WO2019025111A1

WO2019025111A1 - Valve assembly

Info

Publication number: WO2019025111A1
Application number: PCT/EP2018/068151
Authority: WO
Inventors: Peter Howard
Original assignee: Peter Howard
Priority date: 2017-08-01
Filing date: 2018-07-04
Publication date: 2019-02-07
Also published as: GB201712399D0

Abstract

A valve assembly to prevent the disturbance of a haemodialysis patient connection site caused by an unintended force. A disturbed haemodialysis patient connection site may cause catastrophic bleeding. The design of the valve assembly is to prevent the passage of fluid through tubing when force is applied to either end of the valve assembly which is normally attached to tubing that transmits fluid to and from a patient. The prevention of flow causes an increase of pressure in tubing which can be detected by electronic equipment. The valve assembly can be reset to enable flow to continue or resume. The valve assembly can have an optional latch mechanism to prevent the unintended opening of the valve causing an unintended flow. The latching mechanism is manually resettable. The valve assembly can be used to help enable the commencement and conclusion of a therapy.

Description

Valve Assembly

This invention concerns a valve assembly, and especially a selectively closable valve assembly, and particularly a valve assembly for use with tubing usable for the flow of blood or other liquids.

Haemodialysis is a life saving therapy which replaces the basic functions of a human kidney. During haemodialysis, blood is drawn from a patient, treated, and then returned back to the patient at a continuous flow rate, typically of 250 to 350ml/min, via extracorporeal tubing. The haemodialysis machine that processes the blood has various means of ensuring that the patient receives a safe therapy. The blood that is travelling through the extracorporeal tubing is monitored for pressure as the blood is leaving the patient (arterial pressure), as the blood is returning back to the patient (venous pressure), and for any air that may have inadvertently entered the blood line.

Generally, such a treatment is quite safe. Dangers can however occur if for instance a force which could compromise the integrity of the fixing of a blood tubing to a patent is applied to the extracorporeal blood line to the patient, which compromises the fixing thereof. The blood line or needle may become displaced so that returning blood is not received by the patient. This can lead to serious injury or even death. A pressure sensing alarm is provided on the haemodialysis machine, but this would not always be activated in such circumstances, as the pressure differential between connection and disconnection to the patient may be too small to be detected.

According to a first aspect of the invention there is provided a valve assembly, the assembly including an outer elongate member having first and second ends, with a through passage extending through the outer elongate member, the through passage having a narrower first section extending from the first end of the outer elongate member to a wider second section, the assembly also including a hollow elongate inner member with an open first end and a closed second end, the inner elongate member being slidably located in the through passage in the outer elongate member, so as to be extendible from outside of the outer elongate member beyond the first end of the through passage to the wider second section of the through passage, with the first end of the elongate member outside of the outer elongate member, and the second end of the inner elongate member located in the wider second section of the through passage, one or more openings being provided in the outside of the inner member towards the closed second end, the inner member being slidably movable relative to the outer elongate member such that the valve assembly is selectively movable between an open position with the or each opening located in the wider second section of the through passage such that fluid can pass through the or each opening between the through passage and the interior of the inner elongate member, and a closed position in which the or each opening is located in the through passage narrower first section, closing the or each opening.

The hollow elongate inner member may be an interference fit in the through passage narrower first section.

A sealing arrangement may be provided in the through passage narrower first section, and a spaced pair of sealing arrangements may be provided in the through passage narrower first section, and the or each opening in the inner elongate member may locate between the sealing arrangements when the valve assembly is in the closed condition.

The sealing arrangement or arrangements may comprise an O-ring through which the inner elongate member is a sliding fit.

The sealing arrangement or arrangements may provide an intended resistance to free movement between the inner and outer elongate members. A retaining formation may be provided on the inner elongate member at the second end thereof to retain the second end of the inner elongate member in the through passage wider second section. The retaining formation may be provided on the second end of the inner elongate member, and may comprise a flange of greater diameter than the through passage narrower first section.

The inner elongate member may be configured such that tubing can be mounted on the first end thereof.

The second end of the outer elongate member may be configured such that tubing can be mounted thereto.

A latch arrangement may be provided for selectively retaining the valve assembly in the closed position.

The latch arrangement may comprise a resilient member mounted on the outside of the outer elongate member, and extending beyond the first end of the outer elongate member to be engageable with the inner elongate member towards the first end of the inner elongate member.

A latching formation may be provided on the inner elongate member towards the first end thereof. The latching formation may comprise a flange which may be spaced from the first end of the inner elongate member.

In the open position of the valve the resilient member may engage against the outer circumferential surface of the flange.

In a closed position the resilient member may engage against the outer side of the flange facing away from the outer elongate member. A step may be provided on the resilient member which engages against the first end of the outer elongate member when in a relaxed condition. A pivot formation may be provided on the outside of the outer elongate member spaced from the first end thereof, against which the resilient member can be pivoted to cause the resilient member to disengage from the latching formation. The pivot formation may comprise a plurality of radial pins, or may comprise a flange.

Embodiments of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:-

Fig. 1 is a diagrammatic cross-sectional view of a first valve assembly according to the invention in an open condition;

Fig. 2 is a similar view to Fig. 1 but in a closed condition;

Fig. 3 is a diagrammatic end view of the first valve assembly;

Figs. 4 and 5 are respectively diagrammatic side and end views of a first component of the first valve assembly;

Figs. 6 and 7 are respectively diagrammatic side and end views of a second component of the first valve assembly;

Figs. 8, 9 and 10 are respectively diagrammatic cross-sectional side views of a second valve assembly according to the invention, in open, closed and partially closed conditions;

Fig. 1 1 is a diagrammatic end view of the second valve assembly in an open condition;

Figs. 12 and 13 are respectively diagrammatic side and end views of a first component of the second valve assembly; and Figs. 14 and 15 are respectively diagrammatic side and end views of a second component of the second valve assembly.

Figs. 1 to 7 show a first valve assembly 10 suitable for use in haemodialysis as described above, but also usable in a number of other applications. The valve assembly 10 permits selective opening and closing thereof, and also automatic closing if for instance a blood line were to have an unintended or otherwise, force applied to it.

The valve assembly 10 includes outer and inner elongate members 12, 14. The outer elongate member 1 2 has an external cylindrical profile and a through passage 1 6 with a first section 18 extending from a first left hand end 20 for substantially half of the length of the outer elongate member 12, and extending into a wider second section 22 which extends until close to a second right hand end 24 where there is a third narrower section 26 of the same width as the first section 18. A pair of O ring seals 28A, B are provided in the first section 18, one 28A towards the first left hand end 20, and the other 28B towards the right hand end of the first section 18.

The inner elongate member 14 is in the form of a tube 30 which is a sliding fit within the first section 18 of the through passage 16. The tube 30 is open at a first left hand end 32, but closed by a flange 34 at the right hand end. The flange 34 is of a size to be too large to pass through the first section 18 of the through passage 16. A radial opening 36 is provided through the tube 30, spaced a short distance from the flange 34.

As shown in Figs. 1 and 2 the inner elongate member 14 is mounted within the outer elongate member 12, with the first left hand end 32 extending outwardly beyond the first left hand end 20 of the outer elongate member 12, and the second right hand end of the inner elongate member and hence flange 34, located within the wider second section 22 of the through passage 16.

In an open position as shown in Fig. 1 the flange 34 is located generally centrally along the second wider section 22 of the through passage 16, and the opening 36 is also located in the wider second section 22 of the through passage 16. As can be seen a first length 38 of tubing is mounted to the left hand end 32 of the inner elongate member 14, with the left hand end 32 of the inner elongate member 14 located with the end of the first length 38 of tubing. As can be seen in the open position, the inner elongate member 14 is moved to the right until the first length 38 of tubing abuts against the outer elongate member 12.

A second length 40 of tubing is mounted within the right hand third section 26 of the through passage 16. This means that in practice, fluids such as blood can pass either way from the first length 38 of tubing through the interior of the inner elongate member 14 and out through the opening 36 into the wider second section 22 of the through passage 16 and out through the second length 40 of tubing.

In Fig. 2 the inner elongate member 14 has been moved to the left such that the opening 36 is now located between the seals 28A, B. The flange 34 has abutted against the left hand end of the second wider section 22 of the through passage 16. This will mean that fluid cannot pass through the valve assembly 10, and any fluid passing out of the opening 36 will not be able to pass the seals 28A, B.

Therefore, in practice if for instance a blood line is inadvertently exposed to an undesirable force so as to be dislodged, for instance by a patient's clothing, a patient turning or otherwise, this will cause the inner elongate member 14 to be moved to the left to the closed position. The change in pressure will be detected by the haemodialysis machines pressure sensor and an alarm signal given and blood pumping stopped. The fixing of the tubing to a patient can be checked, and if this has not been compromised then the valve assembly 10 can be reset by moving the inner elongate member 14 to the right to the open position. The valve assembly 1 0 can also readily be opened and closed as required by simply moving the inner elongate member 14 relative to the outer elongate member 1 2.

Figs. 8 to 15 show a second valve assembly 50 which is identical to the first valve assembly 10, except that the second valve assembly 50 includes a latching arrangement. The latching arrangement includes a latching formation 54 in the form of a flange 56 is provided spaced a short distance from the first left hand end 32 of the inner elongate member. The diameter of the flange 56 is substantially equal to the external diameter of the outer elongate member 12.

A resilient profiled sealing member 58 with two diametrically opposite parts on either side of the assembly 50, is provided over the outer elongate member 1 2. The member 58 is mounted to the second right hand end 24 of the outer elongate member 12, and in a relaxed condition as shown for instance in Fig. 8, is principally spaced a short distance outwardly from the outer elongate member 12, with an inner step 59 on each part at the right hand end 24. A pivoting arrangement in the form of a pair of diametrically opposite pins 60 is on the outer elongate member 12 provided spaced a short distance from the left hand first end 20 thereof. An inner step 62 is provided on each part of the member 58 at the first left hand end 20 of the outer elongate member 12, leading to a thicker converging end portion 64 of the member 58.

In the open position of the valve assembly 50 as shown in Fig. 8, the inner part of the end portion 64 rests against the circumferential edges of the flange 56. In a closed position of the valve assembly 50 as shown in Fig. 9, the flange 56 has moved beyond the end of the end portion 64, and the end portion 64 has flexed inwardly to engage against the right hand side of the flange 56 to prevent the inner elongate member 14 being moved relative to the outer elongate member 12. To permit the inner elongate member 14 to be moved relative to the outer elongate member 12, pressure can be applied to the member 58 generally mid-way along the outer elongate member as shown by the arrows 66 in Fig. 1 0, which causes the member 58 to pivot about the pins 60 such that the end portion 64 disengages from the flange 56, enabling the inner elongate member 14 to freely move.

There are thus described valve arrangements of relatively simple construction, which can readily be moved between open and closed conditions as required, or for instance if a blood line or other tubing were to be exposed to an undesirable force, which may cause the blood line to become dislodged. Such moving from an open to a closed condition would be detectable for instance by a pressure detector on a haemodialysis machine, so as to provide an appropriate alarm, and stop the blood pumping.

The interference between the outer and inner elongate members 12, 14 provides an intended resistance to relative movement therebetween, such that a predetermined force is needed to provide relative movement.

The latching arrangement on the second valve assembly permits the valve assembly to be retained in a closed condition, and requires manipulation to move between closed and open positions.

Whilst providing this enhanced performance, the valve assemblies can readily be made by conventional techniques to provide long term maintenance free operation. Various modifications may be made without departing from the scope of the invention. For instance, different means may be provided for preventing the inner elongate member moving wholly out of the outer elongate member. More than one holes may be provided in the inner elongate member to provide an increased flow of fluid thereoutof.

Different sealing arrangements may be used, and in some instances the inner elongate member may be an interference fit in the through passage such that no sealing arrangements are required. A different pivoting arrangement may be provided, and this could be in the form of a flange. Different latching formations or configurations may be provided.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1 . A valve assembly, the assembly including an outer elongate member having first and second ends, with a through passage extending through the outer elongate member, the through passage having a narrower first section extending from the first end of the outer elongate member to a wider second section, the assembly also including a hollow elongate inner member with an open first end and a closed second end, the inner elongate member being slidably located in the through passage in the outer elongate member, so as to be extendible from outside of the outer elongate member beyond the first end of the through passage to the wider second section of the through passage, with the first end of the elongate member outside of the outer elongate member, and the second end of the inner elongate member located in the wider second section of the through passage, one or more openings being provided in the outside of the inner member towards the closed second end, the inner member being slidably movable relative to the outer elongate member such that the valve assembly is selectively movable between an open position with the or each opening located in the wider second section of the through passage such that fluid can pass through the or each opening between the through passage and the interior of the inner elongate member, and a closed position in which the or each opening is located in the through passage narrower first section, closing the or each opening.

2. A valve assembly according to claim 1 , in which the hollow elongate inner member is an interference fit in the through passage narrower first section.

3. A valve assembly according to claims 1 or 2, in which a sealing arrangement is provided in the through passage narrower first section.

4. A valve assembly according to claim 3, in which a spaced pair of sealing arrangements are provided in the through passage narrower first section.

5. A valve assembly according to claim 4, in which the or each opening in the inner elongate member locates between the sealing arrangements when the valve assembly is in the closed condition.

6. A valve assembly according to any of claims 3 to 5, in which the sealing arrangement or arrangements comprises an O-ring through which the inner elongate member is a sliding fit.

7. A valve assembly according to any of claims 3 to 6, in which the sealing arrangement or arrangements provide an intended resistance to free movement between the inner and outer elongate members.

8. A valve assembly according to any of the preceding claims, in which a retaining formation is provided on the inner elongate member at the second end thereof to retain the second end of the inner elongate member in the through passage wider second section.

9. A valve assembly according to claim 8, in which the retaining formation is provided on the second end of the inner elongate member.

10. A valve assembly according to claim 9, in which the retaining formation comprises a flange of greater diameter than the through passage narrower first section.

1 1 . A valve assembly according to any of the preceding claims, in which the inner elongate member is configured such that tubing can be mounted on the first end thereof.

12. A valve assembly according to any of the preceding claims, in which the second end of the outer elongate member is configured such that tubing can be mounted thereto.

13. A valve assembly according to any of the preceding claims, in which a latch arrangement is provided for selectively retaining the valve assembly in the closed position.

14. A valve assembly according to claim 1 3, in which the latch arrangement comprises a resilient member mounted on the outside of the outer elongate member, and extending beyond the first end of the outer elongate member to be engageable with the inner elongate member towards the first end of the inner elongate member.

15. A valve assembly according to claims 13 or 14, in which a latching formation is provided on the inner elongate member towards the first end thereof.

16. A valve assembly according to claim 15, in which the latching formation comprises a flange.

17. A valve assembly according to claim 16, in which the flange is spaced from the first end of the inner elongate member.

18. A valve assembly according to claims 16 or 17, in which in the open position of the valve the resilient member engages against the outer circumferential surface of the flange.

19. A valve assembly according to any of claims 16 to 18, in which in a closed position the resilient member engages against the outer side of the flange facing away from the outer elongate member.

20. A valve assembly according to any of claims 14 to 19, in which a step is provided on the resilient member which engages against the first end of the outer elongate member when in a relaxed condition.

21 . A valve assembly according to claim 15 or any of claims 16 to 20 when dependent on claim 1 5, in which a pivot formation is provided on the outside of the outer elongate member spaced from the first end thereof, against which the resilient member can be pivoted to cause the resilient member to disengage from the latching formation.

22. A valve assembly according to claim 21 , in which the pivot formation comprises a plurality of radial pins.

23. A valve assembly according to claim 21 , in which the pivot formation comprises a flange.

24. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.