Exhaust port assembly for a pressure support system

1. An exhaust port assembly comprising:

a conduit having a first end and a second end and adapted to carry a flow of gas, wherein the conduit is generally cylindrical shaped; and

venting means, disposed between the first end and the second end of the conduit and having a fixed area, for venting a flow of exhaust gas from within the conduit to ambient atmosphere while 1) minimizing noise associated with the flow of exhaust gas passing to atmosphere, 2) diffusing the flow of exhaust gas passing to ambient atmosphere over a relatively large area, and 3) minimizing the area occupied by the venting means on the conduit, wherein the venting means comprises an opening defined in the conduit and a cap disposed in a fixed position over the conduit such that the cap does not move relative to the conduit during changes in pressure within the conduit, and having substantially the same width as the opening, wherein the cap overlies the opening so that a gap is defined between an edge of the cap and an edge of the opening, and wherein the gap extends a first length along at least a portion of the conduit, and wherein the opening is an arcuate slot having a length that extends around at least a portion of a perimeter of the conduit.

2. The exhaust port assembly of claim 1 , further comprising a cap attaching assembly adapted to selectively attach the cap to the conduit.

3. The exhaust port assembly of claim 1 , wherein the cap and the conduit are sized and configured such that the gap is not larger than 0.020 in.

4. The exhaust port assembly of claim 1 , wherein an edge of the cap, an edge of the conduit, or both defining the gap are chamfered.

5. A pressure support system comprising:

a) a pressure generating system adapted to generate a flow of breathing gas;

b) a patient circuit having a first end coupled to the pressure generating system and a second end, wherein the conduit is adapted to carry the flow of gas;

c) a patient interface device adapted to communicate the flow of breathing gas to an airway of a patient; and

d) an exhaust port assembly associated with the patient circuit, the exhalation port assembly comprising:

1) a conduit having a first end coupled to the patient interface device and a second end and adapted to be coupled to the patient circuit so that the conduit is disposed in-line in the patient circuit, wherein the conduit is generally cylindrical shaped; and

2) venting means, disposed between the first end and the second end of the conduit and having a fixed exhaust area, for venting a flow of exhaust gas from within the conduit to ambient atmosphere while (i) minimizing noise associated with the flow of exhaust gas passing to atmosphere, (ii) diffusing the flow of exhaust gas passing to ambient atmosphere over a relatively large area, and (iii) minimizing the area occupied by the venting means on the conduit, wherein the venting means comprises an opening defined in the conduit and a cap disposed in a fixed position over the opening such that the cap does not move relative to the conduit during changes in pressure within the conduit, and having substantially the same width as the opening, wherein the cap overlies the opening so that a gap is defined between an edge of the cap and an edge of the opening, wherein the gap extends a first length along at least a portion of the conduit, and wherein the opening is an arcuate slot having a length that extends around at least a portion of a perimeter of the conduit.

6. The system of claim 5 , wherein the cap and the conduit are sized and configured such that the gap is not larger than 0.020 in.

7. The system of claim 5 , wherein an edge of the cap, an edge of the conduit, or both defining the gap are chamfered.

8. An exhaust port assembly comprising:

a conduit having a first end and a second end and including an opening defined in the conduit between the first end and the second end, wherein the conduit is generally cylindrical shaped; and

a cap disposed in a fixed position over the opening such that the cap does not move relative to the conduit during changes in pressure within the conduit, and having substantially the same width as the opening, wherein the cap overlies the opening so that a gap is defined between an edge of the cap and an edge of the opening, wherein the gap extends a first length along at least a portion of the conduit, and wherein the opening is an arcuate slot having a length that extends around at least a portion of a perimeter of the conduit.

9. The exhaust port assembly of claim 8 , further comprising a cap attaching assembly adapted to selectively attach the cap to the conduit.

10. The exhaust port assembly of claim 8 , wherein the cap and the conduit are sized and configured such that the gap is not larger than 0.020 in.

11. The exhaust port assembly of claim 8 , wherein an edge of the cap, an edge of the conduit, or an edge of both the cap and the conduit defining the gap are chamfered.