WO1993008851A1

WO1993008851A1 - Valve device

Info

Publication number: WO1993008851A1
Application number: PCT/GB1992/002032
Authority: WO
Inventors: Trevor William Wilson; David Edward Armstrong
Original assignee: Haemocell Plc
Priority date: 1991-11-04
Filing date: 1992-11-04
Publication date: 1993-05-13
Also published as: GB9123305D0

Abstract

A device for fitting to a hand held instrument, such as a catheter, having a body through which a primary fluid, such as blood, is withdrawn or supplied, and an inlet (25) through which a secondary fluid such as an anticoagulant, may be introduced, for mixing with the primary fluid. A flexible hose (34) terminates at the inlet for supplying the secondary fluid to the inlet. A pinch valve is provided for variably squeezing the flexible hose to control the metering of the second fluid. The pinch valve has an actuating member (6) which is located so as to be actuatable by the same hand of the user as that holding and manipulating the instrument.

Description

VALVE DEVICE

The present invention relates to a valve device for metering a secondary fluid into a flow of primary fluid. Blood is frequently collected during surgery, to allow the surgeon a clear view of the operating site, by a vacuum scavenging technique. When it is intended that this -blood be processed for reinfusion to the patient, it must be anti-coagulated to prevent clotting. This is achieved by mixing the blood with a liquid anticoagulant as the blood is sucked into a catheter. The anticoagulant flow is normally controlled by adjustable hose clamps which are situated between the supply of anticoagulant and the catheter. The control of these clamps is most inconvenient and usually requires a separate dedicated operator to control them while the catheter is manipulated to collect the blood by another operator.

Similar problems arise in other fields where a secondary liquid has to be metered into a flow of a primary liquid through a hand held instrument.

According to the present invention, a valve device for fitting to a hand held instrument having a wand through which a primary fluid may be withdrawn or supplied, an inlet through which a secondary fluid may be introduced for mixing with the primary fluid, and a flexible hose terminating at the inlet for supplying the secondary fluid to the inlet, comprises a body of hairpin shape, one arm of which is arranged to be held on one side of the wand with the other arm spaced from the wand but displaceable towards the first arm against resilient action, and a pinch valve comprising a pair of valve jaws between which the flexible hose, in use, passes, the jaws being on respective opposite internal faces of the arms adjacent to the bight of the hairpin shaped body, whereby, in use, deflection of the second arm relatively to the first arm controls the squeezing of the hose by the jaws. Thus, when the device is fitted to an instrument such as a blood-sucking instrument, it allows the operator of the instrument to control conveniently the flow of the secondary fluid simply by squeezing the hairpin shaped body.

The hairpin shaped body preferably includes means for guiding the flexible hose through the bight of the body and between the jaws.

Advantageously, one of the jaws comprises two spaced apart supporting members and the other jaw is an L-shaped projection which, in use, hooks around the flexible hose and moves in the space between the supports to pull the flexible hose towards the arm on which the L-shape projection is located deforming the flexible hose into a zig-zag shape and blocking the supply of secondary fluid when the first and second arms are resiliently spaced apart. Holes may be provided in the supporting members to help guide the flexible hose through the jaws.

It may be desirable to hold the resilient arms together for an extended period of time such as when the device is in packaging in order to prevent the flexible hose from being permanently deformed. For this purpose, there may be provided a clip which embraces the two arms of the body and is slidable thereon, whereby movement of the clip away from the bight or the body forces and holds the arms closer together.

The new device is particularly applicable when fitted to a blood sucking instrument with a tubular wand which is arranged to be manipulated by a hand to enable one end of the wand to be introduced into a body cavity, the wand being connected at the other end to a primary hose which leads, in use, to a source of suction, whereby blood may be drawn, in use, from the body cavity through the wand and primary hose. In this application, a flexible hose leads, in use, from a reservoir of anticoagulant to the wand between the jaws of the device to enable the anti-coagulant to be mixed, in use, with blood drawn through the wand; whereby the metering of the anti-coagulant is controlled by the pinch valve which is located so as to be actuable by the same hand of the user as that holding and manipulating the wand. The device can be conveniently fitted to the wand using an adaptor, the adapter being slidably fitted to the one arm of the device and having a cavity ^' which communicates at one end with a socket which receives a tubular spigot on the end of the wand as a press fit and at the other end with two sockets each of which receives as a press fit a respective one of the primary hose and flexible hose.

An example of a device, adapter and instrument constructed in accordance with the present invention will now be described with reference to accompanying drawings in which:

Fig. 1 is a side view of the device, adapter and instrument;

Fig. 2 is a section through the device and adapter showing a portion of the instrument;

Fig. 3 is an exploded view of the device, adapter and end of the instrument;

Fig. 4 shows the device in a first position; and

Fig. 5 shows the device in a second position. The illustrated apparatus comprises a valve device 1 and a catheter 2 fitted to the valve device by an adapter 3.

The valve device has a hairpin shaped body, one arm 4 of which is provided with a key 5 for sliding engagement with the adapter 3 and the second arm 6 of which is held away from the catheter 2 by the resilience of the material from which the body is made.

Adjacent to the bight of the hairpin on the first arm

4 is provided a first jaw assembly 7. This consists of a first wall 8 extending perpendicularly away from a first long edge of the arm 4. A top wall 9 extends perpendicularly from the top edge of the first wall 8 towards the opposite long edge of the arm 4. A recess 10 is provided in the first and top walls creating two jaws 11, 12.

The jaw assembly 7 has two side walls, 13, 14 which are provided adjacent to the first wall 8 with holes 15, 16 and grooves 17, 18 in the edge remote from the first wall 8. The holes 15, 16 are aligned with a first recess '19 in the bight of the hairpin shaped body and the grooves 17, 18 are aligned with a second recess 20 in the bight of the hairpin shaped body. A third jaw 21 is L-shaped with a first portion 22 projecting from midway between long edges of the second arm 6 of the hairpin shaped body and a second foot portion 23 extending from the first portion towards the first wall 8 of the first jaw member 7. The second portion 23 is in the form of a triangular prism with one of its long edges pointing towards the second arm 6. The third jaw is reciprocable in the recess 10 by flexing the hairpin shaped body.

The adapter 3 has a groove 24 formed in its lower surface for engagement with the key 5 of the hairpin shaped body 1 to hold the adapter 3 rigidly against the arm 4.

Two inlets 25,26 are provided in the end of the adapter which faces the first jaw assembly 7, the inlets 25 being aligned with the holes 15,16 and the first recess 19 and the inlet 26 being aligned with the grooves 17,18 and second recess 20. The inlets 25,26 communicate with a cavity 27 in the adapter 3 which opens at the end of the adapter remote from the first jaw assembly to provide a socket 28 for receiving the catheter 2. The catheter 2 comprises an elongate hollow wand 29 one end of which is, in use, inserted into a body cavity of a patient and the other end of which has a spigot 30 which is a press fit into the cavity 28 of the adapter.

A restraining clip 31 is shown in figure 3 retained over the arms 4,6 of the hairpin shape body. A pair of ribs 32, 33 run across the lower surface of the first arm 4 to provide a seat for the clip 31, which prevents the arms 4,6 from opening too far.

'A first flexible hose 34 communicates with the cavity 27 in the adapter via the inlet 25 and is guided between the jaws 11,12,21 via the holes 15,16 and through the bight of the hairpin shaped body 1 by the first recess 19. A second larger diameter flexible hose 35 communicates with the chamber 27 via inlet 26 and is guided past the jaws 11,12,21 by the grooves 17,18 and through the bight of the hairpin shape body by the second recess 20. The first pipe 34 is connected to a source of anti-coagulant (not shown) and the second pipe 35 is connected to a vacuum pump (not shown) .

A leg 36 projects from the second arm 6 between the third jaw 21 and the bight of the hairpin shaped body 1. The leg 36 has a bevelled leading edge which can ride over a bevelled projection 37 provided on the side wall 14.

The apparatus described is used in a surgical operation to remove blood from an operating site. The end of the wand 29 remote from the valve device is placed in the operating site and the vacuum pump is turned on. Blood is sucked up through the wand 29, the adapter 3 and the second hose 35 for recycling or storage.

With the arms 4,5 of the hairpin shape body spaced resiliently apart, in the position shown in figure 4, the foot portion 23 of the jaw 21 bears against the first flexible hose 34 and forces it between the jaws 11,12 into a zig-zag formation thus closing the hose and blocking the supply of anti-coagulant to the chamber 27. When, during an operation, an operator requires the anti-coagulant to be metered into the blood passing through the adapter 3, he squeezes the arms 4,6 together thus pushing the foot portion 23 deeper into the recess 10 away from the first and second jaws 11,12 into the position shown in figure 5. This releases the hose 34 which is sufficiently resilient to regain its original shape and allow the anti-coagulant to pass to the cavity 27. Thus, an operator can control the flow of anti-coagulant into blood by manipulating the valve device with the same hand which is being used to guide the catheter.

The clip 31 is fitted over the arms 4,6 before the apparatus is packaged in order to prevent the jaws 11,12,21 from closing on the first hose 34 for an extended period and plastically deforming the first hose 34. When the apparatus is unpacked, the clip is removed and can be discarded. As the arms 4,6 are squeezed together, the leading edge of the leg 36 rides over the bevelled projection 37. As the first hose 34 changes from an open to a closed configuration a "click" is provided which can be felt by the operator to provide an indication that the first hose 34 has opened or closed as the case may be.

Claims

1. A valve device for fitting to a hand held instrument having a wand (29) through which a primary fluid may be withdrawn or supplied, an inlet (25) through which a secondary fluid may be introduced for mixing with the primary fluid, and a flexible hose (34) terminating at the inlet for supplying the secondary fluid to the inlet; the device comprising a body (1) of hairpin shape, one arm (4) of which is arranged to be held on one side of the wand with the other arm (6) spaced from the wand but displaceable towards the first arm against resilient action, and a pinch valve comprising a pair of valve jaws (7,21) between which the flexible hose, in use, passes, the jaws being on respective opposite internal faces of the arms adjacent to the bight of the hairpin shaped body, whereby, in use, deflection of the second arm (6) relatively to the first arm (4) controls the squeezing of the hose (34) by the jaws.

2. A device according to claim l, wherein the hairpin shaped body (1) includes means (15,16,19) for guiding the flexible hose through the bight of the body and between the jaws (23,24).

3. A device according to claim 1 or claim 2, wherein one of the jaws comprises two spaced apart supporting members (11,12) and the other jaw is an L-shape projection (21) which, in use, hooks around the flexible hose (34) and moves in the space (10) between the supports to pull the flexible hose towards the arm (6) on which the L-shaped projection is located deforming the flexible hose into a zig-zag shape and blocking the supply of secondary fluid when the first and second (4,6) arms are resiliently spaced apart.

4. A device according to claim 2 and claim 3, wherein the supporting members (11,12) are provided with holes (15,16) for guiding the flexible hose (34) through the jaws (11,12,21) .

5. A device according to any one of the preceding claims, further comprising a clip (31) which embraces the two arms (4,6) of the body and is slidable thereon, whereby movement of the clip away from the bight of the body forces and holds the arms closer together.

6. A blood-sucking instrument with a tubular wand (2,29) which is arranged to be manipulated by a hand to enable one end of the wand to be introduced into a body cavity, the wand being connected at the other end to a primary hose

(35) which leads, in use, to a source of suction, whereby blood may be drawn, in use, from the body cavity through the wand and primary hose; a device according to any of the preceding claims fitted to the wand; and a flexible secondary hose (34) leading, in use, from a reservoir of anticoagulant to the wand between the jaws (11,12,21) of the device to enable the anti-coagulant to be mixed, in use, with blood drawn through the wand; whereby the metering of the anti-coagulant is controlled by the pinch valve which is located so as to be actuable by the same hand of the user as that holding and manipulating the wand.

7. An instrument according to claim 6, wherein an adapter (3) is provided to join the device to the wand, the adapter being slidably fitted to the one arm (4) of the device and having a cavity (27) which communicates at one end with a socket (28) which receives a tubular spigot (30) on the end of the wand as a press fit and at the other end with two sockets (25,26) each of which receives as a press fit a respective one of the primary hose (35) and secondary hose (34).