Patent Publication Number: US-9402947-B2

Title: Portable fluid delivery system for the nasal and paranasal sinus cavities

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of and claims filing priority rights with respect to currently pending U.S. patent application Ser. No. 13/414,439 filed Mar. 7, 2012, which was published Jun. 28, 2012, as U.S. Publication 2012/0160237; and Ser. No. 13/404,623 filed Feb. 24, 2012, which was published Jun. 21, 2012, as U.S. Publication 2012/0152238; and Ser. No. 12/829,198 filed Jul. 1, 2010, which was published Jan. 5, 2012, as U.S. Publication 2012/0000460. The technical disclosures of all of the above-mentioned applications are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to devices used for administering fluid to the upper airway in mist or droplet form, either for the irrigation of the nasal passages or the delivery of medication. 
     BACKGROUND OF THE INVENTION 
     Devices used for administering liquid medication to a patient by way of mist or liquid droplets are generally called nebulizers and are primarily used for the delivery of medication into the lungs. These devices are best suited for the inhalation of the mist or aerosol through the patient&#39;s mouth. However, some cases require the introduction of liquid droplets to the patient&#39;s nasal passages and the droplet or particles of the aerosol generated by such nebulizers are small and lightweight so as to pass through the nasal cavity to the lungs on the inhaled air leaving very little if any of the aerosol deposited in the nasal cavity. 
     Another device used for delivering liquid through a patient&#39;s nasal passages is a nasal irrigator, or irrigator. Irrigators, however, deliberately deliver liquid to the patient&#39;s nasal passages, rather than bypassing the nasal cavity to reach the lungs. Current irrigators for introduction of medication to or irrigation of the nasal passages generally comprise an air compressor, an irrigator cup for the liquid medication, and compressor tubing to connect the compressor to the irrigator cup. Inevitably, the equipment and parts used with current irrigators are large and extremely bulky, weighing at least ten pounds. Thus, the compressor tubing provides for a convenient way of handling the irrigator cup during irrigation or use; however, the compressor itself is not a portable or lightweight device. To use the irrigator, the compressor must be placed on a sturdy surface in order to support its weight and its power supply cord must be plugged into an outlet. 
     SUMMARY OF THE INVENTION 
     The components of an irrigator comprise a size and weight that simply do not allow for convenient transport, portability or even quick and simple handheld usage. There is a need for an irrigator device that will easily fit in well with a person&#39;s daily needs or activities such that the person need not have to change his or her daily routines or schedule times of day to be close to an irrigator or an outlet for the irrigator. The device should be easy to carry on one&#39;s person and provide convenience to the needs of a patient. There is a need for an all-in-one irrigator device that contains all the components necessary to successfully use an irrigator, without the heavy weight of its components and without tubing connected to heavy equipment, and without compromising the performance needed to penetrate the nasal and paranasal cavities. There is also the need to eliminate the requirement to be close to a power outlet to be able to use an irrigator. 
     A portable, ready-to-use device for nasal irrigation and/or drug delivery of fluid is provided herein, which allows for more convenient use, not requiring connecting tubing, a power supply cord, or a heavy or bulky compressor. The irrigator device has an internal airflow regulating system within a connected pressurized air supply source with airflow regulating components that replace heavy, large components to power atomization of fluid for irrigation or drug delivery to the nasal passages without compromising effectiveness or reach of the atomized fluid. The airflow regulating system comprises an air outlet, a pump, a motor, a filter for filtering incoming air, and a circuit board to control the motor. The pump is in communication with the main canister and the motor, and the filter connects to the pump. The motor is driven by one of: a battery contained within the pressurized air supply source or an external power supply source. A canister for holding fluid attaches on top of the pressurized air supply source and an insert fits that over a fluid channel in the canister to create a venturi effect and draw the fluid out. The entire device described herein, as a whole, (meaning all its parts and components) is lightweight (i.e., less than 2 pounds) and easy to handle and hold either single-handedly or with both hands; thereby, cutting down the weight and bulky equipment otherwise necessary by more than half. Where the device is used without an external power supply, the lightweight device weighs only about one pound. With an external power supply, the portable device described herein weight about 1.5 lbs. In addition, the device is small enough to be carried or moved with ease to provide for convenience while still having the power to reach the desired areas of the nasal passage and the particle size to minimize or eliminate the risk of pulmonary delivery and keep the aerosol in the nasal cavity. The device can also be readily used at any time without having to search for a nearby electrical outlet, when a battery pack within the pressurized air supply source has sufficient charge. 
     The fluid to be administered to a user is contained within a canister of the device. The canister is recessed within a concave top portion of the handheld pressurized air supply source comprising the airflow regulating system therein. A lip of the canister attaches on top of the rim of the pressurized air supply source. An insert with a tapered fluid channel fits over tubular channel or tube having an air exit port at its top end. The insert includes an extension projecting out to the canister from the fluid channel. A vertical groove may extend down the exterior of the fluid channel to a hole in the extension that allows for venting of air or spent fluid into the enclosed canister as the fluid to be delivered is displaced during use. The fluid is atomized via the attached airflow regulating system to create particles sized for dispersion and retention within the nasal cavity delivered via a pressurized flow that is able to drive the aerosol past structures in the nasal cavity that act to filter the inhaled airstream to deliver the resultant mist into the whole of the nasal passages without the need for the patient to create an airstream through inhalation. 
     As stated above, the device requires no connecting tubing and no power cord during use to power the atomization of fluid. Instead, the airflow regulating system within the pressurized air supply source comprises substantially all or all components necessary to regulate and control the air supply. The pressurized air supply source houses a motor that drives a pump, which receives filtered air through a filter on the pressurized air supply source, and an optional rechargeable battery to drive the motor. An inlet air manifold of the filter connects to the pump via a pump air inlet post to eliminate additional tubing within the pressurized air supply source. A circuit board precisely controls the motor speed to ensure the proper airflow, ensures the battery voltage is maintained at a proper voltage for operation and drives indicators to inform the user when the battery requires charging and is being charged. The AC/DC power supply charges the battery and provides the user the option to operate the device on mains power when the battery is discharged. The motor controller board may utilize pulse width modulation or alternatively digital control to control motor speed within a narrow band to regulate airflow generated by the pump. 
     A single membrane on one external side of the pressurized air supply source contains substantially all the electrical components externalized to the user and incorporates a single ribbon connector. A power jack is the only electrical component outside the single membrane. A tethered cover may be used to cover the power jack and reduce fluid and dust ingress to the device when the power supply is not plugged into the irrigator, such as when the pressurized air supply source houses a battery. When pressurized air is introduced through the air inlet of the canister, a venturi effect is created, drawing fluid up between the air exit port and fluid channel and expelling the fluid as a mist through a discharge port in the fluid channel. The mist may comprise medication, saline or other non-active ingredients to provide moisture. 
     Other aspects, embodiments and features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. The accompanying drawings are schematic and not intended to be drawn to scale. In the figures, each identical or substantially similar component that is illustrated in various figures is represented by a single numeral or notation. For purposes of clarity, not every component is labeled in every figure. Nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as mode of use and advantages thereof, will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an exploded view of a nasal irrigator in accordance with an embodiment of the present invention; 
         FIG. 2  shows a cross sectional view of a canister in accordance with an alternate embodiment of the invention; 
         FIG. 3  shows an alternate embodiment of the cover in accordance with the present invention; 
         FIG. 4  illustrates the use of the nasal irrigator of  FIG. 1  in accordance with an embodiment of the present invention; 
         FIG. 5  conceptually illustrates the function of the nasal valve in aerosol delivery that is initiated below the nasal valve; 
         FIG. 6  shows an embodiment of a nasal irrigator in accordance with an embodiment of the present invention; 
         FIG. 7  is a schematic cross sectional view of the assembled nasal irrigator of  FIG. 6 ; 
         FIG. 8  shows a perspective view of an assembled nasal irrigator in accordance with an embodiment of the present invention; 
         FIG. 9 a    shows an exploded view of an embodiment of a nasal irrigator in accordance with an embodiment of the present invention. 
         FIG. 9 b    shows a bottom view of an insert in accordance with an embodiment of the present invention. 
         FIG. 10  shows a perspective view of an assembled nasal irrigator in accordance with an embodiment of the present invention. 
         FIG. 11  is a schematic cross sectional view of the assembled nasal irrigator of  FIG. 10 ; 
         FIG. 12 a    shows an exploded view of a nasal irrigator in accordance with an embodiment of the present invention. 
         FIG. 12 b    shows a bottom view of an insert in accordance with an embodiment of the present invention. 
         FIG. 13 a    shows a top perspective exploded view of the nasal irrigator of  FIG. 12 . 
         FIG. 13 b    shows a cross-sectional side view of an assembled irrigator in accordance with the present invention; 
         FIG. 14  shows a perspective view of an assembled nasal irrigator in accordance with the present invention; 
         FIG. 15  shows an exploded view of a nasal irrigator in accordance with an embodiment of the present invention. 
         FIG. 16  shows a perspective view of an assembled nasal irrigator in accordance with an embodiment of the present invention; 
         FIG. 17  shows a top view of the nasal irrigator of  FIG. 16 . 
         FIG. 18  shows a schematic cross sectional view of a filter in accordance with an embodiment of the present invention. 
         FIG. 19A  shows an exploded view of a portable irrigator according to an embodiment of the present invention. 
         FIG. 19B  shows another perspective view of the portable irrigator shown in  FIG. 19A . 
         FIG. 20  shows a front perspective view of an assembled portable irrigator as shown in  FIGS. 19A and 19B . 
         FIG. 21A  shows a perspective view of an assembled portable irrigator according to an embodiment of the present invention. 
         FIG. 21B  shows a perspective view of a portable irrigator as depicted in  FIG. 21A . 
         FIG. 22  shows a cross sectional detailed view of a portion of the main canister of an assembled portable irrigator according to an embodiment of the present invention. 
         FIG. 23  shows a perspective view of an assembled portable irrigator according to an alternate embodiment of the present invention. 
         FIG. 24  shows an exploded view of another embodiment of a portable irrigator. 
         FIG. 25A  shows a exploded view of a portable irrigator and the insert with the canister attached to the pressurized air supply source. 
         FIG. 25B  shows another perspective bottom view of the insert. 
         FIG. 26A  is a top view of the pressurized air supply source in one embodiment. 
         FIG. 26B  is a partial cross-sectional view of the canister attached to the pressurized air supply source. 
         FIG. 27  shows a perspective view of a portable irrigator with the insert attached to the canister and pressurized air supply source. 
         FIG. 28  shows a cross-sectional view of the insert in one embodiment. 
         FIG. 29  depicts an assembled view of one embodiment of the portable irrigator with a cap over the insert. 
         FIG. 30  shows a side perspective view of a partial cross-section of the canister attached to the pressurized air supply source. 
         FIG. 31  shows a view of the components within the pressurized air supply source of a nasal irrigator in one embodiment 
         FIG. 32  shows a cross-sectional view of the nasal irrigator of  FIG. 31 . 
         FIG. 33A  shows a partial view of one embodiment of the assembled irrigator with one side of the pressurized air supply source removed. 
         FIG. 33B  shows a partial view of one embodiment of the assembled irrigator with the other side of the pressurized air supply source removed. 
         FIG. 34A  shows a perspective view of an inlet air manifold in one embodiment. 
         FIG. 34B  shows another perspective view of an inlet air manifold in one embodiment. 
         FIG. 35  shows a perspective view of a filter cap of the portable irrigator in one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention improves upon current irrigator designs and provides a method of delivering fluid to the nasal passages with little interaction required by the user, under sufficient pressure to stent-open the airway, and with particles of a size to ensure that the majority of the mist is retained or deposited within the upper airway. The invention also provides a nasal irrigator designed to deliver a mist to the upper airway through both nostrils simultaneously. 
     In one aspect, a nasal irrigator of the present invention comprises a main canister with a reservoir for holding fluid, wherein the canister includes at least two air exit ports; a removable insert with a circular base that fits within said main canister, wherein the insert includes at least two fluid channels that mate with said air exit ports of the main canister, said fluid channels comprising two tubes ending in a common bell housing above the base, wherein said base holds the insert just off of the main canister surface, allowing fluid to pass between the base and main canister, and further wherein the fluid channels are larger in diameter than the air exit ports, thereby providing a small space between the outer surface of the air exit ports and the inner surface of the fluid channels that allows fluid from said reservoir to be drawn upward between the air exit ports and fluid channels and expelled as a mist in an aerosol plume through exit holes in the fluid channels due to a venturi effect created by pressurized air from the air exit ports; and at least one nozzle coupled to the bottom of said main canister to create at least one air chamber defined by the nozzle and said air exit ports, wherein the nozzle includes an air inlet for providing pressurized air into said air chamber. 
       FIG. 1  is an exploded view of a nasal irrigator in accordance with an embodiment of the present invention. The nasal irrigation device comprises three major sections. The first major section is the main canister  22  which has an expanded reservoir  10  that is capable of holding up to 50 ml of fluid. The inner portion of the reservoir shaped at the bottom to ensure maximal uptake of fluid to reduce waste. 
     The main canister  22  also includes an air chamber  11  terminating in two air exits  12  (one for each nostril) with holes sufficient to deliver an airstream that is able to atomize fluid and stent-open the upper airway. In one embodiment, each exit port  12  has at least one hole of between 0.020″ and 0.060″ (0.508 mm-1.524 mm) in diameter and a web-thickness or hole length of between 0.030″ and 0.200″ (0.762 mm-5.08 mm). 
     On the bottom of the main canister  22  is a foot section  9  that includes one or more feet for stability and an air inlet  8  for the admission of pressurized air to create the air stream through air exits  12 . The foot section  9  enables the canister  22  to stand up when set on a horizontal surface and is designed to fit into a standard docking port of an air compressor pump to enable the device to remain upright in a hands-free manner so as to remain filled with the air supply tube attached. 
     In the shown example, the main canister  22  has a two-step circumference to fit a holder (not shown) and provide adequate fluid volume for nasal irrigation, with the smaller diameter foot section  9  enabling the user to rest device in the holder with tube attached. In an alternate embodiment (not shown) the foot section  9  is wider than the reservoir section  10 . 
     The second major section of the irrigator is the insert  23 , which is shown with a base  13  that holds the inside surface of the insert  23  just off of the outer surface of the feature within reservoir  10  of the main canister  22 . At least one channel is located in the bottom of the insert  23  to act as a conduit for fluid from the reservoir  10  to enter the base of the insert. The insert  23  includes fluid channels  14  that mate with the air exit ports  12  of the main canister  22 . Peaks or extensions may be included on the air exits  12  to ensure centering of the insert  23  and its fluid channels  14  on the air exits. Similarly, tabs may extend from the inside of the fluid channels of the insert to the outer surface of the main canister to ensure alignment. As shown, fluid channels  14  of the insert  23  comprise two tubes with one end at the bottom of the reservoir  10  and one end that is positioned in the airstream so that the airstream creates a negative pressure in each tube that draws fluid into the airstream where it is atomized (described below). 
     In the embodiment shown in  FIG. 1 , the atomizer outlets  12 ,  14  extend above the edge of the main canister  22 . However, in an alternate embodiment (not shown) the atomizer nozzles are even with or recessed within the edge or portions of the edge of the main canister. 
     The insert  23  is keyed in at least one location with the reservoir  10  to ensure that the insert does not rotate in relation to the exit ports  12  of the main canister and to aid in centering of the insert  23  and its fluid channels  14  on the air exits. The insert may include a feature to ensure that it is inserted into the main canister in only one orientation. In one embodiment, a loop (not shown) extends down to the saddle of the insert  23  to hold down the insert. 
     The fluid channels  14  are slightly larger in diameter than the air exit ports  12  of the main canister, thereby providing a small space (preferably 0.0001″ to 0.010″ (0.00254-0.254 mm)) between the outer surface of the air exit ports and the inner surface of the fluid channels. This space allows fluid from the reservoir  10  to proceed upward between the air exit ports  12  and the fluid channels  14  until being expelled by pressurized air. When the insert  23  is installed in the main canister  22 , the orifices of the fluid channels  14  are positioned relative to the air exits  12  so as to create a venturi effect with the pressurized gas expelled from the gas tubes. Because the fluid exits  14  in the insert  23  are larger than the air exits  12 , when air is forced through the air exits at an appropriate volume and speed, fluid in the reservoir  10  is drawn up into the space between the insert and air exits ports. When this fluid meets the subsequent airstream it is atomized into particles conducive to deposition in the upper airway. The airstream is sufficient to penetrate the nasal cavity above the inferior turbinate so as to deposit the fluid and provide a washing, irrigation, or deposition to the upper reaches the nasal cavity. 
     The exit holes of the fluid channels  14  are small enough to ensure that mist is created but large enough to ensure that the holes of the insert may be chamfered so that the walls of the exit holes are angled away from a central axis at an angle that exceeds the cone of the aerosol plume to reduce agglomeration of the mist particles upon exit, providing a more uniform particle size throughout the plume. The fluid channel size may be adjusted to change the particle size of the mist. In one embodiment the tubes have a mating section on the upper end that enables the changing of the orifice in the air stream via a series of nozzles that can be inserted into the upper end of the tubes such that the size of the nozzle orifice that is placed into the airstream is varied. 
     The third major section of the irrigator is nozzle cone  3 . The nozzle  3  includes an air inlet  6  and a mating surface  7 , which attaches to the air inlet  8  of the main canister  22  to create air chamber  11  defined by the nozzle and the two exit ports  12  described above. The length of all components on the nozzle cone  3  preferably is limited so that the nozzle cone or its components do not extend past the foot section  9  on the main canister  22  when the device is assembled to enable the device to be placed on a flat surface in an upright or standing position. 
     Ribs may also be molded into the nozzle cone  3  to provide radial stiffness. In another embodiment, the nozzle cone is made of rigid plastic. 
     The mating surface between the nozzle  3  and main canister  22  is designed to ensure a tight bond can be created. In an alternate embodiment the mating surface between the nozzle  3  and main canister  22  is essentially straight. 
     In one embodiment, the nozzle cone  3  is attached permanently to the main canister  22 . In an alternate embodiment, the nozzle cone  3  may utilize a friction fit or have a positive connection such as a thread or other mechanism allowing the nozzle cone and main canister  22  to be disconnected for cleaning. This detachable embodiment may include an air seal such as an O-ring as well as a flange to grasp for easy disassembly. 
     An air supply tube  5  connects the air inlet  6  of the nozzle cone with an air supply  17 . 
       FIG. 2  shows a cross section view of a canister  25  in accordance with an alternate embodiment of the invention. In this embodiment, rather than a single air chamber and nozzle, the canister  25  includes separate air passage chambers  26  that terminate in the air exits  27 . These separate air passage chambers  26  can connect to separate air sources via separate nozzles. Alternatively, the separate air passage chambers  26  can be connected to a common air source via split tubing such as a Y or T adapter (not shown). 
     In addition to the three major sections described above, the irrigator may include a cover  4  that has a mating surface  15  that creates an isodiametric connection to the main canister  22 . In the example shown in  FIG. 1 , the cover  4  is a broad cover region to block space between the nose, eyes and the rest of the face when in use as shown (see  FIG. 4 ). In this embodiment the cover  4  is designed to confine the mist expelled from the fluid channels and shield the patient&#39;s eyes, with an opening to provide room for the patient&#39;s nose within the apparatus. The cover  4  is radiused along the distal end away from the main canister  22  to fit a broad variety of faces and is open to enable air to enter as the fluid is drawn down and capture and recycle fluid that falls off the face. 
     The cover may also incorporate a cross member or other device that retains the insert  23  to allow for clearance of the nose and prevent lifting of the insert at the initiation of atomization. In one embodiment a sleeve or partial sleeve extends from the cover  4  to the base of the insert  23  to hold the insert down. 
       FIG. 3  shows an alternate embodiment of the cover in accordance with the present invention. In this embodiment, the cover  28  is a semi-circular lid that does not block the eyes but instead retains the insert and blocks material from re-entering the main canister from the nose. 
     The present invention may incorporate a feature that guides the user to angle the spray into the nose at a set angle from 0-90 degrees from the plane defined as the front of the face from the chin to the forehead (i.e. the vertical plane of the face). For example, the irrigator may include a setoff designed to set a specific angle of 30 degrees, 45 degrees, or 60 degrees from the vertical plane of the face. The setoff may be removable for various size faces or noses. 
     Materials suitable for construction of the irrigator include rigid plastic, glass, metal, ceramic, carbon fiber or other rigid material, or an elastomer plastic or some combination thereof. 
     One embodiment of the nasal irrigation device (not shown) is egg-shaped or ovoid for better fit into the hand and a pleasing look. 
       FIG. 4  illustrates the use of the nasal irrigator in accordance with the present invention. The irrigator is placed over the face of the user  18  and angled such that the cover  4  blocks the eyes. The mist  20  enters the nasal passages  21 , and the patient breathes through both the mouth and nose at the same time ( 24 ). The mist  20  passes into the nasal passages  21  independent of the patient&#39;s breathing. 
     The air-fluid mixture is calibrated to achieve nasal irrigation within a short period of time, without the need for the fluid to exit the nostrils at the time of irrigation, and with a particle size that is designed to loosen the mucous or to enter the sinus cavities, as desired by the end user and not enter the pharynx or the lungs. 
     In one aspect, the method of nasal irrigation comprises providing fluid in a canister that includes at least two air exit ports mated to corresponding fluid channels, wherein the fluid channels are larger in diameter than the air exit ports, thereby providing a small space between the outer surface of the air exit ports and the inner surface of the fluid channels. This space allows fluid from said reservoir to be drawn upward between the air exit ports and fluid channels. Pressurized air is pumped through the air exit ports, thereby creating a venturi effect that draws fluid from said reservoir upward between the air exit ports and fluid channels and expels the fluid as a mist in an aerosol plume through exit holes in the fluid channels and into a user&#39;s nasal cavity above the inferior nasal turbinate independent of the user&#39;s breathing. The pressurized air has a pressure of 0.069-1.035 bar and an airflow rate of 1-12 liters per minute, producing a fluid delivery rate of 1-20 ml per minute. 
     The method of nasal irrigation offers a fast, convenient method of atomizing saline or medication for delivery to the nose, with a variable particle size up to 100 microns. In one embodiment, particle size is at least 10 microns. 
     Using an air pressure of 1-15 psi (0.069-1.035 bar) creates a pressurized airflow that enables the resultant air-mist stream to stent-open the soft tissues of the upper airway. In one embodiment, the air pressure ranges from about 3-12 psi (0.207-0.823 bar), with about 1-12 lpm of airflow, and a fluid delivery rate of about 1-20 ml per minute. In one embodiment, the air pressure ranges from about 4-8 psi (0.276-0.552 bar), with about 3.5-8 lpm airflow, and about 15 ml per minute fluid delivery. 
     The resultant mist reaches the area of the nasal cavity and paranasal sinuses above the inferior nasal turbinate or chonchae to ensure that the mist reaches the areas of the sinus ostia to clear this area of the nasal cavity and enable the natural mucociliary flow to clear the sinuses. 
     Recent medical research has noted that the olfactory and trigeminal nerves may be used as a pathway to deliver large and small molecules to the brain and central nervous system that bypasses the blood brain barrier and first pass metabolism of intravenous and oral delivery routes. (See Dhanda, D., Frey W H 2 nd , Leopold, D., Kompella, U B: “Nose-to-brain delivery approaches for drug deposition in the human olfactory epithelium.”  Drug Delivery Technol.  5(4), 64-72 (2005).) Frey and others have demonstrated that these nerves may be reached via the nasal mucosa overlying the olfactory cleft and cribriform plate where these nerves are concentrated. Furthermore, the frequency of dosing of many of these materials requires a delivery system that is practical and easy to use. In the case where systemic delivery of drugs via the nose is desired, maximizing the surface area of the mucosa covered by the medication may improve the amount of medication that is absorbed by the body and may reduce the variability of absorption between doses and across patients; thus improving the bioavailability of the drug and reducing the variability of bioavailability of the drug. Furthermore, by maximizing the surface area available for absorption of any given drug, the concentration required to deliver an effective dose may be reduced when compared to traditional metered dose inhaler technology, enabling more drugs to be delivered transnasally than with other systems. 
     However, the literature suggests that adequate delivery systems are lacking for the reliable and practical delivery of these substances to these areas. Delivery of large particles (&gt;10 microns) of liquids in the described volumes as provided by the present invention, offers advantages over dry powder, minute volumes and high volume solutions. These advantages include covering the whole nasal mucosa, formulating drugs for patient comfort vs. concentration, reducing the inadvertent delivery of aerosolized materials to the lungs; and the ability to deliver precious materials economically and judiciously while reducing waste. 
     In one aspect, the present invention provides a method of treating neoplasms of the nasal cavity comprising fluid in a canister, wherein the canister includes a reservoir and at least two air exit ports, and wherein said fluid contains corticosteroids. The air exit ports are mated to corresponding fluid channels, wherein the fluid channels are larger in diameter than the air exit ports, thereby providing a space between the outer surface of the air exit ports and the inner surface of the fluid channels, which allows fluid from said reservoir to be drawn upward between the air exit ports and fluid channels. Pressurized air is pumped through the air exit ports, thereby creating a venturi effect that draws fluid from said reservoir upward between the air exit ports and fluid channels and expels the fluid as a mist in an aerosol plume through exit holes in the fluid channels and into a user&#39;s nasal cavity above the inferior nasal turbinate independent of the user&#39;s breathing. 
     The present invention allows for delivering steroids for the long-term control of benign neoplasms of the nasal cavity, such as inflammatory nasal polyps, granulomas, etc., without systemic doses of steroids or steroid injections. It also provides the ability to irrigate the whole nasal mucosa to manage the disruption of natural filtering and humidification often caused by ablative and reconstructive surgical treatment of neoplasms. Unlike prior art saline irrigation and nasal sprays which do not reach many of the areas of concern in the nasal vestibule and paranasal sinus areas, the irrigator of the present invention delivers adequate moisture in less than one minute to the areas of concern. The present invention also avoids pooling of moisture that can otherwise provide a nidus for infection and cause excessive removal of the immunologic mucus blanket of the nose. 
     The high frequency of steroid administration needed to control neoplasm growth requires a delivery system that is practical and easy to use. The irrigator of the present invention can deliver these steroids quickly—in less than one minute—covering the whole nasal cavity and does so without unduly exposing the body to the effects of systemic steroids. 
     For example, using the irrigator of the present invention, 0.60 mgs of corticosteroid is typically delivered to the nasal cavity, between two and ten times the amount delivered via metered dose inhalers. In some instances, antibiotics are delivered along with the corticosteroid to treat infections such as  Staphylococcus aureus. Staph aureus  endotoxin has been shown to up-regulate the beta isoform of cortisol receptor (CR β ) in cell membranes that is responsible for inhibiting the response to corticosteroids, and it is believed that the Staph infection may contribute to steroid-resistant nasal polyps. The concurrent administration of antibiotics with the corticosteroid via the irrigator of the present invention reduces this endotoxin effect on the cortisol receptor, thereby increasing the efficacy of the steroid therapy. 
     The pressure and airflow necessary to deliver material to the upper portion of the nose can be reduced if the aerosol is introduced distal of the nares at or above the nasal valve and proximal to the inferior turbinate. The present invention delivers droplets or mists with an air stream and particle sizes designed to stay in the upper airway under sufficient pressure and airflow to overcome the normal aerodynamics of the nose. Unlike prior art methods, the present invention releases mist at or above the nasal valve, thereby avoiding deflection of the fluid off the walls of the nostril and nasal valve. 
     Effective delivery of material to the nasal cavity requires a particle size that is large enough to fall out of the airway before reaching the oropharynx, delivered under sufficient pressure and airflow to overcome the aerodynamics of the nasal cavity. The nasal cavity is shaped to efficiently deliver air to the lungs. Air enters the nares and passes through the nasal valve, which resides approximately 1.3 cm above the nares and is the narrowest portion of the nose, with a cross-section of at approximately 0.73 cm 2 . The nasal valve is the narrowest anatomic portion of the upper airway, resulting in the volume of air inspired nasally to be efficiently cleansed and humidified by the nasal cavity. 
       FIG. 5  conceptually illustrates the function of the nasal valve in aerosol delivery that is initiated below the nasal valve. Arrows  120  represent an aerosol flowing into the nasal nares. As illustrated by arrows  121 , a portion of this aerosol is reflected off the walls of the nose as the passageway narrows to the nasal valve  130 . This reflected material falls out of the nose and is either wasted or is recollected by the device to be delivered repeatedly. 
     The nasal valve  130  acts to reduce the flow (F) and pressure (P) of that portion of the aerosol stream that crosses the valve and enters the nasal cavity  110 . Thus, Flow in (F I ) is greater than Flow out (F O ), and Pressure in (P I ) is greater than Pressure out (P O ). As a result, aerosol entering the nasal cavity external to the nasal valve requires a higher pressure and flow rate to achieve the same aerosol distribution as an aerosol introduced internal to the nasal valve. 
     Air entering the nose meets additional resistance at the level of the inferior turbinate, which directs air downward along the floor of the nose along the path of least resistance. During inhalation, the airflow is dominated by the negative pressure being generated from the lower airway and is directed to the nose from the pharynx. This negative pressure and the structure of the nasal cavity conspire to direct the majority of the air through the lower third of the nose, with very little air entering the upper portion of the nose. Indeed, studies have shown that to reach the upper portion of the nose under the negative pressure of normal breathing, an aerosol must be placed very precisely at the front of the nares. To overcome the aerodynamics of the nose, the delivery system must provide a positive pressure and sufficient airflow to fill the whole nasal cavity. 
     Prior art devices that deliver aerosol below the nasal valve must generate higher pressure and flow rates since the valve acts to lower the pressure and flow as the aerosol passes through it. The design of the present invention is directed to the self-administration of fluid to the nasal passages of a patient while ensuring the device fits a wide variety of faces and for simplicity of design, ease of manufacturer. It requires lower pressure and airflow and produces less mess by virtue of delivery above the nasal valve, and simplicity of use, including short delivery times. 
     The invention delivers fluid to the nasal passages with little interaction required by the user and under sufficient pressure to stent-open the airway. The invention delivers particles of a size to ensure that the majority of the mist is retained or deposited within the upper airway, while maximizing the amount of drug delivered and eliminating reflection back from the nasal valve. 
       FIG. 6  shows an embodiment of a nasal irrigator in accordance with the present invention. The nasal irrigator comprises three main components. The first component is the main canister  201 , which has a fluid reservoir  202  and an air exit port  203  that extends above the reservoir. In one embodiment, the reservoir  202  holds up to 30 ml of fluid or medication. As shown in  FIG. 1 , the lower portion of the reservoir is downward sloping to ensure fluid collects at the bottom, which allows maximal uptake of fluid through fluid channels (explained below), thereby minimizing waste. 
     The air exit port  203  has at least one exit hole  204  at the top sufficient to deliver an airstream that is able to atomize fluid and deliver the aerosol to the whole nasal cavity. In one embodiment, the exit hole  204  is between 0.020″ (0.508 mm) and 0.060″ (1.524 mm) in diameter and the air exit port has a web-thickness of between 0.030″ and 0.200″ (0.762 mm-5.08 mm). 
     The main canister  201  also included an air inlet  205  on the bottom for the admission of pressurized air to create the air stream exiting the air exit port  203 . 
     In one embodiment, the main canister  201  has optional “feet” on the bottom (as shown in  FIG. 1 ) for stability. The length of all components on the nozzle cone is limited so that the nozzle cone or its components do not extend past the feet on the main canister when the device is assembled to enable the device to be placed on a flat surface in an upright or standing position. The canister  201  may also be designed to fit into a standard docking port of an air compressor to enable the device to remain upright in a hands-free situation so as to be filled with the air supply tube attached. 
     The second main component of the nasal irrigator is an insert  206  that fits over the main canister&#39;s air exit port  203 . The insert  206  can be permanently attached to the canister  201  or it may be removable. The insert  206  has an aerosol exit  210  that is concentrically aligned with the exit hole  204  of the air outlet  203 . A peak or extension on the air exit port  203  may ensure centering of the insert over the air outlet. Similarly, tabs on the insert may be used to center the insert over the air outlet and prevent it from being moved by force. The aerosol exit  210  is slightly larger than the exit hole  204  of the air exit port  203  to enable atomization of fluid in the air stream. 
     The insert  206  has a tapered inner diameter  207  that is larger than and follows the contours of the outer diameter  208  of the air exit port  203 . This difference in diameter creates a space of between 0.0001″ (0.00254 mm) and 0.010″ (0.254 mm) between the inner surface of the insert  206  and the outer surface of the air exit port  203 . This space allows fluid to be drawn from the reservoir  202  through a channel  209  at the base that is sized to control the fluid flow. 
     The third main component of the nasal irrigator is the cover  211  that mates with the reservoir  202  of the main canister  201  and extends over the insert  206  such that the insert does not contact the nose as the device is inserted into the nasal cavity, thereby ensuring that the hole  210  in the insert  206  and the hole  204  in the air exit port  203  remain concentrically aligned. The cover  211  includes a mating surface  212  that creates a preferably isodiametric connection to the main canister  201  and extends around the nozzle formed by the insert  206  and air exit port  203 . The cover  211  extends just above the insert  206  and has its own exit hole  214  designed not to restrict the flow of the aerosol plume. In one embodiment, the cover  211  provides a cross member or other feature that secures the insert  206  to prevent lifting of the insert at the initiation of atomization. 
       FIG. 7  is a schematic cross section view of the assembled nasal irrigator in accordance with the present invention. This view shows the alignment of the canister  201 , insert  206 , and cover  211  and the resulting fluid space  215 . When fluid is in the reservoir  202  and a pressurized air source is introduced to the system via air inlet  205 , a vacuum is created in the space  215  as air exits through outlets  204  and  210 . Because the aerosol exit hole  210  in the insert  206  is larger than the exit hole  204  of the air exit port  203 , when air is forced through the air exit port  203  at an appropriate volume and speed it creates a venturi effect as the pressurized gas is expelled, thereby drawing fluid in the reservoir  202  up into the space  215  between the insert and air outlet. When the fluid reaches the airstream between the exit holes  204 ,  210 , it is atomized in the airstream to create an aerosol. This aerosol is sufficiently dispersed within the nasal cavity above the inferior turbinate so as to the reach the upper nasal cavity. 
     The aerosol exit  210  in the insert  206  is small enough to ensure that a mist is created yet large enough to ensure that the hole can be chamfered on the outer side to reduce agglomeration of the mist particles upon exit. The aerosol exit hole  210  is chamfered so that the walls of the exit are angled away from a central axis of the hole such that the angle is greater than that of the aerosol plume. This chamfering reduces agglomeration of particles on the walls of the aerosol exit hole  210 , resulting in uniformity of particle size across the resultant aerosol plume. 
     The base of the insert  206  sits in a groove  217  at the base of the canister  201 , ensuring that all fluid is drawn from the bottom of the canister. 
     The irrigator components of the present invention can be made from materials such as rigid plastic, glass, metal, ceramic, carbon fiber or other rigid material, an elastomer plastic, or some combination thereof. 
       FIG. 8  shows a perspective view of an assembled nasal irrigator in accordance with the present invention. By maintaining a sufficiently narrow nozzle assembly  218 , and a sufficiently long and smooth cover  219 , the device can be easily and atraumatically inserted into the nose of the patient so that the nozzle  218  extends to or above the nasal valve. The device is then angled by the user to obtain the best distribution based on the user&#39;s anatomy. The mist enters the nasal cavity independent of the patient&#39;s breathing. 
     The nasal irrigator of the present invention may also include a feature that guides the user to angle the spray into the nose to a set angle of between 0 and 90 degrees from the vertical plane of the face (defined as the front of the face from the chin to the forehead). For example, one embodiment of the nasal irrigator includes a setoff that sets a specific angle of 30 degrees from the vertical plane of the face. In another embodiment, the setoff angle is 60 degrees from vertical, and in another embodiment the setoff angle is 45 degrees from vertical. The setoff described above is removable to accommodate various size faces and noses. 
     The method of nasal irrigation of the present invention uses a variable particle size up to 100 microns under a pressure of 1-15 psi (0.069-1.0345 bar), creating a pressurized airflow that enables the resultant air-mist stream to reach the whole nasal cavity independent of the patient&#39;s breathing. The resultant aerosol mist reaches the area of the nasal cavity above the inferior nasal turbinate or chonchae to ensure that the mist reaches the areas of the sinus ostia to clear this area of the nasal cavity and enable the natural mucociliary flow to clear the sinuses. 
     By adjusting the size of the exit holes  204  and  210 , the air-fluid mixture can be calibrated to achieve nasal irrigation within a short period of time, without the need for the fluid to exit the nostrils at the time of irrigation, and with a particle size that is designed to loosen the mucous or to enter the sinus cavities, as desired by the end user. In many applications, ideally a mist of 20 microns is delivered at a rate of 0.5 ml per second. 
     The aerosol mist itself is typically medicated with at least one, and often two or more therapeutic agents. Possible therapeutic agents for use in the medicated mist, either alone or in combination include antibiotics, antifungal agents, corticosteroids and mucolytic agents. The mist may also be medicated with a neurologically-active agent targeting the central nervous system through the cranial nerves innervating at least a portion of the nasal cavity as well as systemically-active agents. 
       FIG. 9 a    is an exploded view of an improved nasal irrigator device according to one embodiment of the present invention. The device comprises a main canister  220 , an insert  221 , and a cap  223 . The main canister  220  and the insert  221  comprise many of the same characteristics of the irrigator described with relation to  FIG. 1 . The main canister  220  comprises a rim surrounding a reservoir  227 , which can hold up to 50 mL of fluid. While the reservoir is depicted as substantially circular, it should be appreciated that the reservoir may comprise any shape. In one embodiment, the reservoir comprises an oval shape. As previously described with respect to  FIG. 1 , the main canister  220  also comprises an air chamber that terminates into at least one air exit port  228 . In one embodiment, as depicted in  FIGS. 9-11 , the air chamber of the canister terminates into two air exits ports  228  (one for each nostril). In another embodiment, as best depicted in  FIGS. 12-14 , the air chamber of the canister terminates into only one single air exit port. 
     As described above with respect to  FIG. 1 , each air exit port  228  has at least one hole of between 0.020″ and 0.060″ (0.508 mm-1.524 mm) in diameter and a web-thickness or hole length of between 0.030″ and 0.200″ (0.762 mm-5.08 mm). In addition, as with the embodiment of  FIG. 1 , on the bottom of the main canister  220  is a foot section  224  that includes at least one foot for stability and an air inlet (as depicted in  FIG. 11 ) for the admission of pressurized air to create the air stream through air exit ports  228 . The foot section  224  enables the canister  220  to remain standing on its own when set on a substantially horizontal surface and is designed to fit into a standard docking port of an air compressor pump to enable the device to remain upright in a hands-free manner so as to remain filled with the air supply tube attached. 
     The insert  221  comprises a base  229  that fits within the canister  220  and sits just off the bottom of the reservoir  227 . In one embodiment, as depicted in  FIG. 9 , the base  229  is circular. However, the base may comprise any number of shapes so long as it fits within the canister. The insert  221  further comprises a fluid channel  225  that fits over the air exit port  228 , said fluid channel  225  comprising a tube portion ending in a common bell housing  234  above the base. In one embodiment, the insert comprises two fluid channels. In another embodiment, described below, the insert comprises one fluid channel. 
     As best depicted in  FIG. 9 b   , the bottom face of the base  229  of the insert  221  comprises at least one groove  226  that forms a communication channel between the canister and the common bell housing of the insert. The groove  226  extends from the outside of the base to the inside of the insert. The base should comprise at least one groove but may also comprise more than one, as depicted in  FIG. 9 b   . The number of grooves as well as the width and depth of the groove will help regulate the flow of fluid up to the point that the airflow takes over the upper limit of flow. In one embodiment, the grooves may range in width from about 0.005″ to about 0.150″ (0.127 mm to about 3.81 mm). In one embodiment, the grooves may range in depth from about 0.001″ to about 0.050″ (0.0254 to about 1.27 mm). The fluid channel  225  is larger in diameter than the air exit port  228 , thereby providing a small space between the outer surface of the air exit port  228  and the inner surface of the fluid channel  225  that allows fluid from said reservoir  227  to be drawn through the communication channel and upward between the air exit port  228  and the fluid channel  225  such that the fluid is expelled as a mist in an aerosol plume through an exit hole  230  in the fluid channel due to a venturi effect created by the introduction of pressurized air from the air exit port. 
     In one aspect, the canister  220  and the insert  221  are preferably affixed together such that the insert  221  and the canister  220  together form an integral piece. As used herein, “affix” relates to a secure attachment between the canister and insert and may include both permanent bonding and temporary bonding, which may only be subsequently manually separated. Preferably, the affixing of the insert and canister will not interfere with or negatively affect the communication channel(s) formed by the grooves in the bottom face of the insert. In one embodiment, the insert  221  is permanently affixed or bonded to the canister  220  at the bottom face of the insert. The bond may be formed by any means known in the art including without limitation use of a solvent bond, glue UV-cured adhesives, mechanical attachment, heat forming, or radiofrequency or ultrasonic welding. In another embodiment, the canister  220  and the insert  221  may mechanically mate together, such as with a friction fit or a snap fit, to form a temporary connection between them that can be subsequently separated by the user as desired. 
     In yet another embodiment, where the insert comprises two fluid channels, the nasal irrigator may further comprise a cross bar component  222  having an edge that fits around the rim of the canister. The crossbar component may comprise a single crossbar  232  that extends from one edge of the component  222  to another edge, dividing the component  222  into two substantially equal halves, as depicted in  FIG. 9 a    for example; or it may comprise a crossbar that extends from one edge to one or more other edges at a different locations around the circumference, dividing the enclosed space into multiple areas. In such embodiments, the crossbar component  222  may be permanently affixed or bonded to the rim of the canister  220 , thereby affixing the insert  221  to the canister  220 . The bond may be formed by any means known in the art including without limitation use of a solvent bond, glue UV-cured adhesives, mechanical attachment, heat forming, or radiofrequency or ultrasonic welding. 
     Covering the canister  220 , insert  221 , and optional crossbar component  222  is a cap  223  without holes therethrough. As depicted in  FIG. 10 , a cap  223  fits over the rim of the canister  220  and covers the tube portion of the insert, plugging the exit hole  230  of the fluid channel  225  and the air exit port  228  to form an airtight, hermetic seal for the irrigator device, preventing the leakage of the fluid from the reservoir. The cap may further comprise an alignment feature or thumb hold 231 along its outer edge, which may align with a similar alignment feature or thumb hold on the exterior of the canister  220 . Thus, the irrigator in one embodiment allows for sterile or non-sterile drug storage and serves as a carrier for the transport or shipment of medication or irrigation fluid. 
       FIG. 11  is a cross sectional view of an assembled nasal irrigator comprising a canister  220 , insert  221 , optional crossbar component, and cap  223 . As best shown here in  FIG. 11 , the cap  223  may comprise sealing plugs  233  recessed within the cap, which extend through both the exit hole  230  of the fluid channel  225  and the air exit port  228 . In one embodiment, the sealing plugs  233  may be comprised of an expandable material, which will expand once removed from the top of the irrigator device. In another embodiment, the cap may be threaded and include a gasket to form a compression seal. When ready for use, a user can remove the cap and connect an air supply to the air inlet beneath the reservoir. 
     A method of forming a disposable nasal irrigator in comprises the steps of providing a canister  220  with an air exit port  228  and a rim surrounding a reservoir  227  for holding fluid; providing an insert  221  with a base  229  that fits within the canister  220 , the insert  221  comprising a fluid channel  225  that fits over the air exit port  228 , said fluid channel comprising a tube portion ending in a common bell housing  234  above the base, said base comprising at least one groove  226  along its bottom face forming a communication channel between the reservoir  227  of the canister  220  and the common bell housing  234 , wherein the fluid channel  225  is larger in diameter than the air exit port  228 , thereby providing a small space between the outer surface of the air exit port  228  and the inner surface of the fluid channel  225  that allows fluid from said reservoir  227  to be drawn through the communication channel and upward between the air exit port  228  and fluid channel  225 ; and affixing the canister  220  together with the insert  221 , thereby forming one integral structure. 
     The providing steps (a) and (b) can comprise the step of manufacturing the canister or the insert, or both the canister and the insert. The manufacturing can be performed by any means known in the art including without limitation molding, forming, shaping or any combination thereof. The providing step (a) may also comprise the step of obtaining the canister from any manufacturer or vendor, for example. Similarly, the providing step (b) may comprise the step of obtaining the insert from any manufacturer or vendor. By way of example, in one embodiment, the insert may be permanently attached to the canister along its base  229 . Preferably, the bond would be formed such that the groove  226  remains a communication channel. Thus, the bonding should not substantially block or plug the groove  226 . In one embodiment, the insert is bonded or permanently attached along its bottom face to an interior side of the canister. A suitable solvent bond includes, for example, any plastic adhesive including without limitation ABS, acrylic, polystyrene, and polycarbonate solvents such as cyclohexanone. With the insert and canister forming one integral structure, fluid may be inserted into the reservoir  227  and the cap  223  can be placed over the rim of the canister to seal the fluid within the irrigator device for transport or shipment. 
       FIG. 12 a    depicts an exploded view of another embodiment of a nasal irrigator. Similar to the above devices, the nasal irrigator comprises a main canister  240  with an air exit port  245  and a rim  243  surrounding a reservoir  247  for holding fluid. The air exit port  245  extends beyond the rim  243  of the irrigator and has at least one exit hole at the top sufficient to deliver an airstream that is able to atomize fluid and deliver an aerosol. The main canister may also comprise the foot section  246  for stability. In addition, if desired, the canister may comprise one or more horizontal marks or lines to indicate specific fluid levels. 
       FIG. 12 b    depicts an embodiment of the insert  241  with a base  248  that fits within the main canister  240 , wherein the insert has a bottom face with at least one groove  244  to form a communication channel between the canister  240  and the common bell housing  249 . In one embodiment, as depicted in  FIG. 12 b   , the groove at the bottom of the insert  241  may extend from the outside edge of the bottom face to a peripheral groove surrounding the opening of the common bell housing. The insert further comprises an extension  250 . As depicted in  FIGS. 12 a  and 13 a   , in one embodiment, the extension  250  protrudes outwardly from the mid-section of the insert  241  above the common bell housing  249 . In other embodiments, however, the extension may also extend from another point along the insert, from the common bell housing to any point closer to the exit  253  of the fluid channel. The extension  250  forms a top, or lid, to the canister  240  that mates with the rim  243  of the canister. In one embodiment, the extension comprises a downward concave shape relative to a plane substantially perpendicular to the fluid channel; or, relative to the top surface of the lid. In one embodiment, the extension comprises a two-step diameter  257  to mate with the rim  243 . The insert  241  further comprises one or more apertures  251  around the fluid channel, each of the apertures lining up with a vertical groove  252  along the exterior of the fluid channel  262 . The groove  252  runs vertically from a point below the exit hole of the fluid channel  253  down to an aperture  251  in the extension  250 . During use, the deflected fluid will begin to flow back down the vertical groove  252 . The aperture  251  communicates with the inner chamber formed by the mating of the main canister  240  and insert  241 . As fluid exits the inner reservoir, a vacuum is created that actually pulls the deflected fluid back into the reservoir  247  through the aperture  251 , thereby ensuring maximum usage and minimized waste of the fluid. 
     The irrigator further comprises a cap  242  without holes that fits over and inserts into the fluid channel  253  and the air exit port  245  to seal the reservoir from the air exit and fluid exit. The cap comprises an elongated portion  256  to ensure a good fit over the tube portion. Optionally, the cap may comprise a flattened edge  255  to help with alignment with the apertures  251  of the insert  242  and also help with the grasping the cap  242 . The bottom portion  258  of the cap mates with a portion of the top face of the extension. Thus, as best depicted in  FIG. 12 a   , the bottom face of the cap  242  is relatively upwardly convex in one embodiment to mate with the downwardly concave extension  250 . The cap  242  further comprises one or more projections  254  on its bottom face, which mates with the apertures  251  of the extension. In particular, the projection  254  aligns with and seals the aperture  251  when the cap  242  is placed over the insert  241 , as best shown in  FIG. 14 . Thus, the number of projections  254  on the bottom face of the cap  242  should equal the number of apertures  251  in the insert  250 . As best depicted in  FIG. 13 b   , the cap further comprises a sealing plug  259  that projects into and fits within the exit hole of the fluid channel  253  in the insert  241  and the air exit port  245 , thereby sealing the nasal irrigator. 
     Similar to the embodiments described above with regard to  FIGS. 9-11 , in order to make a disposable device in accordance with one aspect of the present invention, the canister  240  and the insert  241  are affixed together such that the insert  241  and the canister  240  together form an integral or single piece. In embodiments comprising an extension  250  extending from the insert to the rim of the canister (as depicted in  FIGS. 12-13 ), the extension may form a top that mates with the rim of the canister and the edges of the extension may be permanently affixed to the rim of the canister. Thus, in one embodiment, it is the extension that is permanently affixed to the rim of the canister by way of bonding, for example. In another embodiment, the extension may form a top that mates together with a portion of the canister. A suitable solvent bond includes, for example, any plastic adhesive including without limitation ABS, acrylic, polyacetal, polyethylene, polyester, polypropylene, polystyrene, or polycarbonate solvent, UV-cured adhesive, heat or ultrasonic welding or over molding of materials. Bonding with such materials can be performed by any means known in the art. Having the insert and canister as a single integral piece, fluid may be inserted into the reservoir  247  and the cap  242  can be placed over the exit hole  253  and the aperture(s)  251  of the insert  241  to seal the fluid within the irrigator device for transport or shipment. The cap sits over the tube portion of the fluid channel and the fluid within the reservoir remains sealed within the irrigator device until ready for use.  FIG. 14  depicts an assembled, sealed device  260  ready for transport. 
     As with the above embodiments, the orifices of the fluid channels should be positioned relative to the air exits so as to create a venturi effect with the pressurized gas expelled from the gas tubes. Thus, the affixing step should account for this positioning. Because the fluid channel exits in the insert are larger than the air exits, when air is forced through the air exits at an appropriate volume and speed, fluid in the reservoir is drawn up into the space between the insert and air exits ports. When this fluid meets the subsequent airstream it is atomized into particles conducive to deposition in the upper airway. 
       FIG. 15  is an exploded view of an embodiment of a nasal irrigator device comprising a canister section  270 , an insert  271 , and a filter  272 . Similar to the above devices, the canister section  270  comprises a canister  273  with reservoir  275  and an air exit port  276  having an exit hole  277 . The canister section  270  also comprises one or more feet  274  beneath the canister  273 ; and the insert  271  comprises a base  278  that fits within the reservoir of the canister and at least one fluid channel  280  with an exit hole  281 . As described above, the insert and canister section once formed, shaped, molded or obtained, are affixed to one another. 
     In one embodiment, the nasal irrigator device further comprises a filter component  272  that may be inserted over the insert  271 . The filter component  272  comprises a filter  284  comprised of a mesh structure with holes small enough to prevent any particulate matter or mucus that runs out of the nose from entering the reservoir  275 , while allowing the irrigating or medicating fluid to run back into the reservoir  275  to be re-circulated or re-used. Suitable materials from which to create the filter are plastic, metal, carbon fiber, or other fiber. In embodiments comprising more than one fluid channel, the filter component also comprises a crossbar component  283 . In one embodiment, the crossbar  283  is an integral part of the filter component  272 . However, it should be understood that the crossbar  283  could also form a separate component, which is detached from the filter, and remains optional. 
       FIG. 16  is a perspective view of an assembled irrigator having an insert having two fluid channels  280  and a filter  284  with the optional crossbar  283 , wherein the insert is affixed to the canister to form one single integral structure. As described above, in one embodiment, the insert is affixed to the canister by way of bonding. The bonding may comprise the joining of the bottom face of the insert base to the canister or the joining of the periphery of the base to the canister. In one embodiment, the insert may be affixed to the canister by permanently bonding the periphery  282  of the filter to the rim of the insert. As best depicted in  FIG. 17 , the filter  284  surrounds the tube portion  280  of the insert and extends from the rim of the canister to the tube portion  280 , substantially covering the opening of the canister such that when in use, the filter prevents particulate matter from entering the reservoir. 
     With reference to  FIGS. 12 and 13 , where the nasal irrigator comprises an extension, in one embodiment, a filter entirely covers or fits within the apertures  251  in the extension  250  to similarly keep particular matter out of the reservoir and separate from the fluid for re-circulation. The filter may slide over the fluid channel of 241 or may be bonded over or under the apertures  251  or even molded into the insert  241 . 
       FIGS. 19A and 19  B show an exploded view of a portable nasal irrigator in accordance with an embodiment of the present invention. The portable irrigator comprises four sections. The first major section is the main canister  300 , which comprises a reservoir  305  for receiving fluid. The main canister  300  further comprises an air exit port  301 . As depicted in the figures, the air exit port  301  may extend above the top edge of the main canister  301 . However, in alternate embodiments (not shown), the air exit port  301  may be even with or recessed within the edge or portions of the edge of the main canister  300 . While the reservoir is depicted as substantially circular, it should be appreciated that the reservoir may comprise any shape. In one embodiment, the reservoir comprises an oval shape. Preferably, the reservoir should be shaped to allow for the receipt of a maximum amount of fluid. 
     Returning to the embodiment depicted beginning at  FIG. 19A , the main canister further comprises a curved wall  302  surrounding the opening to the reservoir  305 . The curved wall  302  comprises a convex shape that extends downwardly around the periphery of the opening into a bottom generally rectangular opening configured to mate with a pressurized air supply, as further discussed below. When viewed from below, the main canister  300  thus comprises a generally hollow portion surrounding the reservoir portion  305 . 
     The second major section of the portable irrigator is the insert  307 , which comprises a base  308  that fits within the reservoir section  305  of the canister. As depicted in  FIGS. 19A and 19B , the base  308  is circular. However, the base may comprise any number of shapes so long as it fits within the canister. The insert comprises a fluid channel  309  with one end at the bottom of the reservoir  305  and one end that is positioned in the airstream so that the airstream creates a negative pressure in each tube that draws fluid into the airstream where it is atomized. The end positioned in the airstream comprises an exit hole  313 . The fluid channel  309  is slightly larger in diameter than the air exit port  301  of the main canister  300 , thereby providing a small space (preferably 0.0001″ to 0.010″ (0.00254-0.254 mm)) between the outer surface of the air exit ports and the inner surface of the fluid channels. This space allows fluid from the reservoir  305  to proceed upward between the air exit port  301  and the fluid channel  301  until being expelled by pressurized air. When the insert  307  is installed in the main canister  300 , the orifice  313  of the fluid channel  301  is positioned relative to the air exit  301  so as to create a venturi effect with the pressurized gas. Because the fluid exit in the insert  313  is larger than the air exits  301 , when air is forced through the air exits at an appropriate volume and speed, fluid in the reservoir  305  is drawn up into the space between the insert and air exit port. Thus, when this fluid meets the subsequent airstream it is atomized into particles conducive to deposition in the upper airway. The airstream is sufficient to penetrate the nasal cavity above the inferior turbinate so as to deposit the fluid and provide a washing, irrigation, or deposition to the upper reaches the nasal cavity. The fluid channel size may be adjusted to change the particle size of the mist. 
     The insert  307  may be keyed in at least one location with the reservoir  305  to ensure that the insert does not rotate in relation to the exit port  301  of the main canister  300  and to aid in centering of the insert  307  and its fluid channel  309  on the air exit port  301 . In one embodiment, the insert may also include a feature to ensure that it is inserted into the main canister in only one orientation. 
     At least one channel is located in the bottom of the insert  307  to act as a conduit for fluid from the reservoir  305  to enter the base  308  of the insert. As best depicted above in  FIGS. 9 b  and 12 b   , the bottom face of the base  308  of the insert  307  comprises at least one channel or groove that forms a communication channel between the canister and the insert. The groove extends from the outside of the base to the inside of the insert. The base should comprise at least one groove but may also comprise more than one, as depicted in  FIG. 9 b   . The number of grooves as well as the width and depth of the groove will help regulate the flow of fluid up to the point that the airflow takes over the upper limit of flow. In one embodiment, the grooves may range in width from about 0.005″ to about 0.150″ (0.127 mm to about 3.81 mm). In one embodiment, the grooves may range in depth from about 0.001″ to about 0.050″ ( 0 . 0254  to about 1.27 mm). 
     The canister  300  and the insert  307  may or may not be affixed together to form one integral piece. The bond may be formed by any means known in the art including without limitation use of a solvent bond, glue UV-cured adhesives, mechanical attachment, heat forming, or radiofrequency or ultrasonic welding. Alternatively, the canister and insert may be affixed together via a mechanical interlocking element such as a friction fit or a snap fit to form a temporary connection. 
     The insert further comprises an extension  311 . As depicted in  FIGS. 19A and 19B , the extension  311  protrudes outwardly from the insert  307 . The extension  311  may extend from any point along the insert to form a top, or lid, to the canister  300 . In one embodiment, the extension substantially covers the opening of the reservoir  305 . In another embodiment, the extension entirely covers the opening of the reservoir  305 . In one embodiment, the extension comprises a downward concave shape relative to a plane substantially perpendicular to the fluid channel; or, relative to the top surface of the lid. In one embodiment, the extension comprises a two-step diameter (not shown) to mate with a rim of the opening. The insert  307  further comprises one or more apertures  314  around the fluid channel, each of the apertures lining up with a vertical groove  310  along the exterior of the fluid channel  309 . The groove  310  runs vertically from a point below the exit hole of the fluid channel  309  down to an aperture  314  in the extension  311 . During use, the deflected fluid will begin to flow back down the vertical groove  310 . The aperture  314  communicates with the inner chamber formed between the main canister  300  and insert  307 . As fluid exits the inner reservoir, a vacuum is created that actually pulls the deflected fluid back into the reservoir  305  through the aperture  314 , thereby ensuring maximum usage and minimized waste of the fluid. 
     Another section of the portable nasal irrigator is a removable cap  315  of the nasal irrigator. The cap  315  comprises no holes and fits over and substantially covers the fluid channel  309 . Optionally, the cap may comprise a flattened edge (as shown above in  FIG. 12A ) to help with alignment with the apertures  314  of the insert  307  and also help with the grasping the cap  315 . The bottom portion of the cap should mate with a portion of the top face of the extension. The cap  315  further comprises one or more projections  312  on its bottom face, which mates with the apertures  314  of the extension. The number of projections  312  on the bottom face of the cap  315  should equal the number of apertures  314  in the insert  307 . As best depicted in  FIG. 22 , the cap comprises a projection or sealing plug  323  that projects into and fits within the exit hole  313  of the fluid channel and extending into the air exit port  301  of the canister to seal the reservoir from the air exit port and fluid channel exit when the cap is placed over the insert. 
     A fourth section of the portable nasal irrigator is a handheld pressurized air supply source  317  onto which the main canister  300  fits. Preferably, the pressurized air supply source is a handheld air compressor. As shown in  FIG. 19B , the air supply source comprises an air outlet  319 , which connects with the air inlet  303  of the main canister. In one embodiment, the canister snap fits onto the pressurized air supply source  317  to form an airtight seal between the air inlet  303  and the air outlet  319 . In one embodiment, the airtight seal may comprise an O-ring or soft plastic portion between the air inlet  303  and the air outlet  319  (not shown). An air input  320  supplies air to the pressurized air supply source  317  and may comprise a filter to keep out foreign materials. In order to accommodate for the air input  320 , the main canister  300  comprises an air vent  306 , which allows air into the air input  320  without interrupting the airtight seal between the canister  300  and air supply source  317 . The bottom rim  304  surrounding the generally rectangular bottom of the main canister  300  is fashioned to fit onto the pressured air supply source  317  such that no wiring or connecting tubing is required. Thus, unlike previous embodiments, a foot section at the bottom of the main canister is not necessary in order to stabilize the canister on a substantially flat surface. Instead, the pressurized air supply connects directly and immediately with the main canister. 
     While the pressurized air supply source  317  is depicted as having a generally rectangular shape, the source  317  may comprise any shape so long as it remains portable and capable of directly attaching to the main canister without the use of tubing. In one embodiment, the pressurized air supply source  317  is substantially rectangular. Preferably, the pressurized air supply source comprises an ergonomic shape to increase user comfort. For example, the air supply source  317  may comprise a grasping or gripping portion having a shape that corresponds to a palm of a hand of the user. The gripping portion may be on one side of the air supply source, with a second opposing side substantially flat; or it may comprise curves substantially around the entire periphery of the air supply source such that user may hold the portable device lengthwise with his or her hand around substantially the entire pressurized air supply source  317 . In one embodiment, the air supply source  317  comprises an ergonomic grasping portion. In another embodiment, the pressurized air supply source  317  is substantially rectangular with curves and features that make it easy to hold in the hand. In order to allow for portability of the irrigator device, the pressurized air supply should generally be small enough to easily carry or transport. In one embodiment, the pressurized air supply source comprises a ratio of width:length:depth of about 2.5:3:1. In another embodiment, the pressurized air supply source comprises a ratio of width:length:depth of about 9:15:5. In one embodiment, the pressurized air supply source comprises a ratio of width:length:depth of between about 2.5:3:1 to about 9:15:5. By way of example, in one embodiment, the length may be about 15.5 cm, the width may be about 9.2 cm, and the depth may be about 5.7 cm. It should be recognized that any number of sizes and dimensions is possible while maintaining portability. 
     The pressurized air supply source  317  may employ an AC/DC power supply. The source  317  is DC-operated and may include a rechargeable internal battery or an external, detachable battery for easy exchange of depleted batteries. The source  317  may further be operated using a power switch  321  capable of turning on the air supply. The switch  321  may be an intermittent switch conveniently located on the air supply source  317  such that a user may conveniently reach it with one of his or her fingers. In one embodiment, the air supply source  317  may also comprise an indicator for the level of charge on the battery (not depicted) or a timer that beeps at timed intervals to deliver medication evenly between nostrils (not depicted). As described above, the pressurized air has a pressure of 0.069-1.035 bar and an airflow rate of 1-12 liters per minute, producing a fluid delivery rate of 1-20 ml per minute. 
       FIG. 20  shows a front perspective view of an assembled portable irrigator as shown in  FIGS. 19A and 19B , with the removable cap positioned over the device. Thus, when fully assembled with the cap in place, the portable irrigator device is completely self-contained, prohibiting any leakage of fluids. As depicted in  FIGS. 19A and 19B , in one embodiment, the pressurized air supply source  317  comprises an internal battery, which may or may not be rechargeable.  FIG. 21A  shows a perspective view of an assembled portable irrigator in another embodiment, with a detachable battery compartment  322  for one or more batteries which may or may not be rechargeable. In this embodiment, the battery compartment may detach from a portion of the pressurized air device by way of a switch element.  FIG. 21B  shows a perspective view of a portable irrigator as depicted in  FIG. 21A , with the battery compartment  322  detached from the air supply source  317 . 
       FIG. 22  shows a cross sectional detailed view of the main canister  300 , insert  307  and cap  315  portions in an assembled portable irrigator according to one embodiment of the present invention. As best depicted here, the air exit port  301  and fluid channel  309  form two overlapping, concentric, tapered tubed having the requisite gap or space, as described above, between them in order to allow for the venturi effect. When connected to the pressurized air supply source  317 , the air inlet of the main canister plugs directly the supply source or air compressor by way of its air outlet. An alternate embodiment depicted in  FIG. 23  shows that the air exit port  301  and the fluid channel  309  may also include a common bell housing as with previous embodiments. 
       FIGS. 24-32  depict another embodiment of a portable irrigator  330 . The portable nasal irrigator  330  comprises: a pressurized air supply source  380  comprising a rim  331  surrounding an opening  332  on one end with an air outlet  333  therein; a canister  370  with a reservoir  373  for holding fluid recessed within the opening  332 , the reservoir  373  surrounding a tube  374  tapering to an air exit port  376 ; and an insert  360  comprising a base  391  that fits within the reservoir, an extension  367  above the base  391  protruding outwardly to the canister  370 , and a fluid channel  394  (shown best in  FIG. 25 and 28 ) that fits over the elongated tube  374 , said fluid channel  394  having a discharge port  364  concentrically aligned with the air exit port  376 , said discharge port  364  located at an uppermost end of the irrigator  330  above the extension  367 , thereby providing a small space between the outer surface of the air exit port and the inner surface of the insert, creating a fluid conduit that allows fluid from said reservoir to be drawn upward between the air exit port and the fluid channel and expelled as a mist in an aerosol plume through exit holes in the fluid channel due to a venturi effect created by pressurized air from the air exit port. The fluid is thus expelled from the reservoir  373  as a mist through the discharge port  364 . The canister  370  comprises: a lip  372  extending above and resting on the rim  331  of the pressurized air supply source  380 ; and an air inlet  334  below the reservoir  373 , the air inlet  334  connected to the air outlet  333 ; and wherein the pressurized air supply source  380  houses an airflow regulating system. The canister  370  is retained to and sealed together with the pressurized air supply source  380  by the connection of a mating portion  383  and a tab  378 , as further described below. A seal between the air outlet  333  and the tube  374  of the main canister  370  also helps maintain the connection between the canister  370  and the pressurized air supply source  380 , as shown in  FIGS. 26B and 30 . 
     Similar to the above embodiments, the portable irrigator  330  comprises a cap  350 , insert  360 , and a cup or canister  370 .  FIG. 24  shows an expanded view of each of these components and their general placement over one another and the pressurized air supply source  380 .  FIG. 25A  shows the canister  370  connected to the pressurized air supply source  380 , while  FIG. 27  shows an assembled irrigator  330  with placement of the insert  360  over the canister  370  while connected to the pressurized air supply source  380  for usage by a consumer, and  FIG. 29  shows placement of the cap  350  over the insert for storage or transport by a consumer. 
     As depicted in  FIGS. 24-25 , the pressurized air supply source  380  is a generally elongated structure comprising a concave opening  332  with an airflow regulating system therein, which will be further described below. In one embodiment, the pressurized air supply source  380  comprises a first larger bottom depth and a second smaller top depth, with an angled surface there between. The shape of the pressurized air supply source thus provides for a grip zone along the length of the pressurized air supply source for consumer handling. The size may be any size that allows for handheld usage. The narrow neck top accommodates single-handed use, while the wider bottom section accommodates a two-handed grip, if desired. 
     A single membrane  390  along one external side of the pressurized air supply source  380  incorporates a single ribbon connector (not shown) and comprises an indicator light  393 , and a raised dome switch  392  integrated therein, to turn the irrigator on or off. In one embodiment, the switch  392  is an intermittent operating switch. In another embodiment, the switch is a latching switch. In one embodiment (not shown) the switch is discrete from the other components. 
     In the embodiment depicted in  FIG. 24 , the indicator light  393  comprises a light pipe, which may house one or more light therein. However, in other embodiments, the indicator light may comprise any number of shapes or symbols including, for example, any number of icons or shapes to depict battery power. By way of example, the indicator light  393  may comprise a light pipe, a battery icon, or gas gauge, which may comprise a number of rectangles in a line on the switch. An indicator light may indicate when the irrigation device is charging in one embodiment; or, when the irrigator requires charging in another embodiment; or when the device is operating, in another embodiment. The indicator light may illuminate for a sufficient amount of time for a user to recognize a need for charging after use. For example, the indicator light may illuminate for 5-30 seconds after an operation to indicate when charging is required. In one embodiment, the indicator light may illuminate to indicate when charging is needed while there is still sufficient power to run the device for a full expected dose; ensuring the user is aware of the need to charge and avoid a missed dose. In one embodiment, the indicator light is an LED light source. The LED light source may be a single color LED, multi-color LED or multiple LEDs of a single color or of different colors. In one embodiment, the indicator light uses a light pipe  393  to transmit light to the outside of the device. 
     In one embodiment, the single membrane  390  contains all electrical components externalized to the user except a power jack, which may be optionally used, for example, to power the irrigator or charge a rechargeable battery within the pressurized air supply source or to operate the device when the battery is discharged such that the device cannot be operated with the battery alone. In one embodiment, the irrigator comprises a tethered cover for the power jack designed to reduce fluid and dust ingress to the device when the power supply is not plugged into the device. Optionally, in one embodiment, an audible indicator is incorporated into the pressurized air supply source of the irrigator to indicate a set time of operation, a need for charging, or the initiation of a charge. On an external side, opposite to the membrane  390 , the pressurized air supply source  380  comprises the angled surface having a cover or cap  450  for a filter for incoming air, further described below. 
     With reference to  FIG. 25A , the canister  370  is recessed within the pressurized air supply source  380 , which has a concave opening. More specifically, a bottom portion of the canister rests within the pressurized air supply source once the canister  370  is attached to the pressurized air supply source  380 . A lip  372  extends above the pressurized air supply source  380  and rests on the rim  331  of the pressurized air supply source. In one embodiment, the lip is of an elliptical shape. The lip  372  surrounds the entirety of the top perimeter edge of the canister  370  and prevents spills from the inner volume or reservoir  373 . In one embodiment, the periphery  371  is elliptically shaped to match an elliptical opening of the pressurized air supply source  380 . A flat portion  377  assists with proper placement and alignment of the canister  370  in one embodiment. Thus, the pressurized air supply source  380  and the canister  370  may employ visual or tactile alignments marks to ensure the user is able to easily join the two components. As with the above-discussed irrigator embodiments, within the reservoir  373  is a tube portion  374  that tapers into an air exit port  376 , which is above a rim of the irrigator. In one embodiment, the air exit port  376  comprises a size of between 0.020″ and 0.060″ (0.508 mm - 1.524 mm) in diameter and a web-thickness or hole length of between 0.030″ and 0.200″ (0.762 mm - 5.08 mm). In one embodiment, the canister  370  is reusable. In one embodiment, the canister  370  is disposable. 
     In one embodiment, as best shown in  FIGS. 24 and 26A -B, the canister  370  is positively held to the pressurized air supply source  380  by a locking mechanism, which is comprised of at least one tab  378  on the canister  370  that interfaces with a mating portion  383  that captures the tab  378 . The mating portion  383  protrudes from and is located within the concave opening  332  of the pressurized air supply source  380  and may comprise any shape capable of locking with a corresponding tab  378  of the main canister  370 . In one embodiment, the mating portion  383  comprises one or more rounded or curved protruded edges with a thicker end piece at one end under which one or more tabs  378  may lock. One or more tabs  378  on the base of the canister  370 , below the reservoir  373 , then securely fits within the upper end of the pressurized air supply source  380  by way of the locking mechanism. The tab  378  or bottom of the main canister  370  fits within an opening  332  of the pressurized air supply source  380 , and the canister  370  is then turned in the direction of arrow A. The tab  378  then slides under the mating portion  383  until the canister  370  locks into place. The locking mechanism in effect presses the canister  370  into a seal that seals the air channel between the canister  370  and the pressurized air supply source  380 . In one embodiment, the tab  378  has a protrusion, bump or other feature that mates with a similar feature on the mating portion  383  to securely lock the two pieces together during operation and provide a tactile and auditory indication that the mating process is secure and the canister  370  and the pressurized air supply source  380  are properly connected. 
     Similar to the portable irrigator described above in  FIGS. 19-23 , the canister  370  comprises an air inlet  334  at its bottom end below the reservoir  373 , which connects to an air outlet  333  of the pressurized air supply source  380 . In one embodiment, the air inlet  334  comprises an extended bottom portion to aid in sealing with the pressurized air supply source  380 . In one embodiment, air outlet  333  of the pressurized air supply source  380  comprises an air outlet elbow  382  connected to the air inlet  334  of the main canister  370 . An outlet tubing  385  on an opposing end of the elbow  382  connects to a pump  386  as further described below in one embodiment. More specifically, the outlet tubing  385  connects the air outlet  333  to a pump outlet  389 , as shown in  FIG. 31 . In one embodiment, the air outlet elbow comprises an angle of between about 30 degrees to about 90 degrees in between its substantially vertical portion extending down from the air inlet  334  and its somewhat horizontal portion connected to the tubing  385 , sufficient to circumvent a motor  384  within the pressurized air supply source  380 , as best shown in  FIG. 31 . In one embodiment, an o-ring  381  helps form a seal between the canister  370  and the air outlet elbow  382  of the air outlet  333 . 
     Referring now to  FIGS. 27-28 , when assembled, the irrigator comprises an insert  360  placed over the canister  370 . As shown in  FIG. 27 , only the periphery  371  with the rim  372  of the canister  370  is visible when the insert is present for usage of the irrigator. Generally, the insert  360 , also shown in  FIGS. 28 and 30 , is substantially similar to the inserts described in above embodiments and can thus comprise one or more of the limitations described above. The insert  360  comprises a base  391  that fits within the reservoir  373 , an extension  367  above the base  391  protruding outwardly to the lip  372  of the canister  370 , and a fluid channel  394  that fits over the tube  374 , the elongated fluid channel  394  having a somewhat larger bottom diameter converging up to a smaller diameter at its top end  362 . The discharge port  364  is concentrically aligned with the air exit port  376 . In one embodiment, the base  391  of the insert  360  comprises a curved surface flush with an inner bottom surface of the reservoir  373 . The fluid channel  394  tapers from one diameter around its bottom opening to a smaller diameter at its top end  362  with the discharge port  364 . The fluid channel  394  is slightly larger in diameter than the tube  374  along the entire length of both the fluid channel  394  and the tube  374 , with the tube  374  comprising a similar conical shape having the smaller diameter on its top end. The distance between the outer surface of the tube  374  and the inner surface of the fluid channel  394  should be sufficient to create a venturi effect. When used, the discharge port  364  is the uppermost part of the irrigator  330 , with no additional barrier or structure breaking up the size or flow of the fluid drawn up from the canister  370 . In one embodiment, the distance between the outer surface of the tube  374  and the inner surface of the fluid channel  394  is about 0.0001 to about 0.010 inches (about 0.00254-0.254 mm)). One or more bumps  369  may be used, by way of example, to secure a tight fit and/or proper alignment between the insert  360  and the main canister  370 . 
     An indicator  368  (best depicted in  FIG. 27 ) may be used on one side of the extension  367  to assist with alignment of the flat portion  377  on the main canister  370 . The extension  367  comprises a rim  361  positioned on top of the main canister  370  and below the discharge port  364 , through which mist will pass for irrigation of a nasal passage. In one embodiment, the rim  361  engages the lip  372  of the canister  370 . In one embodiment, the extension  367  is slightly concave. 
     Similar to the inserts described above with extensions, the extension  367  comprises at least one groove  365  extending vertically along an exterior of the fluid channel  394  to an aperture  366  at the bottom of the fluid channel  394  or within the extension  367  adjacent to the fluid channel. The groove  365  runs vertically from a point below the discharge port  364  of the fluid channel  362  down to the aperture  366 . During use, deflected fluid will begin to flow back down the vertical groove  365 . The aperture  366  forms a channel of communication back into the reservoir  373 , which is an inner chamber formed by the mating of the canister  370  and the extension  367  of the insert  360 . As fluid exits the inner chamber, a vacuum is created which is relieved by the inflow of air and the deflected fluid into the reservoir  373  through the aperture  366 , thereby ensuring maximum usage and minimized waste of the fluid. In one embodiment, the aperture  366  in the extension  367  is located at a bottommost level of concavity of the extension  367 . 
       FIGS. 24-32  depict another embodiment of a portable irrigator  330 . The portable nasal irrigator  330  comprises: a pressurized air supply source  380  comprising a rim  331  surrounding an opening  332  on one end with an air outlet  333  therein; a canister  370  with a reservoir  373  for holding fluid recessed within the opening  332 , the reservoir  373  surrounding a tube  374  tapering to an air exit port  376 ; and an insert  360  comprising a base  391  that fits within the reservoir, an extension  367  above the base  391  protruding outwardly to the canister  370 , and a fluid channel  394  (shown best in  FIG. 25 and 28 ) that fits over the elongated tube  374 , said fluid channel  394  having a discharge port  364  concentrically aligned with the air exit port  376 , said discharge port  364  located at an uppermost end of the irrigator  330  above the extension  367 , thereby providing a small space between the outer surface of the air exit port and the inner surface of the insert, creating a fluid conduit that allows fluid from said reservoir to be drawn upward between the air exit port and the fluid channel and expelled as a mist in an aerosol plume through exit holes in the fluid channel due to a venturi effect created by pressurized air from the air exit port. The fluid is thus expelled from the reservoir  373  as a mist through the discharge port  364 . The canister  370  comprises: a lip  372  extending above and resting on the rim  331  of the pressurized air supply source  380 ; and an air inlet  334  below the reservoir  373 , the air inlet  334  connected to the air outlet  333 ; and wherein the pressurized air supply source  380  houses an airflow regulating system. The canister  370  is retained to and sealed together with the pressurized air supply source  380  by the connection of a mating portion  383  and a tab  378 , as further described below. A seal between the air outlet  333  and the tube  374  of the main canister  370  also helps maintain the connection between the canister  370  and the pressurized air supply source  380 , as shown in  FIGS. 26B and 30 . 
     A cap  350  is optional but must be removed during use. When present, as shown in the assembled perspective view of  FIG. 27 , the cap helps seal fluid within the irrigator to provide for storage or travel with the irrigator. The cap comprises no holes and covers the entire fluid channel  394  of the insert  360 , comprising a sealing plug (best shown in  FIG. 30 ) for the discharge port  364 . As with above embodiments, the cap  350  fits over the fluid channel  394  and comprises a sealing plug, in one embodiment, which projects into and fits within both the discharge port  364  and the air exit port  376  of the canister  370  to seal the reservoir  373  from the air exit port  376  and fluid channel discharge port  364  when the cap  350  is placed over the insert, as shown in the assembled view of  FIG. 27 . Similar to above embodiments, the sealing plug of the cap may also seal or fit within only the discharge port  364  in other embodiments. The cap  350  may comprise an elongated conical shape in one embodiment to ensure a good fit over the insert and its apertures. Optionally, the cap  350  may comprise a flattened edge to help with alignment over the insert  360 . The bottom portion  351  of the cap mates with a portion of the top face of the extension  367  and thus its shape will depend on the curvature of the top face of the insert&#39;s extension. The cap  350  may optionally comprise one or more vertically extending indentations  352  or curved ends  353 , as best shown in  FIG. 29 , to mate with the grooves  365  and/or apertures  366 , respectively, of the insert. 
     Beginning with  FIG. 30 , one embodiment of an airflow regulating system within the contiguously attached pressurized air supply source  380  is depicted. Preferably, the internal components of the pressurized air supply source  380  are placed to enhance stability and feel of the irrigation device with a low center of gravity and torque generated by the motor being in the vertical axis. Such an arrangement helps engage the large muscles of the forearm for improved stability. 
     In one embodiment, the airflow regulating system comprises: a pump  386  in communication with a motor  384  and the air inlet  334  (shown in  FIG. 26B ); and a filter  451  (shown in  FIG. 33B ) for filtering incoming air, the filter  451  comprising an inlet air manifold  401  connected to the pump  386  and sealing against a pump air inlet post  395  of the pump  386 , as further described below. The pressurized air supply source  380  further comprises a circuit board  388 . In one embodiment, the circuit board uses a pulse-width modulation to ensure consistent motor speed. In one embodiment, the circuit board uses a programmable digital control to ensure consistent motor speed. In one embodiment, the circuit board also charges the battery from an external AC/DC converter and ensures that the motor behaves consistently whether powered by an AC/DC converter or by the battery. In one embodiment, the circuit board communicates the status of the battery to the user via an LED on the outside of the unit. In one embodiment, the motor  384  is a brushed motor. In one embodiment, the motor  384  employs caged brushes. In another embodiment, the motor  384  is a brushless motor. The outlet tubing  385 , described above, circumvents the motor  384  in one embodiment, to connect the canister  370  to a pump outlet  389  of the pump  386 . A battery  387  within the pressurized air supply source drives the motor  384  in one embodiment. In one embodiment, the battery  387  is a rechargeable lithium ion battery. In some embodiments, the battery  387  may be accessible or removable by a user. In one embodiment, the battery is not accessible to a user. In another embodiment, the motor  384  is driven by an external power supply. In one embodiment, a motor controller board utilizes pulse width modulation to control the motor speed so as to maintain a very narrow band of motor speed to regulate the airflow generated by the pump. More specifically, the motor will operate within a wide range of +/−15% and within an operating range of +/−4% of its set point. In one embodiment motor wires  396  are twisted to mitigate electrical noise to meet IEC-60601-1 third edition requirements for electrical emissions. In one embodiment, the motor wires  396  may also include an electronic filter that may incorporate ferrites to suppress noise. In yet another embodiment, motor wires  396  are comprised of a coaxial cable to mitigate electrical noise to suppress noise. In one embodiment, the motor  384  and the pump  386  contact the pressurized air supply source  380  through vibration dampers. 
       FIGS. 33A and 33B  depict partial views of opposing sides of the pressurized air supply source  380 , with either half of the pressurized air supply source removed to better reflect some of its adjacent interior components; in particular to depict the air inlet manifold or  401  and filter  451  under the filter cover  450 , which resides within the opening  400  of the pressurized air supply source  380 . The air inlet manifold  401  is a small box that forms a small fitting that seals around the air inlet of the pump, eliminating the need for a tube-like communication from the outlet to the pump  386 . An opening  400  is located along the angled surface of the pressurized air supply source  380  in one embodiment. When assembled, the filter cover  450  is visible on an external side of the pressurized air supply source, within the opening  400 . In one embodiment, the filter cover  450  may be removable for access to the filter  451 . 
     In one embodiment, the filter cover  450  is shaped to exactly match the opening  400  in the pressurized air supply source  380 . As best shown in  FIG. 34A , air inlet manifold  401  comprises a cutout  405 , which also matches the opening  400 , wherein the filter  451  is placed. The angled surface  404  of the air inlet manifold  401  matches and seals against the inside of the pressurized air supply source  380 . A cutout  402  forms an air channel within the air inlet manifold  401  to the air inlet of the pump. The cutout  402 , perhaps best shown in  FIG. 34B  is at the bottom of the air inlet manifold  401  aligning with a centerline of the pump  386 . Thus, the air pathway is centered within the air inlet manifold  401 . A flat bottom  403  of the air inlet manifold  401  rests on the pump  386 . The air inlet manifold  401  thus connects and seals against a pump air inlet post  395  of the pump  386  in one embodiment. In one embodiment, the air inlet manifold  401  comprises an anti-rotation tab  407  along its bottom side to prevent movement. In one embodiment, the air inlet manifold  401  may comprise more than one anti-rotation tab  407  adjacent to the cutout  402 . 
     The filter cap or cover  450  is shown in more detail in  FIG. 35 . The filter  451  within the air inlet manifold  401  may be composed of 80 ppi reticulated polyurethane foam in one embodiment. In one embodiment, the filter  451  is pressed and shaped within the filter cover  450 . In one embodiment, the filter  451  is accessible to a user for replacement or cleaning Access to remove or replace the filter  451  may be accomplished by any means known in the art. A centerpiece  454  may comprise a raised, arch ridge, in one embodiment, for removal of the filter cover  450  from the manifold  401 . Face  452  is flush with the pressurized air supply source  380 . Vent  453  opens to filter  451  to allow air to pass and centerpiece  454  secures the filter inside the filter cover  450  and provides for a place for a user&#39;s fingers to insert the filter cover  450  into the manifold  401 . 
     As described for previous embodiments, the portable nasal irrigator  330  creates a variable particle size up to 100 microns under a pressure of 1-15 psi (0.069-1.0345 bar), creating a pressurized airflow that enables the resultant air-mist stream to stent-open the soft tissues of the upper airway and reach the whole nasal cavity independent of the patient&#39;s breathing. A vast majority of the particles are sized at about 20 microns. In one embodiment, the mist expelled through the exit hole comprises air and fluid particles or droplets, 100% of particles or droplets being greater than 5 microns in diameter and 99.8% of the particles or droplets are greater than 10 microns in diameter. In one embodiment, the particle or droplet diameter distribution has a mode centered around 23 microns, the mist is expelled under a pressure of 1-15 psi with a fluid delivery rate of 1-20 ml per minute, and airflow of 3-8 liters per minute, creating an air column that drives the resultant mist past the nasal valve and antrum of the nose to coat the turbinates, middle meatus to reach the posterior and superior regions of the nasal cavity and the paranasal sinus cavities without introducing the aerosol into the lungs. In one embodiment, the air pressure ranges from about 3-12 psi (0.207-0.823 bar), with about 1-12 lpm of airflow, and a fluid delivery rate of about 1-20 ml per minute. In one embodiment, the air pressure ranges from about 4-8 psi (0.276-0.552 bar), with about 3.5-8 lpm airflow, and about 15 ml per minute fluid delivery. The resultant aerosol mist reaches the area of the nasal cavity above the inferior and posterior to the nasal turbinate or chonchae to ensure that the mist reaches the areas of the sinus ostia to clear this area of the nasal cavity and enable the natural mucociliary flow to clear the sinuses. 
     By way of example, a portable nasal irrigator device as described herein may be comprised of ABS, Polycarbonate, glass, stainless steel, styrolene, styrene-butadiene copolymer, co-polyester BPA-free plastics or any other plastics appropriate for medical device use, and any combination thereof. The device may further be comprised of an antimicrobial compound in some embodiments. In one embodiment, the canister and insert are constructed of a BPA-free material. In one embodiment, the canister is USP class VI compliant for the storage and delivery of drugs. In another embodiment, no latex is used in the construction of the device. 
     The invention illustratively disclosed herein suitably may be practiced in the absence of any element, which is not specifically disclosed herein. It should also be noted that the invention is not limited to human use, but may also be used with any number of mammals including without limitation equine, canine, feline, non-human primate, rodent, bovine, ovine, and porcine. 
     The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. It will be understood by one of ordinary skill in the art that numerous variations will be possible to the disclosed embodiments without going outside the scope of the invention as disclosed in the claims.