Patent Application
20050247313
This invention relates in general to an improved breathing system incorporating a nebulizer and, in particular, to an improved breathing system including a non-rebreather mask, a reservoir bag, a rescue valve and an improved nebulizer having an auxiliary gas port carried by a nebulizer head in a position removed from the nebulization chamber to introduce an auxiliary gas into the nebulizer head, when desired, without effecting the rate at which the breathing system applies medication to the nebulizer user.
Persons requiring treatment of certain kinds of respiratory conditions frequently need to have medications delivered directly to the lungs. Nebulized or aerosolized solutions are the preferred method of delivery of respiratory medication because the medicant is fragmented into small particles that are more efficiently deposited near sites of drug activity in the lungs.
While nebulizers are well known to those skilled in the art, aerosolization of medications in a nebulizer is effected by putting a liquefied medication into a container or liquid reservoir and introducing a pressurized flow of gas through an aerosol nozzle carried within a nebulization chamber which is coupled to the liquefied medication contained in the liquid reservoir by a liquid draw tube. As the pressurized high velocity gas flows through the aerosol nozzle, the liquefied medication is drawn through the liquid draw or aspirator tube into the path of the high velocity gas and is fractured thereby into a mist, becoming entrained with the gas flow out of the nebulization chamber through the container and out therefrom through an output port.
In certain applications, nebulization therapy can be enhanced through the use of an auxiliary gas to supplement the nebulizing or driving gas being introduced through the aerosol nozzle. Such supplemental gases may be air, oxygen, helium or a combination of these two gases, referred to as heliox, depending upon the particular driving gas being used. The use of helium, an inert and metabolically stable gas which readily diffuses into swollen airways, or heliox, as a supplement to the nebulizing gas is also known, and these gasses are frequently used to drive the nebulized medication deeper into a user's lungs to deliver medications to bypass obstructed or restricted airways for a greater and more rapid effect from the medication.
One of the problems encountered when using supplemental gases, however, is that the injection of the supplemental gas into the nebulizing gas or into the nebulizing chamber affects the rate at which the liquefied medication passes out from the container through the aerosol output port. Generally, the rate at which the liquefied medication is to be nebulized and delivered to the user, is determined based upon, among other factors, the rate of flow and density of the driving or nebulizing gas being introduced into the nebulization chamber. When a supplemental gas is introduced into the nebulizing gas flow or into the nebulization chamber, the total quantity of medication delivered through the nebulization chamber changes. Accordingly, the predetermined rate at which the liquefied medication is discharged through the aerosol output port varies from that at which it was initially set.
Another problem encountered when a supplemental gas is introduced into a nebulizer breathing system, is that the supplemental gas is introduced at a point in the system close to the patient interface, such as a non-rebreathing (NRB) mask. The introduction of a supplemental gas at such a position relative to the NRB mask frequently results in the application of a non-uniform gas mixture. If a patient does not take uniform breaths, or the patient's breathing pauses, the percentage of the supplemental gas being introduced increases, or spikes, resulting in the patient inhaling a greater percentage of the supplemental gas with the next breath.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the relevant technology. As will be more readily understood and fully appreciated from the following detailed description of a preferred embodiment of the present invention, the invention is embodied in an improved nebulizer breathing system wherein a supplemental gas may be introduced into the nebulizer head at a position after the liquefied medication has been fractured or nebulized, so that the introduction of the supplemental gas does not effect the rate at which the nebulized liquefied medication is applied to the user, and the mixture of gases to be administered to a patient is added to the breathing system at a position removed from the point at which the gas mixture is administered to the patient.
Further objectives of the invention, together with additional features contributing thereto and advantages accruing therefrom, will be apparent from the following description of a preferred embodiment of the invention which is shown in the accompanying drawings, wherein:
Referring now to the drawings, there is illustrated in
The nebulizer 100, illustrated in detail in
The nebulizing head 10 has a closed circular-shaped top 12 and a depending skirt 13 forming a generally cylindrical shape with an open bottom 14 adapted to receive the liquid container 20. A nebulization chamber 30 is formed inside the nebulization head 10 and spaced downwardly from the top 12. The nebulization chamber 30 extends downwardly from a point of attachment 31 on the inner wall 13a of the skirt 13 towards the open end 14 of the nebulizer head, forming a chamber in which the liquid contained in the liquid container 20 is entrained in a driving or nebulizing gas introduced through the top 12 of the nebulizer head 10 into the nebulization chamber 30.
The top 12 of the nebulizer head 10 supports an adapter 15 by which a suitable source of driving or nebulizing gas is connected, such as by a flow meter or tubing 15b, for introduction into the nebulizing chamber 30. A conventional nebulizing nozzle 16 is supported within the nebulizing chamber 30 beneath the top 12, and is coupled to a passageway 15a formed through the adapter 15 by which the driving or nebulizing gas is introduced into the nebulizing chamber 30. The nebulizing nozzle 16 communicates with a suitable orifice at an upper terminal end of an aspirator tube 17 which extends downwardly into the liquid medicant contained in the liquid receptacle 20. In this manner, when a source of driving or nebulizing gas is coupled to the adapter 15, and introduced to the nebulizing nozzle 16, the liquid medicant contained within the receptacle 20 will be entrained in the driving or nebulizing gas and discharged out from the nebulizer chamber 30. The entrained aerosol so formed will then pass through the nebulizing head 10 to be discharged from the nebulizer 100 through a nebulized aerosol discharge outlet 18, formed through the sidewall 13, and into the flexible tubing 200.
To provide for the introduction of a supplemental gas into the nebulizer 100, an auxiliary gas inlet port 19 is formed in the side wall 13 at a point preferably opposite to the nebulized aerosol discharge outlet 18. The auxiliary gas inlet port 19 is coupled to a suitable source of supplemental gas, such as oxygen, helium or heliox, by tubing 19b and the inlet port extends into the nebulizing head 10, but not into the nebulizer chamber 30. In this manner the supplemental gas introduced through inlet port 19 will not affect the rate at which the aerosolized medicant is delivered from port 18. As heretofore described, when a supplemental gas is introduced into the driving or nebulizing gas, or the nebulizing chamber 30, the supplemental gas so introduced effects the uniformity of the administration of the medication. When a supplemental gas is so introduced, the rate of medication application increases with the increased gas flow. By introducing the supplemental gas through the auxiliary gas inlet port 19, the supplemental gas does not change the rate at which medication exiting the nebulizer through port 18 is applied to the nebulizer user. When a source of supplemental gas is not being introduced through auxiliary gas inlet port 19, a conventional cap, not shown, may be placed over the external opening thereto.
When the medication containing gas mixture exits the nebulizer 100 through the discharge or output port 18, the gas passes into the first inlet end 201 of the flexible tubing 200. The flexible tubing is preferably a collapsible type of flexible tubing such as that commercially available and sold under the trademark “POPPLE”. The second outlet end 202 of the flexible tubing 200 is connected to a first input branch 301 of a wye connector 300 to space the output of the gas mixture from the nebulizer 100 a distance away from the inlet to a NRB mask 500 through which a patient breathes the medicant-containing mixture. Preferably, the flexible tubing 200 is at least approximately 18 inches in length, and can be approximately 72 inches in length, to create a mixture that when inhaled by the user will be more uniform, than systems wherein a supplemental gas is administered to the user by means of a supplemental gas source connected to or substantially adjacent to the NRB mask 500, or connected to or substantially adjacent the wye connector 300.
A flexible bag reservoir 400 is connected in fluid communication to a second input branch 302 of the wye connector 300, and functions as an accumulator which holds enough of the incoming gas mixture to compensate for the patient's next breath in the event of over-breathing, as is known to those skilled in the respiratory care art.
The NRB mask 500 is sized to fit to the patient's face, and encompass the nose and mouth thereof. Such masks, or the equivalents thereof, are available in different sizes to accommodate patients from pediatric through adults. The mask 500 has an inlet 501 connected to a discharge outlet 303 of the wye 300. Conventional one-way inhalation 502 and one-way exhalation valves 503, one of which is shown, are carried in the NRB mask. The inhalation valve 502 is open during patient inhalation, and closes during patient exhalation. However, during periods of patient inactivity, the inhalation valve 501 may stay open because of the positive pressure coupled thereto by the nebulizer 100. The valve, however, prevents exhaled breath from traveling back into the wye 300. The exhalation valves 503 open during exhalation, and close during inhalation. In this manner, the expiratory air discharged by a patient is exhausted to atmosphere, and does not go back into the breathing system.
In order to ensure that a patient does not draw a negative pressure in the system in the event the patient is over-breathing, a conventional rescue valve 600 is incorporated into the wye 300. The rescue valve 600 is a one-way inhalation valve which is normally closed, but when a patient over-breathes the nebulizer system, the rescue valve 600 will open permitting the patient to breathe ambient air through the rescue valve, and preventing the patient from drawing a negative pressure or vacuum. When the patient is normally breathing, and does not over breath the system, the rescue valve 600 will remain closed.
While this invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, the structure of which has been disclosed herein, it will be understood by those skilled in the art to which this invention pertains that various changes may be made and equivalents may be substituted for elements of the invention without departing from the scope of the claims. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed in the specification and shown in the drawings as the best mode presently known by the inventors for carrying out this invention, nor confined to the details set forth, but that the invention will include all embodiments, modifications and changes as may come within the scope of the following claims:
