Abstract:
An airway circuit has two modes of operation, dependent upon the presence or absence of a nebulizer in a nebulizer port. When the nebulizer if absent, a patient port is in fluid communications with a ventilation circuit port through a heat and humidity exchange element. When the nebulizer is inserted into the nebulizer port, the nebulizer port (and nebulizer), patient port, and ventilation circuit port are in fluid communications with each other and the heat and humidity exchange element is isolated, thereby protecting the heat and humidity exchange element from medicines emanating from the nebulizer. After the nebulizer is removed from the nebulizer port, the patient port is again placed in fluid communications with the ventilation circuit port through a heat and humidity exchange element.

Description:
FIELD 
       [0001]    This invention relates to the field of patient connectors intended for connecting a patient to a respirator and/or to an anesthesia device. More particularly, the present invention relates to a patient connector that includes a heat and moisture exchange device that is isolated from the circuit when the nebulizer is attached. 
       BACKGROUND 
       [0002]    Patient connectors are generally used for connecting patients to respirators, anesthesia devices, etc. When a patient is interfaced to such respirators and/or anesthesia devices, often the air that the patient breathes in is very dry and often cool. To reduce the negative effects of breathing this cool, dry air, prior patient connectors often include in-line heat and moisture exchange devices (HME devices). Heat and moisture exchange devices capture heat and moisture when the patient exhales and returns the heat and moisture to the patient when the patient inhales. As the patent exhales, the patient&#39;s breath is very humid and warm and this heat and humidity is captured in the HME and the heat and humidity is released when the patient inhales, making the air that the patient inhales warmer and more humid. Unfortunately, the actual membrane used is the heat and moisture exchange is not compatible with medicines. Typically, patients are administered medicine with the help of a nebulizer which finely divides the medicine into fine droplets which are inhaled. If a nebulizer is used in conjunction with a heat and moisture exchange device, exposure of the heat and moisture exchange element to the medication will impact the operation of the heat and moisture exchange element and possibly permanently damage the heat and moisture exchange element. 
         [0003]    In the past, heat and moisture exchange devices had to be removed from the circuit when the patient is given medicine by way of a nebulizer. This method suffered from the complexity of rearranging the airway circuit during the administration of the medicine, then reconnecting the airway circuit and the time lag in which the circuit is disconnected. 
         [0004]    Some circuits introduced the output of the nebulizer downstream, away from the heat and moisture exchange element as in U.S. Pat. No. 5,546,930 issued on Aug. 20, 1996. In this, a long tube separates the heat and moisture exchange element from the medicine injection point and a manually removable cap covers the port in which the nebulizer is removably attached. In this type of circuit, after the patient inhales some air mixed with nebulized medication, some amount of nebulized medication remains in the patient&#39;s airways and in the patient end of this circuit and, upon exhaling, some of this nebulized medication flows through a second leg of the circuit and into the heat and moisture exchange element, which is not desired. 
         [0005]    Recognizing this issue, other devices have a knob, valve, or switch which initiates bypass of the heat and moisture exchange element. One such example is U.S. Pat. No. 7,594,509, issued Sep. 29, 2009. The problem with a manual function that bypasses the heat and moisture exchange element is that a busy caregiver must remember to re-enable the heat and moisture exchange element after the medication is administered, which does not always happen and, the results of such are often not readily know, so the patient starts feeling discomfort after the caregiver has left the patients proximity. Additionally, it is easy for the caregiver to forget to bypass the heat and moisture exchange element and administer the medication while the heat and moisture exchange element is in the circuit, leading to future problems with the heat and moisture exchange element and a potential reduction in the medication administered to the patient, as some of the medication becomes trapped in the heat and moisture exchange element. 
         [0006]    What is needed is a circuit that will automatically remove the heat and moisture exchange element while the nebulizer is attached to the circuit. 
       SUMMARY 
       [0007]    In one embodiment, a patient connector providing heat and humidity exchange is disclosed including an enclosure having a patient port for connection to a patient circuit, a vent communications port for connection to a ventilation circuit, and a nebulizer port for intermittent connection to a nebulizer. Internal to the enclosure is a heat and moisture exchange element. A mechanism fluidly connects the patient port through the heat and moisture exchange element to the vent communications port when the nebulizer port is empty; and the mechanism fluidly connecting the patient port to the vent communications port and to the nebulizer port when the nebulizer port is occupied, thereby isolating the heat and moisture exchange element from the circuit until the nebulizer port is again vacant. 
         [0008]    In another embodiment, a patient connector providing heat and humidity exchange is disclosed including an enclosure having a patient port for connection to a patient circuit, a vent communications port for connection to a ventilation circuit, and a nebulizer port for intermittent connection to a nebulizer. A heat and moisture exchange element holder secured within the enclosure has a heat and moisture exchange element contained there within, an upper port in fluid communication with a first side of the heat and moisture exchange element and a lower port in fluid communication with an opposing side of the heat and moisture exchange element. There is a device for urging that urges the heat and moisture exchange element holder towards the nebulizer port and a linkage between the nebulizer port and the heat and moisture exchange element. The linkage blocks the nebulizer port, the patient port is in fluid communications with the upper port, and the vent communications port is in fluid communications with the lower port allowing fluid communications between the patient port and the vent communications port through the heat and moisture exchange element until insertion of a nebulizer into the nebulizer port. After insertion of a nebulizer into the nebulizer port, the linkage opens the nebulizer port, the patient port is placed in fluid communications with the nebulizer port and the vent communications port allowing fluid communications between the patient port and the vent communications port and the nebulizer port until the nebulizer is removed from the nebulizer port. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0010]      FIG. 1  illustrates an exploded view of an exemplary airway circuit with heat and moisture exchange element. 
           [0011]      FIG. 2  illustrates a cross sectional view of the exemplary airway circuit with the heat and moisture exchange element in the circuit. 
           [0012]      FIG. 3  illustrates a cross sectional view of the exemplary airway circuit with the heat and moisture exchange element isolated from the circuit. 
           [0013]      FIG. 4  illustrates a perspective view of an exemplary heat and moisture exchange element. 
           [0014]      FIGS. 5 and 6  illustrate perspective views of a heat and moisture exchange element holder of the exemplary airway circuit. 
           [0015]      FIG. 7  illustrate a cross sectional view of a heat and moisture exchange element holder of the exemplary airway circuit. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0017]    Although a specific embodiment of the invention is shown in the drawings and used in the description, there is no limitation to any specific design or structure as long as, upon insertion of the nebulizer, the heat and moisture exchange element is isolated from the breathing circuit and upon removal of the nebulizer, the heat and moisture exchange element is placed back into the circuit. 
         [0018]    Referring to  FIG. 1 , an exploded view of an exemplary airway circuit  10  with heat and moisture exchange element  34  is shown. In this exemplary airway circuit  10 , the patient port  14  is for connecting to, for example, tubes that communicate with the patient&#39;s airways, orally, nasally, or through a tracheotomy. A vent circuit communications port  16  is for connection to any ventilation source known in the medical industry. The nebulizer port  18  is for intermittent connection to a nebulizer when medication needs to be administered to a patient that is connected to the patient port  14 . A heat and moisture exchange element holder  31  fits within an enclosure  12  and is allowed to move up/down along an axis of, for example, the nebulizer port  18 . A cap  20  seals the enclosure  12 , maintaining the heat and moisture exchange element holder  31  within the enclosure  12 . A heat and moisture exchange element holder lid  24  maintains the heat and moisture exchange element  34  within the heat and moisture exchange element holder  31 . A main spring  22  urges the heat and moisture exchange element holder  31  into the air circuit, communicating gas flow between the vent circuit communications port  16  and the patient port  14 , through the heat and moisture exchange element  34 . A nebulizer insertion linkage  30  interfaces with the secondary spring  21 . As will be shown, when a nebulizer  50  (see  FIGS. 2 and 3 ) is inserted into the nebulizer port  18 , the nebulizer insertion linkage  30  is displaced by an end of the nebulizer  50 , pushing the secondary spring  21  and, hence, the heat and moisture exchange element holder  31  upward (away from the nebulizer port  18 ) and out of the circuit. With the nebulizer  50  inserted, the heat and moisture exchange element  34  is out of the circuit and gas flows between the vent circuit communications port  16 , the nebulizer port  18  and the patient port  14 , while isolating the heat and moisture exchange element  34 . 
         [0019]    To maintain position and prevent rotation of the heat and moisture exchange element holder  31 , a key  27  mates with a mating hole in the nebulizer insertion linkage  30 . Note that the upper port of the heat and moisture exchange element holder  31  aligns with the upper enclosure port  44  when the heat and moisture exchange element holder  31  rests on the bottom of the enclosure  12  (e.g. urged to the bottom by the main spring  22 ) and the lower enclosure port  44  is occluded by a surface of the heat and moisture exchange element holder  31 . In some embodiments, the insertion linkage  30  is keyed for the nebulizer port  18 . 
         [0020]    Referring to  FIGS. 2 and 3 , cross sectional views of the exemplary airway circuit  10  are shown. In  FIG. 2 , the nebulizer  50  is absent and the heat and moisture exchange element  34  is within the air path. In  FIG. 3 , the nebulizer  50  is inserted and the heat and moisture exchange element  34  is consequently isolated from the air path. 
         [0021]    In  FIG. 2 , there is no nebulizer  50  inserted into the nebulizer port  18  (a nebulizer  50  is shown ready for insertion). Therefore, gases communicate between the patient port  14  through the upper enclosure port  44 , the upper port  29  of the heat and moisture exchange element holder  31 , the heat and moisture exchange element  34 , a lower port  28  of the heat and moisture exchange element holder  31 , a lower vent port  15  of the housing, and the vent circuit communication port  16 . The main spring  22  urges the heat and moisture exchange element holder  31  to rest on the bottom of the enclosure  12 , while the secondary spring  21  urges the nebulizer insertion linkage  30  away from the heat and moisture exchange element holder  31 , seating the nebulizer insertion linkage  30  against the edges of the nebulizer port  18 , thereby preventing/reducing flow of gases in/out of the nebulizer port  18 . 
         [0022]    In  FIG. 3 , the nebulizer  50  has been inserted into the nebulizer port  18 . The main spring  22  gives way to the displacement of the nebulizer  50  and the heat and moisture exchange element holder  31  moves upward (toward the cap  20 , upward with respect the  FIG. 3 ) until the heat and moisture exchange element holder lid  24  approaches or rests against an inside surface of the cap  20 . The nebulizer insertion linkage  30  lifts off of the seat at the nebulizer port  18 , providing gas flow from the nebulizer port  18  into the enclosure  12 . Since nebulizers  50  have varying sizes, the secondary spring  21  compensates for different sizes of nebulizers  50 , such that nebulizers  50  with longer insertion tubes will further displace the nebulizer insertion linkage  30  and the secondary spring  21  will respond by compressing once the primary spring  22  has compressed. With the heat and moisture exchange element holder  31  in position close to or against the cap  20 , both the upper port  29  of the heat and moisture exchange element holder  31  and the lower port  28  of the heat and moisture exchange element holder  31  are occluded by walls of the enclosure  12 , therefore, isolating the heat and moisture exchange element  34  from any gases flowing from the nebulizer  50  or back from the patient port  14 . Instead, gases now communicate between the patient port  14 , with the lower enclosure port  46 , around the nebulizer insertion linkage  30 , with the nebulizer port  18 , with the lower vent port  15  of the housing, and with the vent circuit communication port  16 . 
         [0023]    When the nebulizer  50  is removed from the nebulizer port  18 , the main spring  22  urges the heat and moisture exchange element holder  31  toward the nebulizer port  18 , putting the heat and moisture exchange element  34  back into the circuit while the secondary spring  21  further urges the nebulizer linkage  30  further into the nebulizer port  18 , thereby blocking flow of gases in/out of the nebulizer port  18 . 
         [0024]    As previously stated, the above description and figures represent one exemplary embodiment and the invention is not limited to the mechanical embodiment shown. For example, in other embodiments, insertion of the nebulizer  50  moves walls instead of the heat and moisture exchange element holder  31 , selectively blocking/occluding passages and rerouting gases either through the heat and moisture exchange element  34  or around the heat and moisture exchange element  34 , without moving the heat and moisture exchange element  34  and holder  31 . 
         [0025]    Referring to  FIG. 4 , a perspective view of a heat and moisture exchange element  34  is shown. There is no restriction on the size, shape, and composition of the heat and moisture exchange element  34 . The heat and moisture exchange element  34  shown in the exemplary figures is one typical example of such. In general, the heat and moisture exchange element  34  is constructed in any way known in the field, for example, by a strip of bacterial filter material that is folded laterally into pleats and bent into a loop so that the folds extend radially as disclosed in U.S. Pat. No. 5,035,236 issued Jul. 30, 1991. 
         [0026]    Referring to  FIGS. 5 and 6 , perspective views of a heat and moisture exchange element holder  31  of the exemplary airway circuit with heat and moisture exchange element  34  are shown. The lower port  28  is open to the vent circuit communication port  14  when the nebulizer  50  is absent from the nebulizer port  18 . The upper port  29  is open to the patient port  14  through the upper enclosure port  44  when the nebulizer  50  is absent from the nebulizer port  18 . After the nebulizer  50  is inserted into the nebulizer port  18  and the heat and humidity exchange element holder  31  moves away from the nebulizer port  18 , both the upper port  29  and the lower port  28  are occluded by the side wall of the enclosure  12 . The upper enclosure port  44  is blocked as well, but gases flow in/out of the patient port  14  through the lower enclosure port  46 , beneath the heat and humidity exchange element holder  31  and in/out of the vent circuit communication port  16 . Since the nebulizer insertion linkage  30  also moves away from the nebulizer port  18 , gases and medication from the nebulizer  50  are free to flow into the enclosure and, for example, toward the patient port  14 . 
         [0027]    Referring to  FIG. 7 , a cross sectional view of a heat and moisture exchange element holder  31  of the exemplary airway circuit is shown. When the heat and moisture exchange element  34  is held within the heat and moisture exchange element holder  31 , gas flow is possible onto one side of the heat and moisture exchange element  34  through the upper port  29  and gas flow is possible onto the opposite side of the heat and moisture exchange element  34  through the lower port  28 . 
         [0028]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0029]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.