Abstract:
A system for controlling anesthetic gases exhausting from anesthetic administering equipment is disclosed. The system is designed so as to regulate the anesthetic gases in a manner which isolates gases and prevents them from escaping into the operating room atmosphere. A manually controllable valve having a rubber diaphragm to control the flow of gases exhausted from the system is disclosed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to systems for administering anesthetic gases in general and more particularly to those systems having means for exhausting the anesthetic gases in a manner which prevents pollution of the operating room atmosphere. 
     2. Description of the Prior Art 
     Numerous anesthetic gas administering systems exist in the prior art. Devices may be either rebreathing or nonrebreathing types. A typical system consists of an anesthesia machine to provide fresh gases to a patient. The machine is operatively connected to the patient via breathing tubes and a face mask. Appropriate one-way valving is provided in the breathing tubes and the system usually contains a gas reservoir such as a breathing bag. The breathing bag may be used by the physician to assist the patient in breathing by rhythmically squeezing the bag. Some breathing bags contain a small vent hole in one side. Others have a small open nipple extending from the end of the bag which may be pinched off. In operation, the physician will open or close this vent hole with his thumb or finger to regulate the volume and pressure within the breathing bag. When the hole in the bag is uncovered and anesthetic gases inevitably escape into the operating room atmosphere, these escaping gases may have an adverse effect on on operating room personnel, particularly after long or frequent exposure. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a manually controllable valve is placed in the side vent hole of the breathing bag and provides means whereby anesthetic gases may be exhausted from the gas administering system and out of the operating room or into a closed container while controlling the flow and simultaneously prohibiting any escape of residual gases into the operating room atmosphere. 
     A principal object of the invention is to provide a system for administering anesthetic gases which prohibits the escape of residual gases into the operating room atmosphere. 
     A further object of the invention is to scavenge anesthetic gases and vapors as they exit from the breathing bag and evacuate such gases in a controlled manner. 
     A further object of the invention is to provide manually controllable means for regulating the pressure and volume of gases in the breathing bag while simultaneously controlling the flow of exhaust gases out of the operating room in a closed system under normal conditions. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features, objects and advantages of the invention will be more apparent from the following detailed description which proceeds with reference to the accompanying drawings, wherein: 
     FIG. 1 shows a typical nonrebreathing anesthetic gas administering system having a manually controllable valve attached to the breathing bag. 
     FIG. 2 is a sectional view taken along Line 2--2 of FIG. 1. 
     FIG. 3 is a plan view of the manually controllable valve partially broken away to show the interior details thereof. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, FIG. 1 shows a source of anesthetic gas 1 which is operatively connected to a face mask 3 via gas supply tube 5. As an alternative to the face mask an endotracheal tube or other suitable device could be used. Face mask 3 is connected to breathing bag 7 via a metal fitting 9 and a flexible breathing tube 11. A manually controllable valve 13 is operatively connected to breathing bag 7 through the vent hole 8 in the bag. Valve 13 is attached to an exhaust gas hose 15 which leads uninterrupted to an exit or external vent source, usually a suction system, outside the operating room. As used here, &#34;outside the operating room&#34; is understood to mean an actual vent which carries the gas to a location physically outside the room or to a closed reservoir or collection system located within the operating room. The important point is that with the system as disclosed the gases are isolated from escape into the operating room atmosphere under normal conditions. 
     Valve 13 is connected to breathing bag 7 through bag vent hole 8 as shown in FIG. 2. The valve consists of a cylindrically shaped hollow body 17. Body 17 is open at the top and defines an outwardly protruding lip 19 at its upper edge. A flexible diaphragm 21 made of a suitable elastomer and having a lip at its outer perimeter encloses the upper end of body 17. A slideable gas inlet port 23 is mounted within valve body 17 and protrudes through hole 25 in the bottom of body 17. Inlet port 23 has an upper flange 27 and a lower flange 29 and is open throughout its entire length to provide a passageway for the flow of exhaust gases from bag 7 into the interior of body 17. Inlet port 23 is moveable along its longitudinal axis and spring-loaded within body 17 by spring 31. This spring 31 must provide a large measure of upward bias in order to clamp and seal bag 7 as will be explained below. A gas exit port 33 consisting of a slightly tapered tubular flange is mounted on body 17 A plurality of ports 35 are cut into the side of body 17. These ports are sealed from the inside with an elastomer flapper 37. 
     OPERATION 
     Valve body 17 is mounted on breathing bag 7 by pressing downward on the upper end of port 23 at flange 27 and forcing flange 29 through the side vent hole 8 of bag 7. After release of downward pressure on slideable port 23 the force of spring 31 compresses the edges of vent hole 8 of bag 7 between flange 29 and the bottom side of valve body 17, thus effectively sealing the side hole of the bag. Tube 15 is connected to exhaust port 33 of valve 13 and attached to an exterior vent which is usually a suction system (not shown). Breathing bag 7 is connected to face mask 3 via tube 11, fitting 9, and to the source of gas 1 via Line 5. Face mask 3 is placed upon patient&#39;s face and the source of gas turned on. The system is now ready for use. As the patient breaths, exhaled anesthetic gas and vapors move from the face mask 3 down through tube 11 and into breathing bag 7. Gas flowing into bag 7 flows upward through inlet port 23 into the interior of valve body 17 and on out through exit port 33, tube 15, and out of the operating room or into an alternate closed collection system. Now, if the physician wishes to increase the pressure and/or volume of anesthetic gases in breathing bag 7, he merely presses a finger downward upon flexible diaphragm 21, either partially or completely, closing off the upper end of inlet port 23 throttling the flow of exhaust gases out of the system. Closing off the flow of gas from out of the system will result in an increase in volume and pressure within bag 7. The physician may assist the patient in breathing by rhthymically squeezing the bag 7. He may simultaneously control the volume and pressure in the bag 7 by manually pressing diaphragm 21 against all or part of the upper end of inlet port 23. Fingertip control of the flow of gases exhausted from the system is thus provided. 
     In the event that negative pressure develops in valve body 17, collapse of bag 7 is prevented, as the drop in pressure in the interior of valve body 17 will cause flapper 37 to move away from ports 35 and air from the operating room atmosphere will flow into valve body 17 through holes 35. In an alternate construction without ports 35 and flapper 37 development of negative pressure in body 17 will cause diaphragm 21 to collapse against gas inlet port 23 and seal off the flow of gas. 
     Having described the preferred embodiment of my invention, it will be apparent to those skilled in the art that modifications and changes could be made in the design without departing from the spirit and scope of my invention.