1461027951-fdbbe6b4-1bcf-46ed-8943-12cefc83b044

1. A method for preparing an oxazolidinone derivative of Formula (I):
or a pharmaceutically acceptable salt thereof

wherein,
R1 and R\u20321 are independently hydrogen or fluorine;
R2 is \u2014NR5R6, \u2014OR7, fluorine, alkylphosphate, monophosphate or a metal salt of monophosphate;
R5 and R6 are independently hydrogen or C1-4 alkyl;
R7 is C1-3 alkyl or acylated amino acid, wherein the amino acid is alanine, glycine, proline, isoleucine, leucine, phenylalanine, \u03b2-alanine or valine;
R3 is hydrogen, C1-4 alkyl group that is unsubstituted, or substituted with cyano, \u2014(CH2)m\u2014OR7 or ketone; and
m is 0, 1, 2, 3, or 4;
wherein the method comprises:
reacting the R2 hydroxy group of Formula (V)
under conditions selected to give R2 selected from the group consisting of \u2014NR5R6, \u2014OR7, fluorine, alkylphosphate, monophosphate and a metal salt of monophosphate.
4. The method of claim 3,
wherein the alkylphosphate is ditetrabutylester.
5. The method of claim 3, further comprising
reacting the compound of Formula (I), wherein R7 is the acylated amino acid, with an acid under conditions selected to form a pharmaceutically acceptable salt.
6. The method of claim 3, wherein the acid is hydrochloric acid or trifluoroacetic acid.
7. The method of claim 3, wherein the reacting step comprises reacting the compound of Formula (V) with phosphorous oxy chloride to give the compound of Formula (I) wherein R2 is monophosphate.
8. The method of claim 3, wherein the reacting step comprises reacting the compound of Formula (I) wherein R2 is monophosphate with a metallic salt to give the compound of Formula (I) wherein R2 is a metal salt of the monophosphate or a disodium salt of the monophosphate.
9. The method of claim 3, wherein R1 is hydrogen and R1\u2032 is fluorine.
10. The method of claim 3, wherein R2 is \u2014OR7 and R7 is the acylated amino acid.
11. The method of claim 3, wherein R2 is selected from the group consisting of alkylphosphate, monophosphate and a metal salt of the monophosphate.
12. The method of claim 3, wherein R3 is methyl.
13. The method of claim 3, wherein the compound of Formula (I) is selected from the group consisting of
Compound 12) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one trifluoroacetic acid;
Compound 18) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-fluoromethyl oxazolidin-2-one;
Compound 20) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 33) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-methoxymethyl oxazolidin-2-one;
Compound 38) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3,5-difluorophenyl)-5-hydroxymethyl oxazolidin-2-one;
Compound 40) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(N,N-dimethylaminomethyl)oxazolidin-2-one;
Compound 41) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(N-methylaminomethyl)oxazolidin-2-one;
Compound 42) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 43) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 44) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 45) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one hydrochloride;
Compound 46) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-prolinyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 47) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-prolinyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 49) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 50) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 59) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethyl disodiumphosphate;
Compound 61) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-hydroxymethyl oxazolidin-2-one;
Compound 62) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one trifluoroacetic acid;
Compound 63) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one hydrochloride;
Compound 64) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 65) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 66) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 67) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 68) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 69) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 70) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethyl disodiumphosphate;
Compound 72) mono-(R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethylphosphate; and
Compound 73) mono-(R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethylphosphate.
14. The method of claim 3, wherein the compound of Formula (I) has the structure
wherein R2 is an alkylphosphate, a monophosphate, or a metal salt of the monophosphate.
15. The method of claim 14, wherein the compound has R stereochemistry.
16. The method of claim 3, wherein the compound of Formula (I) has the structure
wherein R2 is an alkylphosphate, a monophosphate, or a metal salt of the monophosphate.
17. The method of claim 16, wherein the compound has R stereochemistry.
18. The method of claim 3, wherein the compound of Formula (I) has the structure
wherein R2 is an alkylphosphate, a monophosphate or a metal salt of the monophosphate.
19. The method of claim 18, wherein the compound has R stereochemistry.
20. The method of claim 3, wherein the compound of Formula (I) has the structure
wherein R2 is an alkylphosphate, a monophosphate, or a metal salt of the monophosphate.
21. The method of claim 20, wherein the compound has R stereochemistry.
22. The method of claim 3, wherein the compound of Formula (I) is
23. The method of claim 3, wherein the compound of Formula (I) is
24. An oxazolidinone derivative of Formula (I), or a pharmaceutically acceptable salt thereof:
wherein,
R1 and R\u20321 are independently hydrogen or fluorine;
R2 is \u2014NR5R6, \u2014OR7, fluorine, alkylphosphate, monophosphate or a metal salt of phosphate;
R5 and R6 are independently hydrogen or C1-4 alkyl;
R7 is hydrogen, C1-3 alkyl or acylated amino acid, wherein the amino acid is alanine, glycine, proline, isoleucine, leucine, phenylalanine, \u03b2-alanine or valine;
R3 is hydrogen, C1-3 alkyl group that is unsubstituted, or substituted with cyano, \u2014(CH2)m\u2014OR7 or ketone; and
m is 0, 1, 2, 3, or 4.
25. The compound of claim 24, wherein R1 is hydrogen and R1\u2032 is fluorine.
26. The compound of claim 24, wherein R2 is \u2014OH.
27. The compound of claim 24, wherein R2 is \u2014OR7 and R7 is the acylated amino acid.
28. The compound of claim 24, wherein R2 is selected from the group consisting of alkylphosphate, monophosphate and a metal salt of the monophosphate.
29. The compound of claim 24, wherein R3 is methyl.
30. The compound of claim 24, wherein the pharmaceutically acceptable salt is formed with an acid selected from the group consisting of hydrochloric acid, bromic acid, sulfuric acid, phosphoric acid, citric acid, acetic acid, lactic acid, maleic acid, fumaric acid, gluconic acid, methane sulfonic acid, glyeonic acid, succinic acid, 4-toluenesulfonic acid, trifluoroacetic acid, galuturonic acid, embonic acid, glutamic acid and aspartic acid.
31. The compound of claim 30, wherein the acid is hydrochloric acid or trifluoroacetic acid.
32. The compound of claim 24, which is selected from the group consisting of
Compound 10) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-hydroxymethyl oxazolidin-2-one;
Compound 12) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one trifluoroacetic acid;
Compound 18) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-fluoromethyl oxazolidin-2-one;
Compound 20) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 33) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-methoxymethyl oxazolidin-2-one;
Compound 38) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3,5-difluorophenyl)-5-hydroxymethyl oxazolidin-2-one;
Compound 40) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(N,N-dimethylaminomethyl)oxazolidin-2-one;
Compound 41) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(N-methylaminomethyl)oxazolidin-2-one;
Compound 42) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 43) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 44) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 45) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one hydrochloride;
Compound 46) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-prolinyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 47) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-prolinyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 49) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 50) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 59) (R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethyl disodiumphosphate;
Compound 61) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-hydroxymethyl oxazolidin-2-one;
Compound 62) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one trifluoroacetic acid;
Compound 63) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-glycyloxymethyl oxazolidin-2-one hydrochloride;
Compound 64) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 65) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 66) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 67) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(L-valyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 68) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one trifluoroacetic acid;
Compound 69) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-(\u03b2-alanyloxy)methyl oxazolidin-2-one hydrochloride;
Compound 70) (R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethyl disodiumphosphate;
Compound 72) mono-(R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethylphosphate; and
Compound 73) mono-(R)-3-(4-(2-(1-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-2-oxo-5-oxazolidinylmethylphosphate.
33. The compound of claim 24, having the structure
wherein R2 is hydroxyl, an alkylphosphate, a monophosphate, or a metal salt of the monophosphate.
34. The compound of claim 33, wherein R2 is hydroxyl, the monophosphate, or a disodium salt of the monophosphate.
35. The compound of claim 33, which has R stereochemistry.
36. The compound of claim 24, having the structure
wherein R2 is hydroxyl, an alkylphosphate, a monophosphate, or a metal salt of the monophosphate.
37. The compound of claim 36, which has R stereochemistry.
38. The compound of claim 24, having the structure
wherein R2 is hydroxyl, an alkylphosphate, a monophosphate or a metal salt of the monophosphate.
39. The compound of claim 38, which has R stereochemistry.
40. The compound of claim 24, having the structure
wherein R2 is hydroxyl, an alkylphosphate, a monophosphate, or a metal salt of the monophosphate.
41. The compound of claim 40, which has R stereochemistry.
42. A compound having the formula
43. A compound having the formula
44. A compound having the formula
45. A pharmaceutical composition comprising the compound of claim 24.
46. A method of treating a bacterial infection in a subject, comprising administering to the subject the compound of claim 24.
47. The method of claim 45, wherein the bacterial infection results from a Gram-positive bacterium.
48. The method of claim 46, wherein the Gram-positive bacterium is selected from the group consisting of Staphylococcus, Enterococcus, Streptococcus, Bacteroides, Clostridium, and Mycobacterium.
49. The method of claim 47, wherein the bacterium is selected from the group consisting of Staphylococcus, Enterococcus, and Streptococcus.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1-56. (canceled)
57. A frame for a respiratory mask assembly that delivers breathable gas to a patient, the frame comprising:
a main body having a front surface and a rear surface adapted in use to face the patient, the main body having an aperture extending through the front surface for the introduction of breathable gas into a nasal breathing cavity defined by the frame; and
an inner wall and an outer wall each extending rearwardly from the rear surface, the inner and outer walls being spaced to define a channel therebetween that is structured to receive a side wall of a cushion such that the cushion may be repeatedly attached to and detached from the frame, wherein the main body and the inner and outer walls are formed in one piece and the inner and outer walls are spaced in parallel, wherein a length of the inner wall is different than a length of the outer wall such that the inner wall protrudes away from the rear surface a distance that is different than a distance the outer wall protrudes away from the rear surface,
wherein at least a portion of the channel is shaped and dimensioned to generally follow a contour of the patient’s face,
wherein the channel has a generally triangular shape, and
wherein the inner and outer walls are adapted to receive the side wall when attached to the frame.
58. A frame according to claim 57, further comprising a headgear assembly removably attachable to the frame, wherein the main body accommodates the cushion and a side frame member provided on each lateral side of the main body, each side frame member including an integrally formed first connector portion adapted to be removably coupled with a second connector portion provided on the headgear assembly.
59. A frame according to claim 57, wherein the channel includes a first surface to engage the cushion, to allow selective removal of the cushion from the frame.
60. A frame according to claim 59, wherein the first surface includes a protrusion on the inner wall.
61. A frame according to claim 57, wherein the channel has a width in the range of about 2-10 mm.
62. A frame according to claim 61, wherein the width of the channel is 5 mm.
63. A frame according to claim 57, wherein the main body comprises an alignment feature on an outer surface configured to align with an alignment feature on the cushion.
64. A frame according to claim 63, wherein the channel includes an upper section dimensioned to be positioned over the patient’s nasal bridge region, a generally horizontal lower section, and side sections to join the upper and lower sections.
65. A frame according to claim 64, wherein the length of the inner wall is greater than the length of the outer wall such that the inner wall protrudes further away from the rear surface.
66. A frame according to claim 57, wherein the channel is structured such that an engagement force for engagement of the cushion to the frame is less than the disengagement force.
67. A frame according to claim 66, wherein the channel is structured such that the disengagement force is greater than a force asserted upon the mask assembly at a maximum treatment pressure.
68. A frame according to claim 57, wherein a length of the side wall is at least equal to a depth of the channel such that the cushion may contact a bottom surface of the channel.
69. A frame according to claim 68, wherein the cushion is retained and sealed without an interior or exterior member.
70. A combination, comprising:
a frame according to claim 57; and
a plurality of cushions, each cushion being configured to be removably attachable to the frame, wherein the cushions are different sizes.
71. A combination according to claim 70, wherein each cushion is configured to accommodate a percentage of a patient population such that the plurality of cushions together accommodate up to 95-100% of the patient population.
72. A frame for a respiratory mask assembly that delivers breathable gas to a patient, the frame comprising:
a base having a front side, a rear side, and an aperture therethrough for the introduction of breathable gas into a nasal breathing cavity;
an elbow assembly movably supported on the front side of the base; and
an inner wall and an outer wall having a generally triangular or trapezoidal channel therebetween that is structured to receive a side wall of a cushion so as to allow repeated attaching and detaching of the cushion and the base, at least a portion of the channel being shaped and dimensioned to generally follow a contour of the patient’s face, wherein
the inner wall includes a protrusion configured to contact the side wall of the cushion so as to removably attach the cushion to the base;
the channel has a width in the range of about 2-10 mm;
the base comprises an alignment feature configured to align with an alignment feature on the cushion;
the cushion can be attached to the frame to substantially simultaneously retain the cushion to the frame and form a seal with the frame; and
a depth of the channel is selected such that at least a portion of an end of the side wall of the cushion may contact a bottom surface of the channel; and
wherein each of the inner and outer walls extends from the rear side, and the inner wall extends a different distance than the outer wall, and
wherein the inner and outer walls are adapted to receive the side wall when attached to the frame.
73. A frame according to claim 72, wherein each of the inner wall and outer wall has a thickness of about 1-2 mm.
74. A frame according to claim 72, wherein the width of the channel is 5 mm.
75. A frame according to claim 72, wherein the channel is structured such that an engagement force for engagement of the cushion to the frame is less than the disengagement force.
76. A mask assembly comprising:
a mask including a seal to contact a user’s nose;
a quick-release elbow to deliver pressurized gas to the mask; and
rigidized support structure to support the mask on the user’s head, the support structure including an upper arm extending along the temple of the user and a lower arm extending below the ear of the user, the upper arm including a slot to receive a headgear strap.
77. A nasal mask assembly for nasal CPAP therapy of a patient, comprising:
a frame with a central aperture;
a nasal cushion permanently attached to the frame;
an elbow with a flexible quick release mechanism adapted to connect to the frame at the central aperture; and
a headgear assembly comprising:
a strap assembly including a pair of relatively flexible straps having a relatively soft fabric and foam material construction, and
a yoke made of a relatively rigid material compared to the strap material and having a degree of flexibility in one direction such that variations in patient physiology can be accommodated in use, said yoke being attached to the pair of straps and the frame,

wherein the nasal mask assembly is not provided with a chin strap.
78. A mask assembly according to claim 77, wherein the yoke is stiffer in another direction generally orthogonal to the one direction to resist vertical rotation of the nasal cushion support structure due to the weight of the nasal cushion support structure and of components attached to the nasal cushion support structure.
79. A mask assembly according to claim 77, wherein a top end of the yoke includes a connector element adapted to connect with the strap assembly.
80. A mask assembly according to claim 77, wherein the pair of straps are generally Y-shaped.
81. A mask assembly according to claim 80, wherein each of the Y-shaped straps comprises a front strap portion, a top strap portion and a rear strap portion.
82. A mask assembly according to claim 77, wherein the pair of straps are made of laminated fabric and foam.
83. A mask assembly according to claim 77, wherein the frame is not provided with a forehead support assembly.
84. A mask assembly according to claim 77, wherein the headgear assembly is connected to the frame below the patient’s eyes.
85. A mask assembly according to claim 77, wherein a potion of the yoke is generally Y-shaped.
86. A mask assembly according to claim 77, wherein the elbow includes an end portion adapted to engage the central aperture of the frame.
87. A mask assembly according to claim 77, wherein the quick release mechanism includes protrusions.
88. A mask assembly according to claim 77, wherein the protrusions are diametrically opposed.
89. A mask assembly according to claim 87, wherein the frame includes a flange provided at a distal end of a wall defining the central aperture, the flange being configured to engage the protrusions when the elbow is connected to the frame.
90. A mask assembly according to claim 89, wherein the protrusions engage the flange to secure the elbow to the frame.
91. A mask assembly according to claim 89, wherein the protrusions are ramped such that engagement between the flange and the protrusions causes an outward movement of each of the protrusions during assembly.
92. A mask assembly according to claim 91, wherein the protrusions move inward to secure the elbow to the frame when the flange moves past the protrusions.
93. A mask assembly according to claim 89, wherein the flange, the wall and the frame define a recess.
94. A mask assembly according to claim 93, wherein the protrusions are received within the recess when the elbow is secured to the frame.
95. A mask assembly according to claim 77, wherein the flexible quick release mechanism includes release points configured to move inwardly and outwardly with respect to the end portion of the elbow.
96. A mask assembly according to claim 95, wherein the release points are provided on diametrically opposed sides of the elbow.
97. A mask assembly according to claim 96, wherein a distance between the release points is approximately 35-45 mm.
98. A mask assembly according to claim 95, wherein the elbow is released from the frame by pinching the release points toward each other.
99. A mask assembly according to claim 98, wherein pinching the release points raises the protrusions radially outwardly to allow passage of the flange.
100. A mask assembly according to claim 77, wherein the elbow is configured to be removed from the frame without accessing an interior portion of the frame.
101. A mask assembly according to claim 77, wherein an engagement between the elbow and the frame makes an audible sound.
102. A mask assembly according to claim 77, wherein the nasal cushion has a double-walled construction.
103. A mask assembly according to claim 77, wherein the nasal cushion and the frame are co-molded together.