reason, the valve body6on which the second concave portion65and the third concave portions66are not formed is shown inFIG. 10(a), and the valve body6on which the second concave portion65and the third concave portions66are formed is shown inFIG. 10(b). Further, inFIG. 10(b) slanting lines, which do not exist on a proper cross-sectional view of the valve body, are applied only to the second concave portion65and the third concave portions66.

As shown in FIGS.3and7-10, the second concave portion65is formed at a middle portion of the valve body6on the concave face641(upper face601) side, that is, a location (position) of the first concave portion64corresponding to the intersecting portion63. The second concave portion65is formed, in the thicknesswise direction of the valve body6(in the upward and downward direction), to an intermediate portion of the first slit61but does not extend to the second slit62. Further, at the opposite end portions of the first slit61of the valve body6on the concave face641side, the third concave portions66are formed.

The second concave portion65, third concave portions66and first slit61are communicated with each other in the natural, state and generally form a single groove (concavity).

Further, while, in the natural state, the second concave portion65exhibits a diamond shape (quadrangle) such as shown inFIGS. 3 and 7. The shape of the second concave portion65need not be a quadrangular shape, as it can also be a circular shape. As shown inFIG. 8, a bottom face651in the second concave portion65is a flat face substantially perpendicular to the moving direction (longitudinal direction of the dilator10) upon insertion and pulling out of the dilator10, and side faces652are inclined by a predetermined angle with respect to the moving direction upon insertion and pulling out of the dilator10. The inclination angle θ1of the side faces652with respect to the moving direction preferably is 45° or more in the natural state, more preferably 60°, and further more preferably approximately 60 to 80°.

Although the dimension of the second concave portion65is not restricted, it is preferably set to such a value that, when the dilator10is inserted into the valve body6, the distal end portion101of the dilator10does not catch the second concave portion65, and for example, the length a (refer toFIG. 8) of the first slit61of the bottom face651preferably is set to a value smaller than the outer diameter of the distal end portion101of the dilator10. Specifically, the length a of the first slit61of the bottom face651preferably is approximately 0.2 to 0.4 mm in the natural state. Further, the depth b of the second concave portion65in the natural state preferably is 0.1 mm or more, more preferably approximately 0.1 to 0.2 mm.

As shown inFIG. 12, when the second concave portion65is mounted on the hub2, it is deformed so as to be compressed toward the intersecting portion63along the major axis direction, and consequently, it is deformed such that the width thereof decreases. However, in the mounted state, the second concave portion65does not fully closely contact the intersecting portion63.

By virtue of this second concave portion65, the contact area of the inner faces612of the first slit61is decreased, and consequently when radiation sterilization is carried out, the area over which blocking occurs can be reduced. Further, upon insertion for the first time, the second concave portion65makes a start of exfoliating at the first slit61which may be in a sticking state. Consequently, upon insertion for the first time, exfoliating at the first slit61occurs rather readily, and otherwise possible damage to the first slit61or the second slit62can be inhibited or prevented. Further, the penetration resistance upon insertion for the first time decreases, and the dilator10can be quite readily inserted into the valve body6.

In the natural state, the pair of third concave portions66have a rather rounded shape as viewed in plan. As shown in, for example,FIGS. 3 and 12, each of the third concave portions66extends over (i.e., spans) the inside and the outside of the first concave portion64(extends from the inside of the first concave portion64to the outside of the first concave portion64).

As shown inFIG. 12, each of the third concave portions66is deformed such that, when the valve body6is mounted on the hub2, the third concave portion66is compressed toward the intersecting portion63along the major axis direction, and consequently, it is deformed such that the width thereof decreases. However, in the mounted state, the third concave portion66does not fully closely contact the intersecting portion63.

By those third concave portions66, the contact area of the inner faces612of the first slit61is decreased, and consequently, the area over which blocking occurs when radiation sterilization is carried out can be decreased. Consequently, upon insertion for the first time, the first slit61exfoliates quite readily, and the occurrence of damage to the first slit61or the second slit62can be inhibited or prevented. Further, the penetration resistance upon insertion for the first time decreases, and the dilator10can be inserted into the valve body6rather readily.

By virtue of the third concave portions66, the volume of the opposite end portions of the first slit61(first space611) of the valve body6decreases, the resistance (sliding resistance) when the dilator10is inserted into the valve body6or pulled out from the valve body6decreases. Consequently, the sliding performance of the dilator10is enhanced, and it is possible to readily insert the dilator10into the valve body6or pull out the dilator10from the valve body6.

Since the third concave portions66are provided at the opposite end portions of the first slit61, even if the third concave portions66are made comparatively large, this does not have any influence on the sealing performance of the opening and closing section60.

Further, as shown inFIG. 8, the total value of the areas of the third concave portions66on a vertical section taken along the first slit61(as viewed in side elevation parallel to the first slit61) in the natural state preferably is greater than the area of the second concave portion65. More preferably, the area of each of the third concave portions66is greater than the area of the second concave portion65.

Consequently, the sliding performance of the dilator10is further improved, and it is possible to insert the dilator10into the valve body6or pull out the dilator10from the valve body6more readily.

In the illustrations, the shapes and the dimensions of the pair of third concave portions66are the same as each other. However, they may be different from one another.

The dimensions of the third concave portions66are not specifically restricted, but the depths of the third concave portions66in the illustrated configuration are equal to the depth of the first slit61.

A plurality of projections67(second projections) are provided on the concave face641side of the valve body6. In the illustrated embodiment, four projections67are provided. The projections67are positioned in the first concave portion64and are disposed such that they are opposed to each other through the first slit61.

In the configuration shown, the four projections67are disposed such that they are line-symmetrical with respect to the first slit61and are point-symmetrical with respect to the intersecting portion63(center of the valve body6) as viewed in plan. Further, the projections67are positioned to extend radially from the intersecting portion63as viewed in plan.

In the configuration shown, the shapes and the dimensions of the projections67are the same as each other, but they may be different from each other. The projections67are preferably elongated in shape, meaning that their radial extent (i.e., dimension in the radial direction relative to the center of the first concave portion64) is greater than their width-wise extent (width dimension).

The dimensions of the projections67are not specifically limited to certain values. However, as an example, the height of the projections67is preferably approximately 0.1 to 0.5 mm, more preferably approximately 0.2 to 0.3 mm.

The illustrated configuration shows two pairs of projections67, but the number of projections67is not restricted to this. For example, only one pair of projections67may be provided or three or more pairs of projections67may be provided. Also, the number of projections67may be an odd number disposed in a non-symmetrical arrangement with respect to the first slit61.

As shown inFIG. 13, when the dilator10is moved downwardly and inserted into the valve body6, the valve body6curves such that a central portion of the valve body is displaced downwardly and the projections67contact (point-contact) the outer circumferential face of the dilator10. Consequently, the contact area between the outer circumferential face of the dilator10and the valve body6decreases, and the resistance (sliding resistance) when the dilator10is inserted into the valve body6decreases. Consequently, the sliding performance of the dilator10is improved, and the dilator10can be inserted into the valve body6rather readily.

Further, when the dilator10is inserted into the valve body6, the dilator10is guided by the projections67such that it is directed to a central portion of the valve body6, that is toward the intersecting portion63. Consequently, the dilator10can be readily inserted into the valve body6, and damage to the valve body6can be inhibited or prevented.

As shown inFIGS. 4,8and14-16, ribs (wall portions)68and projections (first projections)69are formed on the lower face602side of the valve body6. The sliding performance of the dilator10is improved by the ribs68and the projections69, and insertion and pulling out of the dilator10can be carried out rather readily and the sealability (sealing performance) of the opening and closing section60is improved. The ribs68and the projections69are described below in more detail.

A pair of ribs68extending along the lower face602are formed on the lower face602side of the valve body6. The ribs68have an arcuate shape. Further, the ribs68are disposed in an opposing relationship to each other with the second slit62interposed therebetween. The ribs68are positioned so that adjacent ends of the two ribs are spaced from one another, with an imaginary continuation of the line of extension of the second slit62passing between the adjacent ends of the two ribs68. In the mounted state, the outer peripheral surfaces (outer sides) of the ribs68contact the inner circumferential surface of the hub2.

In the configuration shown inFIG. 14, the ribs68are disposed such that they are line-symmetrical with each other with respect to the second slit62and point-symmetrical with each other with respect to the intersecting portion63as viewed in plan.

As shown inFIG. 2, when the valve body6is mounted on the hub2, the outer peripheral faces (outwardly facing arcuate surfaces) of the ribs68contact the inner circumferential surface of the hub2. Consequently, when the valve body6is deformed such that it is compressed toward the intersecting portion63along the major axis direction, the second slit62is inhibited or prevented from being opened further. Consequently, the sealing performance of the opening and closing section60is maintained.

Further, when the inside of the hub2is placed into a negative pressure state, although the valve body6is pulled (downwardly) into the hub2, since the outer peripheral surface of the ribs68contacts the inner circumferential face of the hub2and the valve body6is reinforced by the ribs68, deformation of the valve body6is restrained and the second slit62inhibited or prevented from being opened further. Consequently, the sealing performance of the opening and closing section60is maintained.

Although the dimensions of the ribs68are not specifically restricted, by way of example, the height c (shown inFIG. 15) of the ribs68is preferably 0.3 mm or more, more preferably approximately 0.3 to 1.3 mm, and further preferably approximately 0.5 to 1 mm.

Further, referring toFIG. 14, the length d of the ribs68in the direction of the second slit62preferably is greater than the length of the second slit62, and preferably is equal to, for example, approximately 3 to 7 times the length of the second slit62, more preferably approximately 3.5 to 6 times the length of the second slit62. In the configuration shown, the length d of the ribs68is greater than the length of the second slit62.

A predetermined gap is provided between end portions681of one of the ribs68and end portions681of the other one of the ribs68. In other words, the ribs68are not present on an extension line of the second slit62as viewed in plan (i.e., an extension line of the second slit62does not cross or intersect either of the ribs68).

Consequently, where the valve body6is deformed such that it is compressed toward the intersecting portion63along the major axis direction when it is mounted on the hub2, a relief corresponding to the deformed portion is generally assured. Consequently, the valve body uniformly contacts (closely contacts) the hub2, and the liquid-tightness of the inside of the hub2is maintained with relative certainty.

Further, the resistance (sliding resistance) when the dilator10is moved (inserted and pulled out) with respect to the valve body6can be inhibited or prevented from increasing unnecessarily. Consequently, the sliding performance of the dilator10is improved, and insertion and pulling out of the dilator10can be carried out relatively readily.

Referring toFIG. 14, the gap distance f between the end portion681of one of the arcuate-shaped ribs68and the adjacent end portion681of the other arcuate rib68is preferably such that, in the mounted state, an end portion of one of the ribs68and the adjacent end portion of the other rib68do not contact each other. In particular, in the natural state, the gap distance f preferably is approximately 0.5 to 3 mm, more preferably approximately 1 to 2 mm.

As further shown inFIG. 14, in the natural state, the distance e between the outer peripheral surface of one of the ribs68and the outer peripheral surface of the other rib68(twice the radius of curvature of the outer peripheral surface of the ribs68) is set a little greater than the inner diameter of the hub2at a position at which the hub2corresponds to or engages/contacts the ribs68. Consequently, in the mounted state, the portions of the ribs68marking the distance e are compressed toward the intersecting portion63(in a direction in which the second slit62is closed) by the inner circumferential surface of the hub2. Consequently, the second slit62is closed with good reliability.

The shape of the ribs68is not limited to the arcuate shape as they may possess a curved shape in which portions have different curvatures such as an elliptic arc, a straight shape (bar shape) or the like.

In the configuration shown, a pair of ribs68is provided. However, the number of ribs68is not limited to this, but may be two pairs or more, or may be an odd number of ribs non-symmetrically disposed with respect to the second slit62.

As shown inFIGS. 4 and 14, a plurality of (in the configuration shown, six) projections69exist on the lower face602side of the valve body6. The projections69are disposed between the pair of ribs68and the second slit62. In other words, the projections69are positioned on the inner side of the ribs68(between the pair of ribs68) and are disposed in an opposing relationship to each other with the second slit62interposed therebetween.

In the configuration shown inFIG. 14, the six projections69are disposed line-sequentially with respect to the second slit62and point-symmetrically with respect to the intersecting portion63(center of the valve body6). Further, the projections69are positioned radially with respect to the center of the intersecting portion63as seen in plan and extend from the ribs68toward the intersecting portion63. The six projections69are preferably elongated in shape, meaning that their radial extent (i.e., dimension in the radial direction relative to the center of the lower face602) is greater than their width-wise extent (width dimension).

The projections69on each side of the slit62are positioned at equal angular intervals of 45°. In particular, one pair of projections69is positioned along the first slit61as viewed in plan (i.e., the middle projection on each side of the slit62is positioned along the first slit61), and the other two projections69on each side of the slit62are positioned at equal angular intervals of 45° on opposite sides of the pair of the projections69.

As shown inFIG. 16, when the dilator10is moved upwardly and pulled out from the valve body6, the valve body6is deformed such that a central portion of the valve body is displaced upwardly and the projections69contact (point-contact) with the outer peripheral surface of the dilator10. Consequently, the contact area of the outer peripheral surface of the dilator10and the valve body6decreases, and the resistance (sliding resistance) when the dilator10is pulled out from the valve body6decreases. Consequently, the sliding performance of the dilator10is improved, and the dilator10can be removed from the valve body6rather readily.

Particularly when the dilator10is inserted in the valve body6, the valve body6is reinforced by the projections69, and consequently, the second slit62become less likely to be opened. The sealing performance of the opening and closing section60is improved by this.

Although the shapes and the dimensions of the projections69are not limited, in the configuration shown, distal end portions691(end portions on the second slit62(intersecting portion63) side) of the projections69are rather rounded, and the projections69have the same shape and have the same dimension. The description below describes one projection69as representative of all the projections.

The height g of the distal end portion691of the projection69is preferably greater than 0.2 mm, and is more preferably approximately 0.3 to 0.5 mm.

If the height g is set significantly greater than the lower limit value mentioned above, when an elongated medical member (dilator10) having a comparatively great outer diameter is to be pulled out and when an elongated member having a comparatively small outer diameter is to be pulled out, the projections69are liable to contact the outer peripheral surface of the dilator10.

On the other hand, where the height g is set lower than the upper limit value given above, the increasing amount of the volume of the valve body6can be restricted to a comparatively low value. Consequently, the resistance (sliding resistance) when the dilator10is moved (inserted and pulled out) with respect to the valve body6can be made comparatively low.

Further, the height of a proximal end portion692of the projection69(end portion on the rib68side) is lower than the height c of the rib68. Consequently, the increasing amount of the volume of the valve body6can be set to a comparatively low value, and the resistance (sliding resistance) when the dilator10is moved (inserted and pulled out) with respect to the valve body6can be made comparatively low.

Further, in the illustrated configuration shown inFIG. 15, the height g0of the projection69gradually decreases from the outer circumferential portion toward the central portion of the valve body6, that is from the rib68side toward the second slit62(intersecting portion63) side. Consequently, when the dilator10is inserted into the valve body6, the sliding resistance of the valve body6can be made comparatively low. It is to be understood that the height g0of the projection69may also be fixed.

The inclination angle θ2of a lower face693of the projection69with respect to the lower face602is preferably approximately 0 to 10°, more preferably approximately 0 to 8°.

Referring toFIG. 14, the width w0of the projection69gradually decreases from the rib68side toward the second slit62side. Consequently, when the dilator10is inserted into the valve body6, an increase in the sliding resistance of the valve body6can be suppressed.

Further, the projections69do not extend all the way to the second slit62(i.e., the projections69stop short of the slit62). Consequently, when the dilator10is inserted into the valve body6, the valve body6is liable to be deformed such that a central portion of the valve body is displaced downwardly to a suitable degree, and the projections67of the upper face601side and the outer peripheral face of the dilator10can contact each other with relative certainty.

With reference toFIG. 14, all of the gap distances h between the distal end portions691of the projections69and the lower face693are equal to each other. Consequently, when the dilator10is pulled out from the valve body6, the projections69and the outer peripheral surface of the dilator10can contact each other relatively uniformly. As a result, the dilator10can be readily and stably removed from the valve body6.

Although the gap distance h mentioned above is not specifically limited, in the natural state, it is preferably approximately 0 to 1.5 mm, more particularly approximately 0.3 to 0.5 mm.

There are no projections positioned on an extension line of the second slit62as viewed in plan. Consequently, the resistance (sliding resistance) when the dilator10is moved (inserted and pulled out) with respect to the valve body6can be inhibited or prevented from increasing unnecessarily. As a result, the sliding property of the dilator10is improved, and insertion and pulling out of the dilator10can be carried out readily.

Further, the projections69and the ribs68are connected to each other. Consequently, deformation of the valve body6is suppressed, and the sealability of the opening and closing section60is improved. It is to be understood that the projections69may otherwise be spaced from the ribs68.

In the configuration shown, three pairs of projections69are provided, but the number of projections69is not limited to this. One pair, two pairs or four or more pairs may be provided, or the number of projections69may be an odd number positioned in a non-symmetrical arrangement with respect to the second slit62. As an example of another preferred configuration of the illustrated arrangement, the two projections69at the central location can be eliminated while the other four projections69at the opposite end portions remain. In another example of preferred configuration of the illustrated arrangement, the four projections69at the opposite end portions can be eliminated so that only the two projections69at the central location remain.

Although the valve body6is preferably formed as a single member from the same material, the configuration of the valve body6is not limited to this. For example, two or more different materials may be used to produce the valve body6or a plurality of members may be integrated by fusion, adhesion or the like to produce the valve body6.

As described above, with the present introducer1(valve body6), the sliding performance of the dilator10is improved, and insertion and pulling out of the dilator10can be carried out rather readily. Further, the sealability (sealing performance) of the opening and closing section60is improved.

Further, even if insertion and pulling out of the dilator10is repeated frequently, occurrence of damage to the first slit61or the second slit62is inhibited or prevented (durability is rather high), and the sealability (sealing performance) of the opening and closing section60is maintained. In other words, the liquid-tightness of the inside of the hub2is maintained, and leakage of liquid (for example, blood) filled in the hub2can be inhibited or prevented with good reliability.

The elongated medical member to be inserted into the sheath7through the valve body6is not restricted to the dilator10. Instead, the elongated medical member may be, for example, a catheter or a guide wire.

While the valve body and the medical tool of the present invention are described above in connection with the embodiment shown in the drawings, the present invention is not limited to this. Components can be replaced by alternatives which exhibit similar functions. Further, arbitrary components may be added.

The first slit and the second slit are not limited to those which are open in the natural state, but may be, for example, those which are closed in the natural state.

The first slit and the second slit are not limited to those which have a shape of a straight line as viewed in plan, but only one of the first slit and the second slit may have a shape of a straight line, or the first slit and the second slit may have shapes other than a shape of a straight line.

The medical tool is not limited to an introducer.

While both the first space and the second space are formed such that the depth of each gradually decreases toward the direction away from the intersecting portion, the configuration of the first space and the second space is not limited to this. Indeed, only one space may be formed such that the depth gradually decreases toward the direction away from the intersecting portion.

Although the depth described above gradually decreases toward the direction away from the intersecting portion, the depth is not limited to this, but it may be, for example, uniform.

Both of the first space and the second space have a portion whose width gradually decreases toward the intersecting portion. However, the configuration of the first space and the second space is not limited to this. It is possible for only one of the spaces to have a portion whose width gradually decreases toward the intersecting portion.

WORKING EXAMPLES

Now, particular working examples of the valve body in accordance with the disclosure here are described.

1. Production of the Sheath (Introducer)

Working Example 1

The valve body shown inFIGS. 3-12was produced by transfer molding using silicone rubber without forming the first concave portion64, second concave portion65, third concave portions66and projections67on the upper face601side. Then, the valve body was mounted on the hub to produce the sheath (introducer) shown inFIGS. 1 and 2. Further, to the first slit and the second slit of the valve body, silicone oil (viscosity: 1,000 cSt) was applied. Further, electron beam sterilization (dose: 55 kGy) was carried out on the sheath.

The dimensions of individual portions of the valve body in the natural state are set forth below:

Major axis of the valve body: 8.6 mm

Minor axis of the valve body: 7.7 mm

Thickness of the valve body: 1.3 mm

Height c of the ribs68: 0.8 mm

Length d of the ribs68: 5.3 mm

Length e between the outer peripheral faces of the ribs68: 5.4 mm

Gap distance f between the end portions681of the ribs68: 1.5 mm

Height g of the distal end portions691of the projections69: 0.3 mm

Gap distance h between the distal end portions691of the projections69and the intersecting portion69: 0.9 mm

Inclination angle θ2of the lower face693of the projections69: 8°

Working Example 2

The Working Example 2 was similar to the Working Example 1 except that two projections69at the central portion were not formed so that the total number of projections69was changed to four.

Working Example 3

The Working Example 3 was similar to the Working Example 1 except that four projections69at the opposite end portions were not formed so that the total number of projections69was changed to two.

Working Example 4

Working Example 4 was similar to Working Example 1 except that the valve body had a circular shape having a diameter of 8 mm as viewed in plan, and the first slit and the second slit which were closed in the natural state were formed by cutter working, meaning the slits were formed by cutting the material forming the valve body.

Working Example 5

Working Example 5 was similar to Working Example 1 except that the projections69were spaced away from the ribs68.

Comparative Example 1

Comparative Example 1 was similar to Working Example 1 except that the projections69were not formed.

Comparative Example 2

Comparative Example 2 was similar to Working Example 1 except that the ribs68were not formed.

Comparative Example 3

Comparative Example 3 was similar to Working Example 1 except that the ribs68and the projections69were not formed.

Comparative Example 4

Comparative Example 4 was similar to Working Example 4 except that the ribs68and the projections69were not formed.

The following evaluation was conducted for the working examples and the comparative examples.

[2.1] Evaluation of the Sealability

A dilator (produced by Terumo Corporation) having an outer diameter of 2 mm was inserted into the valve body of the sheath after the electron beam sterilization, and in this state, the sealability was confirmed in the following manner. Further, the sealability was confirmed in the following manner in a state in which three guide wires having different dimensions were inserted and another state in which nothing was inserted. The three guide wires had outer diameters of 0.89 mm, 0.46 mm and 0.36 mm.

As an evaluation, the opening at the distal end portion of the sheath was sealed, and air was injected into the sheath by 0.3 kgf/cm2 through the side port and a flow of the air was confirmed in water by visual observation.

For: each of the working examples and the comparative examples, the evaluation was carried out with regard to 30 samples with the following criteria.

x: rather bad

A dilator (produced by Terumo Corporation) having an outer diameter of 2 mm was inserted into and pulled off from the valve body of the sheath after the electron beam sterilization. Thereafter, the sliding resistance was measured when a catheter (produced by Terumo Corporation, Heartcath) having an outer diameter of 1.7 mm was inserted and when the catheter was pulled off.

In this instance, a maximum load when the Autograph (produced by Shimadzu Corporation, AG-IS) was used and operated at a cross head speed of 100 mm/min by 100 mm was determined.

For each of the working examples and the comparative examples, the determination was carried out with regard to five samples, and an average value was determined.

It is to be noted that the sliding resistance upon insertion was evaluated such that, if it was lower than 150 gf, then the sliding performance was good, and the sliding resistance upon pulling off was evaluated such that, if it was lower than 200 gf, then the sliding performance was good.

[2.3] Evaluation of the Negative Pressure Resisting Property

A dilator (produced by Terumo Corporation) having an outer diameter of 2 mm was inserted into the valve body of the sheath after the electron beam sterilization, the opening at the distal end portion of the sheath was sealed, whereafter air was sucked through the side port by a syringe. Then, after this state is maintained for 5 seconds, presence or absence of inflow of air was confirmed.

For each of the working examples and the comparative examples, the evaluation was carried out with regard to 30 samples with the following criteria.

x: rather bad

The evaluation above mentioned is shown in Table 1.

As apparent from Table 1 above, with the working examples (embodying the aspects of the disclosure here), good results were obtained. In contrast, with the comparative examples, satisfactory results were not obtained.

It is to be noted that, where EOG sterilization was carried out in place of the electron beam sterilization to carry out evaluation similar to that described above, similar results to those given above were obtained.

According to the disclosure here, the sliding performance of the elongated member is improved and insertion and pulling out of the elongated member can be readily carried out, and the sealability (sealing performance) of the opening and closing section is improved. In particular, the valve body is reinforced by the ribs. Also, the ribs contact the mounting section for the valve body, and consequently, deformation of the valve body is suppressed and the sealability of the opening and closing section is improved. On the other hand, when the elongated member is pulled out from the valve body, the valve body is deformed such that the central portion of the valve body is displaced in the direction of movement of the elongated member and the projections contact (point-contact) the outer circumferential surface of the elongated member. Consequently, the contact area of the outer circumferential surface of the elongated member and the valve body decreases, and the resistance (sliding resistance) when the elongated member is pulled out from the valve body decreases. Accordingly, the sliding performance of the elongated member is improved, and the elongated member can be pulled out from the valve body quite readily. Therefore, the valve body disclosed here can be used (installed) in a sheath of an introducer for introducing an elongated medical member for use with medical care such as, for example, a catheter or a guide wire into a living organism.

The detailed description above describes a preferred embodiment and variations of the valve body and medical tool. However it is to be understood that the invention is not limited to those precise embodiment and variations described and illustrated above. 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.