WO2006007604A1

WO2006007604A1 - Catheter valve

Info

Publication number: WO2006007604A1
Application number: PCT/ZA2005/000102
Authority: WO
Inventors: Eric Oliver Macleod Smith
Original assignee: Eric Oliver Macleod Smith
Priority date: 2004-07-08
Filing date: 2005-07-06
Publication date: 2006-01-19

Abstract

A catheter valve including a thermoplastic valve body (10), an open cylindrical cavity (12) in the body, a catheter bore (14) extending from the cavity to the outside of the body, a valve member flap (16) in the cavity, a plastic hinge (18) connecting the flap to the body at the inner end of the cavity, an actuator (22) projecting outwardly from the valve body from a position over the inner end of the cavity to a position between the ends of the cavity, a second plastic hinge (20) connected between the actuator and a position on the flap which is spaced from and outwardly opposite the first hinge so that on the actuator being pressed into the cavity the second hinge will cause the flap to rotate about the first hinge between a position in which the flap is clear of the catheter bore and a second position to close the catheter bore.

Description

CATHETER VALVE

FIELD OF THE INVENTION

[0001] This invention relates to a catheter valve for interrupting the flow of a liquid through the bore of a catheter which is attached to the valve.

[0002] In this specification the term catheter is intended to include any conduit for introducing liquid into or draining fluid from the body of a patient.

BACKGROUND TO THE INVENTION

[0003] Various valve arrangements for occluding the flow of a body fluid through a fluid flow or infusion instrument are well known. Most of the known valve arrangements generally fall into two classes; those which include few components and are so inexpensive and those which include several separately manufactured components which require to be assembled and which are consequently more expensive.

[0004] Typical examples of the valve arrangements of the first type are those disclosed in US Patent Nos. 4,198,973 and 5,429,616 which pinch the fluid bore in a catheter or cannula closed by some finger operated mechanism and which again opens the passage when the finger pressure on the mechanism is released. Although these valve arrangements are relatively cheap compared to the valve arrangements of the second type they require hands-on operation while closing the fluid passage of the conduit to which they are connected so restricting free hand use of the person who is inserting or removing the catheter or cannula into or from the body of a patient. [0005] The catheter valve disclosed in the specification of US Patent No. 6,413,250 is of the first type and largely mitigates the problems associated with the above prior art catheters. It has, however, been found to have operational limitations which have been overcome by the valve of this invention.

SUMMARY OF THE INVENTION

[0006] A catheter valve according to the invention includes:

a valve body which is made from a suitable thermoplastic polymer material,

an open-mouthed substantially cylindrical cavity in the body in which a medical apparatus hub may releasably be located,

a bore which extends from the inner end of the cavity to the outside of the body and in which an end portion of a catheter is located, in use,

a valve member flap in the body cavity,

a plastic hinge connecting an end of the flap to the body contiguous to the inner end of the body cavity,

an actuator which projects outwardly from the outer surface of the cavity portion of the valve body to extend from a forward position over the inner end portion of the cavity to an intermediate position between the ends of the cavity, and

a second plastic hinge which is distinct from the first and is connected between the actuator, at its forward position on the valve body and a position on the flap which is spaced from and substantially opposite the first hinge so that on the forward end of the actuator being pressed into a forward portion of the cavity the second hinge will cause the valve member flap to rotate about the first hinge between a first position in which the flap is clear of the catheter bore and a second position to which it is switched away from the actuator to close the catheter bore.

[0007] The valve body and all of its components may be moulded in one piece.

[0008] The body cavity wall may conveniently be made thinner over the length and on either side of the switch actuator to enable the forward end portion of the actuator to be pressed into the body cavity to cause the valve member flap to be switched from its first position to its second position of operation and vice versa.

[0009] The forward end portion of the body cavity, opposite the actuator, preferably includes a valve member flap guide which includes a groove which has the same shape in cross-section as the outer shape of the valve member flap and which leads from a position in the valve body cavity to the mouth of the catheter bore for guiding movement of the valve member flap from its first to its second position of operation and to prevent skewing of the valve member flap in so doing.

[0010] The valve member flap may include an easily deformable peripheral rib which is compressed between the inner surface of the flap guide groove and the valve member flap in the second position of operation of the flap positively to seal the fluid passage between the body cavity and the catheter bore. [0011] The catheter valve may include a catch arrangement for releasably holding the valve member flap in its second position of operation against liquid under pressure in the catheter, in use.

[0012] The valve body chamber and the catheter bore axes may be parallel to and eccentrically positioned in the body with the catheter bore axis spaced away from the chamber axis in a direction diametrically opposite the switch actuator.

[0013] The catheter valve may include a catheter which has a portion of one end located in the catheter bore.

[0014] The valve body moulding material could be a suitable blend of medical grade polypropylene and thermoplastic elastomeric rubber. The blended moulding material may be mixed in the ratio of 60% polypropylene to 40% of the thermoplastic elastomeric rubber. The material may, however, be blended in any other ratio which is more suitable for a particular application.

BRIEF DESCRIPTION QF THE DRAWINGS

[0015] An embodiment of the invention is now described by way of a non-limiting example only with reference to the drawings in which :

Figure 1 is a sectioned side elevation of the catheter valve of the invention,

Figure 2 is an end elevation of the valve of Figure 1 ,

Figure 3 is a plan view of the Figure 1 valve shown sectioned on the line 3-3 in Figure 1,

Figure 4 is an end elevation of the valve as seen from the right of Figure 1 , Figure 5 is an under plan of the valve shown sectioned on the line 5-5 in Figure 1 ,

Figure 6 is a sectioned side elevation of the valve of Figure 1 shown switched to its closed condition,

Figure 7 is a sectioned side elevation of the valve of the invention shown together with a selection of associated medical apparatus components.

Figure 8 is an enlarged fragmentary view of the switching arrangement of the Figure 1 valve shown in the open position of the valve,

Figure 9 is a view similar to that of Figure 1 showing the switching arrangement switched to the closed position of the valve, and

Figure 10 is an enlarged end elevation of the Figure 1 valve shown sectioned on the line 10-10 in Figure 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] The catheter valve of the invention is shown in the drawings to include a valve body 10 which is moulded in one piece from a suitable thermoplastic polymer material. The moulding material is conveniently a blend of polypropylene and thermoplastic rubber and more particularly a suitable blend of medical grade polypropylene and thermoplastic elastomeric (TPE) rubber. The blend could comprise a mixture of eighty percent polypropylene and twenty percent of the TPE rubber but is preferably mixed in a ratio of sixty percent polypropylene to forty percent TPE rubber.

[0017] The valve body 10 is shown in Figure 1 and the remaining drawings to include a cylindrical needle hub cavity 12 which is open to the rear of the body, a forward nose 13 which includes a catheter bore 14, a valve member flap 16 which is connected to the body by a first plastic hinge 18 and a second plastic hinge 20 which connects the valve member, at a position which is outwardly and radially displaced from the hinge 18, to an actuator 22.

[0018] The body additionally includes a needle guide chamber 24, a grooved valve member flap 16 guide 26 and a zone 28 of the cavity 12 wall which is thinned over the length and on each side of the actuator 22 relatively to the remaining wall thickness of the cavity 12, as is more clearly seen in Figures 5 and 10.

[0019] As shown in Figure 1 the axis of the catheter bore 14 is eccentric to that of the cylindrical cavity 12 and is parallel to and spaced from the cavity 12 axis in a direction diametrically away from the actuator 22.

[0020] Figure 1 illustrates the liquid passage through the valve body 10 to be open with the valve member flap 16 well clear of the liquid path through the body. In Figure 6 the liquid path through the valve body is shown closed by the valve member 16 with this being achieved by a downward finger pressure on the forward portion of the actuator 22 which causes its connection point with the hinge 20 to be rotated about the hinging rear end of the actuator to cause the valve member flap 16 to be rotated in an anticlockwise direction about the hinge 18 as the forward end portion of the actuator resiliently deforms the thinned material in the body zone 28 on entering the cavity 12. Increasing finger pressure on the actuator 22 will cause the valve member flap 16 to enter the valve member flap guide 26 groove 27 at a slight interference fit with the walls of the U- shaped guide groove, the shape of which is most clearly seen in Figures 2 and 10, to shut fluid flow through the valve in the Figure 6 position of the valve member flap 16. To ensure positive sealing of the outer edge of the valve member flap 16 with the U- shaped wall of the valve member flap guide 26, the flap could include a small easily deformable peripheral rib 29 which will be compressed between the U-shaped edge of the valve member flap 16 and the wall of the flap guide 16 groove 27 in the closed position of the valve member. The rib 29 is shown only in Figures 8, 9 and 10. In addition to the guide groove 27 guiding the valve member flap to its second position of operation it also prevents skewing of the flap which might arise as a result of indirect finger pressure on the actuator 22.

[0021] The actuator 22 may conveniently be provided with an upwardly directed finger catch 30 which, in the Figure 6 position of the actuator, may simply be finger lifted to raise the actuator back to the Figure 1 position to cause the valve member flap to be switched back to its Figure 1 open position. To predispose the valve member flap 16 to commence rotation in an anticlockwise direction from its Figure 1 to its Figure 6 position the outer face of the valve flap 16 between the spaced hinges 18 and 20 could be inclined rearwardly from the bottom hinge 18 to be, in the Figure 1 position of the valve, angled at about 5° to either of the body axes.

[0022] Figure 7 illustrates the catheter valve of the invention in use with a number of substantially conventional items of medical equipment as used in an intravenous drip procedure. The needle hub cavity 12 of the valve body is dimensioned frictionally to engage conventional LUER slip medical hub spigots. [0023] The intravenous drip equipment, shown used with the valve 10 in Figure 7, comprises a flexible PTFE catheter 32, a conventional needle guide 34, a needle hub 38 which carries a stainless steel, or like needle 36, an air pervious blanking hub 40 and a needle stick prevention scabbard 42.

[0024] The needle guide 34 has a hollow stem which is frictionally located in an initially outstanding tapered end of the catheter 32 and a plurality of outwardly splayed leaves at its free end. The free end of the catheter, through the needle hub cavity 12, is slid into and from the catheter bore 14 of the valve until the leaves of the needle guide are resiliently splayed outwardly to engage the outer walls of the needle guide chamber 24 to lock the needle guide and catheter to the valve body 10. The needle 36 is introduced into and from the catheter through the needle guide 34 until a spigot 44 of the needle hub 38, in which the needle 36 is eccentrically located, is frictionally engaged in the needle hub cavity 12 of the valve 10. The blanking hub 40 is located in the tapered bore of the needle hub 38. Circumferentially spaced formations, not shown, in the mouth of the needle scabbard 42 are then frictionally engaged over the valve body nose 13 which carries the catheter bore 14, as shown in the drawing.

[0025] In use, the needle scabbard 42 is removed from the valve body 10 and the forward end portions of the needle 36 and catheter 32 are located in the patient's vein. The transparent blanking hub 40, as is conventional, serves as an indicator that the needle 30 is correctly located when it becomes blood-filled. With the needle and catheter competently located in the patient's vein the person carrying out the procedure then presses downwardly with a finger on the forward end of the actuator 22 to switch the valve member flap 16 downwardly in an anticlockwise direction, as described above, towards the closed position of the valve until its free end abuts the upper surface of the needle in the valve member guide 26 and then withdraws the needle 36 together with the blanking hub 42 from the patient. As the sharpened tip of the needle passes the valve member flap, which is pressed down on the needle 30, the continued finger pressure on the actuator 22 causes the valve member flap 16 to be fully switched to the closed position of the valve, as illustrated in Figure 6 to close the valve body bore 14 and that of the catheter 32 connected to it to prevent blood flow from the patient from the needle hub cavity of the valve body. An outlet hub from a conventional giving set, which is longer than the needle spigot 44, is now pressed into the needle hub cavity 12 of the valve body until the nose of the giving set hub comes into contact with a formation 45 (Figures 6 and 9) which projects from the underside of the actuator 22 into the body cavity 12 and on full insertion of the hub causes the formation to move the actuator from its Figure 6 closed position back to its Figure 1 open position to permit the gravity-fed intravenous drip procedure to the patient to commence. To remove the catheter from the patient's vein at the end of the intravenous drip procedure the actuator is again pressed downwardly to switch the valve member flap from its Figure 1 open position to its Figure 6 closed position and the valve body 10 together with the catheter which it carries is withdrawn from the patient's vein in the normal manner.

[0026] From the above description of the catheter valve of the invention it will be appreciated that the one-piece valve body 10 will enable the person carrying out a procedure using it to be largely hands-free to perform tasks involved in the procedure while connecting a giving set, or the like, to the valve body while not needing to close the patient's veins and so on by means of hand pressure.

[0027] Where the catheter of the invention is to be inserted into an artery in a procedure such as the intra-arterial monitoring of blood pressure the downstream face of the valve member flap 16 will be exposed to blood pressure greater than it is in an intravenous procedure. In this event the valve 10, to prevent unintentional pressure opening of the valve member flap 16, the valve will probably need an arrangement for positively locking the flap 16 in its downwardly switched closed position.

[0028] A first form of valve member flap 16 locking arrangement is illustrated in Figures 8 and 9 where the valve member flap is shown to include an upward step 46 in its rear face adjacent the actuator 22 hinge 20. With this locking arrangement additional finger pressure on the actuator 22 is required when the valve member flap 16 has been switched to its closed position to force the leading edge of the actuator 22 formation 48 over the flap step 46. To achieve this the hinge 20 material needs to be stretched in length as shown in Figure 9. The hinge material is shown in Figure 9 to be exaggerated in thickness and length for the purpose of illustration and in practice it is thinned out to line thickness. In this position of the actuator the valve member flap 16 is positively locked in its closed position. Obviously a little more upward finger pressure on the finger catch 30 of the actuator 22 will be required to open the valve than is required with the valve embodiment of Figures 1 to 7.

[0029] A second valve member locking arrangement is illustrated in Figure 10. In this embodiment of the valve of the invention the actuator 22 includes downwardly directed side formations 50 which include grooves 52 on their inner walls adjacent their lower ends which, when the actuator 22 has been depressed to switch the valve member flap 16 to the closed condition of the valve, resiliently engage over ribs 54 on the side wall of the valve body 10 to lock the actuator in its fully depressed position in the valve body 10.

[0030] The invention is not limited to the precise details as herein described. For example, the portion of the body 10 which carries the needle hub cavity could be made longer to the rear of the body than is shown in the drawings and be made to include an infusion port. Yet further, if the valve of the invention is to be used as a urinary catheter it could be moulded from a suitable rubber or rubber-like material with the nose which houses the catheter bore 14 being considerably extended and suitably shaped in cross- section to provide the urinary catheter.

[0031] Additionally, the catheter valve body could be made in a two stage mould procedure in a single mould to make the valve member flap 16 from a thermoplastic rubber or the like to enable an injection needle to be pressed through the flap material in the closed Figures 6 and 9 positions of the flap. The purpose of this is to further simplify the use of the valve of the invention by removing the need to remember to close the valve member flap while extracting the cannula from the catheter and valve.

[0032] In another form of the invention the catheter 32 may be omitted from the valve body and the needle 36 only could be fixed to the body 10 in a smaller diameter bore 14 to enable the valve body and needle to be used as an injection needle which is releasably engageable with an outlet spigot on a syringe.

Claims

1. A catheter valve including

a valve body which is made from a suitable thermoplastic polymer material,

an open mouthed substantially cylindrical cavity in the body in which a medical apparatus hub may releasably be located,

characterised in that the valve further includes:

a valve member flap in the body cavity,

an actuator which projects outwardly from the outer surface of the cavity portion of the valve body to extend from a forward position over the inner end portion of the cavity to an intermediate position between the ends of the cavity,

2. A catheter valve as claimed in claim 1 wherein the valve body and all of its components are moulded in one piece.

3. A catheter valve as claimed in either one of claims 1 or 2 wherein the body cavity wall is thinner over the length and on either side of the switch actuator to enable the forward end portion of the actuator to be pressed into the body cavity to cause the valve member flap to be switched from its first position to its second position of operation and vice versa.

4. A catheter valve as claimed in any one of the above claims wherein the forward end portion of the body cavity, opposite the actuator, includes a valve member flap guide which includes a groove which has the same shape in cross-section as the outer shape of the valve member flap and which leads from a position in the valve body cavity to the mouth of the catheter bore for guiding movement of the valve member flap from its first to its second positions of operation and to prevent skewing of the valve member flap in so doing.

5. A catheter valve as claimed in claim 4 wherein the valve member flap includes an easily deformable peripheral rib which is compressed between the inner surface of the flap guide groove and the valve member flap in the second position of operation of the flap positively to seal the fluid passage between the body cavity and the catheter bore.

6. A catheter valve as claimed in any one of the above claims including a catch arrangement for releasably holding the valve member flap in its second position of operation against liquid under pressure in the catheter, in use.

7. A catheter valve as claimed in any one of the above claims wherein the valve body chamber and the catheter bore axes are parallel to and eccentrically positioned in the body with the catheter bore axis spaced away from the chamber axis in a direction diametrically opposite the switch actuator.

8. A catheter valve as claimed in any one of the above claims including a catheter which has a portion of one end located in the catheter bore.

9. A catheter valve as claimed in any one of the above claims wherein the valve body moulding material is a suitable blend of medical grade polypropylene and thermoplastic elastomeric rubber.

10. A catheter valve as claimed in claim 9 wherein the blended moulding material is mixed in the ratio of 60% polypropylene to 40% of the thermoplastic elastomeric rubber.