# US 5,345,928 A · System arrangement for the evacuation of anaesthesia or analgesia gas

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- Number: US 5,345,928 A
- Document ID: US5345928A
- Status: Granted
- Kind: A
- Application number: 07/910,035
- Filed: 1992-08-06
- Granted: 1994-09-13
- Earliest claimed: 1990-02-07
- Assignees: Medicvent AB; Berner International Corporation
- Inventors: Allan Lindkvist
- Web page: https://patentgrep.com/patent/US5345928A

## CPC

- A61M 16/009: {Removing used or expired gases or anaesthetic vapours (filtering, sterilising or disinfecting the exhaust air in drainage systems A61M1/784; bacterial filters in the expiratory path A61M16/1065)}
- A61M 2205/42: Reducing noise
- Y10S 128/91: Anesthesia gas scavenging system
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A system for collecting and removing leaking anesthesia or analgesia gas from an anesthesia apparatus in an operation theater or the like includes a vacuum source (1) and an anesthesia mask (5) adapted to be placed onto the face of a patient and connected to the anesthesia apparatus by at least one supply and removing device, through which the patient is supplied with a mixture of anesthesia or analgesia gas and air and through which air-gas mixture exhaled by the patient is removed, and a vacuum line (4) connected to the anesthesia mask for removing leaking gas to the vacuum source. A T-shaped joint (10) is connected in the vacuum line (4) and has one opening connected by a branch line (11)to the supply and removing device for removing exhaled gas-air mixture via the vacuum source. A noise damping or reducing device (18) is arranged in the vacuum line to reduce disturbing noise as far as possible. A flow regulator device (19, 20, 21) is provided for controlling the evacuation capacity according to the demand in order to reduce both noise and cooling effect.

## Claims

### Claim 1

A system for collecting and removing anesthesia from an anesthesia device in operation theaters comprising:
an anesthesia gas source;
a vacuum source;
a mask device adapted to be applied to the face of a patient and having collecting means for collecting and removing anesthesia gas leaking out and escaping during operation of said system;
at least one supply and removing means communicating said anesthesia gas source and air to said mask device for supplying a mixture of said anesthesia gas and air to said patient and for removing anesthesia gas and air mixture exhaled by said patient;
a vacuum line connected between said vacuum source and said collecting means on said mask device for conducting said anesthesia gas collected by said collecting means to said vacuum source;
a T-shaped joint in said vacuum line having two aligned openings connected to said vacuum line so that a flow path is produced between said aligned openings;
a third opening in said T-shaped joint;
a branch line connecting said third opening to said at least one supply and removing means for conducting therefrom exhaled gas-air mixture to said T-shaped joint and said vacuum source; and
ejector means in said third opening of said T-shaped joint for producing a vacuum in said branch line differing from said vacuum in said vacuum line.

### Claim 2 (depends on 1)

The system as claimed in claim 1 wherein:
said ejector means comprises a throttling means in said T-shaped joint communicating said branch line with said vacuum line.

### Claim 3 (depends on 1)

The system as claimed in claim 1 wherein:
said ejector means comprises an tubular nozzle affixed to said third opening of said T-shaped joint and having an obliquely cut inner end projecting into said flow path between said first and second openings in said T-shaped joint.

### Claim 4 (depends on 3)

The system as claimed in claim 3 wherein:
said aligned openings in said T-shaped joint have a common central axis; and
said inner end of said nozzle extends substantially to said central axis.

### Claim 5 (depends on 1)

The system as claimed in claim 1 and further comprising:
an upstream end on said vacuum line connected to said mask device; and
throttling means attached to said upstream end of said vacuum line.

### Claim 6 (depends on 5)

The system as claimed in claim 5 and further comprising:
a control device connected to said branch line for limiting the volume capacity of said branch line to a given value.

### Claim 7 (depends on 5)

The system as claimed in claim 5 wherein:
said throttling means comprises said collecting means of said mask device.

### Claim 8 (depends on 1)

The system as claimed in claim 1 and further comprising:
a box shaped air-tight casing having an inlet and an outlet connected in said vacuum line between said collecting means of said mask device and said vacuum source so that said leaking and escaping anesthesia collected by said collecting means flows through said air-tight casing, said air-tight casing having an effective flow area significantly larger than the effective flow area of said vacuum line for damping noise in said system.

### Claim 9 (depends on 8)

The system as claimed in claim 8 wherein:
said vacuum source comprises a fan unit;
said T-shaped joint is between said mask device and said air-tight casing; and
said air-tight casing is between said T-shaped joint and said fan unit.

### Claim 10 (depends on 9)

The system as claimed in claim 9 wherein:
said flow regulator is operatively connected to said fan unit for controlling the speed of said fan unit.

### Claim 11 (depends on 8)

The system as claimed in claim 8 wherein:
said inlet and outlet of said air-tight casing are offset with respect to each other.

### Claim 12 (depends on 11)

The system as claimed in claim 11 wherein:
said inlet and outlet are disposed at the same side of said air-tight casing.

### Claim 13 (depends on 8)

The system as claimed in claim 8 and further comprising:
a volumetric flow regulator in said vacuum line for controlling the volumetric flow in said vacuum line;
a set of masks comprising a plurality of masks each having a different size adapted to the size of a respective patient; and
switch means operatively connected to said flow regulator and adapted to be switched to different positions corresponding to said different mask sizes for adapting said volumetric flow to said different mask sizes.

### Claim 14 (depends on 13)

The system as claimed in claim 13 wherein:
said aligned openings in said T-shaped joint have a common central axis; and
said inner end of said nozzle extends substantially to said central axis.

### Claim 15 (depends on 14)

The system as claimed in claim 14 wherein:
said vacuum source comprises a fan unit; and
said flow regulator is operatively connected to said fan unit for controlling the speed of said fan unit.

### Claim 16 (depends on 14)

The system as claimed in claim 14 wherein;
said vacuum source comprises a fan unit;
said T-shaped joint is between said mask device and said air-tight casing; and
said air-tight casing is between said T-shaped joint and said fan unit.

### Claim 17 (depends on 1)

The system as claimed in claim 1 and further comprising:
a volumetric flow regulator in said vacuum line for controlling the volumetric flow in said vacuum line;
a set of masks comprising a plurality of masks each having a different size adapted to the size of a respective patient; and
switch means operatively connected to said flow regulator and adapted to be switched to different positions corresponding to said different mask sizes for adapting said volumetric flow to said different mask sizes.

### Claim 18 (depends on 17)

The system as claimed in claim 17 wherein:
said volumetric flow regulator has minimum flow positions, maximum flow positions, and intermediary flow positions between said minimum and maximum flow positions, for controlling the volumetric flow in said vacuum line, said different positions of said switch means comprise one extreme position corresponding to said minimum flow, another extreme position corresponding to said maximum flow, and intermediate positions between said extreme positions corresponding to said intermediary flows.

### Claim 19 (depends on 17)

The system as claimed in claim 17 wherein:
said vacuum source comprises a fan unit; and
said flow regulator is operatively connected to said fan unit for controlling the speed of said fan unit.