Patent Publication Number: US-2020282174-A1

Title: Modular pulmonary treatment system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/291,679, filed Oct. 12, 2016, which is a divisional of U.S. patent application Ser. No. 13/747,095, filed Jan. 22, 2013, now U.S. Pat. No. 9,498,592, issued Nov. 22, 2016, which claims the benefit of: U.S. patent application Ser. No. 61/589,671, filed on Jan. 23, 2012; U.S. patent application No. 61/610,828, filed Mar. 14, 2012 and U.S. patent application No. 61/694,020, filed Aug. 28, 2012, each of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to pulmonary treatment equipment and more particularly, relates to a modular pulmonary treatment system that includes a number of interchangeable parts that allow the system to have a number of different operating modes including but not limited to delivery of a gas to a patient; delivery of an aerosolized medication (drug) to a patient; and a combination thereof. 
     BACKGROUND 
     Respiratory care devices are commonly used as a means to deliver gases and medication in an aerosolized form to a patient. Aerosolized medication is typically used to treat patients with respiratory conditions, such as reactive airways disease, asthma, bronchitis, emphysema, or chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis, etc. 
     It is generally accepted that effective administration of aerosolized medication depends on the delivery system and its position in relation to the patient. Aerosol particle deposition is influenced by particle size, ventilatory pattern, and airway architecture, and effective medication response is influenced by the dose of the medication used. 
     An aerosol delivery system includes three principal elements, namely a generator, a power source, and an interface. Generators include small volume nebulizers (SVN), large volume nebulizers (LVN), metered dose inhalers (MDI), and dry powder inhalers (DPI). The power source is the mechanism by which the generator operates or is actuated and includes compressed gas for SVN and LVN and self-contained propellants for MDI. The interface is the conduit between the generator and the patient and includes spacer devices/accessory devices with mouthpieces or face masks. Depending on the patient&#39;s age (ability) and coordination, various interfaces are used in conjunction with SVN and MDI in order to optimize drug delivery. 
     The three primary means for delivering aerosolized medication to treat a medical condition is an MDI, a DPI, or a nebulizer. MDI medication (drug) canisters are typically sold by manufacturers with a boot that includes a nozzle, an actuator, and a mouthpiece. Patients can self-administer the MDI medication using the boot alone but the majority of patients have difficulty synchronizing the actuation of the MDI canister with inhalation causing oropharyngeal drug deposition, decreased drug delivery and therefore effectiveness, and causes other adverse effects. 
     A dry powder inhaler (DPI) is a device that delivers medication to the lungs in the form of a dry powder. DPIs are an alternative to the aerosol based inhalers commonly called metered-dose inhaler (or MDI). The DPIs may require some procedure to allow a measured dose of powder to be ready for the patient to take. The medication is commonly held either in a capsule for manual loading or a proprietary form from inside the inhaler. Once loaded or actuated, the operator puts the mouthpiece of the inhaler into their mouth and takes a deep inhalation, holding their breath for 5-10 seconds. There are a variety of such devices. The dose that can be delivered is typically less than a few tens of milligrams in a single breath since larger powder doses may lead to provocation of cough. Most DPIs rely on the force of patient inhalation to entrain powder from the device and subsequently break-up the powder into particles that are small enough to reach the lungs. For this reason, insufficient patient inhalation flow rates may lead to reduced dose delivery and incomplete deaggregation of the powder, leading to unsatisfactory device performance. Thus, most DPIs have a minimum inspiratory effort that is needed for proper use and it is for this reason that such DPIs are normally used only in older children and adults. 
     Small volume nebulizers (SVN) and large volume nebulizers (LVN) have been used to overcome difficulties encountered with MDI and DPI during acute exacerbation of obstructive airways disease but even these devices are fraught with problems especially significant waste of medication and not adequately reaching the target airways. 
     Problems with prior art devices include that the devices are inefficient and significantly waste medication, they provide a non-uniform concentration of delivered medication, they are expensive, and they are difficult to use. In addition, multiple pieces of equipment are needed to treat a plurality of different conditions. 
     The modular pulmonary treatment system of the present invention overcomes these deficiencies and provides a system that includes a number of interchangeable parts that allow the system to have a number of different operating modes including but not limited to delivery of a gas to a patient; delivery of an aerosolized medication (drug) to a patient; and a combination thereof. 
     SUMMARY 
     According to one embodiment, a patient interface device for delivering a gas to a patient includes a main body for placement against a face of the patient for delivering the gas to the patient. The main body includes a conduit portion that is open at a first end to a hollow interior of the main body and a free second end for attachment to another object in a sealed manner. The device also includes: (1) at least one exhalation valve assembly that is disposed within a first port formed in the main body and includes an exhalation valve member that is configured to vent exhaled air when open; (2) a primary inhalation valve assembly that is disposed within the conduit portion and includes a primary valve member that moves between open and closed positions; and (3) a secondary inhalation valve assembly that is disposed within a second port formed in the main body and includes a secondary valve member that moves between open and closed positions. The body includes an HME (heat moisture exchange) seat for receiving an HME unit and being located in relationship to the least one primary inhalation valve assembly and the at least one exhalation valve assembly to: (1) allow passage of inhaled gas, that flows through the primary inhalation valve assembly, through the HME seat before flowing into the hollow interior of the main body and to the patient and (2) allow passage of exhaled gas from the patient through the HME seat before exiting to atmosphere through the at least one exhalation valve assembly. The HME seat is at least partially defined by a wall that is integral to the main body and defines a hollow space for receiving the HME unit, the wall being constructed for mating with the HME unit for the secure, yet releasable, attachment of the HME unit to the HME seat. 
     According to another embodiment, a patient interface system for delivering a gas to a patient includes a patient interface device that includes a main body for placement against a face of the patient for delivering the gas. The patient interface device includes at least one inhalation valve and at least one exhalation valve. The system also includes a venturi device that is fluidly connected to the free second end of the conduit portion. The venturi device has at least one port for connection to a gas source. The venturi device has at least one primary air entrainment window and at least one secondary air entrainment window which is downstream of the at least one primary air entrainment window and thus closer to the main body of the patient interface device. The at least one inhalation valve is disposed between: (1) the main body and (2) the primary and secondary air entrainment windows of the venturi device. At least one of the primary air entrainment window and secondary air entrainment window includes a means for closing the respective window, thereby changing a degree at which the respective window is open and changing a flow rate of the air flowing through the respective window. 
     In another embodiment, a patient interface system for delivering a gas to a patient includes a patient interface device for delivering a gas to a patient. The patient interface device includes a main body for placement against a face of the patient. The main body includes a conduit portion that is open at a first end to a hollow interior of the main body and a free second end for attachment to another object in a sealed manner. The patient interface delivery device also includes: (1) at least one exhalation valve assembly that is disposed within a first port formed in the main body and includes an exhalation valve member that is configured to vent exhaled air when open; (2) a primary inhalation valve assembly that is disposed within the conduit portion and includes a primary valve member that moves between open and closed positions; and (3) a secondary inhalation valve assembly that is disposed within a second port formed in the main body and includes a secondary valve member that moves between open and closed positions. The system also includes a first accessory that is fluidly attached to the conduit portion. 
     The primary inhalation valve assembly has a first flow resistance associated therewith and the second inhalation valve assembly has a second flow resistance associated therewith which is greater than the primary inhalation valve assembly and as a result, the secondary inhalation valve assembly acts as an emergency inhalation valve. 
     The first accessory can be any number of different pieces of equipment including but not limited to a reservoir member, a device for delivering gas and/or aerosolized medication, etc. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         FIG. 1  is a front and side perspective view of a patient interface system/modular pulmonary treatment system according to one embodiment and configured for delivery of gases to a patient including aerosolized medication; 
         FIG. 2  is a close-up perspective view of the patient interface system/modular pulmonary treatment system of  FIG. 1 ; 
         FIG. 3  is a rear perspective view of the patient interface system/modular pulmonary treatment system of  FIG. 1 ; 
         FIG. 4  is a top plan view of a patient interphase valve assembly according to one embodiment for use with a facemask as shown in  FIG. 1 ; 
         FIG. 5  is a rear elevation view of the patient interphase valve assembly of  FIG. 4 ; 
         FIG. 6  is a partially exploded view of the patient interphase valve assembly; 
         FIG. 7  is a perspective view of the patient interphase valve assembly of  FIG. 6  in an assembled state; 
         FIG. 8  is a partially exploded view of the patient interphase valve assembly illustrating a directional valve according to the present invention; 
         FIG. 9  is a perspective view of the patient interphase valve assembly of  FIG. 8  in an assembled state; 
         FIG. 10  is a front and bottom perspective view of the system of  FIG. 1  prior to mating the primary treatment module valve assembly with the patient interphase system; 
         FIG. 11  is a front and bottom perspective view of the system of  FIG. 10  in the assembled position; 
         FIG. 12  is a front perspective view of the patient interface system of  FIG. 1  attached to an expandable conduit for delivering gas in accordance with a first operating mode; 
         FIG. 13  is a front perspective view of the patient interface system of  FIG. 12  shown in accordance with a second operating mode; 
         FIG. 14  is a front perspective view of the patient interface system of  FIG. 12  shown in accordance with a third operating mode; 
         FIG. 15  is a front perspective view of the patient interface system of  FIG. 1  attached to a gas reservoir assembly and venturi mechanism for delivering gas in accordance with a first operating mode; 
         FIG. 16  is a front perspective view of the patient interface system of  FIG. 15  shown in accordance with a second operating mode; 
         FIG. 17  is a front perspective view of the patient interface system of  FIG. 1  attached to a dual gas reservoir assembly and two venturi mechanism shown in accordance with a first operating mode; 
         FIG. 18  is a front perspective view of patient interface system of  FIG. 17  shown in accordance with a second operating mode; 
         FIG. 19  is a front perspective view of the patient interface system of  FIG. 1  attached to a nebulizer for aerosol drug delivery; 
         FIG. 20  is a front perspective view of the patient interface system of  FIG. 19  in further combination with an expandable conduit for aerosol drug delivery; 
         FIG. 21  is a front perspective view of the system of  FIG. 20  in further combination with a multi-port low concentration venturi for aerosol drug and controlled low concentration gas delivery; 
         FIG. 22  is a front perspective view of the patient interface system of  FIG. 1  in further combination with a nebulizer and a gas reservoir assembly for aerosol drug and controlled high concentration gas delivery; 
         FIG. 23  is a front perspective view of the patient interface system of  FIG. 1  in further combination with a nebulizer and a dual gas reservoir assembly shown in accordance with a second operating mode; 
         FIG. 24  is a front perspective view of the patient interface system of  FIG. 23  shown in accordance with a third operating mode; 
         FIG. 25A  is an exploded perspective view of a multi-port, variable concentration, gas delivery venturi connector; 
         FIG. 25B  is a perspective view of the multi-port, variable concentration, gas delivery venturi connector in an assembled position; 
         FIG. 26  is an exploded perspective view of a patient interface system/modular pulmonary treatment system according to another embodiment and configured for delivery of gases to a patient including aerosolized medication; 
         FIG. 27  is a perspective view of the system of  FIG. 26  in an assembled state; 
         FIG. 28  is an exploded perspective view of cassette style venturi connector according to one embodiment; 
         FIG. 29  is a perspective view of the cassette style venturi connector assembly in the assembled state; 
         FIG. 30A  is a side perspective view of a patient interface system according to another embodiment for low concentration gas delivery; 
         FIG. 30B  is a side perspective view of a patient interface system according to another embodiment for low concentration gas delivery; 
         FIG. 31  is a side perspective view of a patient interface system according to another embodiment for standard dose aerosol drug delivery; 
         FIG. 32  is a side perspective view of a patient interface system according to another embodiment for high dose aerosol drug delivery; 
         FIG. 33A  is a side perspective view of a patient interface system according to another embodiment for 100% non-rebreather gas (oxygen) delivery; 
         FIG. 33B  is a side perspective view of a patient interface system according to another embodiment for 100% non-rebreather gas (oxygen) delivery 
         FIG. 34A  is a side perspective view of a patient interface system according to another embodiment for low concentration gas (oxygen) delivery with heat and moisture exchange; 
         FIG. 34B  is a side perspective view of a patient interface system according to another embodiment for low concentration gas (oxygen) delivery with heat and moisture exchange; 
         FIG. 35A  is a side perspective view of a patient interface system according to another embodiment for high concentration gas (oxygen) delivery; 
         FIG. 35B  is a side perspective view of a patient interface system according to another embodiment for high concentration gas (oxygen) delivery; 
         FIG. 36A  is a side perspective view of a patient interface system according to another embodiment for high concentration gas (oxygen) delivery with heat and moisture exchange; 
         FIG. 36B  is a side perspective view of a patient interface system according to another embodiment for high concentration gas (oxygen) delivery with heat and moisture exchange; 
         FIG. 37  is a side perspective view of a patient interface system according to another embodiment for high dose drug delivery with 100% oxygen or other premixed gas like heliox delivery; 
         FIG. 38A  is an exploded perspective view of a patient interface mask system with valves for use in some of the systems of  FIGS. 30-37 ; 
         FIG. 38B  is a perspective view of the system of  FIG. 38A  in the assembled condition; 
         FIG. 38C  is a rear perspective view of the system of  FIG. 38A ; 
         FIG. 38D  is an exploded perspective view of a patient interface mask system without valves for use in some of the systems of  FIGS. 30-37 ; 
         FIG. 38E  is a front view of the system of  FIG. 38D  in the assembled condition; 
         FIG. 38F  is a rear perspective view of the system of  FIG. 38D ; 
         FIG. 39A  is an exploded perspective view of a first multi-port valve connector for use in some of the systems of  FIGS. 30-37 ; 
         FIG. 39B  is perspective view of the connector of  FIG. 39A  in an assembled condition; 
         FIG. 40  is an exploded perspective view of a second multi-port valve connector for use in some of the systems of  FIGS. 30-37 ; 
         FIG. 41  shows both exploded and assembled perspective views of a single bag reservoir assembly; 
         FIG. 42  shows both exploded and assembled perspective views of a dual bag reservoir assembly; 
         FIG. 43  shows both exploded and assembled perspective views of a dual bag reservoir system used in embodiment  37  for high dose drug delivery with 100% gas (oxygen) delivery system; 
         FIG. 44A  is a 100% non-rebreather gas (oxygen) delivery with heat and moisture exchange; and 
         FIG. 44B  shows another embodiment for 100% non-rebreather gas (oxygen) delivery with heat and moisture exchange; 
         FIG. 45  is a side and front perspective view of a patient interface system according to a different embodiment and showing a mask valve assembly and a primary gas valve assembly exploded therefrom; 
         FIG. 46  is a side and front perspective of the assembled patient interface system of  FIG. 45 ; 
         FIG. 47  is a perspective view of the primary gas valve assembly with a valve member shown exploded therefrom; 
         FIG. 48  is a top plane view of the primary gas valve assembly; 
         FIG. 49  is a side elevation view of the primary gas valve assembly; 
         FIG. 50  is a cross-sectional view of the primary gas valve assembly taken along the lines  50 - 50  of  FIG. 49 ; 
         FIG. 51  is an exploded perspective view of the patient interface-mask valve assembly; 
         FIG. 52  is a side elevation view of the patient interface-mask valve assembly; 
         FIG. 53  is a front elevation view of the patient interface-mask valve assembly; 
         FIG. 54  is a rear perspective view of the patient interface system showing an HME assembly exploded therefrom; 
         FIG. 55  is a rear perspective view of the patient interface system with the HME assembly installed therein; 
         FIG. 56  is an exploded perspective view of the HME assembly; 
         FIG. 57  is also an exploded perspective view of the HME assembly; 
         FIG. 58  is an exploded perspective view of a respiratory treatment system for low concentration gas (oxygen) delivery; 
         FIG. 59  is a side perspective view of a multi-port venturi member that is part of the venturi assembly of  FIG. 58 ; 
         FIG. 60  is a side elevation view of the multi-port venturi member of  FIG. 59  and according to a first embodiment; 
         FIG. 61  is a top plan view of the multi-port venturi member of  FIG. 60 ; 
         FIG. 62  is a cross-sectional view of the multi-port venturi member taken along the lines  62 - 62  of  FIG. 61 ; 
         FIG. 63  is a side elevation view of the multi-port venturi member according to a second embodiment; 
         FIG. 64  is a top plan view of a multi-port venturi member of  FIG. 63 ; 
         FIG. 65  is a side elevation view of the multi-port venturi member according to a third embodiment; 
         FIG. 66  is a top plan view of a multi-port venturi member of  FIG. 65 ; 
         FIG. 67  is a side elevation view of the multi-port venturi member according to a fourth embodiment; 
         FIG. 68  is a top plan view of a multi-port venturi member of  FIG. 67 ; 
         FIG. 69  is a side perspective view of a secondary gas entrainment valve member that is part of the assembly of  FIG. 58 ; 
         FIG. 70A  is a side elevation showing the secondary gas entrainment valve member in a fully open position; 
         FIG. 70B  is a side elevation showing the secondary gas entrainment valve member in a partially open position; 
         FIG. 70C  is a side elevation showing the secondary gas entrainment valve member in a partially open position; 
         FIG. 70D  is a side elevation showing the secondary gas entrainment valve member in a fully closed position; 
         FIG. 71  is an exploded perspective view of a respiratory treatment system for high concentration gas (oxygen) delivery; 
         FIG. 72  is an exploded elevation view of a device of the system of  FIG. 71 ; 
         FIG. 73  is an elevation view of the device of  FIG. 72  in an assembled condition; 
         FIG. 74  is a top plan view of the device of  FIG. 73 ; 
         FIG. 75  is a cross-sectional view taken along the line  75 - 75  of  FIG. 74 ; 
         FIG. 76  is a rear elevation view thereof; 
         FIG. 77  is an exploded perspective view of a respiratory treatment system for a 100% non-breather gas delivery; 
         FIG. 78  is an exploded perspective view of a respiratory treatment system for standard dose aerosol drug delivery; 
         FIG. 79  is an exploded perspective view of a respiratory treatment system for enhanced dose aerosol drug delivery; 
         FIG. 80  is an exploded perspective view of a respiratory treatment system for high dose aerosol drug delivery with gas delivery with single bag reservoir system; 
         FIG. 81  is an exploded perspective view of a respiratory treatment system for high dose aerosol drug delivery with gas delivery with dual bag reservoir system; 
         FIG. 82  is an exploded perspective view of a respiratory treatment system for high dose aerosol drug delivery with controlled concentration gas delivery with dual reservoir bag system; 
         FIG. 83  is an exploded perspective view of the high dose aerosol drug delivery/gas delivery mechanism of  FIG. 82 ; 
         FIG. 84  is a top plan view of the system of  FIG. 83 ; 
         FIG. 85  is a cross-sectional view taken along the line  85 - 85  of  FIG. 84 ; 
         FIG. 86  is a top plan view of a valve seat in accordance with a different embodiment of the present invention; and 
         FIG. 87  is a cross-sectional view taken along the lines  87 - 87  in  FIG. 86 . 
     
    
    
     DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS 
       FIGS. 1-7  illustrate a patient interface/modular pulmonary treatment system  100  in accordance with one embodiment of the present invention. The system  100  is formed of a number of components that mate together to form the assembled system  100  and in particular, the patient interface system  100  includes a face mask  200  and a primary treatment module valve assembly  300  that intimately mates with the face mask  200 . 
     The illustrated face mask  200  is merely exemplary in nature and it will therefore be understood that any number of different face mask geometries/constructions can be utilized. The face mask  200  includes a face mask body  210  that has a front surface or face  212  and an opposite rear surface or face  214 . The face mask body  210  includes a nose portion  216  that is defined by a planar underside wall  217  and a front planar portion  218 . The planar underside wall  217  and the front planar portion  218  generally are formed at a right angle. The face mask body  210  has a peripheral edge  211  that seats and seals against the face of a user. 
     As shown in  FIG. 3 , a hollow interior of the face mask body  210  has a landing or planar floor  213  that is part of the nose portion  216 . 
     The face mask body  210  can be formed of any number of different materials including but not limited to polymeric materials. 
     The primary treatment module valve assembly (main module)  300  intimately mates with the face mask body  210  to form a complete assembly. In one embodiment, the main module  300  is integrally attached to the face mask body  210  so as to provide a single disposable structure. In other words, the main module  300  is not meant to be detached from the face mask body  210 . However, the present invention is not limited to such a construction and covers, as well, an arrangement where the main module  300  is detachable. 
     In the illustrated embodiment as best shown in  FIGS. 10 and 11 , the module  300  can be received into an opening  219  formed in the planar underside wall  217  of the facemask  200 . Any number of different types of coupling can be used between the module  300  and the face mask  200 . In the illustrated embodiment, the module  300  can include a lip  309  that seats above the edge of the planar underside wall  217  that defines the opening  219 . The lip  309  thus prevents the module  300  from moving downward within the opening  219 . 
     The main module  300  includes a number of interconnected conduits that provide various flow paths for gas(es) as described herein. In particular, the main module  300  has a top  301 , a bottom  303 , a front  305 , and a rear  307 . The main module  300  also includes a main body  310  that is in the form of a hollow structure (e.g., tubular structure) that is open at a first end  312  and a second end  314 . In the illustrated embodiment, the main body  310  is a hollow tubular structure that has a generally circular shape. 
     The main module  300  also includes a first conduit  320  that fluidly communicates with the hollow interior of the main body  310 . The first conduit  320  is a hollow structure that represents a leg that extends downwardly from the main body  310  and is open at a bottom end  322  thereof. In the illustrated embodiment, the first conduit  320  is in the form of a hollow tubular structure, such as a hollow circular tube. Similarly, the main module  300  includes a second conduit  330  that fluidly communicates with the hollow interior of the main body  310 . The second conduit  330  is similar or identical to the first conduit  330  in that it is hollow structure that represents a leg that extends downwardly from the main body  310  and is open at a bottom end  332  thereof. In the illustrated embodiment, the second conduit  330  is in the form of a hollow tubular structure, such as a hollow circular tube. The first conduit  320  is near the first end  312  of the main body  310 , while the second conduit  330  is located near the second end  314  of the main body  310 . 
     Along the front  305 , there is a first port  340  that fluidly communicates with and forms an entrance into the hollow main body  310  above the first conduit  320  at the first end  312  of the main body  310 . As shown, the first port  340  and the first conduit  320  are formed at a right angle relative to one another. Along the front  305 , there is also a second port  350  that fluidly communicates with and forms an entrance into the hollow main body  310  above the second conduit  330 . As shown, the second port  350  and the second conduit  330  are formed at a right angle relative to one another. The first port  340  has an open end  342  that faces forwardly and the second port  350  has an open end  352  that faces forwardly. 
     Along the rear  307 , a safety port  315  is provided and defines an opening into the hollow interior of the main body  310 . The safety port  315  is axially parallel with the second port  350  and is generally located across therefrom. 
     The main module  300  also includes a third conduit  360  that extends upwardly from the main body  310  and is in fluid communication with and forms an entrance into the hollow main body  310 . Like the other conduits, the third conduit  360  can be in the form of a tubular structure that has an open free end  362 . The third conduit  360  also includes a side port  370  that extends outwardly from a side of the third conduit  360 . The side port  370  is open at a free end  372  thereof. The third conduit  360  and the side port  370  can be tubular structures. 
     The third conduit  360  is located generally above the second conduit  330  and communicates with the open interior of the hollow main body  310 . At this end of the main body  310 , there is an interior portion at which six ( 6 ) openings or ports intersect. 
     Along the top of the main body  310  there is also another port or opening  380  that opens into the hollow interior of the main body  310 . The opening  380  provides one of the primary flow paths in addition to the third conduit  360  as described herein. The opening  380  is located next to the third conduit  360 . 
     In accordance with the present invention, a number of accessories mate with the main body  310  to provide a modular and easily reconfigurable assembly. For example, a first closure  400  can be provided and disposed within the open first end  312  to close off and seal the first end  312  of the main body  310 . The first closure  400  can be in the form of a plug or cap. A second closure  410  can be provided and disposed within the open second end  314  to close off and seal the second end  314  of the main body  310 . The second closure  410  can be in the form of a plug or cap. The first and second closures  400 ,  410  have a lip or flange portion that allows the user to easily grasp and pull the closure out to remove it and open up the respective end of the main body  310  and also to insert the closure into the main body  310  so as to seal the main body  310 . The first and second closures  400 ,  410  can be the same or different (as shown) structures. 
     In addition, a third closure  420  can be provided and disposed within the first port  340 . As with the other closures  400 ,  410 , the third closure  420  can be in the form of a plug or cap. The third closure  420  has a lip or flange portion that allows the user to easily grasp and pull the closure  420  out of the main body  310  and conversely, insert the closure  420  into the first port  340 . 
     Within or on top of the opening  380 , a first inhalation valve assembly  500  is provided, which can be in the form of a swing (pivot) or flapper or any other form of one-way valve mechanism. The first inhalation valve assembly  500  can be in the form of a one-way inhalation valve that opens&#39; upon inhalation. More specifically, the first inhalation valve assembly  500  includes an inhalation valve member  510 , which opens when the patient inhales. In the illustrated embodiment, the inhalation valve member  510  has a main body  512  and a coupling member  514  that serve to couple (in a pivotal manner) the main body  512  to a portion of the main body  310  of the device. The coupling member  514  can be in the form of an axle or a hinge pin or the like that has free ends that are received within a structure  515  that is part of the main body  310  and is in the form of a pair of mounts or brackets that include openings for receiving the free ends of the coupling member  514 . The valve member  510  pivots open by rotating within the opposing mounts that form the structure  515 . 
     The mating between the coupling member  514  and the structure  515  serves to securely hold the valve member  510  in place and permit it to open upon patient inhalation since as described herein, inhalation by the patient causes air flow in an upward direction through opening  380 , thereby causing a lifting of the valve member  510  from the main body  310  (the valve seat defined therein). 
     Within the safety port  315 , an emergency valve assembly  550  is provided and in the illustrated embodiment is in the form of an emergency air valve that opens when a patient needs additional air flow for breathing. The emergency air valve can be in the form of a flapper or swing (pivot) style valve or any other form of one-way valve mechanism. The emergency valve assembly  550  includes a valve seat  552  and a valve member  554  that mates with the valve seat  552 . The valve assembly  550  is of a type commonly referred to as a one-way valve in that the valve opens in one direction to allow flow in only one direction. The valve member  554  can be a flapper type valve that mates with the valve seat  552  which can be in the form of a body (i.e., spoke structure) that receives the valve member  554  which covers the openings in the seat when closed and lifts from the seat  552  when opened. The emergency valve assembly  550  is thus located along the rear of the module and faces the wall  218  of the face mask  200 . There is a space/gap between the module  300  and the wall  218  through which air flows and can enter the emergency valve assembly  550 . Air entering through the valve assembly  500  is routed to the hollow interior of the main body  310  where it flows accordingly as described herein. 
     The system  100  also includes an exhalation valve assembly  590  that is designed to exhaust (vent) gas from the patient to the exterior (atmosphere). The exhalation valve assembly  590  is a one way valve assembly that is designed to only open during exhalation and only allows flow of gas in one way, namely, out of the system  100  and into the atmosphere. The exhalation valve assembly  590  is disposed within the side port  370  and in particular, at the free end  372  thereof. The exhalation valve assembly  590  can be any number of different types of one way valve assemblies including the one illustrated herein. The exhalation valve assembly  590  can be in the form of a valve seat  592  that supports a valve member  596 . The valve seat  592  includes a plurality of openings  594  formed therein to allow gas to flow therethrough. In the illustrated embodiment, the valve seat  592  is a spoked structure and has a central mounting structure that is received through a center opening of the valve member  596  to attach the valve member  596  to the valve seat  592 . 
     The exhalation valve assembly  590  is thus located above the main body  310  and gas reaches the exhalation valve assembly  590  by flowing through the third conduit  360  (which is open to the interior of the mask body  210  as described herein) and then the side port  370 . 
     The system  100  also includes a supplemental gas valve assembly  600  that serves to allow a flow of supplemental gas to the patient. The valve assembly  600  is disposed at or near the interface between the main conduit body  310  and the conduit  360  and below the exhalation valve assembly  590 . The supplemental gas valve assembly  600  is thus located at the entrance to the third conduit  360  from the main body  310  and thus, the supplemental gas valve assembly  600  allows gas flow between the main body  310  and the third conduit  360  when it is open and conversely, when the valve assembly  600  is closed, gas flow is prevented between these two conduit structures. 
     The supplemental gas valve assembly  600  is a one way valve assembly that is designed to only open during inhalation and only allows flow of gas in one way, namely, from the main conduit body  310  and into the third conduit  360 . The supplemental gas valve assembly  600  can be any number of different types of one way valve assemblies including the one illustrated herein. The supplemental gas valve assembly  600  can be in the form of a valve seat  610  that supports a valve member  620 . The valve seat  610  includes a plurality of openings  612  formed therein to allow gas to flow therethrough. In the illustrated embodiment, the valve seat  610  is a spoked structure and has a central mounting structure that is received through a center opening of the valve member  620  to attach the valve member  620  to the valve seat  610 . 
     The third conduit  360  not only receives the supplemental gas valve assembly  600  but it can also include HME (heat and moisture exchange) media  700 . As is known, HME media is constructed to heat and humidify inhaled gas and in the present system  100 , the HME media  700  is disposed within the third conduit  360  above the supplemental gas valve assembly  600 . The HME media  700  is thus in fluid communication with both the gas that flows through the main body  310  and into the third conduit  360  for inhalation by the patient and also exhaled gas that flows from the patient to the side port  370  where it flows out of the exhalation valve assembly  590 . Thus, inhaled air flowing through the third conduit  360  to the patient and exhaled gas from the patient both are required to flow through the HME media  700 . In this manner, the naturally warm and moist exhaled gas serves to treat the HME media  700  by adding heat and moisture thereto which is then transferred to the inhaled gas that flows through the HME media  700 , thereby resulting in the inhaled gas being heated and humidified. 
     The shape and size of the HME media  700  are thus selected in part by the shape and size of the third conduit  360 . In the illustrated embodiment, the HME media  700  is in the form of a cylindrical shaped body that snugly (sealingly) fits within the hollow tubular structure of the third conduit  360 . The HME media  700  can be inserted and removed from the open top end  362  of the conduit  360 . It is understood that the HME media can be designed alternatively in a non-cylindrical shape to conform to the shape of conduit  360  which could also be shaped non-cylindrical. 
     It will be appreciated that the HME media  700  is positioned such that it does not interfere with the normal operating movement of the supplemental gas valve assembly  600 . In other words, the supplemental gas valve assembly  600  can freely open and close without interfering with the HME media  700 . 
     In accordance with the present invention, the present invention includes a directional valve  800  that allows the gas flow paths within the system  100  to be defined and varied. The directional valve  800  thus opens up and closes off certain flow paths within the main body  310  and the related conduits and ports connected thereto so as to allow the user to define how the gas flows within the system  100 . This allows the system  100  to have a significant number of different operating modes as described herein. 
     As shown, the illustrated directional valve  800  has a valve body  810  that includes a number of strategically placed openings. In particular, the valve body  810  is shaped and sized so that it is received into the second port  350  and can rotate therein to allow the position of the valve  800  to be varied. The valve body  810  can be a cylindrical shaped body as shown and includes a closed outer face  812  that is at a first end  813  of the body  810 . The closed outer face  812  is exposed and accessible to the user and represents the portion of the valve body  810  that is manipulated by the user to change the position of the valve body  810  within the main body  310 . The closed outer face  812  includes a protrusion or tab  816  that allows the user to manipulate the valve body  810  and more specifically, provides a contact surface from which the user can rotate the valve body  810 . 
     An opposite second end  815  is an open end and in the case of a cylindrical valve body  810 , the second end  815  is an open circular end. 
     The openings formed in the valve body  810  are spaced about the body at specific locations. In particular, a first side opening  820  is formed in the valve body  810  along the side wall of the valve body  810  that extends between the first end  813  and the second end  815 . A second side opening  830  is formed in the valve body  810  along the side wall and at a location such that the axis of the opening  820  and the axis of the opening  830  are generally about 90 degrees disposed to one another. The valve body  810  also includes a third side opening  840  formed therein along the side wall and at a location such that the axis of the opening  840  and the axis of the first side opening  820  are about 180 degrees disposed to one another and the axis of the opening  840  and the axis of the third side opening  830  are about 90 degrees disposed to one another. In the illustrated embodiment, the first side opening  820  is located in the 12 o&#39;clock position, the second side opening  830  is located in the 3 o&#39;clock position and the third side opening  840  is located in the 6 o&#39;clock position. When the valve body  810  is placed in this orientation, the 9 o&#39;clock position does not include an opening and instead represents a closed end. 
     The closed outer face  812  includes indicia that indicate the direction of the openings  820 ,  830 ,  840 . In particular, as illustrated, the closed outer face  812  includes arrows that point toward the open regions of the valve body, through which fluid (gas) can flow, in that the arrows point toward the three openings  820 ,  830 ,  840 . The region of the valve body that does not include an opening does not include an arrow indicator since fluid (gas) cannot flow in this direction through the valve body  810 . The indicia on the closed outer face  812  also include a solid semi-circular line that indicates that fluid cannot flow in this direction. 
     When inserted into the second port  350 , the valve body  810  extends into the hollow interior of the main body  310  and is adjacent the entrances to the other ports and conduits, such as the third conduit  360 , the second conduit  330 , and the safety port  315 . The openings  820 ,  830 ,  840  are sized and shaped in view of the openings that are defined between the main body  310  and the various legs (conduits) that extend therefrom. As shown in  FIG. 8 , the main body  310  has a first internal opening  313 , at the 9 o&#39;clock position, that is within the main body  310  between the ports  320 / 340  on one side and  330 / 350  on the other; a second internal opening  319 , at the 6 o&#39;clock position, that is between the main body  310  and the leg port  330 ; a third internal opening  321 , at the 3 o&#39;clock position that is between the main body  310  and leg port  314 ; a fourth internal opening  323 , at the 12 o&#39;clock position that is between the main body  310  and leg port,  360 ; and a fifth internal opening  317  that is between the main body  310  and the rear conduit in which the safety (emergency) port  315  is located. It will therefore be appreciated that the location in which the directional valve  800  is disposed is defined by the intersection of five openings or conduits which define fluid flow paths. In particular, as shown in  FIG. 8 , a first flow path is in the direction of end  312 ; a second flow path is in the direction of end  314 ; a third flow path is in the direction of conduit  360 ; a fourth flow path is in the direction of the safety port  315 ; and a fifth flow path is in the direction of conduit  330 . 
     When the directional valve body  810  is rotated within the main body  310 , the openings  820 ,  830 ,  840  are placed in registration with the various internal openings, with the degree of registration being variable depending upon the positioning between the openings  820 ,  830 ,  840  and the internal openings defining the conduits. 
     It will therefore be understood that the directional valve body  810  is constructed to allow simultaneous flow along three flow paths that can be along three directions. 
     The system  100  also includes other accessories that mate with various openings/conduits thereof. In particular, a port cap  900  can be provided for mating with the open end  332  of the conduit  330 . The port cap  900  has a closed end  901  that effectively seals off the conduit  330  so as to prevent fluid flow from the conduit  330 . The port cap  900  has a tab  902  that assists the user in removing the port cap  900 . The port cap  900  is thus used when use of the conduit  330  is neither desired nor necessary and the cap  900  thus effectively dead ends the conduit  330 . 
       FIGS. 12-24  show different operating modes for the system  100  of the present invention. 
       FIG. 12  shows a venturi style, low concentration oxygen delivery with humidification. In this operating mode, an expandable external conduit  1000  fluidly mates with the module  300  as described below. The expandable external conduit  1000  has a first end  1002  and an opposing second end  1004 . The expandable external conduit  1000  is expandable along its length (i.e., it can be elongated and subsequently contracted). In the illustrated embodiment, the conduit  1000  is in the form of a collapsible corrugated tube. The conduit  1000  includes one or more air entrainment ports  1005  that are located along the length of the conduit  1000 . An air entrainment port  1005  is an opening or hole formed along the conduit  1000  that freely allows air to flow into the hollow interior of the conduit  1000 . The air entrainment port  1005  is a complete hole formed in the side wall of the conduit  1000  to allow free flow of air into the conduit  1000 . The air entrainment port  1005  can be located at any location along the conduit  1000  and there can be 1 or more ports  1005  formed in the conduit  1000 . 
     The first end  1002  of the conduit  1000  sealingly mates with the open end  332  of conduit  330  so as to allow the gas (such as air) flowing through the conduit to enter into the conduit  330 . Any number of different types of fits or couplings between the two parts can be achieved; including but not limited to a mechanical fit, such as a frictional fit, snap-fit, etc. 
     A multi-port low concentration venturi  1050  is also provided for mating with the second end  1004  of the conduit  1000 .  FIGS. 25A-B  illustrate the venturi  1050  in greater detail. The venturi  1050  can include a first connector  1060  that includes a plurality of venturi tubes  1070  that are attached to and pass through a first connector body  1062  which can be in the form of a plate or disk that has a center hole  1063  formed therein. The venturi tubes  1070  are elongated tubular structures having a center bore and distal orifice  1072  formed therein. As shown, the tubes  1070  can have different diameter orifices  1072 . It will be understood that the flow rate through the tubes  1070  differs depending upon the diameter of the orifice  1072  and therefore, the tubes with smaller diameter orifices have lower flow rates than the tubes with larger diameter orifices. 
     The venturi  1050  also includes a second connector  1080  that mates with the first connector  1060 . The second connector  1080  includes a first part that is in the part of a tubular structure  1082  that is open at both ends and includes a second part in the form of an annular shaped base ring  1084  that has a center opening. The first part  1082  is connected to the ring  1084  by means of a first leg  1085  that is attached to a peripheral edge of the ring  1084 . A second leg  1087  also extends downwardly from the tubular structure  1082 . The second leg  1087  terminates in a small disk  1089  that is disposed within the center of the opening that is defined within the center of the ring  1084 . The disk  1089  and annular base ring  1084  thus define an annular shaped opening or track  1090 . 
     An outer peripheral side edge of the ring  1084  includes ribs  1092  to assist in positioning the axes of the venturi tubes  1070  to the axis of the tubular structure  1082 . 
     It will be appreciated from  FIGS. 25A-B  that a portion of the annular shaped opening/track  1090  extends underneath the hollow tubular structure  1082  and thus the hollow interior (bore) of the structure  1082  intersects the arcuate shaped portion of the opening  1090 . 
     The first and second connectors  1060 ,  1080  mate together by inserting the small disk  1089  into the hole  1063  of the connector body  1062 , thereby allowing the first connector  1060  to rotate within the annular shaped opening or track  1090 . As shown, the tubular structure  1082  is constructed such that only one of the venturi tubes  1070  and in particular the center bore  1072  thereof is centrally located within the bore of the tubular structure  1082 . 
     In accordance with the present invention, the first connector  1060  can rotate relative to the second connector  1080  and within the annular shaped opening/track  1090  to vary which venturi tube  1070  is centrally located within the bore of the tubular structure  1082 . Thus, the user can vary the flow rate of the fluid being discharged from the venturi tube  1070  into the bore of the tubular structure  1082  by selecting the desired venturi tube  1070  which is centrally located within the tubular structure  1082 . To change the characteristics of the fluid flowing into the bore of the tubular structure  1082  and thus into the conduit  1000 , the user simply rotates the first connector  1060  within the track  1090  such that the venturi tubes  1070  rotate about the disk  1089  until the desired venturi tube  1070  is properly located underneath the bore of the tubular structure  1082 . 
     The present invention thus allows the user to easily alter how the venturi functions and how the gas is delivered to the patient. 
       FIG. 12  shows an operating mode in which humidification is provided to the gas (e.g., oxygen) being injected into the module  300 . In particular, the directional valve  800  is positioned such that the openings  820 ,  830 ,  840  are in registration with the internal opening  319  and the openings leading to the conduit  360  and the conduit portion to the end  314 . In other words, the direction valve  800  is positioned such that the conduit  330 , the conduit  360  and the main body  310  toward the end  314  are open and fluid can flow therein. However, the second end  314  is closed off with the cap  410  and thus gas cannot exit or flow into the second end  314 . In addition, the internal opening  313  is closed and thus gas cannot flow toward the first end  312  within the main body  310 . 
     In this position of the directional valve  800 , fluid can only flow through the conduit  330  into the main body  310  and into the conduit  360  and thus, when the patient inhales and the supplemental gas valve assembly  600  opens (under the patient inhalation), gas flowing through the conduit  1000  flows into the conduit  330  and through the open valve assembly  600  into contact with the HME media  700  which acts to heat and humidify the inhaled gas. 
     When the patient exhales, the exhaled gas flows through conduit  360  and the HME media  700  located within the conduit  360  thereby capturing the heat and moisture from the patients exhaled gas and is vented through the valve assembly  590 . Note that during exhalation, swing valve  500  is closed, valve  620  is also closed, both the first conduit  320  and the first end  312  are capped, and hence exhaled air can only exit via HME  700  and then through the exhaled valve  590 . 
       FIG. 12  thus shows a venturi style, low concentration oxygen delivery (by means of the conduit  1000 ) with humidification. 
       FIG. 13  illustrates an operating mode that is similar to the operating mode that shown in  FIG. 12  with the exception that the gas (oxygen) is delivered to the patient without humidification. The directional valve  800  is rotated in the operating mode such that the conduit  360  is closed off and thus gas does not flow into the conduit  360  and thus does not flow into contact with the HME media  700 . Instead, the gas flowing through the conduit  1000  enters the conduit  330  and can flow in the main body  310  towards both the first end  312  and the second end  314 . Since the second end  314  is closed off with the cap  410  and other conduits are closed off as shown, the gas entering the main body  310  through the conduit  1000  flows toward the first end  312 . Upon patient inhalation, the main inhalation valve assembly  500  opens and thus the gas flowing within the main body  310  enters the interior of the patient interface  200  by flowing through the valve assembly  500  and thereby reaches the patient. 
     When the patient exhales, the exhaled gas can only flow through the HME media  700  within conduit  360  and exits through the side port  370  through the exhalation valve assembly  590  to atmosphere. 
       FIG. 14  illustrates a different operating mode and in particular, shows a venturi style, low concentration oxygen delivery with reduced humidification/resistance. In this operating mode, the directional valve  800  is positioned such that the conduit  330 , the conduit  360  and the internal opening  313  are open to flow, while the main body  310  toward the second end  314  is closed off (as shown by the indicator arrows). The conduit  320  is closed off with the cap  900 . 
     It will be appreciated that in this embodiment, the gas (e.g., oxygen) flowing through the conduit  1000  enters the main body  310  and flows both (1) into the conduit  360  and (2) flows through the internal opening  313  toward the first end  312 . Upon patient inhalation, the main inhalation valve assembly  500  opens and gas flows into the face mask  200  to the patient and also flows through the open supplemental gas valve assembly  600  (inhalation valve  620 ) and through the HME media  700  to the patient. Thus, gas flows along two flow paths to the patient during inhalation, with one path being a path that humidifies the gas. It will also be appreciated that in all of the operating modes, the amount of gas flowing into a conduit through the directional valve can be varied by rotating the directional valve to cause less registration between the openings  820 ,  830 ,  840  and the respective conduits. This arrangement though allows intermediate level of heated and moist gas to be inhaled, it has the advantage of overall reduced resistance during inhalation. 
       FIG. 15  shows another operating mode in which an accessory module in the form of a gas reservoir assembly  1100  and the venturi mechanism via venturi connector  1150  are used to deliver variable concentration of oxygen. The gas reservoir assembly  1100  is in the form an expandable bag that includes a neck portion  1110 . The neck portion  1110  includes a connector  1120  that allows the bag  1100  to be sealingly attached to the module  300 . The connector  1120  attaches to the conduit  330  to permit the conduit  330  to be in free communication with the interior of the bag  1100 . The cap  900  is placed on the conduit  320  to close off this conduit  320 . 
     The second end  314  of the main body  310  is an active port in this embodiment and a venturi connector  1150  mates with the second end  314  to allow gas to be delivered thereto. The venturi connector  1150  includes an outer part  1160  that includes a tubing connector (nipple)  1162  that protrudes outwardly therefrom and provides an entrance into the hollow interior of the connector  1150 . The outer part  1160  also includes one or more and preferably a plurality of openings or windows  1170  that are located circumferentially about the side wall of the outer part  1160 . The venturi connector  1150  also includes an inner part that is a tubular structure and likewise includes one or more openings or windows that are located circumferentially about the side wall of the inner part  1140 . Registration between the windows  1170  of the outer part  1160  and the openings of the inner part  1140  can be achieved by moving the outer part  1160  relative to the inner part  1140  or vice versa. It will be appreciated that air enters through the overlying window  1170  and the inner opening  1140  and into the interior of the tubular structure of the inner part that is in fluid communication with the hollow interior of the body part  310 . 
     As gas, such as oxygen flows through the connector  1162  and into the hollow interior of the inner part, air is entrained into the flow stream through the openings of the inner part 1140  and the window 1170 . The amount of air entrained can be varied by increasing or decreasing the relative size of the openings formed by the relationship of the outer part  1150  and the inner part  1140  by rotating the outer part windows with respect to the stationary inner part windows. 
     The cap  900  closes off the conduit  320  and the first end  312  is also closed off. 
     The directional valve  800  is positioned such that the conduits  330 ,  360  are open along with the second end  314  of the main body  310 . Since the conduit  330  is open, the gas reservoir assembly (bag)  1100  is freely open to the main body  310  and gas can both flow into and flow out of the bag  1100  relative to the main body  310 . 
     Gas, such as oxygen, flowing into the main body  310  can flow directly into the bag  1100  and thus, the bag  1100  serves a structure that stores excess gas (that enters through the venturi connector  1150 ) that is not immediately needed by the patient. However, since the inside of the bag  1100  is in communication with the conduit  360  when the supplemental gas valve assembly  600  opens, the gas within the bag  1100  can be inhaled by the patient during inhalation since the valve member  620  is an inhalation valve. 
     In this embodiment, all of the gas inhaled by the patient passes through valve assembly  600  and thus passes through the HME media  700  resulting in heat exchange and humidification thereof. The exhaled air exists through the HME media  700  and the exhalation valve assembly  590 . 
       FIG. 16  shows an operating mode that is very similar to the operating mode shown in  FIG. 15  with the exception that the inhaled air is provided without humidification. In this embodiment, the directional valve  800  is rotated such that the conduit  360  is closed off and instead, the internal opening  313  is open to allow gas that enters through the venturi connector  1150  at the second end  314  and additional gas, if needed, from the bag  1100  to flow toward the first end  312  which is closed off with a cap. As a result, when the patient inhales, the main inhalation valve  500  opens and the gas flows therethrough into the face mask  200 . When the main inhalation valve  500  is closed as during exhalation, the gas flowing into the main body  310  from the venturi connector  1150  can flow into the bag  1100  for storage. As a result, the only inhalation flow path is through the main inhalation valve assembly  500  and thus, the inhaled air is not heated or humidified since no inhaled air flows through the HME media  700 . 
       FIG. 17  shows another operating mode which is similar to the modes shown in  FIGS. 15 and 16  except that in this embodiment, a dual gas reservoir assembly  1200  is provided. The operating mode shown in  FIG. 17  is a variable concentration gas (oxygen) delivery with partial heat exchange and humidification. The dual gas reservoir assembly  1200  includes two different storage compartments that are located within the expandable bag structure. In particular, a body  1210  of the assembly  1200  is partitioned into a first compartment  1220  and a second compartment  1230  by an inner dividing wall  1225 . Gas cannot pass through this wall  1225 . 
     The body  1210  includes two neck portions, namely a first neck portion  1222  that is associated with the first compartment  1220  and a second neck portion  1232  that is associated with the second compartment  1230 . The first neck portion  1222  includes a first neck connector  1227 , while the second neck portion  1232  includes a second neck connector  1237 . The first neck connector  1227  is sealingly attached to the conduit  320 , while the second neck connector  1237  is sealingly attached to the conduit  330 . Gas can thus flow from the main body  310  into and out of each of the first and second compartments  1220 ,  1230 . 
     In this embodiment, there is a pair of venturi style variable concentration delivery means  1150 , one at the open first end  312  and the other at the open second end  314 . As described above, each of these venturi style variable concentration delivery means  1150  is constructed to let gas, such as oxygen from an oxygen source, to flow therethrough and the windows  1170  formed therein allow a user to select the amount of air that is also introduced into the venturi connector  1150  to mix with the gas being injected therethrough. 
     In  FIG. 17 , the directional valve  800  is positioned such that the conduit  360  is open and the conduit  330  is open and the end  314  is open. The internal opening  313  is closed and thus gas cannot flow toward the first end  312  into contact with the main valve assembly  500  from the second end  314  and from the second compartment  1230 . As a result, the inhaled air is humidified since the gas introduced through the connector  1162  and mixed with air through window  1170  flows through the supplemental gas valve assembly  600  (upon patient inhalation) and through the HME media  700  where the inhaled gas is humidified before flowing into the face mask  200  to the patient. 
     Gas (oxygen) flowing through the connector  1162  at the first end  312  (along with air introduced through the window  1170 ) can flow into the first compartment  1220  and also upon inhalation by the patient, the gas flows through the main inhalation valve  500  into the interior of the face mask  200  to the patient. 
     It will be appreciated that the gas introduced at the first end  312  can be the same or a different gas than the gas introduced at the second end  314 . When it is a different gas, the patient thus receives two different gases. 
       FIG. 18  shows another operating mode and in particular, it illustrates variable concentration gas (oxygen) delivery without humidification. The main difference between the modes shown in  FIG. 17  and  FIG. 18  is that the system of  FIG. 17  humidifies the inhaled air, while  FIG. 18  does not. As a result, the directional valve  800  is positioned such that the conduit  360  is closed off and the internal opening  313  is open as well as the second end  314  of the main body  310  and the conduit  330  is open. 
     In this position, the direction valve  800  allows gas that is injected into either the first end  312  and/or the second end  314  to flow to the main inhalation valve assembly  500  and upon inhalation, the gas flows into the face mask  200  as a result of the valve assembly  500  opening. Thus, gas can only flow into the face mask  200  by means of the opening of the inhalation valve assembly  500 . However, gas that flows into the venturi connector  1150  at the first end  312  can flow both into the first compartment  1220  and the second compartment  1230  since the internal opening  313  is open. Similarly, gas that flows into the venturi connector  1150  at the second end  314  can flow into both the second compartment  1230  and the first compartment  1220 . It will be appreciated that the two gases can thus mix to a degree and flow into the various compartments  1220 ,  1230 . However, based on fluid dynamics and flow paths based on the path of least resistance, more of the gas that enters into the first end  312  flows into the first compartment  1220  and similarly, more of the gas that enters into the second end  314  flows into the second compartment. In any event, both gases must flow through the main valve assembly  500  in order to reach the patient. 
       FIG. 19  shows the system  100  in a standard aerosol drug delivery mode. In this operating mode, the conduits  320 ,  330  are open and conduit  360  is closed. Both ends  312 ,  314  of the main body  310  are closed off with plugs and/or caps  400 ,  410  and therefore gas only flows into the mask through the conduits  320 ,  330 . In this case, a nebulizer  1300  is provided and a neck portion  1310  of the nebulizer  1300  mates with the conduit/port  320  to sealingly attach the nebulizer  1300  to the module  300 . 
     In this operating mode, the conduit  330  is open and thus acts as a supplemental gas source as described below. The directional valve  800  is positioned such that the conduit  360  is closed off and thus inhaled air does not pass through the HME media  700 . The aerosolized drug is discharged from the nebulizer  1300  and enters the conduit  320  and flows into the main body  310  in which is it available for delivery to the patient upon inhalation and upon opening of the main inhalation valve assembly  500 . It will be appreciated that excess aerosolized drug can flow through the main body  310  and be vented through the conduit  330  to atmosphere. This is especially the case when the patient is exhaling and the main inhalation valve assembly  500  is closed and thus the aerosolized drug cannot flow to the patient. Conduit  330  also provides a supplemental gas source in addition to the gas being injected into the module  300  by the nebulizer  1300  to meet the inhalation requirements of the patient. 
       FIG. 20  shows an operating mode for enhanced aerosol drug delivery. In this operating mode, the only difference compared to the arrangement of  FIG. 19  is the inclusion of the conduit  1000  which is attached to the conduit/port  330 . The conduit  1000  is sealingly attached to the conduit/port  330  and is open at the other end to allow venting of gas through the conduit/port  330 . The conduit  1000  serves as at least a partial reservoir for storing aerosolized drug when the patient exhales. In other words, when the patient exhales, gas can flow from the main body  310  into the conduit  1000  where some remains captured therein and when the patient subsequently inhales, the main inhalation valve assembly  500  opens and aerosol drug in the conduit  1000  can flow to the face mask  200  and the patient. The conduit  1000  is adjustable-collapsible and expandable to adjust the length of the reservoir for medication storage during exhalation and thereby enhancing controlled and predictable medication delivery during inhalation 
     When the user desires to operate the system in this mode, the conduit  1000  can be selected so as to have no or only a few air entrainment ports  1005 . 
       FIG. 21  shows another operating mode that is similar to the one shown in  FIG. 20  with the exception that the system in  FIG. 21  also includes the multi-port low concentration venturi device  1050 . This operating mode is standard aerosol drug and low concentration oxygen delivery. The venturi device  1050  mates with the free end of the conduit  1000  and allows delivery of a gas (e.g., oxygen). This arrangement allows to control the desired oxygen concentration while simultaneously administering medication. 
     Since the venturi device  1050  mates with conduit  1000 , the gas flowing therethrough flows into the conduit  1000  to the patient via the main body  310 . 
       FIG. 22  shows another operating mode that is defined as standard aerosol drug and variable concentration oxygen delivery. In this operating mode, the gas reservoir assembly  1100  is sealingly attached to the conduit/port  330 . The conduit/port  320  is closed off by the cap  900 . A nebulizer  1400  is sealingly attached to the nebulizer port  340  for delivery of aerosol drug to the patient by flowing through the main body  310 . Upon inhalation, the main inhalation valve assembly  500  opens and the aerosol drug flows into the face mask  200  to the patient. 
     In this operating mode, the conduit  360  is closed off. Gas flowing through the venturi connector  1150  at the second end  314  flows to the main inhalation valve assembly  500  and can mix with the aerosol drug for delivery to the patient. The bag  1100  is open and serves to collect and store both the gas delivered through the venturi connector  1150  and by means of the nebulizer  1400 . 
       FIG. 23  shows another operating mode, namely, a high efficiency drug and variable concentration oxygen delivery mode. The dual gas reservoir assembly  1200  is provided and includes the first compartment  1220  and the second compartment  1230  segregated by the inner dividing wall  1225 . 
     The directional valve  800  is positioned such that the conduit  360  is closed. The conduits  320 ,  330  are open to permit gas to flow into the first and second compartments  1220 ,  1230 . Variable concentration of the gas is achieved by manipulating the mechanism  1150  as discussed herein. 
       FIG. 24  shows another operating mode, namely, another high efficiency drug and variable concentration oxygen delivery mode. The difference between the operating mode of  FIG. 24  and the operating mode of  FIG. 23  is the position of the directional valve  800 . In particular, the directional valve  800  is positioned such that the internal opening  313  is closed off, while the conduit  330  and conduit  360  are open, as well as the end  314 . At the second end  314 , the venturi style delivery mechanism  1150  is provided for delivering gas (oxygen) to the main body  310 . Gas from the mechanism  1150  can flow into the second compartment  1230  of the bag  1200  when the patient exhales. The gas from the mechanism  1150  flows to the patient by passing through the supplemental gas valve assembly  600  and through the HME media  700 , thereby heating and humidifying the inhaled gas. 
     The aerosolized drug flows from the nebulizer  1400  and enters the main body  310  and can only flow to the patient through the main inhalation valve assembly  500  when it opens since the internal opening  313  is closed and thus the aerosol drug cannot flow to the directional valve  800 . 
     This operating mode thus delivers humidified gas (oxygen/air) to the patient along one flow path and the aerosol drug is delivered along another flow path. This arrangement allows preferential flow of medication through path of lower resistance system and additional gas as needed through a relatively higher resistance system thereby maximizing medication delivery. 
       FIGS. 26 and 27  illustrate another embodiment that is very similar to the system shown in the previous figures except for the inclusion of an intermediary valve assembly  1500 . The intermediary valve assembly  1500  is disposed within the internal opening  313  between the conduits  320 ,  330 . The intermediary valve assembly  1500  includes a valve body  1510  and a valve member  1520 . The intermediary valve assembly  1500  is in the form of a one way valve that opens in one direction to only allow fluid to flow in the direction from the second end  314  to the first end  312 . The intermediary valve assembly  1500  is an inhalation valve that opens on inhalation by the patient. Thus, when the patient inhales, gas can flow through the valve assembly  1500 . 
       FIGS. 28 and 29  show a venturi connector  1600  according to one embodiment for use in the system  100  of the present invention in place of the venturi connector  1150 . The venturi connector  1600  includes a connector body  1610  that has a first open end  1612  and an opposite second end  1616 . The connector body  1610  has an intermediary lip  1614  with the portion from the lip  1614  to the first end  1612  is a tubular structure with a hollow interior. From the lip  1614  to the end  1616  is a cassette loading port  1620  that is open along the side wall of the connector body  1610 . In particular the side wall includes an opening or notch  1625  that permits access to the interior of the body  1610 . An inner surface of the side wall of the cassette loading port  1620  includes a locking feature, such as a locking channel  1629  or other structure such as a snap, tab, etc. 
     The cassette loading port  1620  receives a venturi port cassette  1700 . The cassette  1700  is in the form of an elongated tubular structure that has a center bore formed therein. The size of the bore can vary as discussed above with reference to the tubes  1070 . The cassette  1700  includes locking feature, such as a locking flange  1640 . The cassette  1700  is received within the notch  1625  and the locking flange  1040  mates with the locking channel  1629 , thereby removably locking the cassette  1700  in place. The cassette  1700  is positioned such that the bore thereof is axially aligned with the hollow interior of the body  1610  and therefore, gas flowing through the cassette flows into the top portion of the connector body  1610 . 
     The main module  300  and the various components and accessories described herein can be formed of any number of different materials including but not limited to a plastic material. 
     Now referring to  FIGS. 30A and 38-40 , a patient interface system (modular pulmonary treatment system)  1800  is shown in accordance with one embodiment of the present invention. The system  1800  is formed of a number of components that mate together to form the assembled system  1800  and in particular, the patient interface system  1800  includes a face mask  1900  and one or more accessories that intimately mate with the face mask  1900 . 
     The illustrated face mask  1900  is merely exemplary in nature and it will therefore be understood that any number of different face mask constructions can be utilized. The face mask  1900  includes a face mask body  1910  that has a front surface or face  1912  and an opposite rear surface or face  1914 . The face mask body  1910  includes a nose portion  1916  that is defined by a planar underside  1917  and a front beveled portion  1918 . The face mask body  1910  has a peripheral edge  1911  that seats and seals against the face of a user. 
     As shown in  FIGS. 38A-C , a hollow interior of the face mask body  1910  can have a landing or planar floor  1913  that is part of the nose portion  1916 . 
     The face mask body  1910  can be formed of any number of different materials including but not limited to polymeric materials. 
     As shown in  FIGS. 38A-C , the face mask  1900  includes a number of valve assemblies and in particular, includes a first valve assembly  1920  and a second valve assembly  1940 . The first valve assembly  1920  is in the form of an inhalation valve assembled and thus opens only when the patient inhales. The first valve assembly  1920  is defined by a primary valve body  1922  that has a first end  1924  and a second end  1926 . The valve body  1922  can be in the form of a tubular body with the first end  1924  defining an annular valve seat and the second end  1926  defining a portion that can be connected to another member including a conduit, such as tubing as described herein. The valve seat at the first end  1924  of the valve body  1922  can be constructed to receive a first valve  1930  which can be in the form of a flapper valve. When in the form of a flapper valve  1930 , the first end  1924  includes a coupling means (members)  1932  that receive a pin  1934  that pass through bores that are formed through a pair of fingers  1936  that extend from the valve  1930 . A hinge is thus formed and the valve  1930  pivots relative to an axis that extends through the pin  1934 . The valve  1930  opens only when the patient inhales. 
     The planar underside  1917  of the nose portion  1916  includes an inhalation port or opening  1919  that is formed therein for receiving the first valve assembly  1920  and in particular, the first end  1924  of the first valve assembly  1920  is disposed within the inhalation port  1919  with the valve  1930  being at least partially disposed within the open interior space of the face mask  1900 . The valve  1930  thus opens inwardly into the interior space. Any number of different means can be used to attach the first valve assembly  1920  to the face mask body including mechanical means. 
     The second valve assembly  1940  is in the form of an exhalation valve and mates with an exhalation port or opening  1941  formed in the nose portion  1916 . In the illustrated embodiment, the opening  1941  is a circular shaped opening. The opening  1941  is formed generally perpendicular to the opening  1919  in that a central axis through opening  1919  intersects a central axis through opening  1941  to form a right angle. The opening  1941  is located above the opening  1919 . 
     The second valve assembly  1940  includes an exhalation valve body  1942  that has a first end  1943  that is inserted into the opening  1941  and a second end  1945  that is located outside of the face mask body  1910 . The valve body  1942  includes a central post  1946  that is attached to the inner wall of the body  1942  by a support structure, such as a spoke structure. The second valve assembly  1940  includes an exhalation valve  1950  that has a center hole to allow the exhalation valve  1950  to be received on the central post  1946 . A valve retainer  1960  (that acts as a cap) mates with the post  1946  to securely attach and hold the valve  1950  in place. The valve  1950  seats against the support structure (spoke structure) when the valve  1950  is in the closed position. The valve  1950  opens only when the patient exhales to allow exhaled air out of the inside of the face mask  1900 . 
     The face mask body  1910  itself preferably does not include internal exhalation ports, valves, openings, vents, etc. 
     In accordance with the present invention, a multi-port valve body (connector or adapter)  2000 , as shown in  FIG. 39A , is provided for use with the patient interface system (modular pulmonary treatment system)  1800 . As described herein, depending upon the precise application, the various components of the system  1800  are configured to achieve the desired treatment objective. The multi-port valve body connector  2000  includes a first end  2002  and an opposing second end  2004 . The connector  2000  is a tubular structure with a hollow center that is open at the ends  2002 ,  2004 . 
     As shown, the connector  2000  does not have a uniform outer diameter but instead can be defined by two different regions, namely, a first region  2001  being located at the first end  2002  and a second region  2003  being located at the second end  2004 . The second region  2003  can have an outer diameter that is less than the first region  2001 . A shoulder  2005  can be formed between the two regions  2001 ,  2003 . 
     The connector  2000  also includes a pair of side conduits in the form of a first leg  2010  and a second leg  2020  that extend radially outward from the main body of the connector  2000 . The first and second legs  2010 ,  2020  are spaced from one another (e.g., at a 90 degree angle) and can be formed in the same plane. The legs  2010 ,  2020  can be circular shaped tubular structures that are in fluid communication with the bore (hollow interior) of the main connector body. It will be understood that the sizes (e.g., diameters) of the legs  2010 ,  2020  can be different or can be the same. 
     The first leg  2010  is in the form of an inhalation valve assembly and thus includes a valve seat  2012 . The valve seat  2012  is disposed within and secured to the first leg  2010 . The valve seat  2012  includes a body that has air passages formed therein and includes a center post  2013  that is received within a hole  2015  formed in an inhalation valve  2017  for attaching the valve  2017  to the valve seat  2012 . The inhalation valve  2017  opens when the patient inhales. 
     The second leg  2020  can be an open leg in that it does not include a valve member but instead is merely a free vent to allow air to flow into and out of the inside of the connector  2000 . The second leg  2020  can thus be completely open. 
     The system  1800  also includes another multi-port valve body (connector or adapter)  2100  as shown in  FIG. 40 . The multi-port valve body connector  2100  is similar to the connector  2000  and includes a first end  2102  and an opposing second end  2104 . The connector  2100  is a tubular structure with a hollow center and is open at the ends  2102 ,  2104 . 
     As shown, the connector  2100  does not have a uniform outer diameter but instead can be defined by two different regions, namely, a first region  2101  being located at the first end  2102  and a second region  2103  being located at the second end  2104 . The second region  2103  can have an outer diameter that is less than the first region  2101 . A shoulder  2105  can be formed between the two regions  2101 ,  2103 . 
     The connector  2100  also includes a pair of side conduits in the form of a first leg  2110  and a second leg  2120  that extend radially outward from the main body of the connector  2100 . The first and second legs  2110 ,  2120  are spaced from one another (e.g., at a 90 degree angle) and can be formed in the same plane. The legs  2110 ,  2120  can be circular shaped tubular structures that are in fluid communication with the bore (hollow interior) of the main connector body. It will be understood that the sizes (e.g., diameters) of the legs  2110 ,  2120  can be different or can be the same. 
     The first leg  2110  is in the form of an inhalation valve assembly and thus includes a valve seat  2112 . The valve seat  2112  is disposed within and secured to the first leg  2110 . The valve seat  2112  includes a body that has air passages formed therein and includes a center post  2113  that is received within a hole  2115  formed in an inhalation valve  2117  for attaching the valve  2117  to the valve seat  2112 . The inhalation valve  2117  opens when the patient inhales. 
     The second leg  2120  is in the form of an exhalation valve assembly and thus includes a valve seat  2122 . The valve seat  2122  is disposed within and secured to the second leg  2120 . The valve seat  2122  includes a body that has air passages formed therein and includes a center post  2123  that is received within a hole  2125  formed in an exhalation valve  2127  for attaching the valve  2127  to the valve seat  2122 . The exhalation valve  2127  opens when the patient exhales. A valve retainer  2129  is used to couple the valve  2127  to the seat  2122 . 
     In addition, the connector  2100  includes a second inhalation valve assembly  2150 . The inhalation valve assembly  2150  includes a valve seat  2152 . The valve seat  2152  is disposed within and secured to the inner wall of the main body of the connector  2100 . In particular, the second inhalation valve assembly  2150  is disposed between the legs  2110 ,  2120  and the second end  2104 . The valve seat  2152  includes a body that has air passages formed therein and includes a center post  2153  that is received within a hole  2155  formed in a second inhalation valve  2157 . The second inhalation valve  2157  opens when the patient inhales. The second valve  2157  can be located at the interface between the regions  2101 ,  2103  below the first leg  2110  and the second leg  2120 . 
     When the patient inhales, the inhalation valves  2117 ,  2157  open and air can flow to the patient through the main body of the connector  2100  and through the first leg  2110 . 
     Now referring back to  FIG. 30A , the system  1800  includes accessories as mentioned above and in particular,  FIG. 30A  shows system  1800  being configured for low concentration gas (oxygen) delivery. The system  1800  includes a main external conduit  2200  that has a first end  2202  and a second end  2204 . The external conduit  2200  is in the form of a tubular structure that permits gas to be delivered from a source to the inside of the face mask and thus be delivered to the patient. The external conduit  2200  can be in the form of a corrugated tube (e.g., 22 mm tube); however, other tube structures and other conduits can be equally used. The length of the external conduit  2200  can be varied (expanded/contracted) as a result of the structure of the conduit  2200 . 
     The external conduit  2200  is fluidly connected to the second end  1926  of the valve body  1922  as by a frictional fit or some other suitable attachment means. 
     In the embodiment of  FIG. 30A , the multi-port valve body connector  2000  is coupled to the conduit  2200  and a venturi device  2300 . The second end  2004  of the connector  2000  is attached to the conduit  2200  and the first end  2002  of the connector  2000  is attached to the venturi device  2300 . The second region  2003  can be frictionally fit with the conduit  2200  as by being received within the conduit  2200 . Similarly, a connector portion of the venturi device  2300  is mated with the first region  2001  of the connector  2000 . 
     In this configuration, the second end  2004  represents a top end of the connector  2000  and the first end  2002  represent a bottom end of the connector. The open second leg  2020  represents a means for entraining air into the external conduit  2200  for mixing with the gas from the gas source that is controlled (metered) by the venturi device  2300  to thereby delivery the proper concentration of gas to the patient. 
     As the patient inhales, the inhalation valve  1930  in the face mask opens to allow a gas mixture (e.g., mixture of air and oxygen flowing in from venturi  2300  and the entrainment port  2020  of connector  2000  at a concentration between about 24% to about 50%) to flow to the inside of the face mask for breathing by the patient. When the patient exhales, the inhalation valve  1930  closes and the exhalation valve  1950  opens to allow exhaled gas to be exhausted from the face mask  1900 . 
     It will be appreciated that the venturi device  2300  can be any number of different venturi devices that are configured to meter the flow of gas from the gas source to the external conduit  2200 . The venturi device  2300  can be of the type which delivers a fixed contraction of gas or can be of a type that delivers a variable concentration of gas. In addition, the venturi device  2300  can be of the type that is disclosed in commonly owned, U.S. patent application Ser. No. 61/610,828, which is hereby incorporated by reference in its entirety. 
     In the illustrated embodiment, the venturi device  2300  is of a type that allows the gas concentration (oxygen) to be between about 24% to 50%. 
       FIG. 30B  shows an alternative system  1801  for low concentration gas (oxygen) delivery (e.g., between about 24% and 50%). The system  1801  is similar system  1800  but includes a different face mask  1901  ( FIGS. 38D-F ). The face mask  1801  does not include the exhalation valve  1950  and does not include primary inhalation valve  1930  within the valve body  1922 . Instead the mask  1901  includes an elongated port  1921  a tubular structure that does not include any valve structure and is free of such elements. Fluid can freely flow therethrough into the inside of the mask  1901 . 
     Instead, the system  1801  includes the connector  2100  disposed between the port  1921  and the upper end  2202  of the external conduit  2200 . The connector  2100  is arranged such that the first region  2101  is attached to the port  1921  and thus the main valve  2157  is disposed below the side ports  2110 ,  2120  closer to the external conduit  2200 . When the patient inhales, the main inhalation valve  2157  opens to allow the gas (oxygen and air) to flow through the conduit  2200  to the inside of the mask  1901  to the patient. The inhalation valve  2117  serves as an emergency valve and does not normally open or does not open to the degree main valve  2157  opens and instead opens only when there is no other source of gas for the patient. The exhalation valve  2127  in the second port  2120  serves as the main exhalation valve and exhaled air flows therethrough. During exhalation, the gas from the venturi device  2300  remains in the conduit  2200 . 
     An air entrainment port  2301  can be formed in the venturi device  2300  as shown for drawing additional air into the venturi device  2300  and into the conduit  2200  for delivery to the patient. 
     As with the system  1800 , the system  1801  can deliver gas concentrations between about 24% to 50%. 
     Now referring to  FIG. 31  in which a standard dose aerosol drug delivery system  2400  is shown. The system  2400  has many of the components of the system  1800  and therefore, like elements are numbered alike. 
     In this embodiment, the connector  2000  is attached to the second end  1926  of the valve body  1922 . The open end  2004  of the connector  2000  is fluidly attached to a drug delivery means  2410  that delivers aerosolized drug. For example, the drug delivery means  2410  can be in the form of a nebulizer that delivers aerosolized drug. The second leg  2020  of the connector  2000  is connected to a first end  2422  of an elbow shaped connector  2420  while an opposite second end  2424  is connected to one end of the external conduit  2200 . 
     The system  2400  is of an open nature in that the opposite end of the external conduit  2200  remains free of any connection and therefore is open to atmosphere. As a result when the main inhalation valve  1930  within the main body of the connector  2100  is closed (as when the patient is exhaling), the aerosolized drug from the means  2410  flows through the connector  2000  and through the open side port  2020  into the conduit  2200  for storage and future use. End  2204  remains open to atmosphere so the aerosolized drug can be vented if needed to atmosphere when the patient is exhaling through the exhalation valve  1940 . The conduit  2200  is adjustable-collapsible and expandable to adjust the length of the reservoir for medication storage during exhalation and thereby enhancing controlled and predictable medication delivery during inhalation 
     Now referring to  FIG. 32 , a system  2500  is shown in the form of high dose aerosol drug delivery. 
     The system  2500  includes connector  2000  attached to the open end  1926  of the valve body  1922  that extends through the port  1919 . In particular, the connector  2000  is oriented such that the first region  2001  attaches to the valve body  1922  (friction fit) and the second region  2003  attaches to the source of aerosolized medication (e.g., nebulizer  2410 ) as by a friction fit. 
     The connector  2420  (e.g., elbow connector) is attached at its first end  2422  to the second leg  2020  of connector  2000 . The second end  2424  of the connector  2420  is attached to a reservoir  2450  that receives and stores gas (e.g., aerosolized medication from the nebulizer  2410 ) under select conditions. The reservoir  2450  can be in the form of a reservoir bag that includes a connector  2460  at an open first end. The connector  2460  is a hollow member and includes a side port  2465  that extends radially outward from one side of the connector  2460 . The other end of the connector  2460  is attached to and in fluid communication with the inside of an expandable reservoir bag  2470 . The reservoir bag  2470  can be in the form of a 1.5 liter bag that holds overflow aerosolized medication from the nebulizer  2410 . 
     Gas (aerosolized medication) can flow into the bag  2470  when the patient exhales since the inhalation valve  1930  is closed and the second leg  2020  of connector  2000  is always open leading to the reservoir  2470 . Exhalation is through valve  1940 . 
     The side port  2465  can be left open (so as to allow the venting of the contents of the reservoir bag  2470  or can be closed with a cap or the like so as to close off the bag  2470  and create a closed system. The side port  2465  permits control of the concentration of the dose and in particular, if the side port  2465  is not closed and left open, the concentration of the aerosolized medication that is delivered to the patient is reduced. Conversely, if the side port  2465  is left closed (capped), the aerosolized medication that flows into the bag  2470  remains collected in the bag  2470  and is not mixed with or vented to atmosphere outside of the bag  2470 . 
     Now referring to  FIG. 33A , a system  2600  is shown and is in the form of a 100% non-rebreather gas (oxygen) delivery system. 
     The system  2600  includes reservoir bag  2470  which is connected to the face mask  1900  via the valve body  1922  and in particular, the reservoir bag  2470  is connected to the connector  2000  which in turn is connected to the valve body  1922 . More specifically, the connector  2000  is connected at region  2001  to the end  1926  of the valve body  1922  and the region  2003  of the connector  2000  is connected to the connector  2460  associated with the reservoir bag  2470 . 
     The inhalation valve  2017  of the connector  2000  serves as an emergency inhalation valve to allow air to be delivered to the patient under select conditions. 
     The side port  2465  of the connector  2460  is fluidly connected to a gas source, such as oxygen, for delivery to the patient. The connector  2460  does not include an inhalation valve within the main body thereof (unlike the connector  2100 ) and therefore, gas flowing through the side port  2465  flows into the connector  2460  and the reservoir bag  2470  and into the valve body  1922  such that when the patient inhales and the inhalation valve  1930  opens, the gas from the gas source and reservoir bag  2470  is delivered to the inside of the face mask  1900  to the patient. 
     The gas stored in the reservoir  2470  is available once the patient inhales since it can freely flow through the connector  2460  and valve body  1922  to the patient when valve  1930  is open. 
     It will be appreciated that a conduit, such as tubing or the like, is used to connect the gas source to the side port  2465 . 
       FIG. 33B  shows an alternative system  2601  (100% non-rebreather gas (oxygen) delivery) using the face mask  1901 . The connector  2100  is connected to the port  1921  at the first region  2101  thereof. Thus the main inhalation valve  2157  is located below the side ports  2110 ,  2120 . The second region  2103  is connected to the connector  2460  of the reservoir  2450  (bag  2470 ). 
     The inhalation valve  2117  in the side port  2110  is an emergency valve as discussed herein and the exhalation valve  2127  disposed in the second port  2120  is the main exhalation valve. The side port  2465  is connected to the gas source (e.g., oxygen) and when the patient inhales and valve  2157  opens, the gas is delivered to the inside of the face mask  1901  to the patient. When the patient exhales and valve  2157  is closed, the gas flows to the bag  2470  and exhaled air is vented through the side port  2120  (valve  2127 ). 
     Now referring to  FIG. 34A , a system  2700  is shown in the form of low concentration gas (oxygen) delivery with heat and moisture exchange. The system  2700  includes components previously discussed; however, these parts are arranged to provide the intended treatment. In this embodiment, a heat and moisture exchanger (HME)  2710  is used and is configured to attach to different components and in particular, includes a first end  2712  and an opposite second end  2714 . The ends  2712 ,  2714  act as connector ends. In between the ends  2712 ,  2714 , the HME  2710  includes HME media to perform the heat and moisture exchange. As previously mentioned, the HME media is constructed to heat and humidify inhaled air and in the present system  2700 , the HME media is disposed within the hollow tubular structure of the HME  2710 . The HME media is thus in fluid communication with both the gas to the patient as discussed below for inhalation by the patient and also exhaled gas that flows from the patient as discussed below. 
     In the HME mode, the main exhalation valve  1940  of the face mask  1900  is capped so as to disable this valve and this venting port during exhalation. In addition, the main inhalation valve  1930  of the face mask  1900  is also disabled so as to allow exhaled gas to flow into and through the valve body  1922 . Any number of different means can be used to disable the inhalation valve  1930  and in one embodiment, the HME device  2710  includes an element (not shown) for disabling the main inhalation valve  1930 . For example, the HME device  2710  can include an extension (pin, rod, etc.) that is integrally attached thereto and extends outwardly therefrom and can be received within valve body  1922  so as to forcible contact and open the valve  1930  as by lifting the valve  1930  away from its seat  1924  (this disables the valve  1930  by preventing it from closing). Since the exhalation valve  1940  is capped and the inhalation valve  1930  is disabled, both inhalation and exhalation is performed through the valve body  1922  and through the HME  2710 . This is required since for the HME  2710  to function, the HME media needs to be in fluid contact with the warm, moist exhaled gas and also in communication with the gas that is inhaled by the patient. 
     The end  2712  is connected to the end  1926  of the valve body  1922 , while the end  2714  is connected to the first region  2101  of the connector  2100 . The region  2103  of the connector  2100  is connected to the first end  2202  of the external conduit  2200 . The second end  2204  of the conduit  2200  is connected to the venturi device  2300 . As mentioned herein, the venturi device  2300  can be any number of different types of venturi devices including but not limited to a variable venturi device in which the concentration of the gas being delivered from a gas source to the external conduit  2200  and then ultimately to the patient can be varied. 
     The inhalation valve  2117  that is disposed in the first leg  2110  serves as an emergency valve. The exhalation valve  2127  disposed in the second leg  2120  serves as the main exhalation valve of the system since the exhalation valve  1940  of the face mask  1900  is closed as discussed above. 
     The system  2700  includes an air entrainment port to permit air to be drawn into the external conduit  2200 . The air entrainment port can be formed in any number of different locations so long as it functions to permit air to flow into the conduit  2200  to mix with the gas delivered through the venturi device  2300 . For example, a connector with an air entrainment port (i.e., an open side port) can be connected between the external conduit  2200  and the venturi device  2300 . Alternatively, the external conduit  2200  can include an air entrainment port (i.e., an open port formed in the side of the external conduit  2200 ) to allow air to flow into the external conduit  2200  for mixing with the gas (oxygen) from the gas source. Alternatively, the venturi device  2300  can include an air entrainment port (an open side port) that is in fluid communication with atmosphere to draw air therein for mixing with the gas delivered through the venturi device  2300 . 
     The system  2700  is a low concentration gas (oxygen) delivery system since the gas concentration can be controlled by the venturi device  2300  in the manner described hereinbefore. As mentioned earlier, the venturi device  2300  is configured to deliver low concentration (e.g., about 24% to 50%) of gas. 
     The system  2700  operates in the following manner. When the patient inhales, the inhalation valve  2157  in the connector  2100  opens and gas can flow into the external conduit  2200  by way of the venturi mechanism  2300 . The inhalation valve  1930  is disabled (remains open) and therefore, the mixed gas flows through the external conduit  2200  to the inside of the face mask  1900 . The mixed gas flows through the HME media  2710  and therefore, is heated and humidified before delivery to the patient. Upon exhalation, the exhaled gas flows through the inside of the face mask  1900  to the HME device  2710  where it contacts the HME media is exhaled through exhalation valve  2127 . As mentioned, the HME media serves to capture heat and moisture from the exhaled air. This allows recharging of the HME media upon each exhalation, thereby allowing the inhaled air to be heated and humidified. 
       FIG. 34B  is similar to  FIG. 34A  and discloses a system  2701  which uses mask  1901 . The main inhalation valve is valve  2157  with the valve  2117  being an emergency valve as discussed herein. The exhalation valve  2127  is the main exhalation valve of the system. Since connector  2100  is below the HME  2710 , both inhaled and exhaled air passes through the HME. The advantage of this mask assembly is that it does not require disabling of inhalation and exhalation valves as described before for embodiment  34 A mask where valves  1930  and  1960  had to be disabled. 
     The venturi device  2300  can be of a variable type and allows the concentration of gas (oxygen) to be varied and can include an air entrainment port to allow air to flow into the device  2300 . The concentration can be varied between about 24% to 50%. Any number of different venturi devices  2300  can be used. 
     Now referring to  FIG. 35A  in which a system  2800  is shown. The system  2800  is a high concentration gas (oxygen) delivery system without heat and moisture exchange. 
     In this embodiment, the connector  2100  is connected at its first region  2101  to the end  1926  of the valve body  1922  and the second region  2103  is connected to the reservoir  2450  (e.g., reservoir bag). In particular, the second region  2103  is attached to the connector  2460  associated with the reservoir  2450 . The connector  2460  includes the side port  2465 . 
     Connector  2420  (e.g., elbow connector) is attached at its first end  2422  to the first leg  2110  of connector  2100  and thus, the inhalation valve  2117  is in fluid communication with the connector  2420  and allows fluid to flow into the face mask  1900  under select conditions. The second end  2424  of the connector  2420  is attached to a tee connector  2810  that has a first end  2812  and an opposite second end  2814  with the first end  2812  being attached to the second end  2424  of the connector  2420  and an opposite second end  2814  being attached to the venturi device  2300 . The tee connector  2810  includes an intermediate port  2820  that is located between the ends  2812 ,  2814 . The intermediate port  2820  is an open port that functions as an air entrainment port for drawing air into the system at a location above the venturi device  2300  and therefore, the air drawn into the tee connector  2810  is mixed with the gas delivered through the venturi device  2300 . 
     The venturi device  2300  has an inlet port  2301  associated therein in which the gas (e.g., oxygen) is delivered. 
     As in the other embodiments, the venturi device  2300  can be any number of different types of venturi devices. 
     In  FIG. 35A , a gas source  2850  is shown. The gas source  2850  can be any number of different types of gas sources and the gas can be any number of different types of gas including but not limited to oxygen (e.g., it can also be heliox, etc.). A wye connector  2860  is provided and includes a main leg  2862  that is connected to the gas source  2850  and a pair of split first and second legs  2870 ,  2880 . A distal end  2872  of the split leg  2870  is connected to the inlet port  2301  of the venturi device  2300  for delivering gas thereto. A distal end  2882  of the split leg  2880  is attached to the side port  2465  of the connector  2460  that is associated with the reservoir  2450 . 
     As described in detail in Applicant&#39;s U.S. Pat. No. 7,841,342, which is hereby incorporated by reference in its entirety, the first and second legs  2870  and  2880  can function to meter the flow of the gas to the respective inlet (i.e., to the inlet  2301  and to the side port  2465 ). For example, the first and second legs  2870 ,  2880  do not necessarily have a uniform construction relative to one another but instead, the restrictive inside diameter of one leg  2870 ,  2880  can be different than the other leg for changing the gas flow rate to the respective port. For example, by reducing the diameter of the leg, the flow rate of the gas is reduced, thereby allowing the user to customize and tailor the concentration of the gas that is delivered to the patient. The system  2800  is configured such that gas concentrations of between about 50% and about near 100% is delivered under select conditions described below. 
     To achieve maximum gas concentration, the intermediate port  2820  of the tee connector  2810  is capped to prevent air from flowing into the tee connector  2810  and by constructing the tubing wye connector  2860  such the flow rates to the venturi device  2300  and the connector  2460  maximize gas concentration. For example, the leg  2870  connected to the venturi device  2300  can have a reduced gas flow rate compared to leg  2880  and thus, a greater amount of gas is delivered to the patient through the connector  2460  which is located below the internal inhalation valve  2157  of the connector  2100 . Thus, when the patient inhales and the inhalation valve  2157  opens, the gas from the gas source flows through the connector  2460  and the valve body  1922  and into the inside of the face mask  1900  to the patient. 
     When the patient inhales, gas is also delivered through the venturi device  2300  and through the elbow connector  2420  and the first leg  2110  of the connector  2100  due to the inhalation valve  2117  in the first leg  2110  opening. Thus, both the gas delivered through the first leg  2870  and through the second leg  2880  meet in the connector  2100  and is delivered into the primary valve body  1922  and to the patient as the valve  1930  opens. It will be appreciated that each of the gas flowing through the first leg  2870  and the gas flowing through the second leg  2880  has to pass through one inhalation valve (i.e., valves  2117 ,  2157 ) before meeting in the first region  2101  of the connector  2100  and thus the relative flow paths have equal resistance in terms of flow to the face mask  1900 . Thus, one route is not favored over the other at least in terms of flow resistance associated with the individual flow paths. This permits the customization of the gas concentration to be possible and controlled as described herein. Thus, altering/modifying the flow properties (flow rate) of the legs  2870 ,  2880  has direct effects on the overall concentration of the gas delivered to the patient. 
     It will be appreciated that two separate conduits can be used instead of the wye-connector  2860 , with one conduit connected to the venturi device  2300  and the other conduit connected to the port  2465 . The two conduits (tubes) can be connected to the same gas source  2850  or can be attached to separate gas sources (which can be the same or different gases). 
       FIG. 35B  shows a system  2801  using mask  1901 . The port  1921  is connected to the connector  2100  with the side port  2110  being connected to the elbow connector  2420 . The other end  2424  of the elbow connector  2420  is connected to the venturi device  2300 . The device  2300  includes an inlet port  2301  connected to gas source  2850 . The illustrated device  2300  is of a type that allows the flow rate to be adjusted and also permits adjustment of the degree of air entrainment as by having an adjustable air entrainment window (as by rotating the device to change the degree of openness of the window  2305 , thereby altering the gas concentration). 
     The exhalation valve  2127  is the means for exhaling air and the valve  2117  is an emergency valve as discussed herein. As in the previous embodiment, the flow paths through the device  2300  and connector  2460  offer equal degrees of resistance since each has one inhalation valve within the flow path. 
     As in  FIG. 35A , two conduits instead of a wye-connector  2860  can be used and more than one gas source can be used in  FIG. 35B . 
       FIG. 36A  shows a system  2900  that is very similar to system  2800  with the exception that system  2900  is high concentration gas (oxygen) delivery with heat and moisture exchange. The set-up and arrangement of the components of the system  2900  is virtually identical to the system  2800  with the one exception being the inclusion of the HME device  2710  between the connector  2100  and the primary valve body  1922 . The first end  2712  of the HME device  2710  is attached to the valve body  1922 , while the second end  2714  is attached to the first region  2101  of the connector  2100 . 
     As with the previous HME application described herein, the main exhalation valve  1940  is capped (disabled) and the primary inhalation valve  1930  is disabled so as to remain always open. This causes both inhaled and exhaled air (gas) to flow through the HME device  2710  thus causing the media to be charged. 
     The tee-connector  2810  can include the port  2820 . Gas flows to the patient when inhaling due to the opening of valves  2117 ,  2157 . The main exhalation is at exhalation valve  2127  in side port  2120  of the connector  2100 . 
     As in the other embodiment, the wye-connector can be substituted with two conduits attached to the device  2300  and the connector port  2465  and one or more gas sources can be used. 
       FIG. 36B  shows system  2901  using face mask  1901  in which the HME media  2710  is connected to the port  1921 . The venturi device  2300  is connected to port  2110  using elbow connector  2420  and the reservoir (bag  2470 ) is connected via connector  2460 . Thus, gas flowing through the port  2465  being stored in reservoir bag  2470  flows through valve  2157  (when patient inhales) and the gas flowing through the venturi device  2300  and connector  2420  flows through the valve  2117  in side port  2110 . 
     Exhalation is through the valve  2127  in side port  2120  of the connector  2100 . 
     As in the other embodiment, the wye-connector can be substituted with two conduits attached to the device  2300  and the connector port  2465  and one or more gas sources can be used. 
       FIG. 37  shows a system  3000  which is a high dose drug deliver with 100% gas (oxygen) delivery. 
     The system  3000  uses face mask  1900  and a first region  2001  of the connector  2000  is connected to the valve body  1922 . The open side port  2020  is attached to the elbow connector  2420  at end  2422  thereof. The other end  2424  of the connector  2420  is attached to a dual reservoir  3010 . As shown also in  FIGS. 42-43 , the dual reservoir  3010  can be in the form of a bag that has a first compartment  3020  and a second compartment  3030 . The compartments  3020 ,  3030  can be divided by a shared inner wall  3015 . As shown in  FIG. 42 , the compartments  3020 ,  3030  has openings or ports  3022 ,  3032  and can include connector  3023 ,  3033  that are attached to the ports  3022 ,  3032  to allow the bag  3010  to be easily attached to another structure. 
     In particular, a U-connector  3100  ( FIG. 43 ) is used to connect the reservoir  3010  to the elbow connector  2420 . The U-connector  3100  includes a connector body  3110  that includes a first conduit section  3120  and an adjacent, separate second conduit section  3130  that merge into an upper conduit section  3140 . The first conduit section  3120  has a side inlet  3125  and a side port  3127 , as well as an inhalation valve  3150  formed of a valve seat  3152  and inhalation valve  3154  that mates thereto as described previously with respect to other inhalation valves. The inhalation valve  3150  is positioned within the first conduit section  3120  at a location above the ports  3125 ,  3127 . The side port  3127  contains a relief valve  3160  and includes a relieve valve seat  3152  and a relief valve  3162  that seats thereto and a valve retainer  3164 . The relief valve  3160  opens when excess pressure exists in the compartment  3020 . The second conduit section  3130  is free of ports and valves and is merely open. 
     The side port  3125  is connected to a gas source that flows into the first compartment  3020  for storage therein so as to provide a supplemental gas source for the patient during inhaling. 
     The device  2410  (nebulizer) is connected to the region  2003  of the connector  2000 . The gas from the nebulizer  2410  is in free communication with bag  3030  and thus when the patient exhales and the inhalation valve  1930  is closed, the aerosolized gas from the nebulizer  2410  flows into the compartment  3030  for storage therein. The supplemental gas stored in the compartment  3020  can flow to the patient when the inhalation valve  3154  opens to allow the supplemental gas to flow through the first conduit section  3120  to the section  3140  and then through connectors  2420 ,  2000  to the main valve body  1922  and through the main inhalation valve  1930  during inhalation. Thus, the gas flow path from the nebulizer  2410  is preferred since the gas only passes through one inhalation valve ( 1930 ) as opposed to the supplemental gas which passes through two inhalation valves  3154 ,  1930 . There is greater resistance in the flow path of the supplemental gas. 
     Exhalation is through valve  1940  in the mask  1900 . 
       FIG. 44A  shows a system  3200  that uses mask  1900  and is in the form of 100% non-rebreather gas (oxygen) delivery with heat and moisture exchange. The HME device  2710  is connected to the valve body  1922 . As in some of the other HME embodiments, the exhalation valve  1940  is capped and the primary inhalation valve  1930  is disabled (so as to remain open all the time). For example, the HME  2710  can include an extension that forces the valve  1930  open. 
     The inhalation valve  2117  is an emergency valve that can open during select conditions. 
     The gas flows into the port  2465  and upon inhalation the valve  2157  opens to allow flow to the patient. Exhalation is through the valve  2127 . 
       FIG. 44B  is a system  3201  using the face mask  1901 . The HME device  2710  is connected to the primary port  1921  of the mask  1901  at end  2712  and the opposite end  2714  of the HME device  2710  is attached to the first region  2101  of the connector  2100 . The region  2103  of the connector  2100  is connected to the connector  2460 . Exhalation is through the exhalation valve  2127  in the connector  2100 . The inhalation valve  2157  is located above the side port  2465  and the gas flows to the mask  1901  when the valve  2157  opens during inhalation and when it closes during exhalation, the gas is stored in the bag  2470  to be available during the next breath. 
     The gas source is connected to the port  2465 . 
       FIGS. 45 and 46  illustrate a patient interface system (modular pulmonary treatment system)  4100  in accordance with one embodiment of the present invention. The system  4100  is formed of a number of components that mate together to form the assembled system  4100  and in particular, the patient interface system  4100  includes a patient interface member (face mask)  4110 . 
     The illustrated face mask  4100  includes a face mask body  4110  that has a front surface or face  4112  and an opposite rear surface or face  4114 . The face mask body  4110  includes a nose portion  4116  that is defined by an underside  4117 . The face mask body  4110  can be formed of any number of different materials including but not limited to polymeric materials. 
       FIG. 45  shows the body  4110  in shell form with some of the operating components being exploded therefrom. While shown in exploded form, it will be understood that the assemblies  4200 ,  4300  are intended to be integral with the mask body  4110  and not separable therefrom by a user. 
     As shown in the shell form, the body  4110  has a number of openings formed therein and in particular, the body  4110  includes a first (front) opening or port  4120 ; a pair of side openings or ports  4130 ,  4140  and a bottom opening or port  4145 . The openings  4120 ,  4130 ,  4140  are formed in the nose portion  4116  of the mask body  4110 . The two side openings  4130 ,  4140  are located opposite one another such that they are formed along the same axis and an axis extending centrally through the front opening  4120  is preferably at a right angle to the axis extending centrally through the two side openings  4130 ,  4140 . A bottom opening  4145  can be formed such that an axis extending centrally therethrough is perpendicular the axis extending centrally through the two side openings  4130 ,  4140  and can also be perpendicular the axis extending centrally through the front opening  4120 . 
     The primary gas valve assembly  4200  is in the form of an elongated hollow body  4210 , such as a tubular structure that is defined by a first end  4212  and an opposing second end  4214 . Between the first and second ends  4212 ,  4214 , there is a side port  4220  that is open to atmosphere. The functionality of the side port  4220  is discussed below and generally, the side port  4220  can function as a secondary gas port. The first end  4212  is intended to mate with the bottom port  4350  of the valve body  4310  such that the hollow interior of the body  4210  communicates with the bottom port  4350  of the valve body  4310 . Fluid (gas) that thus flows longitudinally through the hollow body  4210  enters or exits the mask body  4110  through the bottom port  4350  of the valve body  4310 . In use, the side port  4220  faces outwardly as shown. 
     It will be understood that the primary gas valve assembly  4200  and the mask valve assembly  4300  are intended to be integral to the mask body  4110  and thus, are not intended to be separated from the mask body  4110 . For example, the assembly  4200  and the assembly  4300  can be permanently assembled with the mask body  4110  at the point of manufacture. Any number of different techniques can be used to attach assemblies  4200 ,  4300  to the mask body  4110  including but not limited to using a non-releasable snap-fit. When attached, the primary gas valve assembly  4200  provides a conduit member that extends downwardly from the nose portion of the mask body  4110 . 
     The mask valve assembly  4300  is intended for placement within the hollow interior of the mask body  4110  and as described herein, the mask valve assembly  4300  provides a plurality of valves that operate during use of the system. 
     The mask valve assembly  4300  includes a valve body  4310  that is intended for insertion into and coupling within the hollow interior of the mask. The body  4310  has a complementary construction as the nose portion of the face mask since it is intended to be placed therein. The body  4310  thus houses a plurality of valves and in particular, the body  4310  includes a first valve member  4320 , a second valve member  4330 , and a third valve member  4340 . The first valve member  4320  is disposed within the front opening  4120  of the mask body  4110 . The body  4310  also includes second and third valve members  4340 ,  4350  that are opposite one another in that they are formed along the same axis. The second and third valve members  4330 ,  4340  are disposed within the pair of side openings or ports  4130 ,  4140 , respectively, of the mask body  4110 . 
     As best shown in  FIG. 51 , the first valve member  4320  serves as an inhalation valve, while the second and third valve members  4330 ,  4340  serve as exhalation valves. As shown and according to one exemplary embodiment, the first valve member  4320  is formed of a valve seat  4322  and a valve  4324  that is coupled to the seat  4322  as by being seated over a valve retention knob  4345  that is formed as part of the valve seat  4322 . Since the valve member  4320  functions as an inhalation valve, the valve  4324  is a one-way valve that lifts off of the seat when the patient inhales. The valve seat  4322  can have a spoke construction as shown to permit air flow therethrough. 
     As described below, the first valve member  4320  acts as an emergency air valve. 
     The second valve member  4330  is similar or identical to the first valve member  4320  and is formed of a valve seat  4334  and a valve  4332  that is coupled to the seat  4334  as by being seated over a valve retention knob  4345  that is formed as part of the valve seat  4334 . Since the valve member  4330  functions as an exhalation valve, the valve  4334  is a one-way valve that lifts off of the seat when the patient exhales. The valve seat  4334  can have a spoke construction as shown to permit air flow therethrough. 
     The third valve member  4340  is similar or identical to the second valve member  4330  and is formed of a valve seat  4342  and a valve  4344  that is coupled to the seat  4342  as by being seated over a valve retention knob  4345  that is formed as part of the valve seat  4342 . Since the valve member  4340  functions as an exhalation valve, the valve  4344  is a one-way valve that lifts off of the seat when the patient exhales. The valve seat  4342  can have a spoke construction as shown to permit air flow therethrough. 
     As mentioned and shown, the two valve members  4330 ,  4340  are disposed 180 degrees apart. 
     As best shown in the side elevation view of  FIG. 52 , the body  4310  includes a rear notch  4315  that is formed therein. The notch  4315  functions to receive and mount an HME member within the face mask body as described below. The body  4310  also includes a key slot  4317  and a hinge pin retention posts  4319  that are located along the rear face of the body  4310  below the notch  4315 . 
     As shown in  FIGS. 46-53 , the primary gas valve assembly  4200  and the mask valve assembly  4300  can be configured to mate directly to one another and thus be coupled to one another while being maintained integral to the mask body  4110 . As shown in  FIG. 47 , the primary gas valve assembly  4200  includes a key  4201  in the form of a protrusion that is designed to be received within the key slot  4317  for coupling the two together. The key  4201  and key slot  4317  thus serve as locating members for properly orienting the primary gas valve assembly  4200  and a mask valve assembly  4300 . The body of the primary gas valve assembly  4200  includes a locating shoulder  4211 . 
     In accordance with the present invention, a primary inhalation valve  4250  is disposed within the body of the primary gas valve assembly  4200 . As best shown in the cross-sectional view of  FIG. 50 , the body of the primary gas valve assembly  4200  includes an annular seat  4260  formed therein and located above the secondary gas (side) port  4220 . Along the annular seat  4260 , a mounting cradle  4270  is formed. The primary inhalation valve  4250  is of a swing type in that the inhalation valve pivots or swings between open and closed positions depending upon the degree of force and the direction of the force. The primary inhalation valve  4250  includes a valve member  4252  and a pin  4255  that is received through a bore formed in an enlarged section of the valve member  4252 . In the illustrated embodiment, the valve member  4252  generally has a circular shape; however, other shapes are possible. The pin  4255  is thus coupled to the valve member  4252  by being disposed within the bore, thereby allowing the two parts to move (rotate) independently with respect to one another. The hinge pin  4255  has a length that is such that the ends thereof extend beyond the sides of the valve member  4252 , thereby allowing the hinge pin  4255  to be received within the mounting cradle  4270  for attaching the primary inhalation valve  4250  to the body of the primary gas valve assembly  4200 . As shown in  FIG. 50 , the primary inhalation valve  4250  is disposed above the side port  4220 . The opening (port)  4251  which is covered by the primary inhalation valve  4250  in the closed position thereof can be an eccentric opening  4251  relative to the body of the primary gas valve assembly  4200  as shown in  FIG. 48 . 
     In accordance with one embodiment of the present invention, the primary inhalation valve  4250  has two different degrees of rotation. In particular, the valve  4252  itself rotates along the axis of the pin  4255  as the pin  4255  itself rotates when an appropriate force is applied to the valve  4252 . The additional degree of rotation is that, in some embodiments, the valve  4252  can rotate physically relative to the pin  4255  itself. Thus, the combined pin  4255  and valve  4252  can rotate together and/or the valve  4252  can rotate independently relative to the pin  4255 . 
       FIGS. 51 and 53  also show another feature of the present invention in that an MDI nozzle connector feature is incorporated into the port  4320 . In particular, the port  4320  includes an opening  4390  formed in the side wall of the port  4320  and open to the exterior. Opening  4390  serves as an MDI port. Within the inside of the port  4320 , there is a depending finger  4392  that extends inwardly into the port  4320 . The finger  4392  has a central bore formed therein, with the opening  4390  defining an entrance into the central bore. At an opposite end of the bore, an MDI injection orifice  4394  is formed. As shown, an axis through the orifice  4394  is formed at an angle (e.g., 90 degree) relative to an axis through the central bore (and opening  4390 ). When the MDI is connected to the port  4320 , the MDI nozzle partially enters into the central bore and the discharged medication flows through the bore and exits the orifice  4394  and flows directly to the patient (the orifice  4394  directly faces the patient and the finger  4392  is located behind the emergency inhalation valve assembly. 
     While  FIGS. 46-53  show the use of a valve seat that has a flat valve seat surface, it will be appreciated that different valve seat constructions can be used such as the construction shown in  FIGS. 86-87 . For example, each of the exhalation valve assemblies and the secondary (emergency) inhalation valve assembly can use the valve seat construction illustrated in  FIGS. 86-87 . As shown in  FIGS. 86-87 , a valve seat  4395  is provided and includes hub  4396  and a valve retention knob (integral to the hub)  4397 . The valve seat  4395  includes a valve seat surface  4398  that is a non-planar surface and in particular, as illustrated, the valve seat surface  4398  has a conical shape (but can have any of the shapes described above). 
     In contrast to a flat seat geometry, the valve seat surface can have a non-planar construction and more particularly and in accordance with the present invention, the valve seat construction can be a construction selected from the group consisting of: a conical valve seat ( FIGS. 86-87 ); a conical valve seat, a concave valve seat and a parabolic valve seat. It will be understood that a flat valve can still be used with any of the above seat geometries. A flat valve tends to take the shape of the valve seat and by taking the shape of the seat the valve remains in a non-relaxed state causing internal stresses within the valve. The internal stresses within the valve tend to push the valve into the valve seat creating a more effective seal between the valve and the seat. The dimensional distance between the seat and the under-side of the valve retention knob  4397  forces the valve to take the shape of the seat. 
     Now turning to  FIGS. 54-55  which are rear perspective views showing the hollow interior of the patient interface  4100 .  FIG. 54  shows the patient interface  4100  and an HME assembly  4280  that is shown exploded therefrom. As shown and as mentioned above, the mask valve assembly  4300  is a hollow structure and includes a rear opening  4311  that is defined by an annular shaped flange or lip  4313 .  FIG. 55  shows the HME assembly  4280  inserted and securely attached to the mask valve assembly  4300  (i.e., disposed within the rear opening  4311 ). The HME assembly  4280  is positioned within the mask so as to function as an HME exchange in that both inhaled air and exhaled air of the patient passes through the HME assembly  4280 . 
       FIGS. 56-57  show the HME assembly  4280  in more detail. The HME assembly  4280  includes an HME housing  4290  that is a generally hollow structure with an open first end  4292  and an open second end  4294 . The housing  4290  generally includes an annular wall  4295  that terminates at the second end  4294  and an annular sealing flange  4296  at the first end  4292 . The annular flange  4296  has a greater diameter than the annular wall  4295  and thus protrudes outwardly therefrom. As a result, an annular shaped space is formed between the annular wall  4295  and the annular flange  4296 . 
     The annular wall  4295  has integrally formed therewith one or more HME retention snaps  4297  that assist in retaining the HME media  4299  within the annular wall  4295  of the HME housing  4290 . The HME assembly  4280  also includes HME media  4299  that is sized and configured to fit within the hollow space inside the annular wall  4295 . Any number of techniques can be used to securely couple the HME media  4299  within the hollow space inside the annular wall  4295 . For example, the HME media  4299  can be frictionally fit, bonded using adhesive or snapped into the hollow space inside the annular wall  4295 . The HME media  4299  can be a traditional heat moisture exchange media (i.e., foam, wovens, pleated paperboard, etc.). The illustrated HME media  4299  has a solid cylindrical shape. 
     The annular sealing flange  4296  can include a tab  4309  that serves as finger hold for both insertion and removal of the HME assembly  4280  from the mask valve assembly. The tab  4309  extends outwardly from the annular flange  4296 . 
     The HME assembly  4280  is intended to be securely attached to the body of the mask valve assembly  4310  by a mechanical fit, such as a frictional fit or snap-fit. For example, the lip  4313  of the body of the mask valve assembly can be received within the annular shaped space that is formed between the annular wall  4295  and the annular flange  4296 . This is very much similar to how a lid of a plastic food container mates with the base in a sealing manner. When inserted into the rear opening  4311  of the body of the mask valve assembly, the HME assembly  4280  is securely contained and held in place within the interior of the face mask body in a location in which the open end  4292  faces the patient and thus, one end (face) of the HME media  4299  is exposed and faces the patient. 
     It will be appreciated that the HME assembly  4280  is thus designed to receive the inhaled breath and exhaled breath of the user (patient) and thereby serve as a heat moisture exchanger. 
       FIG. 58  shows one operating mode for the patient interface system (modular pulmonary treatment system)  4000  and in particular, the system of  FIG. 58  is arranged for low concentration oxygen delivery with or without heat and moisture exchange dependent upon whether or not the HME assembly  4280  is placed within the patient interface  4000  as previously described. As shown, the secondary gas port  4220  is capped in this operating mode by means of a cap  4190  (that can be integrally attached to the body of the primary gas valve assembly as by a tether). In this operating mode, a venturi entrainment assembly  4400  is used. The assembly  4400  is formed of a number of parts (components) that interact with one another to provide for controlled gas delivery to a patient. The assembly  4400  is meant for use with a patient interface member (assembly)  4000  that is designed to interact with the patient and in one exemplary embodiment, the interface member  4000  is in the form of a mask assembly. It will be appreciated that the illustrated interface member  4000  is merely exemplary in nature and any number of other types of interface members can be used for delivery gas to the patient. The interface member  4000  includes the primary gas valve assembly  4200  for receiving the gas from the venturi assembly  4400 . An elongated conduit member  4410  is connected to the primary gas valve assembly  4200  and to the venturi assembly  4400  for delivering the gas from the venturi assembly  4400  to the interface member  4000 . The elongated conduit member  4410  can be in the form of an elongated tube which can be of a type which is expandable/retractable in that a length of the elongated conduit member  4410  can be varied. Conventional methods of attachment can be used to attach the elongated conduit member  4410  to both the interface member  4000  and the venturi assembly  4400 . 
       FIGS. 59-70D  illustrate in more detail the venturi assembly  4400  according to one embodiment of the present invention. The venturi assembly  4400  is formed of two main components, namely, a multi-port venturi member  4500  and a secondary gas entrainment valve member  4600 .  FIGS. 59-68  show the multi-port venturi member  4500  according to one embodiment. The multi-port venturi member  4500  has a first end  4502  and an opposite second end  4504 . The multi-port venturi member  4500  is a generally hollow body  4501  that includes a main hollow space  4503  at the first end  4502 . In the illustrated embodiment, the body  4501  has a cylindrical shape; however, it will be appreciated that the body  4501  can have any number of other shapes. 
     The body  4501  also has an air entrainment window  4560  formed therein below the main hollow space  4503 . The air entrainment window  4560  is thus located intermediate to the ends  4502 ,  4504 . The member  4500  also includes a lower body section  4562  that is connected to the hollow body  4501  by means of a pair of opposing walls  4565  (e.g., a pair of vertical walls located 180 degrees apart). The wall  4565  thus partially defines the air entrainment window  4560 . The lower body section  4562  is a disk shaped structure that lies below the air entrainment window  4560  and serves as a floor of the air entrainment window  4560 . The air entrainment window  4560  is thus open to atmosphere and serves to allow air to flow into the hollow space  4503  and then flow ultimately to the patient (by means of the elongated conduit member  4410  to the interface member  4000 ). 
     The member  4500  also includes at least one and preferably a plurality of gas port members  4570 ,  4580  that extend downwardly from the lower body section  4562 . The gas port members  4570 ,  4580  are configured to be individually connected to a gas source (such as an oxygen gas source). As shown in the cross-sectional view of  FIG. 62 , the gas port members  4570 ,  4580  are elongated hollow conduits that each allows a fluid, such as gas, to enter at an exposed, free distal end  4572 ,  4582  and flow therethrough into the hollow space  4503  while flowing by the air entrainment window  4560  which is designed to allow atmospheric gas (air) to be entrained by the gas flow through the gas port orifices  4571 ,  4581 . Entrainment of air through the window  4560  results due to the pressure drop created by the gas flowing through one of the gas port members  4570 ,  4580  and its respective orifice  4571  or  4581 . The distal ends  4572 ,  4582  can be barbed ends to facilitate mating of the gas port members  4570 ,  4580  to conduits (tubing) that is connected to the same, single gas source or to different gas sources. 
     In another embodiment, the member  4500  includes only a single gas port member. 
     It will be understood that at any one operating time, gas is flowing through only one of the gas port members  4570 ,  4580 . As described below, the gas port members  4570 ,  4580  have different gas flow characteristics and therefore, depending upon the desired gas concentration that is chosen to be delivered to the patent, the user selects one of the gas port members  4570 ,  4580  to use. Once again, at any one point in time, only one of the gas port members  4570 ,  4580  is active in that gas is flowing therethrough. Alternatively, both gas ports could be used simultaneously using two gas sources or via a single gas source using a wye-tubing. 
     As best shown in  FIGS. 59-62 , the gas port members  4570 ,  4580  are constructed so as to provide known gas flow rates. In particular, a top wall  4585  is formed across the tops of the gas port members  4570 ,  4580  and defines the ceiling of the gas port members  4570 ,  4580 . An orifice (through hole)  4571 ,  4581  is formed in the top walls  4585  of the gas port members  4570 ,  4580 , respectively. The shape and dimensions of the orifices  4571 ,  4581  define the gas flow characteristics base upon the flow and pressure of the gas provided by the gas source to either of the gas port members  4570 ,  4580 . Hence the degree of pressure drops could be influenced to allow predictable air entrainment to ultimately influence the final oxygen concentration of the gas mixture. 
     As a result, the gas port member  4570  has different flow characteristics than the gas port member  4580 . It will be appreciated that the system  4400  can include a plurality of multi-port venturi members  4500  that can be grouped as a kit. This allows the user to select the venturi member  4500  that has the desired, chosen gas flow characteristics. The venturi members  4500  can be interchanged as part of the overall system  4400  depending upon the precise application and desired gas concentration to be delivered to the patient. 
     As best shown in the cross-sectional view of  FIG. 62 , first lengths of the elongated gas port members  4570 ,  4580  are located above the lower body section  4562  and second lengths of the elongated gas port members  4570 ,  4580  are located below the lower body section  4562  (which is generally in the form of a disk that defines a floor of the member). The second lengths are greater than the first lengths and therefore, more of the gas port members  4570 ,  4580  are located below the lower body section  4562 . The lower body section  4562  defines a solid wall structure between the gas port members  4570 ,  4580 . The tops of the gas port members  4570 ,  4580  are disposed within the air entrainment window. In other words, the height of the gas port members  4570 ,  4580  is such that the tops are disposed within the air entrainment window and therefore, gas exiting the top of one of the gas port members  4570 ,  4580  is mixed with entrained air flowing into the air entrainment window  4560 . 
     The gas flow rates associated with the gas port members  4570 ,  4580  can be the same or the flow rates can be different.  FIGS. 60-61  illustrate a laterally disposed gas injection arrangement in which the gas port members  4570 ,  4580  are located adjacent the vertical walls  4565  as best shown in  FIG. 60  and the orifices  4571 ,  4581  are centrally located with respect to the center bore of the gas port members  4570 ,  4580 . The orifice  4571  has a greater size than the orifice  4581  and therefore, different flow characteristics. It will be appreciated that the orifices  4571 ,  4581  thus serve to meter the gas from the gas source as it flows through the gas port members  4570 ,  4580  into the hollow space  4503 . 
     As will be appreciated by the following discussion, the arrangement in  FIG. 58  serves as a low concentration gas (oxygen) delivery system. The dual nature of the air entrainment windows provides for a reduced or lower concentration of gas being delivered to the patient. As described herein, the user can control the concentration of the gas (oxygen) being delivered to the patient by selecting the desired gas port member  4570 ,  4580  and by manipulating the shutter  4650  to thereby change the degree the air entrainment window is open (or whether it is closed). 
     During inhalation, the primary inhalation valve  4250  (which is located within the hollow body of the primary gas valve assembly  4220  opens in such a way, at least in one embodiment, that it gets significantly out of the way of the flow passage of the gas and/or aerosolized medication flow through the member  4200 . This can be achieved by constructing the valve body  4252  as a flapper valve, umbrella valve, or swing valve and the valve body  4252  can be of a rigid construction or of a flexible construction. 
     It will be appreciated that the emergency inhalation valve member  4324  does not open during normal inhalation activity as a result of the construction and design differences between the primary and emergency inhalation valves  4250 ,  4324 . In particular, the two valves  4250 ,  4324  can be specifically designed to generate differential resistance and differential opening in response to an applied inspiratory flow or pressure. In other words, the two different valves are constructed such that the emergency valve  4324  only opens when an elevated force is applied thereto as compared to the primary valve  4250  which opens when normal inhalation forces are applied. As a result, when normal inhalation forces (pressures) are applied to both during patient inhalation, the primary valve  4250  only will open since the opening pressure requirement of the primary valve is reached; however, the normal inhalation forces (pressures) are not sufficient to open the emergency valve  4324 . As a result, the emergency valve  4324  requires more applied force (pressure) to open and only in an emergency are such elevated applied forces (pressures) achieved especially when the gas flow through the primary inhalation valve may not be sufficient to meet patient&#39;s gas flow requirement. 
     Once the primary valve  4250  opens, the gas (oxygen) can flow directly into the inside of the mask to the patient. When the patient exhales, the primary valve  4250  closes and one or both of the exhalation valves  4332 ,  4334  open to release the exhaled air. 
     As will be appreciated by  FIGS. 54-57 , the HME assembly  4280  can be used as part of this gas delivery operating mode. When the HME assembly  4280  is installed, the HME media  4299  is positioned between the patient and each of the patient interface system  4000  valves and valves of the primary gas valve assembly system  4200  that form a part of the overall system. 
     Thus, it will be appreciated that the HME assembly  4280  is so positioned within the patient interface  4100  that inhaled emergency air passes first through the emergency valve  4324  before coming into contact with the HME media  4299  and passing therethrough to the patient. Even in the unlikely event that the emergency inhalation valve  4324  opens and air flows therethrough, such air flows also through the HME media  4299  before reaching the patient. Similarly, exhaled air passes through the HME media  4299  before then exiting through one or both of the exhalation valves  4332 ,  4334 . 
     The HME assembly  4280  is thus positioned strategically within the mask such that both inhaled and exhaled air pass therethrough and at the same time, the modular nature (cartridge nature) of the HME assembly  4280  permits the user to easily implement the HME functionality. 
     The HME assembly  4280  can easily be inserted and removed from the patient interface  4000  due the unique manner in which it seats within the interface  4000  and therefore, the user can easily convert the face interface  4000  between both an HME operating mode and a non-HME operating mode. 
     The present invention also provides for user adjustment in real-time to alter the concentration of the gas being delivered to the patient since the shutter ( 4650 ,  FIG. 69 ) can be readily adjusted. 
     In the embodiment of  FIGS. 60-61 , the gas port members  4570 ,  4580  are thus not located directly within the air entrainment window due to the members  4570 ,  4580  being disposed adjacent the vertical walls  4565 . 
       FIGS. 63-64  show a different embodiment and in particular, show laterally disposed eccentric gas injection. As with  FIGS. 63-64 , the gas port members  4570 ,  4580  are disposed laterally in that these members are formed adjacent the vertical walls  4565 ; however, in this embodiment, the orifices  4571 ,  4581  are not located centrally within the gas port members  4570 ,  4580 , respectively. Instead, the orifices  4571 ,  4581  are eccentrically formed within the gas port members  4570 ,  4580 . 
       FIGS. 65-66  show a different embodiment and in particular, show centrally disposed gas injection. Opposite to the arrangement shown in  FIGS. 60-61 , the gas port members  4570 ,  4580  in  FIGS. 65-66  are disposed centrally in that the gas port members  4570 ,  4580  are not located adjacent the pair of vertical walls  4565  as best shown in  FIG. 65 . Instead, the gas port members  4570 ,  4580  are located spaced (offset) from the vertical walls  4565  and are disposed directly within the air entrainment window  4560 . The orifices  4571 ,  4581  are located centrally within the gas port members  4570 ,  4580 , respectively. 
       FIGS. 67-68  show a different embodiment and in particular, show centrally disposed eccentric gas injection. Opposite to the arrangement shown in  FIGS. 63-64 , the gas port members  4570 ,  4580  in  FIGS. 67-68  are disposed centrally in that the gas port members  4570 ,  4580  are not located adjacent the pair of vertical walls  4565  as best shown in  FIG. 67 . Instead, the gas port members  4570 ,  4580  are located spaced (offset) from the vertical walls  4565  and are disposed directly within the air entrainment window  4560 . Unlike the centrally disposed gas injection of  FIGS. 65 and 66 , the orifices  4571 ,  4581  in  FIGS. 67 and 68  are eccentrically formed within the gas port members  4570 ,  4580 . 
     It will be appreciated that the relative sizes of the orifices  4571 ,  4581  are merely exemplary in nature and the sizes of orifices  4571 ,  4581  can be readily changed. For instance, the orifice  4581  can be larger in size than orifice  4571 . 
     In one exemplary embodiment, the end  4502  of body  4501  has a outside diameter of about 22 mm. 
       FIG. 69  shows the secondary gas entrainment valve member  4600  which is formed of a generally hollow body  4610  that has a first end  4612  and an opposing second end  4614 . As shown in  FIG. 58 , the second end  4614  is configured to mate with the first end  4502  of the multi-port venturi member  4500 . The second end  4614  can be a female connector type, while the first end  4502  of the multi-port venturi member  4500  is of a male connector type. Similarly, the first end  4612  can be a male connector type that is designed to mate with the elongated conduit member  4410 . 
     The generally hollow body  4610  has a secondary air entrainment window  4620  formed integrally therein. The air entrainment window  4620  extends circumferentially about the body  4610  and thus is defined by a first end (in the form of a vertical edge) and a second end (in the form of a vertical edge). The air entrainment window  4620  is intended to allow atmospheric gas (air) to flow into the hollow interior of the body  4610  where in mixes with the gas that flows out of the multi-port venturi member  4500  (which one will appreciate is already mixed gas due to air being entrained through the air entrainment window  4560  (which can be thought of as being a main or primary air entrainment window). The air entrainment window  4620  is a secondary window since it serves as a second window between the gas source and the patient interface  4000  in which air can be entrained through to mix with the gas for purposes of altering the characteristics, and in particular, the gas concentration, of the gas that is delivered to the patient. 
     In accordance with the present invention, the secondary gas entrainment valve member  4600  includes a rotatable shutter  4650  that is cylidrically and vertically coupled to the body  4610  and more specifically, the shutter  4650  is disposed about the body  4610  in the location of the air entrainment window  4620  to allow the shutter  4650  to either open or close the secondary gas entrainment window  4620  depending upon the desired setting as described below. The shutter  4650  has a first (top) end  4652  and an opposite second (bottom) end  4654 . 
     Any number of different techniques for coupling the shutter  4650  to the body  4610  can be used. For example, different types of mechanical attachment techniques can be used including a friction fit, a snap fit, etc. In  FIG. 69 , the body  4610  includes a shutter retaining mechanism in the form of tabs  4665  spaced apart from one another and located circumferentially about the body  4610 . The top end  4652  of the shutter  4650  is located below the tabs  4665 . 
     The shutter  4650  itself has an air entrainment window  4660  formed therein. The air entrainment window  4660  is defined by a first end  4662  (vertical wall) and a second end  4664  (vertical wall). 
     There is a rotational correlation between the degree of registration between the air entrainments windows  4620 ,  4660  and more particularly, the degree of overlap and openness of the two windows  4620 ,  4660  factors into the amount of air being entrained through the secondary gas entrainment valve member  4600  and thus, the concentration of the gas delivered to the patient. 
     The shutter  4650  rotates about the body  4610  as mentioned above and therefore, the shutter  4650  can include features  4655  as a means to assist the user in rotating the shutter  4650 . In particular, the features  4655  can be in the form of ribs that are spaced apart and extend circumferentially about the shutter  4650 . The ribs  4655  are raised structures that permit the user to more easily grip and rotate the shutter  4650  relative to the body  4610 . 
     The secondary gas entrainment valve member  4600  also preferably includes indicia to allow the user to set the degree of air entrainment and thus, to position the secondary gas entrainment valve member  4600  at a setting that achieves the desired gas concentration being delivered to the patient. 
     For example, the shutter  4650  can include a gas concentration pointer  4665  that is formed along the bottom edge  4654  of the shutter  4650  and the lower region of the body  4610  includes gas concentration indicator markings  4670 . For example, the markings  4670  include a plurality of gas concentrations (in percentages) that correspond to the concentration of the gas that is delivered to the patient. The markings  4670  directly correspond to the degree of overlap between the windows  4620 ,  4660  in that the greater the overlap (registration) between the windows  4620 ,  4660 , the greater the openness of the secondary air entrainment window resulting in a greater flow of atmospheric air into the member  4600  (thereby resulting in a reduced gas concentration being delivered to the patient as a result of more mixing between atmospheric gas and the mixed gas from the multi-port venturi member  4650 ). 
     The rotatability of the shutter  4650  allows the user to effectively and easily “dial in” the desired gas concentration for delivery to the patient by simply rotating the shutter  4650  to cause the pointer  4665  to point to the desired, selected gas concentration indicator marking  4670  (which has the desired gas concentration indicia listed). This results in the window being open the proper desired amount to achieve the target mixing, etc. 
       FIGS. 70A-70D  shows the various operating states of the secondary gas entrainment valve member  4600 . 
       FIG. 70A  shows the air entrainment port in a fully opened position (i.e., complete registration between the windows  4620 ,  4660 ). As will be seen in  FIG. 70A , the markings  4670  include two numbers, namely, a first number that is disposed on top of a second number. These two numbers correspond to the gas concentrations (%) that are obtained depending upon which of the venturi gas port members  4570 ,  4580  is used. In the example shown in  FIG. 70A , the second number (35%) corresponds to the gas port member  4570  (which has a larger orifice  4571  compared to the orifice  4581  of gas port member  4580 ). The first number (24%) corresponds to the gas concentration obtained with gas port member  4580 . 
       FIG. 70D  shows the air entrainment port in a fully closed position (i.e., complete non-registration between the windows  4620 ,  4660 ). As will be seen in  FIG. 70D , the markings  4670  include two numbers, namely, a first number that is disposed on top of a second number. These two numbers correspond to the gas concentrations (%) that are obtained depending upon which of the gas port members  4570 ,  4580  is used. In the example shown in  FIG. 70D , the second number (50%) corresponds to the gas port member  4570  (which has an larger orifice  4571  compared to the orifice  4581  of gas port member  4580 ). The first number (31%) corresponds to the gas concentration obtained with gas port member  4580 . 
       FIGS. 70B and 70C  show the air entrainment window in partially open positions in which the window  4660  formed in the shutter  4650  is not in complete registration with the window  4620  formed in the body  4610 . It will be appreciated that  FIG. 70B  is a partially open window. 
     It will be appreciated that the openness of the air entrainment window is very similar in  FIG. 70B  and in  FIG. 70C ; however, the two different resulting gas concentrations (e.g., 28% vs. 40%) is based on whether the gas port member  4570  or gas port member  4580  is used. When the larger sized gas port member  4570  is used, the 40% is obtained when the window is in the position of  FIG. 70C . Conversely, when the smaller sized gas port member  4580  is used, a gas concentration of 28% is obtained when the air entrainment window is placed in the partially open position of  FIG. 70B . It is to be appreciated that the openness of the entrainment windows in  70 B and  70  C may be different and varied to achieve different concentrations of oxygen delivery based on whether the gas port member  4570  or gas port member  4580  is used. 
     It will be appreciated that other partially open positions can be used with the present system. 
     It will also be understood that the gas entrainment valve member  4600  can be used with other venturi members besides the multi-port venturi member  4500  that is shown paired with the member  4600  in assembly  4400 . For example, the venturi connector assemblies of  FIGS. 25A  and B,  28 - 29 ,  30 A and B and  34 A and B,  35 A and B, and  FIG. 36A  and B can be used with the gas entrainment valve member  4600 . In particular and similar to the system of  FIG. 58 , the combination of any of the above mentioned venturi connector assemblies and with the gas entrainment valve member  4600  provides two different air entrainment windows that are spaced apart from one another. More specifically, the combination provides two air entrainment windows that are located in series between the gas source and the patient interface (mask)  4000 . It will also be appreciated that the gas entrainment valve member  4600  can be used with any traditional venturi (venturi connector) to provide a dual air entrainment window structure. 
     Unlike conventional venturi design, the present invention teaches the use of two connector members that provide the dual window design (dual air entrainment windows) with one air entrainment window being located serially downstream from the other window and at least one window is adjustable in nature in that the degree of which the window is open can be adjusted by the user. 
     It will be appreciated that the elongated conduit  4410  can vary in its diameter and/or length and the size and length of the elongate conduit  4410  dictates the reservoir capacity and provides a means of reducing the noise level of the gas delivery mechanism experienced by the patient. 
       FIG. 71  illustrates one operating mode of the system in accordance with the present invention and in particular, utilizes the patient interface (mask)  4000 . The operating mode shown in  FIG. 71  can be characterized as being a high concentration oxygen delivery operating mode. In this operating mode, the second (distal) end  4214  of the primary gas valve assembly  4200  is attached to a high concentration gas delivery assembly  4700 . The assembly  4700  includes a reservoir member  4710  which can be in the form of an inflatable bag that has an opening  4712  at one end. 
     The assembly  4700  also includes a high concentration gas valve connector  4720  which is configured to mate with and seal to the bag opening  4712 . As best shown in  FIGS. 72-76 , the connector  4720  is formed of a valve body  4722  that has a first end  4724  and an opposing second end  4726 . The valve body  4722  is an elongated hollow structure to allow fluid (gas) to readily flow therethrough. The valve body  4722  includes a retaining ring  4725  that assists in coupling the reservoir member  4710  to the valve body  4722 . However, it will be appreciated that other retaining mechanisms can be used. 
     As shown, the valve body  4722  includes a first gas port  4730  and a second gas port  4740 , each of which is disposed along one side of the body  4722 . The first gas port  4730  is located closer to the first end  4724  and can be in the form of a barbed gas port that is attached to a conduit (e.g., tube) that is attached to a gas source (e.g., oxygen). The second gas port  4740  is located below the first gas port  4730  and includes a main port body  4750  that is integrally formed with the body  4722 . The main port body  4750  is a hollow structure (tubular) that has an open end  4751  and includes along its outer surface a detent ring  4752 . The main port body  4750  also includes an air entrainment window  4755  that is formed therein circumferentially about the main port body  4750 . 
     The second gas port  4740  is of an adjustable type in that it includes a rotating shutter  4760  that is cylindrically and horizontally coupled to the main port body  4750 . As shown, the rotating shutter  4760  can be in the form of cap-like structure that is received on the open end of the main port body  4750 . The shutter  4760  has an open end (which receives the main port body  4750 ) and an opposite closed end. The shutter  4760  has a main section that has an air entrainment window  4762  formed therein. The air entrainment window  4762  extends circumferentially about a portion of the body  4750 . The air entrainment window  4762  is formed at a location on the shutter  4760  such that it overlaps (is in registration) with the window  4755  of the main port body  4750  and preferably, the dimensions of the window  4762  are greater than the dimensions of the window  4755 . 
     The rotating shutter  4760  also includes a (barbed) gas port member  4770  that extends radially outward from the closed end of the shutter  4760  and also is formed internally within the shutter  4760  as shown in  FIG. 75 . The internal section of the member  4770  serves as a gas injection orifice that directs the gas into the hollow interior of the body  4722 . The open end of the internal section of the member  4770  is located preferably in-line with the windows  4755 ,  4762  since the internal section is physically received within the hollow interior of the main port body  4750 . Orifice  4770  could be of variable size (diameter) to allow variable gas flow and pressure drop for air entrainment from window  4762 . Multiple venturi arrangement can be made like  FIGS. 25A  and B,  28 - 29 ,  30 A and B and  34 A and B,  35 A and B, and  FIG. 36A  and B. 
     Similar or identical to the shutter  4650 , the shutter  4760  also includes a gas concentration pointer  4767  that extends outwardly from (and beyond) the open end of the shutter  4760 . The valve body  4722  includes gas concentration indicator markings  4769  that are formed thereon. For example, the markings  4769  can be vertically displayed along the connector body  4722 . As the user rotates the shutter  4760 , the degree of registration between the windows  4755 ,  4762  changes (between a fully open position and a fully closed position, as well as intermediate, partially open states). To change the concentration of the gas being delivered through the second gas port  4750 , the user simply adjusts the shutter  4760  and thereby changes the amount of air entrainment that occurs. In the fully open position of the shutter, more air is entrained with the gas flow and therefore, the concentration of the gas (e.g., oxygen) that is delivered to the patient is lower.  FIG. 76  shows the air entrainment window partially open. 
     One will appreciate that by having two different gas port entry points, different concentration of gas can be achieved and then delivered to the patient. For example, the first gas port  4730  is unmetered and therefore produces a fixed flow rate of the gas (gas concentration) that flows therethrough into the main body. However, as discussed above, the second part port  4740  is metered and produces a variable gas concentration since an amount of air is entrained with the gas that flows through the port member  4770 . Much like the shutter  4650  described hereinbefore, the shutter  4760  can be rotated to adjust the degree of air entrainment and thereby, directly alter the mixed gas that is delivered into the main port body to the patient. It is expected that in most applications, both the first and second gas ports  4730 ,  4740  are attached to the gas source and are both actively receiving the gas at the same time. In the event that the shutter  4760  is closed, the concentration of the gas flowing through the first and second gas ports  4730 ,  4740  is the same. However, in one embodiment, at least one of the first gas port  4730  and the second gas port  4740  can be sealingly closed, as by a cap, thereby leaving one active gas port. 
     As shown in  FIG. 71 , the first and second gas ports  4730 ,  4740  are located below the primary inhalation valve  4250  (that is part of the patient interface  4000 ); however, there is free, unobstructed flow between the first and second gas ports  4730 ,  4740  and the interior of the reservoir member  4710 . Thus, when the primary inhalation valve  4250  is closed, any gas flowing through the first and second ports  4730 ,  4740  flows directly into the interior of the reservoir member  4710 . The bag  4710  can expand as it fills up. 
     When the patient inhales, the primary inhalation valve  4250  opens as discussed herein before and gas can flow directly from the first and second gas ports  4730 ,  4740  and also any gas stored in the reservoir bag  4710  can flow to the patient through the primary inhalation valve  4250 . 
     Now turning to  FIG. 77  which shows another operating state of the system  4000  in accordance with the present invention. The embodiment shown in  FIG. 77  can be thought of as a 100% non-rebreather gas (oxygen) delivery system. In this embodiment, the reservoir member  4710  is connected to a connector  4800  that is a hollow (tubular) structure that includes a single gas port  4810  extending outwardly therefrom. This gas port  4810  is intended for connection to a gas source, such as oxygen. 
     Since gas is delivered through the gas port  4810  by means of the gas port  4810 , the concentration of the gas is fixed and there is no air entrainment (venturi) in this embodiment (thus, the concentration of the gas is not diluted with air). When the primary inhalation valve  4250  is closed, the gas flows through the gas port  4810  into the reservoir member  4710  for storage therein. When the primary inhalation valve  4250  opens, the gas flowing through the gas port  4810  and the gas stored in the reservoir member  4710  can flow to the patient interface  4000 . 
     Now turning to  FIG. 78  which shows another operating mode of the system  4000  of the present invention and in particular, shows a standard dose aerosol drug delivery system. In this embodiment, the secondary port  4220  is not capped with a cap or plug  4190  and a nebulizer device  4900  is sealingly fitted to the open second (distal) end of the primary gas valve assembly  4200 . The nebulizer device  4900  is thus located below the primary gas valve  4250 . The aerosolized medication from the nebulizer device  4900  is thus delivered into the hollow space of the assembly  4200  and upon opening of the primary gas valve  4250 , the aerosolized medication flows directly into the interior of the face mask  4110  to the patient. 
     Since the secondary gas port  4220  remains open and is located below the primary gas valve  4250 , the aerosolized medication is free to flow out of the secondary gas port  4220  when the primary gas valve  4250  is closed as during exhalation. The secondary gas port  4220  thus serves as exit or outlet for the aerosolized medication during exhalation and as a supplemental gas source in addition to the aerosolized medication delivered by the nebulizer  4900  during inhalation. 
       FIG. 79  shows a different operating mode of the system  4000  of the present invention and in particular, this operating mode is an enhanced dose aerosol drug delivery mode. As with the standard dose aerosol drug deliver mode of  FIG. 78 , the operating mode of  FIG. 79  includes the nebulizer  4900  attached to the distal end of the primary gas valve assembly  4200 . Instead of the secondary gas port  4220  being used as a vent or supplemental gas source, a reservoir assembly  5000  is attached to the secondary gas port  4220  for storing the aerosolized mediation when the primary gas valve  4250  is closed. 
     In the illustrated embodiment, the reservoir assembly  5000  comprises several components that mate together to provide a reservoir for storing the aerosolized medication. For example, the illustrated assembly  5000  includes a connector  5010  that sealingly mates with the secondary gas port  4220 . As shown, the connector  5010  can be in the form of a 90 degree elbow connector that attaches at a first end  5012  to the secondary gas port  4220  and has an opposite second end  5014 . The assembly  5000  also includes a reservoir member  5100  which, as illustrated, is in the form of an elongated reservoir tube that has a first end  5102  and an opposite second end  5104 . The first end  5102  is sealingly attached to the second end  5014  of the connector  5010 . 
     It will be appreciated that the reservoir tube  5100  can be a corrugated tube and can have an adjustable length. In addition, the diameter of the tube  5100  can vary. It will be appreciated that by changing one or both of the length and diameter of the tube  5100 , the storage capacity of the reservoir changes. 
     The secondary gas port  4220  is located below the primary gas valve  4250  and the aerosolized drug is introduced into the assembly  4200  at a location below the primary gas valve  4250  and therefore, when the primary gas valve  4250  is closed, the aerosolized mediation flows directly into the reservoir assembly  5000  and more particularly, the aerosolized medication can flow through the secondary gas port  4220  through the connector  5010  and into the reservoir tube  5100 . The aerosolized medication thus resides within the tube  5100  and is stored therein. 
     The enhancement in the drug delivery of the aerosolized drug (medication) results as a result of the secondary gas port  4220  not being simply open to atmosphere as in the embodiment of  FIG. 78  but instead is configured to a reservoir member in the form of the tube  5100  in which aerosolized medication is contained (stored) therein. 
     Now referring to  FIG. 80  in which yet another operating mode of the system  4000  is shown and in particular, the illustrated operating mode is a high dose aerosol drug delivery operating mode. In this embodiment, the patient interface (mask)  4000  is connected to components previously described herein and therefore, like numbers are used in the figures to identify the same components. More specific, the elbow connector  5010  is sealingly attached to the secondary gas port  4220 ; however, instead of the connecting the nebulizer device  4900  to the open end of the primary gas valve assembly  4200 , the nebulizer device  4900  is attached to the end  5014  of the elbow connector  5010 . 
     Similar to the operating mode shown in  FIG. 71 , the operating mode of  FIG. 80  includes the use of the high concentration gas delivery assembly  4700 , which is connected to the second (distal) end of the primary gas valve assembly  4200 . The reservoir member  4710  is in the form of an inflatable bag. The gas delivery assembly  4700  includes the first gas port  4730  and the second gas port  4740  and as previously discussed, this permits one of these ports to be connected to a gas (e.g., oxygen or heliox, etc.) that is for delivery to the patient. As discussed with reference to  FIG. 71 , a wye tube can be used to connect the two ports  4730 ,  4740  to a single gas source or separate tubes (conduits) can be used to connect the two ports  4730 ,  4740  to two different gas sources. As mentioned herein, during normal operating conditions both the first and second gas ports  4730 ,  4740  are attached to the gas source and are both actively receiving the gas at the same time. When a wye tube is used, it will be appreciated that the two distal legs of the wye tube can have the same or different diameters. By controlling the diameters of the distal legs, different gas flow rates can be achieved in the distal legs and thus, different gas flow rates are provided to the nebulizer and one of the gas ports  4730 ,  4740 . Though two separate gas sources could be used, the system of delivery is intended to be used in conjunction with a wye tube, as previously discussed, with the exception that in this case one leg of the wye tube provides gas to the nebulizer  4900  and the other leg of the wye is connected to either one of gas ports  4730  or  4740  to control the oxygen concentration of the gas delivered to the patient. The other port that is not connected to the tubing may remain open or can be capped/plugged using a tethered cap or plug. One could in an alternative mode of delivery simultaneously choose two sources of gas and connect one gas source to the nebulizer and one gas with a wye-tubing to both the ports at the same time during medication delivery to adjust medication delivery and oxygen concentration at the same time. 
     The shutter  4760  can be rotated to adjust the degree of air entrainment and thereby, directly alter the mixed gas that is delivered into the main port body to the patient. The first and second gas ports  4730 ,  4740  are located below the primary inhalation valve  4250  (that is part of the patient interface  4000 ); however, there is free, unobstructed flow between the first and second gas ports  4730 ,  4740  and the interior of the reservoir member  4710 . Thus, when the primary inhalation valve  4250  is closed, any gas flowing through the first or second ports  4730 ,  4740  flows directly into the interior of the reservoir member  4710 . The bag  4710  can expand as it fills up. 
     When the patient inhales, the primary inhalation valve  4250  opens as discussed hereinbefore and gas can flow directly from either the first or second gas port  4730 ,  4740  and also any gas stored in the reservoir bag  4710  can flow to the patient through the primary inhalation valve  4250 . 
     It will also be appreciated that the reservoir member (bag)  4710  stores aerosolized medication from the nebulizer device  4900  as a result of its positioning and based on the fact that there is a free, unobstructed flow path from the nebulizer device  4900  to the inside of the reservoir bag  4710 . In particular, since the nebulizer device  4900  is connected to the secondary gas port  4220 , which is below the primary inhalation valve  4250 , the aerosolized medication from the nebulizer device  4900  can freely flow into the assembly  4200  (at a location below the primary inhalation valve  4250 ) and then through the connector  4720  and into the inside of the bag  4710  when the primary inhalation valve  4250  is closed (i.e., as during exhalation of the patient). 
     Conversely, when the patient inhales, the primary inhalation valve  4250  opens and the aerosolized medication (drug) can flow directly from the nebulizer device  4900  through the assembly  4200  to the patient. In addition, the connector  4720  is fluidly connected to the assembly  4200  and thus, the gas delivered through either of the ports  4730 ,  4740  is delivered through the open primary inhalation valve  4250  to the patient. There are thus two gas flow paths to the patient when the patient inhales. During exhalation, the reservoir bag  4710  stores both the gas delivered through either port  4730  and/or  4740 , and/or the aerosolized medication delivered from the nebulizer device  4900  through the connector  5010 . 
     The embodiment of  FIG. 80  thus provides a high dose aerosol drug delivery system. 
       FIG. 81  illustrates another operating mode for the system  4000  and in particular, this operating mode is a high dose aerosol drug delivery with gas delivery operating mode. This operating mode is similar to the operating mode of  FIG. 80  with the exception that the high concentration gas delivery assembly  4700  is replaced with a high dose aerosol drug/gas delivery mechanism  5100  which is shown in more detail in  FIGS. 83-85 . 
     The high dose aerosol drug/gas delivery mechanism  5100  is a dual reservoir system that is formed of a dual reservoir member (bag)  5110  that has two different (separate) interior compartments for storage of a fluid (gas). In the illustrated embodiment, the dual reservoir member  5110  is in the form of a bifurcated bag that has a first chamber (compartment)  5112  and a second chamber (compartment)  5114 . The bag  5110  includes a neck portion that includes a first opening  5115  and a second opening  5117  (side by side relationship). Note that the dual bag reservoir system for dose drug delivery and high concentration oxygen delivery has been described earlier in  FIGS. 37 and 43   
     The mechanism  5100  includes connectors  5120  that are constructed to mate with the two openings  5115 ,  5117  of the reservoir bag  5110 . Each connector  5120  has a retaining member  5125 , such as a retaining ring, which serves to attach the connector  5120  to the bag  5110 . The conduit members  5122 ,  5124  of connectors  5120  define fluid flow paths allowing gas to flow into and out of the bag  5110 . 
     The mechanism  5100  also includes a high dose valve body  5130  that includes a first end  5132  and an opposing second end  5134 . The first end  5132  is a single conduit member  5135  in that it defines a single flow path, while the second end  5134  has a dual conduit structure in that the second end  5134  includes two side-by-side conduit members  5140 ,  5150  as best shown in the cross-sectional view of  FIG. 85 . The conduit members  5140 ,  5150  resemble legs. The conduit members  5135 ,  5140 ,  5150  are all in fluid communication with one another; however, as discussed below, the conduit member  5140  has a selective fluid communication due to the presence of a valve therein. The second end  5134  can thus generally have a U-shape as shown. The first end  5132  can be in the form of a  22  mm female connector. 
     The valve body  5130  also includes an over-inflation valve assembly  5200 . More specifically, the valve body  5130  has a side port  5210  formed therein which is formed in the conduit member (leg)  5140 . The valve assembly  5200  is disposed within the side port  5210  and more particularly, the valve assembly  5200  includes a valve seat  5220  that is disposed within the side port  5210  and is securely attached to the valve body  5130 . The valve seat  5220  can be a spoke-like structure with a plurality of openings formed between the spokes and also includes a valve mounting post  5222  extending outwardly therefrom. An over-inflation valve  5230  is mated to the post  5222  (by reception of the post  5222  within an opening) and lies over the valve seat  5220 . 
     In accordance with the present invention, a valve retention thimble  5240  is provided and is received over the post  5222 . The valve retention thimble  5240  is constructed and intended to control valve movement. The thimble  5240  is adjustable on the post  5222  and thereby can control the maximum valve movement distance. In other words, the thimble  5240  can be set at a specific distance from the valve seat  5220  and thus from the valve  5230  itself since the thickness of the valve  5230  is known. For a given valve  5230 , the greater the distance from the thimble  5240  to the valve seat and the valve, then the greater the degree of permitted movement for the valve  5230 , thereby allowing a greater degree of opening for the valve  5230 . In one embodiment, the thimble  5240  is adjusted until it is at a desired location along the post and is then set at the site of the manufacturer. Any number of techniques can be used to set it in place including using an adhesive. The use of an adjustable thimble  5240  allows the manufacturer to select and set the position of the thimble  5240 , thereby controlling the degree of movement of the valve. It will be appreciated that the thimble  5240  can be used on the exhalation valves described herein with respect to the face mask. 
     The valve body  5130  also includes a gas valve assembly  5300  that is disposed within the conduit member (leg)  5140 . The gas valve assembly  5300  includes a valve seat  5310  that is disposed within conduit member  5140  and is securely attached to the valve body  5130 . The valve seat  5310  can be a spoke-like structure with a plurality of openings formed between the spokes and also includes a valve retention knob (protrusion) or the like  5312  extending outwardly therefrom. A gas valve  5320  is mated to the knob  5312  (by reception of the knob  5312  within an opening in the valve) and lies over the valve seat  5310 . As best shown in  FIG. 85 , the gas valve  5320  is positioned proximate to the interface between the leg  5140  and the single conduit  5135  and is thus located above the over-inflation valve assembly. 
     The gas valve assembly  5300  serves as an inhalation valve that opens upon inhalation. 
     The valve body  5130  also includes a side gas port assembly  5400  that permits a gas, of variable concentration, to be delivered into the leg  5140  at a location below the gas valve assembly  5300 . The side gas port assembly  5400  has a hollow side port body  5410  that extends outwardly from the side of the leg  5140 . The side port body  5410  includes an air entrainment window  5415  formed therein to allow fluid flow into the hollow interior thereof. The side gas port assembly  5400  is similar to or identical to the second gas port  4740  and therefore, is of an adjustable type in that it includes a rotating shutter  5420  that is rotatably coupled to the side port body  5410 . 
     As shown, the rotating shutter  5420  can be in the form of cap-like structure that is received on the open end of the side port body  5410 . The shutter  5420  has an open end (which received the side port body  5410 ) and an opposite closed end. The shutter  5420  has a main section that has an air entrainment window  5422  formed therein. The air entrainment window  5422  extends circumferentially about a portion of the shutter. The air entrainment window  5422  is formed at a location on the shutter  5420  such that it overlaps (is in registration) with the window  5415  of the side port body  5410  and preferably, the dimensions of the window  5422  are greater than the dimensions of the window  5415 . 
     A (barbed) gas port member  5430  that extends radially outward from the closed end of the shutter  5420  and also is formed internally within the shutter  5420 . The internal section of the member  5430  serves as a gas injection orifice that directs the gas into the hollow interior of the body  5410 . The open end of the internal section of the member  5430  is located preferably in-line with the windows  5415 ,  5422  since the internal section is physically received within the hollow interior of the side port body  5410 . 
     Similar or identical to the shutter  4650 , the shutter  5420  also includes a gas concentration pointer  4767  that extends outwardly from (and beyond) the open end of the shutter  5420 . The body  5410  or some other proximate structure includes gas concentration indicator markings (similar to markings  4769 ) that are formed thereon. As the user rotates the shutter  5420 , the degree of registration between the windows  5415 ,  5422  changes (between a fully open position and a fully closed position, as well as intermediate, partially open states). To change the concentration of the gas being delivered through the side gas port, the user simply adjusts the shutter  5420  and thereby changes the amount of air entrainment that occurs. In the fully open position of the shutter, more air is entrained with the gas flow and therefore, the concentration of the gas (e.g., oxygen) that is delivered to the patient is lower.