WO1985001559A1

WO1985001559A1 - Anaesthetic apparatus and a valve assembly therefor

Info

Publication number: WO1985001559A1
Application number: PCT/AU1984/000189
Authority: WO
Inventors: Andy Roussos
Original assignee: Andy Roussos
Priority date: 1983-09-30
Filing date: 1984-10-01
Publication date: 1985-04-11
Also published as: GB2172206B; EP0188423A1; GB2172206A; AU560885B2; GB8602572D0; AU3439684A

Abstract

A valve assembly (10) for anaesthetic apparatus has a first and second valve bodies (11, 12) fitted with respective first and second valve members (19, 30). Each valve member (19, 30) is a plug valve, rotatably mounted on its respective valve body (11, 12) having a diametrical bore (22, 31) and radial passage (23, 32) which operatively connects the inlet (16, 24) of the valve bodies (11, 12) to one or both of the outlets (17, 18; 25, 27) of the bodies. A lost motion mechanism (33) interconnects the valve members (19, 30) so that when the first valve member (19) is rotated by the lever (20) through 180o, the second valve member (30) will be rotated through 90o after the initial 90o rotation of the first valve member (19) in either direction. The valve assembly (10) is fitted to the anaesthetic apparatus for operation in either the controlled (Mapleson D/E) ventilation or spontaneous (Mapleson A) ventilation.

Description

Title: "ANAESTHETIC APPARATUS AND A VALVE ASSEMBLY

THEREFOR" BACKGROUND OF THE INVENTION (1 ) Field of the Invention This invention relates to anaesthetic apparatus and to a valve assembly. (2) Prior Art

Most surgical operations are now carried out with the patient undergoing either controlled breathing or spontaneous breathing. The apparatus for such breat ing is well-known and has been generally classified as Mapleson A (or McGill) for spontaneous breathing and Mapleson D (or Bain) for controlled breathing, the latter relying on a mechanical ventilator. (For childr controlled breathing is effected using equipment classi ied as Mapleson E which basically varies only from Mapl son D in the type of mouthpiece used).

Previously two different types of equipment are required for the different classifications but it is no possible to obtain equipment which can be operated unde both classifications. The major problem is that such equipment incorporates at least two valves which must b separately operated to ensure that the equipment config ures for each classification, (e.g. see European Patent Publication No. 0047185 by David Humphrey).

SUMMARY OF THE PRESENT INVENTION It is an^' object to provide a valve assembly for -anaesthetic apparatus which can rapidly change the apparatus from Mapleson A to Mapleson D/E configuration. It is a preferred object to provide such a valve assembly which has a single central handle or lever to effect the conversion.

It is a further preferred object to provide a valve assembly which can be effectively locked in either configuration. It is a still further preferred object- to provide anaesthetic apparatus incorporating the valve assembly.

In one aspect the present invention resides in a valve assembly for anaesthetic apparatus including: a first valve body having an inlet, an outlet and a port; a first valve member in the first valve body operable between a first position and a second position to interconnect the inlet and the outlet, or the inlet, the outlet .and the port, respectively; a second valve body having an inlet, a first outlet and a second outlet; a second.valve member in the second valve bod operable between a first position and a second position to interconnect the inlet to the first and second outlets, or the inlet and the second outlet, respectively; means to move one of the valve members betwee its respective first and second positions; and a lost motion connection between the first an second valve members to cause the other of the valve membe to move between its first and second positions after initi movement of the one valve member.

Preferably the first and second valve bodies ar provided in'a main valve body, with no communication betwe the valve bodies.

Preferably both the first and second valve memb ar^"e plug valves with a diametrical bore and a radial passa connected to the bore. Alternatively, the second valve member is a plug valve with an elbow-shaped bore i.e. the bore has two radially extending legs at right angles.

Preferably the means to operate the valve assembly includes a handle or lever connected to the first valve member. Preferably the handle or lever is releasabl locked in its respective position e.g. by a pin or detent, ball and socket or like arrangement.

Preferably the lost motion connection includes a peg on one valve membe^'r engageable in a slot in the other valve member, a peg on one valve member engageable between a pair of pegs or abutments on the other valve member, or a block or abutment on one valve member engag eable with a block or abutment on the other valve member Preferably one valve member is rotatable through 180°, a the other valve member is rotatable through 90°, the los motion being operable for the first 90°of rotation of th one valve member in either direction.

In a second aspect the present invention resid in anaesthetic apparatus including: a valve assembly as hereinbefore described; a fresh gas supply connected to the inlet of the first valve body; an inspiratory tube or hose connected to the outlet of the first valve body; a reservoir bag connected to the port of the first valve body; an expiratory tube or hose connected to the inlet of the second valve body; a mouth piece interconnecting the inspirator and expiratory tubes or hoses; a ventilator connected to the first outlet o the second valve body; and an_. expiratory or blow-off valve connected to the second valve body, the first and second valve members being movable from their respective first position for controlled ventilation of a patient and their respective second position for spontaneous ventilation of the patien

With the valves in their first positions, the apparatus operates a a Mapleson D or E (or Bain) type apparatus dependent on the mouthpiece being used. With the valves in their second positions, the apparatus opera

™° -li¬ es on a Mapleson A or Magill-type apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a number of preferred embodiments will now be described with reference to the accompanying drawings, in which:-

FIG. 1 is a perspective view of the anaesthetic apparatus arranged for controlled (Mapleson D) ventilatio FIG. 2 is a sectional view showing the respecti position of the first and second valve members for controlled ventilation;

FIG..3 is a perspective view of the apparatus arranged for spontaneous (Mapleson A) ventilation;

FIG. 4 is a sectional view, corresponding to FIG. 2, for spontaneous ventilation; FIG. 5 is a front exploded view of the valve;

FIG. 6 is an end view of one embodiment of the two valve members taken on line X-X, X-Y respectively;

FIG. 7 is an end view corresponding to FIG. 6 o a second embodiment; and FIG. 8 is an end view corresponding to FIG. 6 o a third embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1, 3 and 5, the valve assemb 10 has a first valve body 11 and a second valve body 12 connected by a housing 13, the three components having a common plain bore 14 closed at one end by a wall (not shown) and at the other end by a screw-threaded removable plug 15.

- The first body 11 has an inlet 16 and an outlet 17 which are diametrically opposed, and a port 18 extend¬ ing from the underside of the body, the inlet, outlet and port all being in communication with the bore.

A first valve member 19 is rotatably mounted in the bore 14. The member is in the form of a plug valv which is rotated by a handle or lever 20 via an extension shaft 21 which extends through the plug 1 . A diamm- etrical bore 22 is provided through the valve member and a radial branch passage 23 is connected thereto. In the first position of the valve member 19, the bore 22 inter connects the inlet 16 and outlet 17, while in the second position, the bore 22 and passage 23 interconnect the inlet 16, outlet 17 and port 18.

The second valve body 12 has an inlet 24 aligned with the outlet 17 of the first valve body. A first outlet 25 extends downwardly from the valve body 1 and a "blow-off" or expiratory■valve 26 is fitted to the second outlet 27 diametrically opposed to the first outl The blow-off pressure of the expiratory valve 26 is con¬ trolled by a knurled knob 28, the gas released passing through an exhaust outlet 29.

The second valve member 30 , which is also a pl valve, is rotatably mounted in the bore 14 and has a diametrical bore 31 and a radial branch passage 32.

When the second valve member 30 is in its firs position, the inlet 24 and first and second outlets 25, are interconnected, while the inlet 24 and the second outlet 27 ( and the expiratory valve 26) are interconnec ed when the second valve member 30 is in its second position. Referring to FIG. 6, the two valve members 19,

30 are interconnected by a lost motion mechanism 33- A semi-circular block or abutment 34 extends from the inne face of the first valve member 19, while a quarter-.circul block 35 extends from the inner face of the second valve member 30.

When the lever 20 is in its first position, the upper faces of the blocks 34, 35 abut each other. When the locking pin 36 on the lever 20 is released and the lever is' rotated, the first valve member 19 is rotated through 90° until the lower faces of the blocks 34, 35 abut each other. Further rotation of the first valve member 19 through 90° (for a total of 180°), cause the second valve member 30 to be rotated through 90 so that both valve members are in their respective second positions. (The rotation of the respective valve member 19, 30 is illustrated in FIGS. 2 (first position) and 4 (second position) respectively).

In a second embodiment, FIG. 7, a pair of pins 36, 37 extend from the inner face of the first valve member 19 and are spaced approximately 90 apart to receive and engage a pin 38 on the adjacent inner face of the second valve member. When the valve members are in their respective first positions, the pin 38 abuts pin 37. As the first valve member 19 is rotated through 90 by the lever 20, the second valve member does not rotate until the pin 38 engages pin 36. Further rotatio of the first valve member through 90° (i.e. to a maximum of 180°) now rotate the second valve member through 90° so that both are now in their respective second position When the first valve member is returned to its first position, the lost motion mechanism 33 again only rotate the second valve member 90° fo^'r the 180° rotation of the first valve member.

In a further modified embodiment (see FIG. 8), the pin 37 may be engaged on the second valve member 30 in a 180° slot 40 in the inner end of the first valve member 19. In use, the inlet 16 is connected to a fresh gas supply (FGS) (not shown), the outlet 17 to an inspir atory pipe 41-, the port 18 to a reservoir bag 42, the inlet 24 to an expiratory pipe 43, the first outlet 25 to a ventilator (not shown) and the second outlet 27 to the expiratory valve 26 (the exhaust outlet 29 of the latter being connected to the extension of the- operating room by a hose). A mouthpiece 44 is provided at the upp ends of the inspiratory and expiratory pipes 41 , 43 to b received by the patient.

For controlled ventilation, the lever 20 is rotated to move both valve members to their first positions (see FIG. 2) while for spontaneous ventilation the lever is rotated and both valve members are moved to their second positions (see FIG. 4). As one lever moves both valves, the anaesthetist is always sure that the two valves are in their correct positions. The spring loaded lock pin 36 is provided on the lever to lock it in either position to ensure both valve members are full home.

Referring to FIGS. 1 and 2, for controlled (Mapleson D) ventilation, the gas enters the first valve member and passes through the inspiratory pipe 41 and the expiratory pipe 43 and is directed to the ventilator connected to the first outlet 25 by the second valve member 30, the expiratory valve 26 being closed. When the ventilator has drawn the required volume of gas e.g. 1 litre, it pumps the gas back along the expiratory pipe 43 to the mouthpiece 44 and thereby to the patent , the gas pressure in the inspiratory pipe 42 limiting its flow along the latter. As the ventilator draws the stale gas from the patient, fresh gas enters via the inspiratory pipe and the CO- laden gas is expelled via the ventilator When the manually operated bag is used to control the ventilator of the patient instead of the mechanical vent¬ ilator, the expiratory valve 26 is partially opened to limit the gas pressure pumped to the patient's lungs via the expiratory pipe 43. Referring now to FIGS. 3 and 4 for spontaneous

(Mapleson A) ventilation, the valve members 19, 30 are rotated to their second positions. The reservoir bag 42 is connected to the fresh gas supply (FGS) by the branch passage 23 in the first valve member 19 while only the second outlet 27 (and the expiratory valve 26) are

WIPO connected to the inlet 24 of the second valve member 30. The expiratory valve 26 is fully opened and so the fresh gas enters the inspiratory pipe 42, is breath¬ ed in by the patient and exhaled out through the expir- atory pipe 43 and exhausted via the expiratory valve 26. In a modified embodiment of the valve, the second valve member 30 may have an elbow shaped bore, with perpendicular legs, replacing the diametrical bore 31 and branch passage 32, the wall of the elbow shaped bore being indicated by the dashed lines 45 on FIG. 4. For controlled ventilation ( by a mechanical ventilator only), the inlet 24 is only connected to the first outlet 25 and the expiratoryvalve 26 is isolated, while for spontaneous ventilation, the inlet 24 is only connected to the expiratory valve 26.

To ensure that the whole valve 10 can only be assembled one way, pegs 46 and sockets 47 may be provid on the respective components in preset rating patterns and the locking pin 36 can only engage suitable detents 48 in the plug 15 when the lever 20 is fully raised

(controlled ventilation) or lowered (spontaneous ventil ation) .

The invention provides a simple, yet efficient and foolproof means for controlling_^ the ventilation of patients and ensures that the patient is properly venti ated at all times.

It will be readily apparent to the skilled addressee that various changes and modifications may be made to the embodiments described without departing fro the scope of the present invention as defined in the appended claims.

Claims

1. A valve assembly for anaesthetic apparatus including: a first valve body having an inlet, an outlet and a port; a first valve member in the first valve body operable between a first position and a second position to interconnect the inlet and the outlet, or ^' the inlet, the outlet and the port, respectively, a second valve body having an inlet, a first outlet and a second outlet; a second valve member in the second valve body operable between a first position and a second position to interconnect the inlet to the first and second outlets, or the inlet and the second outlet respectively; means to move one of the valve members between its respective first and second positions; and a lost motion connection between the first and second valve members to cause the other of the valve members to move between its first and second positions after initial movement of the one valve member.

2. A valve assembly as claimed in Claim 1 wherein: the first and second valve bodies are provided in a main valve body with no communication between the first and second valve bodies.

3. A valve assembly as claimed in Claim 1 wherein: the first valve member is a plug valve with a diametrical bore and a radial passage connected to the bore.

4. A valve assembly as claimed in Claim 1 wherein: the second valve member is a plug valve with a diametrical bore and a radial passage connected to the bore, or a plug valve with an elbow shaped bore having radially extending legs at right angles.

5. ^"A valve assemb-ly as claimed in Claim 1 wherein: the means to operate the valve assembly includes a handle or lever connected to the first valve member; and locking means releasably locks the handle or lever in the first and second position of the valve member.

6. A valve assembly as claimed in ^"Claim 1 wherein the lost motion connection includes : a peg on one valve member engageable with a slot on the other valve member, a peg or pin on one valve member engagable between a pair of pegs or pins on the other valve member; or a block or abutment on one valve member engagable with a block or abutment on the other valve member.

7. A valve assembly as claimed in Claim 6 wherein: the first valve member is rotatable ^'through 180 and the second valve member is rotatable through 90 , the lost motion being operable for the first 90° of rotation of the first valve member in either direction

8. An anaesthetic apparatus including a valve assembly as claimed in Claim 1 ; a fresh gas supply -connected to the inlet of the first valve body; an inspiratory tube or hose connected to the outlet of the first valve body; a reservoir bag connected to the port of the first valve body; an expiratory tube or hose connected to the inlet of-the second valve body; a mouth piece interconnecting the inspirat¬ ory and expiratory tubes or hoses; a ventilator, connected to the first outlet of the second valve body; and an expiratory or blow-off valve connected to the second valve body, the first and second valve members being movable from their respective first position for controlled ventilation of a patient and their respective second position for spontaneous ventil¬ ation of the patient.

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