Abstract:
An application for a PEEP valve includes a filter media in the air flow between a patient interface and exit vent(s). The patient interface is connected to a patient airway system and the exit vents exhaust exhalation gasses into the atmosphere. The filter prevents or reduces the passage of microbes from the patient&#39;s exhalation gasses into the atmosphere. The PEEP valve provides positive gas pressure to a patient&#39;s lungs, requiring a predetermined exhalation gas pressure to be exceeded before releasing exhalation gasses into the atmosphere.

Description:
FIELD 
     This invention relates to the field of medicine and more particularly to a device that provides positive end expiatory pressure valve and has an integral filter. 
     BACKGROUND 
     This invention relates to a positive end expiratory pressure valve (referred to as a PEEP valve). In the current art, PEEP valves usually include a hollow cylinder or port providing a gas flow path for exhalation gas from a patient to which the PEEP valve is connected. The PEEP valve requires an adjustable exhalation gas pressure before it releases exhalation gasses into the atmosphere, thereby maintaining pressure in a patient&#39;s lungs. 
     Numerous devices are known to the art which provide flow paths for gasses such as air, oxygen, anesthesia gas, and the like. Numerous medical apparatus are also known to the art which provide a gas flow path for exhalation gas from a patient&#39;s lungs such as air, oxygen, anesthesia gas, etc. 
     PEEP valves, as known to the art, are used to maintain a predetermined pressure level in the lungs of a patient who is being ventilated with oxygen, air or anesthetized by an anesthesia gas. Typical PEEP valves includes a spring biased relief valve which remains closed and prevents the patient from exhaling until the pressure of the patient&#39;s exhalation gas exceeds the force of the spring after which the valve opens and the patient&#39;s exhalation gas is exhausted through a exit port on the PEEP valve and into the atmosphere. As the patient continues to exhale, the pressure of the exhalation gas decreases until it reaches the force set by the spring biased relief valve and the valve closes thereby preventing the further flow of exhalation gas from the patient&#39;s lungs. The gas remaining in the patient&#39;s lungs which otherwise would be exhaled, remains in the patient&#39;s lungs at a pressure equal to, or at least substantially equal to, the pressure setting of the spring. It is advantageous for a patient being ventilated or anesthetized to have at least some pressure remaining in their lungs and to prevent the patient&#39;s lungs from being totally evacuated during exhalation. The maintenance of such gas pressure is believed to have a salutary effect on the sacks or alveoli of the patient&#39;s lungs. 
     FIG. 1 of U.S. Pat. No. 6,135,108 to Richard Hoenig shows a patient being ventilated by air or oxygen from a suitable source. This patent is hereby included by reference. Gas enters the flowmeter, flows through the heated humidifier, through tubing (12), through a T-piece, and into the endotracheal tube with which the patient is intubated. When the patient exhales, the exhalation gas from the patient&#39;s lungs flows through the endotracheal tube, the T-piece and into the PEEP valve. When pressure exceeds the spring force of the PEEP valve, the patient&#39;s exhalation gas exits through the PEEP valve&#39;s exit port and into the ambient air in the patient&#39;s room. 
     Existing PEEP valves allow exhalation gasses to exit into the atmosphere around the patient. In many hospital situations, the patient has a communicable disease ranging from the common cold to bacterial pneumonia. As the patient exhales, pathogens, microbes or microorganisms are released, for example, in aerosolized droplets. These pathogens exit the PEEP valve exit port when the patient exhales as described above. Many pathogens will cause an infectious disease in a healthy adult, but those pathogens and a host of other pathogens cause an infectious disease in a person with depressed resistance (e.g. a patient suffering from another disease such as HIV or cancer). The later are classified as opportunistic pathogens. Being that many other patients in a hospital or even in the same room as the person using the PEEP valve potentially have depressed resistance; they are more susceptible to acquiring such a disease from the person using the PEEP valve. Likewise, for certain diseases and pathogens, caretakers are also susceptible to such microbes and pathogens. 
     In the past, recognizing the dangers of allowing such pathogens to leave the patient&#39;s lungs and into the atmosphere, medical facilities have attached filters between the PEEP valve and the patient airway. This reduces pathogen emission into the atmosphere, but requires a separate filter device inserted into the flow path. A separate filter device adds costs for the housing and connections, creates a larger, more cumbersome connection and increases the chances of a disconnected flow path. 
     What is needed is a PEEP valve with integral filter that prevents or reduces the emission of pathogens into the air surrounding the patient using such device. 
     SUMMARY 
     A PEEP valve is disclosed that provides positive gas pressure to a patient&#39;s lungs, requiring a predetermined exhalation gas pressure to be exceeded before releasing exhalation gasses into the atmosphere. The PEEP valve has an integral filter in the air flow between a patient interface and exit vents. The patient interface is connected to a patient airway system and the exit vents exhaust exhalation gasses into the atmosphere. The filter prevents or reduces the passage of microbes from the patient&#39;s exhalation gasses into the atmosphere. 
     In one embodiment, a PEEP valve for maintaining pressurized gas in a patient&#39;s lungs is disclosed. The PEEP valve includes a patient interface and a valve biased by a spring to inhibit passage of exhalation gasses from the patient interface and out of vents formed in the PEEP valve until a pressure of the exhalation gasses exceeds a force of the spring. A biological filter is positioned between the patient interface and the vents. The exhalation gasses pass through the biological filter before exiting through the vents, thereby preventing or reducing the passage of microbes into the atmosphere. 
     In another embodiment, a method of reducing emissions of microbes from a patient into the atmosphere is disclosed including connecting a PEEP valve to an airway system connected to a patient to pressurize exhalation gasses of the patient. The PEEP valve has a patient interface for connecting to the airway system with a valve that is biased by a spring to inhibit passage of the exhalation gasses from the patient interface and out of vents formed in the PEEP valve until a pressure of the exhalation gasses exceeds a force of the spring. The PEEP valve has a biological filter positioned between the patient interface and the vents. The exhalation gasses pass through the biological filter before exiting through the vents. The method includes the patient exhaling. When the pressure of the exhalation gasses exceeds the force of the spring, the valve opens and the exhalation gasses pass through the biological filter and out of the PEEP valve and through the vents. Microbes in the exhalation gasses are retained by the biological filter. 
     In another embodiment, a PEEP valve for maintaining pressurized gas in a patient&#39;s lungs is disclosed including, an enclosure having a patient interface with a biological filter interfaced to the patient interface. The biological filter allows passage of exhalation gasses from the patient interface while preventing the passage of at least some microbes from the patient interface. A valve is biased by a first end of a spring. The valve inhibits passage of the exhalation gasses from the patient interface until a pressure of the exhalation gasses exceeds a force of the spring. A knob is interfaced to the enclosure by threads. The knob is also interfaced to a second end of the spring such that tightening of the knob compresses the spring, increasing the force of the spring against the valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  illustrates a perspective view of a PEEP valve with an integrated filter. 
         FIG. 2  illustrates a sectional view of a PEEP valve with an integrated filter. 
         FIG. 3  illustrates an exploded view of a PEEP valve with an integrated filter. 
         FIGS. 4-21  illustrate individual components of the PEEP valve with integrated filter. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     Referring to  FIG. 1 , a perspective view of a PEEP valve  10  with an integrated filter will be described. From the outside, the PEEP valve  10  with integral filter looks similar to other PEEP valves having a spring tension adjustment knob  11  that is screw fitted to the knob base  12  such that, as the spring tension adjustment knob  11  is turned in one direction, it tightens the tension of one or more adjustment springs  36 / 38  (see  FIGS. 2 ,  3 ,  8  and  9 ) and as the tension adjustment knob  11  is turned in the opposite direction, it loosens the tension of the adjustment spring(s)  36 / 38 . An indicator marker  14  is attached or molded into the knob base  12  to show the approximate pressure setting of the adjustment spring(s)  36 / 38 . A base member  20  has a one or more exhaust port openings or vent windows  16 , whereby exhalation gasses exit when the tension of the adjustment spring(s)  36 / 38  is exceeded. An interface port  18  is connected to the airway system (not shown), typically through an exhalation port or a T-connector (not shown). 
     Referring to  FIG. 2 , a sectional view of a PEEP valve  10  with an integrated filter media  50  will be described. The spring tension adjustment knob  11  is screw fitted to the knob base  12  with threads  15 . As the spring tension adjustment knob  11  is turned in one direction, it tightens the tension of springs  36 / 38  and as the tension adjustment knob  11  is turned in the opposite direction, it loosens the tension of the spring  36 / 38 . Above the interface port  18  is a filter media  50  that blocks pathogens or biological hazards emanating from the patient, passing through the airway system (not shown) and into the interface port  18 . Biological filters are known in the industry, for example, those used in face masks, electrostatic filters, etc. Electrostatic filters include a presence of an electrostatic charge on the particles of the fabric, leading to an increase in capture of small particles. 
     It is anticipated that, in some filter media  50 , anti-microbial materials such as silver nitride are present to neutralize the pathogens, further reducing the possibility of release into the atmosphere and introduction to people in the area. 
     Referring to  FIG. 3 , an exploded view of a PEEP valve  10  with an integrated filter will be described. The structure and components shown are exemplary and there are many ways to fabricate and manufacture a fluid valve that exhausts a person&#39;s exhalation gas after a pre-determined and preferably settable exhalation gas pressure is reached. The general structure is shown as an enablement of a PEEP valve  10  showing one way to implement a filter media  50  within such a PEEP valve  10 . Other structures with filter media  50  are anticipated and included herewithin. Likewise, the location of the filter media  50  is a preferred location, but other locations are also anticipated such as within the vent windows  16 , etc. 
     The PEEP valve  10  shown has a threaded adjustment knob  11  that is threaded onto the knob base  12 . Tightening of the knob  11  compresses the spring(s)  36 / 38 , requiring a greater exhalation gas pressure to open the valve seal  70  that is normally seated on the valve seat  72 , thereby releasing the exhalation gas through the vent windows  16 . The knob is fitted on a shaft  40  a stopper  30 , shaft cap  32  and spring stop  34  which support an upper end of the springs  36 / 38 . The bottom of the adjustment spring  36  seats against the valve cap  60 , providing pressure to the valve seal  70  against the valve seat  72 . When the patient exhales, once the exhalation gas pressure exceeds the pressure of the adjustment spring  36 , the valve seal  70  lifts from the valve seat  72  and exhalation gasses exit though the vent windows  16 . 
     In some embodiments, a label  14  or marking  14  indicates the position of the knob  11  and hence, the exhalation gas pressure setting. In this example, various other components are present including a valve cap  60 , a large grease cap  64 , a small grease cap  66 , an upper retainer  62 , and a lower retainer  68 . These components are present in some exemplary PEEP valves  10  to improve operation and reduce chatter noise when the user exhales. In this embodiment, a filter media  50  is situated between the valve seat  72  and the filter case/patient interface  18 . It is anticipated that the filter media  50  be located in other locations of the PEEP valve  10  as long as gas flows through the filter before exiting the PEEP valve  10 . The filter media  50  allows exhalation gasses to enter the PEEP valve  10  from the patient interface  18  and, once the preset pressure is reached, the exhalation gasses exit the vent windows  16 . The filter prevents certain biological agents from passing from the patient interface  18  and out through the vent windows  16 . The simplest filter media  50  would be a fiber filter similar to those used in hospital face masks, though many different types of filters  50  are anticipated. It is anticipated that some classes of PEEP valves  10  have one type of filter media  50  while other classes of PEEP valves  10  have a different type of filter; each type is used for a patient with a different disease. For example, one class of PEEP valves have filters selected for patients with HIV and another class have filters selected for patients with pneumonia. 
     In some embodiments, the filter media  50  includes an antimicrobial substance such as silver nitrite. Filters  50  that include antimicrobial substances not only prevent the microbes from exiting the PEEP valve  10  and into the atmosphere, the antimicrobial substances also neutralize the microbes. This is important to reduce emissions of microbes once the PEEP valve  10  is disconnected from the patient airway system, at which time, it is possible that microbes lodged on the patient side of the filter media  50  will escape into the atmosphere. The antimicrobial substance(s) will neutralize the microbes before they have a chance to escape into the atmosphere. 
     Referring to  FIGS. 4-21 , individual components of the PEEP valve with integrated filter will be described.  FIG. 4  shows the knob  11 .  FIG. 5  shows the stopper  30 .  FIG. 6  shows the shaft cap  32 .  FIG. 7  shows the spring stop  34 .  FIG. 8  shows the adjustment spring  36 .  FIG. 9  shows the cone spring  38 ,  FIG. 10  shows the shaft  40 .  FIG. 11  shows the label  14 .  FIG. 12  shows the top cover  20  with knob base  12  and vent windows  16 .  FIG. 13  shows the valve cap  60 .  FIG. 14  shows the upper retainer  62 .  FIG. 15  shows the large grease cap  64 .  FIG. 16  shows the small grease cap  66 .  FIG. 17  shows the lower retainer  68 .  FIG. 18  shows the valve seal  70 .  FIG. 19  shows the valve seat  72 .  FIG. 20  shows the filter media  50 . Finally,  FIG. 21  shows the filter case/patient interface  18 . 
     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. 
     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.