Abstract:
A heat-moisture exchanger (HME) and nebulization device for connection to a mechanical ventilator or anesthesia apparatus, to provide humidification or an aerosolized medication without disconnection of the HME from the ventilator circuit, a respiratory device comprising a first housing having an output fitting to provide a connection to an artificial airway of a patient, and a rotatable second housing connected to the first housing, having an input fitting to provide a connection to a ventilator circuit, the input fitting, and the output fitting are in communication with a primary gas flow, the first housing is partitioned into at least two chambers, a chamber to provide an enclosure for an absorbent material, and a chamber to provide a passageway for conveyance of an aerosol, the second housing to provide an enclosure for a nebulizer having a reservoir for a liquid medication, an instillation port to inject the liquid medication, interior to the chamber or passageway, a reciprocating member to open and close valves or having valves in linkage with the second housing, and controlled by the rotational direction of the second housing, the second housing in the horizontal orientation to position the valves to control the flow path of the primary gas flow through the chamber having the absorbent material, and control the exhaled gas flow from the patient to pass through the chamber to conserve heat and moisture, then through the ventilator circuit, rotation of the second housing to the vertical orientation to operate the nebulizer, to position the valves for the primary gas flow to entrain an aerosolized medication, and control the flow path of the primary gas flow through the passageway to bypass the absorbent material, and control the exhaled gas flow from the patient through the passageway, then through the ventilator circuit.

Description:
FIELD OF THE INVENTION 
     This invention utilized in the medical field, generally relates to an apparatus for the humidification of inspired gases and the administration of aerosolized medication in connection with mechanical ventilators, or anesthesia devices. 
     BACKGROUND OF THE INVENTION 
     Hygroscopic condensers humidifiers (HCH), heat and moisture exchangers (HME), or an artificial nose are well known in the art. These devices are routinely used for the humidification of inspired gases during mechanical ventilation. 
     These devices essentially work by conserving heat and moisture from the exhaled humidified gas during the exhalation phase from a patient, then recycling the heat and moisture to the subsequent inspiratory phase to humidify the dry gas from the ventilator. Recent studies have indicated, patients requiring mechanical ventilation with adequate hydration, without secretion problems, and no history of severe lung disease, can tolerate these devices for extended periods of time. Also the studies reveal, there are no increased risk of nosocomial infections with the use of these passive humidification devices, compared to heated humidification. 
     Due to the challenges to reduce costs in providing medical care, and as the studies have shown positive results, there is an increased acceptance and justification for the utilization of an HME. 
     A patient requiring mechanical ventilation with the usual method of an electronic humidification apparatus demand constant observation. For example the respiratory practitioner or nurse must assure that the reservoir of the humidifier is maintained with an adequate level of water, as well as the alarm system and heater are operating properly, and to assure a physiological proximal airway temperature. 
     Often the ventilator circuit must be drained from the condensation to prevent the potential drowning of a patient, and to maintain proper ventilator function. This requires often disconnecting the ventilator circuit temporarily from the patient. Another method may employ the connection of a container inline in the ventilator circuit, and a vacuum applied to remove the condensate collected in the container. 
     Heated wire circuits are frequently employed to reduce the amount of water condensation in the ventilator circuit. However, there is a greater cost associated with the combination of an electronic humidifier and heated wire circuit, compared to an electronic humidifier alone. 
     In most cases, a patient requiring mechanical ventilation will receive an aerosolized medication with a nebulizer, or metered dose inhaler (MDI). If a nebulizer is used to aerosolize a bronchodilator, the HME must be quickly removed from the ventilator circuit, and replaced with the nebulizer prefilled with a liquid medication, and “T” adaptor. After the nebulization is complete, the nebulizer and “T” adaptor are quickly disconnected, and then reattach the HME to the ventilator circuit. 
     If a sidestream nebulizer with “T” adaptor were connected in series in a position prior to the HME, obviously the aerosol would be filtered out, and the patient would not receive the aerosolized medication. Also, the added moisture from the aerosol would rapidly clog the HME. If the nebulizer and “T” adaptor were connected in series between the artificial airway and the HME, the patient would receive some medication, but likewise any excess aerosol would rapidly clog the HME. 
     The obstruction of the heat and moisture exchanging unit from the added excessive moisture will cause an increased resistance to the inspiratory gas flow, resulting in an increase work of breathing of the patient. This can have a dramatic effect on the debilitated patient, particularly during synchronous intermittent mandatory ventilation, pressure support, or spontaneous breathing with continuous positive airway pressure. 
     Preferably the exchange of components occurs synchronously during the brief period of time between the end of the exhalation phase, and just prior to the next inspiratory phase. The capability of the practitioner to exchange these components without interruption of ventilation, becomes increasingly more difficult with increased frequency of ventilation. If a patient is receiving continuous positive airway pressure, cessation of positive pressure occurs during the disconnection of the circuit, resulting in an intermittent drop in the intrathoracic pressure to the level of atmospheric pressure. 
     Obstruction of the HME device does not readily occur following a few actuations with an MDI. Therefore the HME is usually not removed prior to the use of an MDI alone. However, the HME should be removed with the combination of an MDI and spacer device, due to the added deadspace volume. 
     Another disadvantage of frequent disconnections of the ventilator circuit to attach a nebulizer, are the increase risk of nosocomial infections from the hospital environment, or secondary to improper hand washing technique. Moreover, the medical personnel has an increased risk of occupational hazards to the exposure of infectious airborne pathogens from a patient, such as tuberculosis, antibiotic resistant bacteria, and potential lethal viruses. 
     U.S. Pat. No. 5,505,568 issued to Altadonna sets forth a HUMIDITY MOISTURE EXCHANGER in which the HME having a first and second chamber, the second chamber with a pair of fluid ports. Inside the housing, is a filter or heat and moisture collecting material. To permit the uninhibited passage of aerosol from the nebulizer, the absorbent material is removed from the second chamber area, and temporarily stored within the first chamber area. 
     Although the device is designed to obviate the need for ventilator circuit disconnection, the device requires additional components and a nebulizer to administer an aerosol. It is unclear whether the described sealing engagement to minimize potential deadspace, could also provide an adequate seal to prevent aerosol clogging the filter, or heat and moisture collecting material when temporarily stored in the second chamber. 
     U.S. Pat. No. 5,546,930 issued to Wikefeldt sets forth a PATIENT CONNECTOR WITH HME, FILTER, AND NEBULIZER CONNECTION in which a Y-piece is to provide an inhalation and exhalation conduit, a patient conduit for connecting the nipple to the Y-piece, an HME disposed in the patient conduit, a nebulizer connector between the nipple and the HME, or an inhalation connector downstream to the HME for connecting the patient conduit to the nebulizer. In another embodiment a powder inhaler is also provided in connection to the nipple so that powder can be supplied to the patient. 
     Although Wikefeldt, has developed a method to permit the introduction of aerosols in conjunction with an HME without the interruption of mechanical ventilation, the apparatus reveals a substantial increase in the deadspace and requires several external connections of flexible tubing, and connected nebulizers. This has a disadvantage due to the increase number of connections resulting in an increased risk of potential leaks and ventilator circuit disconnection. An increase in the deadspace volume will increase the alveolar partial pressure of carbon dioxide, which could have a deleterious effect on a patient diagnosed of chronic obstructive airway disease. When an aerosolized medication is delivered by the nebulizer, a major portion of the aerosol exhaled by the patient is taken up by the HME. 
     While the foregoing devices are representative of the prior art, to provide an aerosolized medication in combination with an HME device, without the interruption of mechanical ventilation, which require adaptors, additional components, and nebulizers, these devices do not describe the instant invention claimed. 
     OBJECTS AND ADVANTAGES 
     Several objects and advantages of the present invention are: 
     (a) to provide a convenient method for the safe delivery of both humidification and aerosolization of medication with mechanical ventilators or anesthesia devices; 
     (b) to provide a method to maintain the continuity of a closed ventilator circuit when administering an aerosolized medication, and preventing the interruption of mechanical ventilation to a patient; 
     (c) to provide a method to maintain the continuity of a closed ventilator circuit, to reduce the incidence of nosocomial infections resulting from frequent disconnections of the ventilator circuit, when administering an aerosolized medication; 
     (d) to provide a method to maintain the continuity of a closed ventilator circuit, to reduce the exposure and occupational hazards of airborne infectious bacterial and/or viruses, from a patient to medical personnel; 
     (e) to provide a method to conveniently add moisture such as an aerosolized isotonic saline for the hydration of the respiratory tract, thus reducing the incidence of inpissated secretions and airway occlusion; 
     (f) to provide a method to reduce the number of components. Therefore reducing personnel time by eliminating the requirement to exchange components, to connect a nebulizer in a ventilator circuit with a heat and moisture exchange unit. 
     (g) to provide a method to deliver an aerosolized medication in conjunction with a heat and moisture exchange device, with a minimum of added deadspace volume. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention there is provided a device for both humidification and aerosolization for connection to a mechanical ventilator, or anesthesia device. The apparatus comprising of a first housing containing a material capable of absorbing heat and moisture from the exhaled air and transferring the heat and moisture to the inhaled air. A second housing for a nebulizer, is rotatable with respect to the first housing to provide an aerosol. 
     The first housing having an output fitting to be connected to an artificial airway of a patient. The second housing having an input fitting to be connected to a ventilator circuit and a second connection to a pressurized gas supply to the nebulizer. The first housing is partitioned into chambers. A mid chamber having at the forward end and integrated with the first housing, a flexible diaphragm. 
     In other embodiments the mid chamber is constructed of a separate corrugated, or flexible casing. Disposed in the mid chamber, are two sections of an absorbent material, or a heat and moisture exchanger optionally impregnated with conventional hygroscopic substances. Two chambers lateral to the mid chamber provide passageways for the conveyance of the aerosol. 
     Internal to the the mid chamber, and between the two sections of the absorbent material, is a reciprocating member to open and close valves. The reciprocating member is pulled backward and pushed forward by a linkage with the rotatable second housing. The linkage is provided by two pins at the rearward end of the reciprocating member, which engage two arcuate channels. Each arcuate channel is offset at an incline, having an arc length of 90 degrees, and located oppositely 180 degrees with respect to the other arcuate channel. In the forward position, the valves divert the primary gas flow or inspiratory stream to bypass the lateral chambers, to pass through the absorbent material and through the output fitting to the artificial airway. At the end of the inspiratory phase, the patient passively exhales through the output fitting, into the absorbent material to conserve heat and moisture. 
     When the second housing is rotated 90 degrees counterclockwise, the reciprocating member is pulled backward, by the rotation of the arcuate channels which engage the two pins. In the pulled backward position, the reciprocating member positions the valves to divert the inspiratory stream to bypass the heat and moisture exchanger, and to pass through the lateral chambers, through the output fitting, to the artificial airway of the patient. At the end of the inspiratory phase, the patient passively exhales through the output fitting, through the lateral chambers and through the ventilator circuit. 
     The second housing provides a reservoir for receiving a liquid, a liquid nozzle, and a gas nozzle which is supplied by a pressurized gas source by means of a pressurized gas connector, an instillation port with cap to inject a liquid medication. The second housing or nebulizer, is rotatable 90 degrees clockwise or counterclockwise on a conduit extending from the first housing. Therefore the conduit also provides an axle for the second housing. The conduit having rectangular openings are normally closed by a concentric cylindrical sleeve of the second housing. The concentric sleeve having the same sized rectangular openings, are 90 degrees out of alignment with respect to the openings of an internal conduit, to provide a rotational sleeve valve. This prevents the inspiratory stream from the ventilator escaping out of the instillation port when removing of the cap to instill the liquid medication. The closed openings on the conduit prevent back pressure regurgitation of liquid from the reservoir, and the spillage of liquid into the heat and moisture exchanger and reduction of the deadspace volume when not delivering an aerosolized medication. 
     In the horizontal orientation of the second housing, the reservoir is filled with an appropriate quantity of liquid medication, via the instillation port. The second housing is then rotated 90 degrees counterclockwise. The vertical orientation of the second housing will allow the liquid medication to gravitate to a region of the liquid reservoir to be aspirated and aerosolized, when the pressurized gas source has been switched on to the gas nozzle. The 90 degree counterclockwise rotation opens the rectangular openings of the conduit automatically, to allow the aerosol from the interior of the second housing to be combined with the inspiratory stream. After the aerosolization is complete, the second housing is returned to the horizontal orientation by rotating the second housing 90 degrees clockwise to resume the inspiratory stream through the heat and moisture exchanger. 
     The horizontal to vertical orientation of the second housing or nebulizer, is readily visualized by the medical personnel. This has the advantage to determine at a glance, whether the device is adjusted for the inspiratory stream to pass through the heat and moisture exchanger, or the device is adjusted for the inspiratory stream to deliver an aerosol, during operation of the nebulizer 
     In another embodiment, the input fitting is equipped with a nozzle and metered dose inhaler (MDI) adaptor. In this configuration, the second housing is rotated 90 degrees counterclockwise, and the MDI is actuated in the usual manner. The reservoir of the second housing, and lateral chambers of the first housing provides a spacer device for the MDI. 
     In another embodiment, the mid chamber of the first housing provides a passageway for the conveyance of the aerosol, and the lateral chambers contain the heat and moisture exchange unit. Internal to the mid chamber is a reciprocating member, which is pushed forward or pulled backward by the same mechanism as described above, relative to the 90 degree clockwise and counterclockwise rotation of the second housing. The reciprocating member is comprised of a resilient material having side walls. At each end of the reciprocating member, the side walls collapse or expand to provide valves. When the second housing is in the horizontal orientation, the reciprocating member is pulled backward to provide a force to collapse the valves. This prevents the inspiratory stream from entering the mid chamber. The inspiratory stream from the ventilator by means of the internal conduit, will bypass the second housing and is directed out the openings of the mid chamber, through the heat and moisture exchange unit, to the output fitting, to the artificial airway. At the end of the inspiratory phase, the patient passively exhales through the output fitting, and through the absorbent material, to conserve heat and moisture. 
     The 90 degree counterclockwise rotation of the second housing in the vertical orientation pushes the reciprocating member forward. This releases the closing force on the resilient valves, and therefore the valves expand. The side walls of the reciprocating member in the forward position also closes the openings of the mid chamber. The inspiratory stream from the ventilator flowing through the second house entraining the aerosol from the interior chamber of the second housing, to bypass the heat and moisture exchange unit through the output fitting to the artificial airway. The patient passively exhales through the mid chamber through the ventilator circuit. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention together with the further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements and in which: 
     FIG. 1 is a perspective illustration of the invention; 
     FIG. 2 is a perspective illustration of the invention, illustrating the rotational second housing; 
     FIG. 3 is a cross sectional view taken along lines  3 — 3  of FIG. 1; 
     FIG. 3A is a detail enlargement of the valve sealing and thread means illustrated in FIG. 3; 
     FIG. 4 is a cross sectional view taken along lines  4 — 4  of FIG. 2; 
     FIG. 4A is a detail enlargement of the valve sealing means illustrated in FIG. 4; 
     FIG. 5 is a cross sectional view taken along lines  5 — 5  of FIG. 3; 
     FIG. 6 is a cross sectional view taken along lines  6 — 6  of FIG. 4; illustrating the rotational second housing; 
     FIG. 6A is a detail enlargement of the gas and liquid nozzle means, baffle and diminutive space illustrated in FIG. 6; 
     FIG. 7 is a cross sectional view taken along lines  7 — 7  of FIG. 3; 
     FIG. 7A is a detail enlargement of the valve sealing means illustrated in FIG. 7; 
     FIG. 8 is a cross sectional view taken along lines  8 — 8  of FIG. 4; 
     FIG. 9 is a cross sectional view taken along lines  9 — 9  of FIG. 7; 
     FIG. 10 is a cross sectional view taken along lines  4 — 4  of FIG. 2, illustrating the attachment of a metered dose inhaler container; 
     FIG. 11 is a cross sectional view of an alternate embodiment taken along lines  3 — 3  of FIG. 1; 
     FIG. 12 is a cross sectional view of the alternate embodiment taken along lines  4 — 4  of FIG. 2; 
     FIG. 13 is a cross sectional view of the alternate embodiment taken along lines  13 — 13  of FIG. 12; 
     FIG. 14 is a cross sectional view of the alternate embodiment taken along lines  14 — 14  of FIG. 13; 
     FIG. 15 is cross sectional view of an alternate embodiment taken along lines  3 — 3  of FIG. 1; 
     FIG. 16 is a cross sectional view of the alternate embodiment taken along lines  16 — 16  of FIG. 16; 
     FIG. 17 is a cross sectional view of the alternate embodiment taken along lines  4 — 4  of FIG. 2; 
     FIG. 18 is a cross sectional view of the alternate embodiment taken along lines  18 — 18  of FIG. 17; 
     FIG. 19 is cross sectional view of the alternate embodiment taken along lines  19 — 19  of FIG.  17 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG.  1  and FIG. 2, are perspective views of the heat-moisture exchanger and nebulization device constructed in accordance to the present invention, and generally referenced by numeral  30 . The heat and moisture exchange unit and nebulizer includes a first housing  32  and a second rotatable housing  34 . The second rotatable housing  32 , further includes a generally cylindrical input fitting  38 , and a generally cylindrical output fitting  36 , of the first housing  34 . 
     Second rotatable housing  34 , further defines an outwardly extending pressure gas connector  40 , with gas conduit  42 , and a removable instillation cap  44 . 
     Referring to FIGS. 3,  7 , and  9  the first housing  32  is comprised of an elliptical shell  48 . The ends of the elliptical shell  48 , are sealed by elliptical end wall  46 , and elliptical end wall  50 . The interior of the first housing is partitioned into a mid chamber  90  and lateral chambers  88 . Within the mid chamber are two sections of an absorbent material  86 . Positioned between the two sections of the absorbent material is a reciprocating member  80 . At the forward end on the reciprocating member  80  is a cylindrical sleeve  98 . Toward the opposite end on the reciprocating member  80 , a conical plug  83  and another cylindrical sleeve  100 . 
     In the embodiment shown in FIGS. 3,  4 ,  7 , and  8 , the reciprocating member  80 , elliptical end wall  46 , elliptical end wall  50 , and elliptical shell  48 , are constructed from a resilient material such as polypropylene, by injection and blow molding methods. At the forward end of the elliptical shell  48 , is a flexible diaphragm  92 . 
     Referring to FIG. 7A, the flexible diaphragm  92  having a central aperture  97  is fitted in an annular groove  93  to join to the cylindrical sleeve  98 . The ring  99  on the annular surface of the cylindrical sleeve  98  provides a seal between the cylindrical sleeve  98  and the inner diameter of the output fitting  36 . The ring  99  also reduces the drag force of the seal during the backward and forward movement of the reciprocating member  80 . Extending from the elliptical end wall  46 , is a strut  96  which supports disc plug  94  with gussets  95 . 
     The dimension of the outer diameter of the disc plug  94  has a dimension in close tolerance to the inner diameter dimension of the cylindrical sleeve  98 . Therefore when the the reciprocating member  80  is pulled backward, the cylindrical sleeve  98  is guided by the strut  96  to the disc plug  94 , to form a seal between the outer diameter of the disc plug  94 , and the inner diameter of cylindrical sleeve  98 . 
     Returning to FIGS. 3,  4 ,  7 , and  8 , the elliptical end wall  50  is comprised of a double wall. The exterior elliptical end wall  50  to seal the end of the elliptical shell  48 , and the internal wall  51 , to seal the end of the mid chamber  90 . Between the elliptical end wall  50  and the internal wall  51 , is a cylindrical passageway  75  with outlet ports  84 . 
     Referring to FIG. 3A, at the end of the cylindrical sleeve  100  are interlocking pins  87 . Each interlocking pin  87  is positioned 180 degrees relative to the other pin. The slots  82  are parallel to the reciprocating member  80 , having a length to accommodate the forward and backward distance of travel of the reciprocating member  80 . Each slot  82  is positioned 180 degrees relative to the other slot, in which the interlocking pins  87  project slightly through the corresponding slot  82 . The notch  102  allows the interlocking pins  87  to partially bend inward on the cylindrical sleeve  100 , for the conduit  64  to receive the cylindrical sleeve  100  during assembly. The concentric sleeve  66  provides two arcuate channels  78 , in which the arc length of the arcuate channel  78  is equivalent to accommodate the rotation of 90 degrees of the concentric sleeve  66 . The arcuate channels  78  are offset at an incline, and engage the interlocking pins  87 , partially projecting through the slots  82 . The engagement of the interlocking pins  87  into the arcuate channels  78 , secures the rotatable second housing  34  to the conduit  64 . Rotational motion of the arcuate channels  78 , to provide a pull or push forward movement on the reciprocating member  80 . 
     On the annular surface of cylindrical sleeve  100  are rings  99 , to provide a seal between the cylindrical sleeve  100 , and within the lumen of the cylindrical passageway  75 . 
     Referring again to FIGS. 3,  4 ,  7 ,  8 , the second housing  34  is constructed of transparent plastic, such as polystyrene or K-Resin® by injection molding methods. The second housing  34  is comprised of an elliptical shell  56  having an end wall  53 , and the opposite end of elliptical shell  56 , sealed by the elliptical end wall  54 . The concentric sleeve  66  with sleeve inlets  68 , extends from the internal end wall  53  to the end wall  54 . Extending from the end wall  53 , and adjacent to the concentric sleeve  66 , is a projection  71 . Projection  71  is comprised of two parallel plane side walls to support a plane shelf wall, having two interior right angles, with respect to the two parallel plane side walls. Central to the shelf wall, is an orifice or, gas nozzle  70 . Extending outward and perpendicular from the plane shelf wall, and between the two parallel plane side walls is a pressurized gas connector  40 , with a gas conduit  42  in communication with the gas nozzle  70 . 
     Extending from the elliptical end wall  54  to the end wall  53 , is projection  73 . Projection  73  is a slightly larger, and analogous in structure to projection  71  having two parallel plane side walls and a plane shelf wall with respect to the two parallel plane side walls, having two interior right angles. Central to the plane shelf wall is an orifice, or liquid nozzle  72 . Referring to FIG.  4 A and FIG. 6A, during the assembly, the second housing  34 , projection  73  from the end wall  54 , slides over, to overlap projection  71  to form a diminutive space  74 , and provide the concentric alignment of gas nozzle  70  with liquid nozzle  72 . 
     The high velocity gas exiting the gas nozzle  70  passing through the liquid nozzle  72 , will produce a subatmospheric pressure. The negative pressure will aspirate a liquid within the diminutive space  74 , to the liquid nozzle  72 . The liquid is entrained and is added into the high velocity gas exiting the gas nozzle to create an aerosol. The aerosol comprised of large and various sized liquid particles, impact on the baffle  76 , of the concentric sleeve  66 . This produces smaller and more uniform aerosol particle sizes. 
     The assembled second housing  34  is then swiveled on to the conduit  64 . The arcuate channels  78  snap over the interlocking pins  87  protruding through the slots  82 , preventing the removal of the the second housing  34 . 
     Referring to FIG.  5  and FIG. 6, extending from the elliptical end wall  50  are tabs  58 , and extending from the elliptical shell with end wall  56  are tabs  60 . Tabs  58 , and tabs  60  provide stops to prevent rotating the second housing  34  beyond the 90 degree clockwise, or counterclockwise rotation. 
     In operation, the device is connected between the wye adaptor (not shown) of the ventilator circuit at the inlet fitting  38 , and the artificial airway of a patient (not shown) via the output fitting  36 . A flexible connecting tube (not shown) is connected from a pressurized gas source to the pressurized gas connector  40 . FIG. 3, FIG. 5, and FIG. 7 illustrates the horizontal orientation of the second housing  34  with respect to the first housing  32 . Referring to FIG. 7, the flow path of the primary gas flow or inspiratory stream from the ventilator is indicated from left to right by the arrows “A” through the device to arrows “B”. In the horizontal orientation of the second housing  34 , the concentric sleeve  66  cover and seal the inlet ports  62  of conduit  64 . With the reciprocating member  80  in the forward position, the cylindrical sleeve  100  is within the cylindrical passageway  75  to seal the outlet ports  84 , to prevent the primary gas flow entering the lateral chambers  88 . The cylindrical sleeve  98  is within the output fitting  36 , to also seal the primary gas flow from entering the lateral chambers  88 . Thus providing a bypass for the inspiratory stream entering input  38 , to flow through the mid chamber  90 , after deflection by the conical plug  83 , to pass through the heat and moisture exchange unit  86 , around the disc plug  94  through the cylindrical sleeve  98 , and exiting through the output fitting  36 , to the artificial airway of the patient. At the end of the ventilator inspiratory cycle, the patient passively exhales designated by the exhalation flow path arrows “PE”. The flow path of “PE” through the output fitting  36 , into the heat and moisture exchange unit  86 , and through the input fitting, then through the ventilator circuit. 
     In FIG. 3, and FIG. 7 to administer an aerosol, the plug  44  is first removed from the instillation port  52 , with the second housing  34  in the horizontal orientation. Due to the closure of the inlet ports  62  by the concentric sleeve  66 , no ventilator pressures or flows will escape out of the instillation port  52 . Also the regurgitation of liquid medication out of the instillation port  52  is prevented. An appropriate quantity of liquid medication is injected into the reservoir of the second housing  34  via the instillation port  52 . The plug  44  is returned and pressed fitted into the instillation port  52 . 
     Referring now to FIGS. 2,  4 ,  6 ,  8 , the second housing  34 , or nebulizer is rotated 90 degrees to a vertical orientation. The vertical orientation of the second housing will allow the liquid medication to gravitate to the liquid reservoir. The pressurized gas source connected to the pressure gas connector  40  is switched on to generate an aerosol. In FIG. 8, the flow path of the primary gas flow or inspiratory stream is indicated from left to right by the arrows “C” through the device to arrows “D”. The rotation of the second housing  34  to cause rotation of the concentric sleeve  66  to align the sleeve inlet  68  to the inlet port  62 , and the rotation of the arcuate channels  78  to pull the reciprocating member  80  backward. The distance moved by the reciprocating member  80 , opens the outlet ports  84  by the backward displacement of the cylindrical sleeve  100 . The conical plug  83  having an outer diameter dimension in close tolerance to the inner diameter of the cylindrical passageway  75 , is withdrawn within the cylindrical passageway  75  to seal and prevent the inspiratory stream from entering the mid chamber, and to divert the inspiratory stream to the lateral chambers  88 . The cylindrical sleeve  98  is withdrawn to provide a seal around disc plug  94  to provide a seal to prevent the inspiratory stream to enter the mid chamber. The inspiratory stream enters input  38 , to be directed through the lateral chambers  88 , through the output fitting  36 , to bypass the heat and moisture exchange unit  86 . The opened inlet ports  62 , allow for aerosol entrainment indicated by the arrows “AE” to admix with the inspiratory stream. At the end of the inspiratory cycle, the patient passively exhales indicated by the arrows “PE” through the output fitting  36 , through the lateral chambers  88 , through the input fitting  38 , then through the ventilator circuit. 
     FIG. 10 demonstrates an optional feature of the device as an MDI spacer. The input fitting  36  is equipped with an MDI adaptor  106 , having a nozzle  108 . To administer an aerosolized medication with a metered dose inhaler, the second housing  34  is rotated 90 degrees counterclockwise, to the vertical orientation. The outlet stem of the MDI is placed within the MDI adaptor  106 , then actuated in the usual manner, and removed after the delivery of the aerosolized medication. The second housing  34  is then rotated 90 degrees clockwise to the horizontal orientation. 
     FIGS. 11,  12 ,  13 ,  14 , is a alternate embodiment which utilizes the novel principle of operation set forth above. In the alternate embodiment, the mid chamber is comprised of a resilient plastic material such as polypropylene to provide a corrugated mid chamber  90 . The lateral chambers  88  are formed between the corrugated mid chamber  90  and the internal wall of the elliptical shell  48 . Alternatively, the mid chamber  90  can also be comprised of a substantially thin polyethylene encasing(not shown), or similar plastic material. One end is sealed around the cylindrical sleeve  98 . The cylindrical sleeve  98 , and cylindrical sleeve  100 , reciprocating member  80 , conical plug  83 , is injection injection molded into a unitary component. 
     The two sections of the open-cell material are placed into the polyethylene mid chamber  90 , and sealed around the internal end wall  51 . The elliptical end wall  50  with mid chamber  90  assembly, is ultrasonically welded to the elliptical shell  48 , having elliptical end wall  46 . 
     In FIG.  11  and FIG. 12 is an optional socket  112  and cap  114  for the connection to a sampling tubing to monitor exhaled carbon dioxide. 
     Referring to FIG. 13, with the second housing  34  or nebulizer in the horizontal orientation, illustrates the position of the cylindrical sleeve  98 , conical plug  83  and cylindrical sleeve  100 , by the reciprocating member  80 . The flow path of the inspiratory stream is indicated by arrows “A” through the device to arrows “B” to flow through the heat and moisture exchange unit  86 , through the output fitting  36 , to the artificial airway of the patient. The patient passively exhales indicated by arrows “PE” through the heat and moisture exchange unit  86 , through the input fitting, and through the ventilator circuit. 
     In FIG. 14 the liquid medication has already been added via the instillation port  52 , with plug  44  secured. The second housing  34  rotated 90 degrees counterclockwise, and the reciprocating member  80  is pulled backward by the same mechanism as previously described. The position of the cylindrical sleeve  98  is sealed around the disc plug  94 , and the sealing position of the conical plug  83 , and cylindrical sleeve  100 , provide a bypass from the heat and moisture exchange unit. The pressurized gas source connected to the pressurized gas connector  40 , is switched on to generate an aerosol. The aerosol “AE” is entrained into the inspiratory stream indicated by arrows “C” through the device to arrows “D”. The inspiratory stream is directed through the lateral chambers  88 , and through the output fitting  36 , to the artificial airway of the patient. The patient passively exhales indicated by “PE” through the output fitting  36 , through the lateral chambers  88 , through the input fitting, and through the ventilator circuit. 
     FIGS. 15,  16 ,  17 ,  18 ,  19 , is an alternate embodiment which utilizes the novel principle of operation set forth above. The interior of the first housing  32 , is partitioned into a mid chamber  90 , and lateral chambers  88 . The mid chamber  90  in this configuration provides a passageway for the conveyance of an aerosol, and the lateral chambers  88  to contain the two sections of the heat and moisture exchange unit  86 . Disposed in the mid chamber  90 , is reciprocating member  80 . The reciprocating member  80  is fabricated from a resilient material, which conforms within the internal structure of the mid chamber  90 . On the opposite ends of the reciprocating member  80 , are valves  118  and  120 . The reciprocating member  80  is pushed forward and pulled backward in the same manner previously described. 
     In FIG.  15  and FIG. 16, the second housing  32  is in the horizontal orientation. Located on the floor and roof in the interior of the mid chamber  90  are beveled guides  128 . As the reciprocating member  80  is pulled backward, the beveled guides  128 , provide a closing force on the valves  120 . At the same time the valves  118  are forced closed between the lateral tabs  126  and the internal wall of the mid chamber  90 . Located on the floor and roof at the forward end of the reciprocating member  80 , are beveled supports  130 . The valves close against the beveled supports  130 , to provide additional sealing between the valves  118 , and beveled supports  130 . 
     Referring to FIG. 16, with the second housing  34  in the horizontal orientation, with the reciprocating member  90  pulled backward, the flow path of the primary gas flow or inspiratory stream is indicated from arrows “A” through the device to arrows “B”. The inlet port  62  is closed by the concentric sleeve  66 . The flow of the inspiratory stream after entering the conduit  64 , is prevented from entering the mid chamber  90  by the collapsed valves  120 , then exiting through the outlet ports  84 , through the heat and moisture exchange unit  86 , through the inlet openings  116 , and through the output fitting  36 , to the artificial airway. At the end of the inspiratory cycle, the patient exhalation flow path indicated by arrows “PE” through the output fitting port  36 . The collapsed valves  118  deflect the patient exhaled gases indicated by “PE” from the mid chamber  90 , through the heat and moisture exchange unit  86  by means of the inlet openings  116 , through the input fitting, and through the ventilator circuit. 
     Referring to FIG.  17  and FIG. 18, the second housing  34  or nebulizer, is rotated 90 degrees counterclockwise, in the vertical orientation. The reciprocating member  80  is pushed forward. This releases the force on the valves  120  by the beveled guides  128 , allowing the valves  118  to expand. At the same time, the force is released on the lateral tabs  126 , to open the valves  120 . To assure that the valves  118  are fully opened, as the reciprocating member  80  moves forward, the valves  118  are separated, and sealed between wedge support  122 , and the interior wall of the output fitting  36 . This provides a seal to close the inlet opening  116 . Additionally, the forward displacement of the reciprocating member  80  will move the rectangular sleeve  124  to close and seal the outlet ports  84 . 
     Referring to FIG. 18, the second housing  34  is charged with an appropriate quantity of liquid medication, in the manner previously described. The pressurized gas source is switched on to generate an aerosol. The inspiratory stream is indicated from arrows “C” through the device to arrows “D”. The aerosol is entrained indicated by arrows “AE”, from the inspiratory stream, via the opened inlet ports  62 . Since the outlet port  84  and the inlet opening  116  are closed and sealed, the flow path of the inspiratory stream combined with the aerosol “AE”, is directed through the mid chamber  90 , to the output fitting  36 , providing a bypass from the heat and moisture exchange unit  86 . At the end of the inspiratory cycle, the patient passively exhales “PE” through the mid chamber  90 , and through the ventilator circuit. 
     Thus, what has been shown is a heat-moisture exchanger and nebulization device, relatively simple and low cost to manufacture. To conveniently deliver an aerosolized medication with an HME. To prevent the interruption of mechanical ventilation, and eliminating potential adverse effects to the patient, and decreasing the probability of transferring microbial contamination to, or from the patient. 
     While particular embodiments of the invention have shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.