Respiratory face mask and breathing circuit assembly

1. A breathing circuit apparatus for use with a face mask, the fresh gas output of a gas delivery device, and a vacuum source, comprising:

a main tubular limb, a branched coupling, and a scavenging limb;

said main tubular limb having opposed first and second ends;

said main tubular limb defining a gas supply lumen of first diameter and an exhalation lumen of second diameter disposed co-axially with respect to said first diameter lumen along substantially the entire length thereof;

said first end of said main tubular limb in fluid communication with a gas coupling member for removable attachment to said face mask;

said branched coupling being attached to said second opposed second end of said main tubular limb and defining a main tubular limb connection port, a gas supply connection port and a scavenging limb connection port;

said branched coupling including a first gas flow passage extending between said main limb connection port and said fresh gas supply port for supplying fresh gas to said main limb gas supply lumen and a second gas flow passage extending between said main limb connection port and said scavenging limb connection port for receiving exhaled waste gas from said face mask through said gas coupling member and said main limb exhalation lumen;

said scavenging limb further including a one-way valve, a flexible exhalation bag, and a scavenging tube;

said flexible exhalation bag having an entry opening and an exit opening, said one-way valve being disposed in said scavenging limb between said branched coupling scavenging limb connection port and said entry opening of said flexible exhalation bag such that said entry opening is connected to said branched coupling scavenging limb connection port through said one-way valve, permitting unidirectional flow of exhaled waste gas from said face mask through said branched coupling scavenging limb connection port into and through said entry opening; and

said scavenging tube connected to said exit opening for conveying to said vacuum source exhaled waste gas received in said flexible exhalation bag from said branched coupling scavenging limb connection port through said one-way valve;

said exhaled waste gas being evacuated from the environment surrounding a patient when said breathing circuit apparatus is disposed in fluid communication between said face mask, said gas delivery device and said vacuum source and said patient breathes through said mask and said breathing circuit;

said breathing circuit apparatus being disposable after a single-use to avoid cross-contamination from one patient to another.

2. The apparatus of claim 1 further comprising:

a vacuum modulating valve for modulating the vacuum produced by said vacuum source to prevent collapse of said flexible exhalation bag;

said vacuum modulating valve disposed in said scavenging tube portion of said scavenging limb.

3. The apparatus of claim 2 , further comprising:

said vacuum modulating valve for modulating the vacuum produced by said vacuum source including an outer tube having a first diameter and an inner tube having a second diameter, said first diameter being greater than said second diameter;

at least one opening formed in said vacuum modulating valve enabling ambient air to enter said outer tube and to flow through said inner tube;

said inner tube adapted to be connected to said vacuum source.

4. The apparatus of claim 3 wherein said outer tube of said vacuum modulating valve is connected distally to said scavenging tube, and a supplemental flexible vacuum-connecting tube is connected to said inner tube of second diameter for ultimate connection to said vacuum source.

5. The apparatus of claim 3 wherein said vacuum modulating valve is fabricated of one-piece plastic molded material.

6. The apparatus of claim 1 , further comprising:

said disposable face mask being adapted to cover at least the nose and mouth of said patient.

7. The apparatus of claim 6 , further comprising:

said disposable face mask adapted to engage said underside of the patient's chin; and

said disposable face mask including a sealing cushion adapted to engage said underside of said patient's chin.

8. The apparatus of claim 7 , further comprising:

a kit of disassembled parts;

said disassembled parts including said breathing circuit and said disposable face mask.

9. The apparatus of claim 1 , further comprising:

said gas being selected from a group of gases including nitrous oxide, oxygen, or mixtures of nitrous oxide and oxygen.

10. The apparatus of claim 1 wherein said main tubular limb is fabricated of flexible corrugated plastic material.

11. The apparatus of claim 1 wherein said scavenging tube is fabricated of flexible plastic material.

12. The apparatus of claim 1 wherein said flexible exhalation bag has a first end and an opposed second end, said first entry opening being located in said first end and said second exit opening being located in said second opposed end;

wherein said first entry opening in said first end is connected to said one-way valve, permitting unidirectional flow of exhaled waste gas from said face mask through said branched coupling scavenging limb connection port into and through said first entry opening of said flexible exhalation bag; and

wherein said second exit opening in said opposed second end of said flexible exhalation bag is connected to said scavenging tube.