US20100294269A1 - Nebulizing drug delivery device with an increased flow rate - Google Patents

Abstract

The present invention provides a nebulizing drug delivery system for delivering an aerosolized drug to a user having various features to increase the capacity of the drug delivery device. The drug delivery system includes a heater to increase the viscosity of the drug, a double aerosolizing system to double the capacity of the device, and a valve system to continuously replenish drug to the aerosol generator thereby providing a high speed delivery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority under 35 U.S.C. §119(e) from provisional U.S. Patent Application No. 60/659,919 filed Mar. 9, 2005; and U.S. application Ser. No. 11/367,649 filed Mar. 3, 2006, entitled “Nebulizing Drug Delivery Device with an Increased Flow Rate” the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to drug delivery devices, and, in particular, to nebulizers used in an aerosolized drug delivery.
• 2. Description of the Related Art
• • Nebulizing drug delivery devices that use ultrasonic energy to nebulize a drug solution are generally known. Such devices typically include an acoustic wave generator to generate acoustic waves that are transmitted to a drug solution. The ultrasonic energy transmitted to the drug solution in the form of the acoustic waves energizes the drug solution such that nebulized particles of the drug solution are formed. The ultrasonic energy may be delivered with a maximum density at a focal point of the acoustic waves, and nebulization efficiency of the drug solution may be enhanced when an upper surface of a pool of the drug solution is located at or near the focal point of the acoustic waves. However, the ability to take advantage of enhanced nebulization efficiency in this manner has been limited by the fact that the upper surface of the drug solution lowers during nebulization as the amount of drug solution in the device is depleted.
• It should be appreciated that several conventional nebulizing drug delivery devices are configured to deliver drug solutions to a user's lungs via inhalation. But these devices may not be capable of effectively or efficiently nebulizing various types of drug solutions for delivery that are typically delivered directly into a patient's lungs, such as through injection. Thus, typical nebulizing drug delivery devices may not be particularly effective or efficient in delivering drug solutions of a higher viscosity, and/or drug solutions that must be delivered at higher flow rates.
SUMMARY OF THE INVENTION
• • In accordance with the broad teachings of the invention, one aspect of the invention relates to a nebulizing device comprising a housing including an outlet and a drug reservoir for receiving a drug solution within the housing. An aerosol generator is disposed in communication with a fluid, and a barrier separates the fluid from a portion of the drug solution residing on the barrier. The barrier is capable of transmitting acoustic waves in the fluid to the portion of drug solution residing thereon. The acoustic waves in the drug solution operate to form nebulized particles from the portion of drug solution residing on the barrier to enable nebulized particles of the drug solution to be communicated to a user through the outlet. A valve permits drug solution within the reservoir to replenish the portion of drug solution residing on the barrier when the portion is less than a threshold amount.
• In one embodiment, the valve comprises a float that floats on the portion of drug solution residing on the barrier, the float substantially sealing the reservoir from the barrier when the amount of drug solution residing on the barrier is above the threshold amount. The float permitting drug solution to flow from the reservoir to the barrier when the amount of drug solution residing on the barrier is less than the threshold amount.
• In another aspect the invention relates to a nebulizing device comprising a housing having an inlet and an outlet, and a plurality of aerosol generators in communication with a fluid. A barrier is disposed between the fluid and a drug solution provided within the housing, the barrier being capable of transmitting acoustic waves in the fluid to the drug solution. The plurality of aerosol generators form a corresponding plurality of fountains that generate nebulized particles of the drug solution. The plurality of fountains are in communication with the outlet to enable a user to inhale nebulized particles of the drug solution from the plurality of aerosol regions through the outlet.
• These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and in the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.
BRIEF DESCRIPTION OF THE DRAWINGS
• A specific embodiment of the invention is now described with reference to the accompanying drawings, wherein:
• FIG. 1 illustrates a perspective view of the nebulizing device in accordance with an embodiment of the invention.
• FIG. 2A is a top plan view of an embodiment of the nebulizing device with a fixed length cord.
• FIG. 2B is a top plan view of an embodiment of the nebulizing device with a cord in a retracted position.
• FIG. 3 is a cross sectional view of the nebulizing device ofFIG. 2A, taken along section line3-3 ofFIG. 2A, according to an embodiment of the invention.
• FIG. 4 is a sectional view of the nebulizing device similar toFIG. 3, but illustrating the device with the valves between the barrier chambers and the drug reservoir open.
• FIG. 5 is an exploded perspective view of the nebulizing drug delivery device, in accordance with one embodiment of the invention.
• FIG. 6 is a cross-sectional view of the nebulizing device similar toFIG. 3, but including an alternative valve arrangement between the barrier chambers and the drug reservoir.
• FIG. 7 is a cross-sectional view of the nebulizing device similar toFIG. 4, but including a solenoid to operate a valve for opening and closing the drug reservoir.
• FIG. 8 is a cross-sectional view of the nebulizing device similar toFIG. 7, but illustrating the valve for opening and closing the drug reservoir as being open.
• FIG. 9 is an exemplary illustration of the circuitry of the nebulizing device according to one embodiment of the invention.
• FIG. 10 is an exemplary illustration of a method of controlling the nebulizing device in accordance with an embodiment of the invention.
• FIGS. 11A-11C illustrate a front perspective view, a side plan view, and a rear plan view of the nebulizing drug delivery device, according to one embodiment of the invention.
• FIG. 12 is a sectional view of the nebulizing device ofFIG. 11B, taken along section line12-12 ofFIG. 11B, in accordance with an embodiment of the invention.
• FIG. 13 is a cross sectional view of the nebulizing device ofFIG. 11B, take along section line13-13FIG. 11B, according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS OF THE INVENTION
• FIG. 1 is a front perspective view, andFIG. 2A is a top view of a nebulizingdevice110, according to an embodiment of the invention. Nebulizingdevice110 is adapted to nebulize and deliver a drug solution to a user. Nebulizingdevice110 provides various advantages in nebulizing and/or delivering the drug solution to the user. For example, nebulizingdevice110 is capable of nebulizing viscous drug solutions such as drug solutions containing a surfactant, or other viscous drug solutions, delivers the drug solution at an enhanced flow rate, and provides other advantages as described herein. As shown, nebulizingdevice110 includes ahousing112, agas inlet114, a nebulizeddrug delivery outlet116, and auser control interface118.
• In one embodiment of the invention,housing112 includes a plurality of housing members.Housing112 includes anupper housing portion120, amiddle housing portion121, and alower housing portion122. The front surface ofupper housing portion120 has astep region124 formed thereon. Specifically,upper housing portion120 has atop surface126, anangled surface128 extending downwardly fromtop surface126, and a longitudinalhorizontal ledge surface130 extending outwardly from the bottom ofangled surface128. Thus,top surface126 andledge surface130 are formed as offset parallel planar surfaces withangled surface128 structurally joiningtop surface126 andledge surface130 to formstep region124.
• According to one embodiment of the invention,gas inlet114 includes one ormore inlet ports132 formed inhousing112.Inlet ports132 are located atmiddle housing portion121 ofhousing112.
• The nebulizeddrug delivery outlet116 includes afirst outlet port134 and asecond outlet port136.First outlet port134 andsecond outlet port136 are formed inhousing112 atangled surface128. In an alternate embodiment,first outlet port134 andsecond outlet port136 may be formed as a single outlet port.
• User control interface118 includes acontrol knob138.Control knob138 is located onhousing112. In a non-limiting example,control knob138 is located atlower housing portion122 ofhousing112. Of course, various other user interfaces could be used without departing from the scope of the present invention such as keypads, touch screens, wirelessly via a memory storage device, sent over a radio frequency, or Infrared communication link.
• FIGS. 3 and 4 are cross sectional views, taken along cross section line3-3, as illustrated inFIG. 2A, ofnebulizing device110. Referring toFIG. 3,nebulizing device110 includes adrug solution reservoir310, afirst nebulization section312, asecond nebulization section314,control electronics316, and a power source/connection318.
• Drug solution reservoir310 is contained in areservoir housing member319, included withinhousing112.Drug solution reservoir310 includes an upper drugsolution receiving opening320, adrug dispensing opening322, areservoir wall324, and areservoir floor326. Drugsolution reservoir wall324 is generally cylindrical in shape, or may be otherwise shaped. Drugsolution receiving opening322 is defined by the upper periphery ofreservoir wall324, and is circular, or otherwise shaped.Reservoir floor326 angles fromreservoir wall324 in a downward slope todrug dispensing opening322 formed withinreservoir floor326.
• In one embodiment of the invention, thenebulizing device110 also includes a heating/sensor unit327 for heating the drug solution. This may be useful with higher viscosity drug solutions, or for increased comfort of a user. For example, to warm the drug solution prior to inhalation in instances when the device and/or drug solution contained therein have been exposed to cold temperatures. As shown in the embodiments ofFIGS. 3-8 and as can be particularly appreciated from the exploded view of the embodiment ofFIG. 5, heating/sensor unit327 may be annularly disposed about theouter wall324 that containsdrug reservoir310. As illustrated inFIG. 5, heating/sensor unit327 may include anannular band member1022, with a resistive heating element (or heater)1024 and atemperature sensor1026 disposed thereon. Thetemperature sensor1026 within heating/sensor unit327 is in functional communication with theheater1024, to sense a temperature of the drug solution or theheater1024 itself. Heating/sensor unit327 is operatively coupled to one or both ofcontrol electronics316 and power source/connection318. Heating/sensor unit327 is controlled viacontrol electronics316, and is powered via power source/connection318.
• The heater is operable in response to thetemperature sensor1026. In some instances, heating/sensor unit327 maintains the temperature of theheater1024 in a temperature range between an upper threshold temperature and a lower threshold temperature. Or, heating/sensor unit327 maintains the temperature of theheater1024 above a threshold temperature. It is contemplated that heating/sensor unit327 is configured and/or arranged to heat the drug solution in at least one ofdrug reservoir310,first barrier chamber332,second barrier chamber432,first reservoir channel328,second reservoir channel330,first aerosol region340, and/orsecond aerosol region440.
• In another embodiment, the heater/sensing unit327 can be separated so that either the heater or the sensor is disposed within thedrug solution reservoir310, in contact with the drug solution, and the other element (heater or sensor) is in contact with theouter wall324 that containsdrug reservoir310. Thesensor1026 may be a thermocouple or other temperature sensing element such as a thermistor, resistance thermal detector, bimetallic, or Infrared.
• It is further contemplated that theheater element1024 need not be a resistive heater, but can be any suitable heater that can be used to raise the temperature of the drug solution.
• According to various embodiments of the invention,first nebulization section312 includes afirst reservoir channel328, afirst valve330, afirst barrier chamber332, afirst barrier334, a firstfluid chamber336, transmittingfluid337, afirst aerosol generator338, and afirst aerosol region340.First reservoir channel328 is formed withinhousing112 and runs fromdrug dispensing opening322 tofirst valve330.First valve330 is positioned outwardly fromdrug dispensing opening322 withinhousing112, betweenfirst reservoir channel328 andfirst barrier chamber332.
• In one embodiment, seen best inFIG. 4,first valve330 includes afirst valve opening342, and avalve seal344.First valve opening342 is formed withinhousing112 as an outer opening offirst reservoir channel328.First valve structure344 is disposed at first valve opening342 to selectively sealfirst valve opening342. In one embodiment,first valve structure344 includes afirst float346, disposed withinfirst valve330 at a firstfloat reception cavity348.First float346 is composed of a material that enablesfirst float346 to float in the drug solution, such as, for example, a closed cell foam. Firstfloat reception cavity348 is formed inhousing112 betweenfirst reservoir channel328 andfirst barrier chamber332.First valve344 includes a first float/cavity interface350 that includes corresponding surfaces offirst float346 and firstfloat reception cavity348. First float346 seals first valve opening342 asfirst float346 rises to sealfirst valve opening342. For example, as is illustrated inFIGS. 3, and4, first float/cavity interface350 includes corresponding angled surfaces offirst float346 and firstfloat reception cavity348.
• Referring toFIG. 6, an exemplary illustration ofnebulizing device110 provides an alternate configuration forvalves330 and430. According to the embodiment illustrated inFIG. 6, floats346 and446 include abody510 and anannular protrusion512.Annular protrusion512 surroundsbody510, and extends outward frombody510 in a direction normal to the surface ofbody510 thatannular protrusion512 protrudes from. Asfloats346 and446 rise up to contact float/cavity interfaces350 and450,bodies510 offloats346 and446 contact an upper surfaces514 offloat cavities348 and448,annular protrusions512 effectively sealvalve openings342 and442, closingvalves330 and430.
• In other embodiments,valves330 and430 may take the form of one or more electrically operated solenoid valves. Such valves can each be open in response to an associated liquid level detector that detects the amount of drug solution on one of the barriers. When the detector detects that the amount of drug solution is at or below a threshold level, it sends a signal that is used to open the associated valve and permit the drug solution to flow from the associated reservoir to the associated barrier. In such an embodiment, the liquid level detector can optionally be an adjustable detector to enable the threshold level at which the drug solution will be released from the reservoir to the barrier to be adjusted.
• In the embodiment illustrated inFIGS. 3, and4,first barrier chamber332, which communicates withfirst reservoir channel328 viafirst valve330 is formed withinhousing112 betweenfirst barrier334 andfirst aerosol region340.First barrier334 is mounted withinhousing112 to a first mountingsurface352 that is formed on an upper surface of firstfluid chamber336, betweenfirst barrier chamber332 and firstfluid chamber336. First barrier forms a physical separation (i.e., a seal) betweenfirst barrier chamber332 and firstfluid chamber336.First barrier334 is composed of one or more materials designed to enablefirst barrier334 to be capable of transmitting ultrasonic energy therethrough, even under high temperature conditions. For example, polyetheretherketone (PEEK), or other materials may be used.
• According to one embodiment of the invention, firstfluid chamber336 is formed withinhousing112 betweenfirst barrier334 andfirst aerosol generator338. In one embodiment, thefirst aerosol generator338 is an acoustic wave generator, such as a piezoelectric transducer, and firstfluid chamber336 holds a fluid337 in communication withfirst barrier334 andfirst aerosol generator338.Fluid337 can be selected to be capable of transmitting acoustic waves, such as, for example, water, or other fluids.Fluid337 may include one or more sterilants, such as, alcohol, or other sterilants.
• In one embodiment of the invention,first aerosol generator338 is disposed at afirst seating portion354 formed withinhousing112. In embodiments wherefirst aerosol generator338 comprises a piezoelectric transducer, it may be formed to have a concave configuration with a silver electrode.First aerosol generator338 generates acoustic waves at a generator frequency, such as, for example, 2.5 MHz, or another frequency. The acoustic waves are focused at a focal point, or focal band, that is a focal length fromfirst aerosol generator338.First seating portion354 is formed withinhousing112 such that the focal point will be withinfirst barrier chamber332.First aerosol generator338 is operatively linked to controlelectronics316 so thatcontrol electronics316 can control various aspects of acoustic wave generation byfirst aerosol generator338, such as, for instance, activation and deactivation.First aerosol generator338 is operatively linked to power source/connection318 so that power can be provided tofirst aerosol generator338 via this operative link.
• Power source/connection318 may include apower cord140.Power cord140 can be connected to a contemporary household socket to deliver power to thenebulizing device110.Cord140 could have a fixed length or could have a mechanism to retract a majority ofcord140 intohousing112. This feature of the present invention could be used regardless of the aerosol generator being used. The present invention contemplates thatcord140 could also be used with a variety of nebulizers including jet nebulizers, traditional planar ultrasonic nebulizers, vibrating mesh nebulizers, vibrating plate nebulizers, or electro spray nebulizers. The unique advantage this feature of the present invention provides is that it preventscord140 from becoming tangled with objects present in the user's environment when not in use.
• According to an embodiment of the invention,first aerosol region340 includes afirst fountain region356, one or more firstaerosol region inlets358, afirst chimney360, a firstdrug delivery region361, and a firstdrug return region362.First fountain region356 is formed withinhousing112 betweenfirst barrier chamber332 andfirst chimney360.First fountain region356 includes a lowerfirst fountain region364 and an upperfirst fountain region366. Lowerfirst fountain region364 is open at a first end tofirst barrier chamber332 and at a second end to upperfirst fountain region366. Lowerfirst fountain region364 is cylindrical, or may be otherwise shaped. Upperfirst fountain region366 is open at a first end to lowerfirst fountain region364 and at a second end tofirst chimney360. Upperfirst fountain region364 is formed as a funnel with a smaller opening at the first end and a larger opening at the second end, or may be otherwise shaped.
• As is illustrated inFIGS. 3, and4, firstaerosol region inlets358 are formed inhousing112 atfirst fountain region356. Firstaerosol region inlets358 provide an opening for one or morecorresponding inlet channels368.Inlet channels368 are formed inhousing112, and run between firstaerosol region inlets358 andinlet ports132.
• In one embodiment,first chimney360 is formed inhousing112, and opens at a first end tofirst fountain region356. Afirst chimney ceiling370 is formed withinhousing112 at a second end offirst chimney360. At a side offirst chimney360, proximate tofirst chimney ceiling370,first chimney360 opens to firstdrug delivery region361.
• According to an embodiment of the invention, firstdrug delivery region361 is formed withinhousing112 to communicate withfirst chimney360,first outlet port134, and firstdrug return region361. Firstdrug delivery region361 is open to firstdrug return region361 at a first end, and is bounded at a second end by first drugdelivery region ceiling372. First drugdelivery region ceiling372 andfirst chimney ceiling370 form a firstaerosol region ceiling374.
• In one embodiment of the invention, firstdrug return region362 is formed inhousing112 to be open at a first end todrug reservoir310. Firstdrug return region362 also communicates with firstdrug delivery region361.
• According to the embodiment of the invention shown inFIGS. 3,4,second nebulization section312 includes asecond reservoir channel428, asecond valve430, asecond barrier chamber432, asecond barrier434, a secondfluid chamber436, asecond fluid437 within secondfluid chamber436, asecond aerosol generator438, and asecond aerosol region440.Second reservoir channel428 is formed withinhousing112 and runs from drug dispensing opening422 tosecond valve430.Second valve430 is positioned outwardly from drug dispensing opening422 withinhousing112, betweensecond reservoir channel428 andsecond barrier chamber432.
• The invention contemplates thatfirst aerosol generator338 andsecond aerosol generator438 may be any device capable of forming aerosol. For instance, the unique aspects of the present invention can also be used with compressor driven jet nebulizers, traditional planar ultrasonic nebulizers, vibratory mesh nebulizers, vibrating plate nebulizers, or electrospray nebulizers without departing from the teachings of the present invention.
• Thesecond valve430 includes a second valve opening442, and avalve seal444.Second valve opening442 is formed withinhousing112 as an outer opening ofsecond reservoir channel428.Second valve seal444 is disposed at second valve opening442 to selectively sealsecond valve opening442. In some instances,second valve seal444 includes asecond float446, disposed withinsecond valve430 at a secondfloat reception cavity448.Second float446 is composed of materials that enablesecond float446 to float in the drug solution. Secondfloat reception cavity448 is formed inhousing112 betweensecond reservoir channel428 andsecond barrier chamber432.Second valve444 includes a second float/cavity interface450 that includes corresponding surfaces ofsecond float446 and secondfloat reception cavity448, and is arranged to biassecond float446 against second valve opening442 assecond float446 rises to sealsecond valve opening442. For example, as is illustrated inFIGS. 3, and4, second float/cavity interface450 includes corresponding angled surfaces of second float146 and secondfloat reception cavity448.
• According to an embodiment of the invention,second barrier chamber432, which communicates withsecond reservoir channel428 viasecond valve430 is formed withinhousing112 betweensecond barrier434 andsecond aerosol region440.Second barrier434 is mounted withinhousing112 to asecond mounting surface452 that is formed on an upper surface of secondfluid chamber436, betweensecond barrier chamber432 and secondfluid chamber436. Second barrier forms a physical separation (i.e., a seal) betweensecond barrier chamber432 and secondfluid chamber436.Second barrier434 is composed of one or more materials designed to enablesecond barrier434 to be capable of transmitting ultrasonic energy therethrough, even under high temperature conditions. For example, polyetheretherketone (PEEK), or other materials may be used.
• In accordance with the embodiment of the invention illustrated inFIGS. 3, and4, secondfluid chamber436 is formed withinhousing112 betweensecond barrier434 andsecond aerosol generator438. Theaerosol generator438, in one embodiment, is a concave shaped piezoelectric transducer with a silver electrode. Thepiezoelectric aerosol generator438 achieves its functionality by generating acoustic waves in the drug solution as described with respect to thefirst aerosol generator338.Second fluid chamber436 holds a fluid in communication withsecond barrier434 andsecond aerosol generator438.Fluid337 includes one or more fluids capable of transmitting acoustic waves, such as, for example, water, or other fluids.Fluid337 may include one or more sterilants, such as, alcohol, or other sterilants.
• In one embodiment of the invention,second aerosol generator438 is disposed at asecond seating portion454 formed withinhousing112. In some instances,second aerosol generator438 includes a concave piezoelectric transducer with a silver electrode.Second aerosol generator438 generates acoustic waves at a generator frequency, such as, for example, 2.5 MHz, or another frequency. The acoustic waves are focused at a focal point, or focal band, that is a focal length fromsecond aerosol generator438.Second seating portion454 is formed withinhousing112 such that the focal point will be withinsecond barrier chamber432. Other embodiments ofsecond aerosol generator438 exist.Second aerosol generator438 is operatively linked to controlelectronics316 so thatcontrol electronics316 can control various aspects of acoustic wave generation bysecond aerosol generator438, such as, for instance, activation and deactivation, or other aspects.Second aerosol generator438 is operatively linked to power source/connection318 so that power can be provided tosecond aerosol generator438 via this operative link.
• Thesecond aerosol region440 includes asecond fountain region456, one or more secondaerosol region inlets458, asecond chimney460, a seconddrug delivery region461, and a seconddrug return region462.Second fountain region456 is formed withinhousing112 betweensecond barrier chamber432 andsecond chimney460.Second fountain region456 includes a lowersecond fountain region464 and an uppersecond fountain region466. Lowersecond fountain region464 is open at a first end tosecond barrier chamber432 and at a second end to uppersecond fountain region466. Lowersecond fountain region464 is cylindrical, or may be otherwise shaped. Uppersecond fountain region466 is open at a first end to lowersecond fountain region464 and at a second end tosecond chimney460. Uppersecond fountain region464 is formed as a funnel with a smaller opening at the first end and a larger opening at the second end, or may be otherwise shaped.
• In one embodiment of the invention, secondaerosol region inlets458 are formed inhousing112 atsecond fountain region456. Secondaerosol region inlets458 provide an opening for one or morecorresponding inlet channels468.Inlet channels468 are formed inhousing112, and run between secondaerosol region inlets458 andinlet ports132.
• In one embodiment,second chimney460 is formed inhousing112, and opens at a first end tosecond fountain region456. Asecond chimney ceiling470 is formed withinhousing112 at a first end ofsecond chimney460. At a side ofsecond chimney460, proximate tosecond chimney ceiling470,second chimney460 opens to seconddrug delivery region461.
• According to the embodiment of the invention shown inFIGS. 3, and4, seconddrug delivery region461 is formed withinhousing112 to communicate withsecond chimney460,second outlet port134, and seconddrug return region461. Seconddrug delivery region461 is open to seconddrug return region461 at a first end, and is bounded at a second end by second drugdelivery region ceiling472. Second drugdelivery region ceiling472 andsecond chimney ceiling470 form a secondaerosol region ceiling474.
• The seconddrug return region462 is formed inhousing112 to be open at a first end todrug reservoir310. Seconddrug return region462 also communicates with seconddrug delivery region461.
• According to an embodiment of the invention,barrier chambers332 and432 hold an amount of the drug solution at each ofbarriers334 and434. Fountains are formed atbarrier chambers332 and432. The fountains create nebulized particles of the drug solution that are delivered toaerosol regions340 and440. The nebulized particles of the drug solution are formed by acoustic waves within the drug solution held inbarrier chambers332 and432 atbarriers334 and434. The acoustic waves are generated by aerosolgenerators338 and438. The acoustic waves transmitted fromaerosol generators338 and438 tobarrier chambers332 and432 via the fluid held influid chambers336 and436. The transmitted acoustic waves pass fromfluid chambers336 and436 tobarrier chambers332 and432 viabarriers334 and434.
• In accordance with the embodiment of the invention illustrated inFIGS. 3, and4, the acoustic waves transmitted tobarrier chambers332 and432 are focused at the focal point. The drug solution inbarrier chambers332 and432 absorbs the ultrasonic energy provided by the focused acoustic waves to create a fountain within each ofbarrier chambers332 and432. The ultrasonic energy delivered by the acoustic waves has a maximum density at or near the focal point of the acoustic waves. The fountains shed a portion of the drug solution as particles. Some of these particles are so large they immediately fall out. Some are small enough to pass intodrug return regions362,462 before falling out. The remaining particles which are appropriately sized, pass out through first and secondouter ports134,136. In this manner, substantially consistent particle size is achieved.
• In one embodiment of the invention, the nebulized particles are communicated frombarrier chambers332 and432, throughaerosol regions340 and440, and to the user viaoutlet ports134 and136 included inoutlet116. More particularly, the nebulized particles and the larger droplets of the drug solution formed at the fountains are received byaerosol regions340 and440 atfluid chambers364 and464, and pass intochimneys360 and460. Fromchimneys360 and460, the nebulized particles are communicated to the user viadrug delivery regions361 and461 andoutlet ports134 and136. In contrast, due to size and/or weight, the larger droplets may not be communicated to the user, but instead may contact a surface ofaerosol regions340 and440, such asaerosol ceilings372 and472, or other surfaces. The larger droplets then condense on the contacted surface(s), thereby separating the larger droplets from the nebulized particles prior to delivery to the user. The condensed larger droplets are passed back todrug solution reservoir310 viadrug return regions362 and462.
• The nebulization of the drug solution at the fountains is enhanced when the focal point of the acoustic waves coincides (exactly or substantially) with an upper surface of the drug solution infirst barrier chamber332. This requires a level of the upper surface to be controlled with some particularity to enhance the operation of the fountains. To control the level of the upper surface, a flow of the drug solution fromdrug reservoir310 tobarrier chambers332 and432 viareservoir channels328 and428 are controlled viavalves330 and430 by independently sealing and unsealingvalve openings342 and442 withvalve seals344 and444. For example, when the level of the upper surface of the drug solution on either ofbarriers334 and/or434 reaches a threshold level at or near the focal point of the acoustic waves, corresponding ones offloats346 and/or446 are positioned to sealvalve openings342 and/or442 by virtue of the buoyancy offloats346 and446 with respect to the drug solution. However, as particles are formed at the fountains, the level of the upper surface in one or both ofbarrier chambers332 and432 may drop below the threshold level, which in turn lowers one or both offloats346 and446 fromvalve openings342 and442, thereby openingvalves330 and/or430, as is illustrated inFIG. 4.
• Referring toFIG. 3, in some embodiments of the invention, activation ofaerosol generators338 and438 enable generation of particles of the drug solution to be propelled by the fountains intoaerosol regions340 and440. As particles are propelled by the fountain intoaerosol regions340 and440, the atmosphere withinaerosol regions340 and440 is disturbed such that intake gas present withininlet channels368 and468 is pulled intoparticle receiving regions366 and466 viaaerosol region inlets358 and458. Pulling air intoparticle receiving regions366 and466 may initiate the flow of intake gas throughaerosol regions340 and440 tooutlet ports134 and136, which may in turn motivate the nebulized particles formed at the fountains towardoutlet ports134 and136. Thus, the atmospheric disturbances that may be caused by the nebulized particles from the fountains, and the resulting flow of intake gas throughaerosol regions340 and440 may function in a cooperative manner to “drive” the delivery of nebulized particles from the fountains to the user without requiring additional active moving parts such as a pump or compressor.
• FIG. 5 is an exploded view ofnebulizing device110 according to an embodiment of the invention.Housing112 includes anoutlet housing member1010, a drugreturn housing member1012, areservoir housing member319, a drugreservoir seating member1016, a barrierchamber housing member1018, and abase housing member1020.
• Theoutlet housing member1010 is disposed at theupper housing portion120 ofhousing112.Outlet116 is formed inoutlet housing member1010. As may be seen inFIGS. 3,4,7, and8 illustrating cross sections taken alongcross section line3, show various components ofaerosol regions340 and440 are formed withinoutlet housing member1010. For example,aerosol region ceilings374 and474, anddrug delivery regions361 and461 are formed withinoutlet housing member1010.
• According to one embodiment of the invention, drugreturn housing member1012 may be disposed adjacentoutlet housing member1010. As may be seen in theFIGS. 3,4,7, and8 illustrating cross sections taken along cross section line3-3, show various components ofaerosol regions340 and440 are formed within drugreturn housing member1012. For example,chimneys360 and460, anddrug return regions362 and462 are formed within drugreturn housing member1012.Inlet ports132 ofgas inlet114, andcorresponding inlet channels368, are partially formed in drugreturn housing member1012.
• In the embodiment illustrated inFIG. 5, heating/sensor unit327 is disposed around an outer surface ofreservoir housing member319. Drugreturn housing member1012 may be adapted to receive heating/sensor unit327 andreservoir housing member319.Reservoir housing member319 is disposed primarily within drugreturn housing member1012, and formsdrug reservoir310.
• According to various embodiments of the invention, drugreservoir seating member1016 is disposed adjacent to drug returnhousing member1012. A drugreservoir seating portion1028 is formed on drugreservoir seating member1016. Drugreservoir seating portion1028 is configured to receive aseating portion1030 ofreservoir housing member319 therein. Upperfluid chambers366 and466 are formed in drugreservoir seating member1016.Inlet ports132 ofgas inlet114, andcorresponding inlet channels368, are partially formed in drugreservoir seating member1016. As may be seen inFIGS. 3,4,7, and8 illustrating cross sections taken along cross section line3-3, when drugreservoir seating member1016 is disposed adjacent to drug returnhousing member1012,inlet ports132 ofgas inlet114, and thecorresponding inlet channels368 are formed inhousing112 at aninlet interface1032 between drugreturn housing member1012 and drugreservoir seating member1016.
• As is illustrated inFIG. 5, barrierchamber housing member1018 is disposed inhousing112 adjacent to drugreservoir seating member1016.Barrier chambers332 and432, and an upper portion of aplunger channel618 are formed in barrierchamber housing member1018. When barrierchamber housing member1018 is disposed inhousing112 adjacent to drug reservoir seating member1016 avalve interface1034 is formed. As may be seen inFIGS. 3,4,7, and8 illustrating cross sections taken alongcross section line3,reservoir channels328 and428, andvalves342 and442 are formed atvalve interface1034. Also illustrated inFIGS. 3,4,7, and8, barrierchamber housing member1018 includes mountingsurfaces352 and452.
• Returning toFIG. 5,base housing member1020 is disposed adjacent to barrierchamber housing member1018, atlower housing portion122 ofhousing112, forming a base forhousing112.Base housing member1020 may formfluid chambers336 and436,solenoid cavity610, and a lower portion ofplunger channel618. Asolenoid612 is mounted withinsolenoid cavity610 viasolenoid bracket1036.Aerosol generator338 is seated withinbase mounting member1020 atseating portion354, formed therein.Base mounting member1020 is adapted to receiveuser control interface118.
• It will be appreciated that the configurations ofhousing112 shown, includinghousing members1010,1012,319,1016,1018, and1020 are illustrated for exemplary purposes only, and that other embodiments ofhousing112 and its various members exist.
• FIGS. 7 and 8 illustrate another embodiment of the invention that enables the drug solution held withinhousing112 to be heated prior to, during, and/or after nebulization. The drug solution may be heated to enhance a comfort of the user, to lower a viscosity of the drug solution to augment nebulization of the drug solution, increase drug delivery flow rate, or for other purposes.
• As illustrated inFIGS. 7 and 8,nebulizing device110 includes asolenoid cavity610 formed inhousing112. Asolenoid612 is mounted insolenoid cavity610.Solenoid612 has asolenoid body613 and asolenoid shaft616, which is joined to amovable plunger614. InFIG. 7, the solenoid is shown energized, while inFIG. 8 it is de-energized. When thesolenoid612 is actuated,shaft616 extends from thesolenoid body613. Of course one of ordinary skill in the art can best appreciate that the solenoid could be reconfigured so that when it is energized it retracts into the solenoid body.
• Plunger614 is joined to thesolenoid body613 at a first end and includes aplunger head620 at a second end.Plunger head620 interacts withdrug dispensing opening322 to comprise areservoir valve622.Plunger614 is actuated between the engaged position (illustrated inFIG. 7) and the disengaged position (illustrated inFIG. 8) to open andclose reservoir valve622. In the engaged position,plunger head620 engagesdrug dispensing opening322 ofdrug solution reservoir310 such thatplunger head620 sealsdrug dispensing opening322. Sealingdrug dispensing opening322 keeps the drug solution indrug solution reservoir310 from flowing tobarrier chambers332 and432 alongreservoir chambers328 and428 respectively. In the disengaged position,plunger head620 is withdrawn fromdrug dispensing opening322 to enable the drug solution held indrug solution reservoir310 to flow tobarrier chambers332 and432.Solenoid612 is operatively coupled to controlelectronics316 and power source/connection318.Solenoid612 is controlled viacontrol electronics316.Solenoid612 is powered via power source/connection318. It can be appreciated that while at rest, thesolenoid612 is positioned to seal theopening322 and activated to unseal it, the opposite arrangement can alternatively be provided so that thesolenoid612 is activated to seal the opening and deactivated to unseal theopening322
• FIG. 9 is an exemplary illustration ofcircuitry626 that may be used innebulizing device110 according to an embodiment of the invention. As shown,control electronics316 are operatively linked with various components ofnebulizing device110, such as, for example,user control interface118, power source/connection318,aerosol generators338 and438,reservoir valve622, heating/sensor unit327, and/or other components.
• FIG. 10 is an exemplary illustration of amethod910 of controlling a nebulizing device according to one embodiment of the invention.Method910 is commenced from a state in which the device is deactivated. In this state, a drug solution is held indrug reservoir310 withclosed valve622, the heater/sensing unit327 associated with the device is at room temperature, andaerosol generators338 and438 associated with the device are deactivated.
• An activation command is conveyed from the user to the device at anoperation912. For example, the activation commend is input viauser control interface138, or otherwise conveyed from the user to the device.
• Method910 includes anoperation914, at which a first threshold temperature and a second threshold temperature is determined. The first threshold temperature and/or the second threshold temperature is determined, in non-limiting examples, according to an input from the user, determined based on a default setting, determined automatically based on one or more measured variables, and/or otherwise determined. The inventors presently contemplate that the preferred operating temperature is 37 degrees Celsius or between 33 degrees to 41 degrees Celsius. Of course, delivery temperatures outside this range could also be used without departing from the scope of the present invention as dictated by the requirements of the particular drug being delivered and/or user preferences.
• Method910 includes anoperation916, at which the heater in heater/sensing unit327 associated with thenebulizing device110 is activated. Activating the heater includes transmitting power to the heater. Activation causes the temperature of the heater to rise.
• As is shown inFIG. 10,method910 includes anoperation918, at which the temperature of the heater associated with heater/sensing unit327 is sensed to determine if the temperature is above the first temperature threshold. If the temperature of the heater is below the first threshold temperature,method910 returns tooperation916.
• If the temperature of the heater is above the first threshold temperature,method910 proceeds to anoperation920. Atoperation920, the drug solution is released from thedrug reservoir310 for nebulization. For example, the drug solution is released tobarriers334 and434 by openingvalve622.
• Method910 includes anoperation922, at whichaerosol generators338 and438 are activated. The acoustic waves generated by the activatedaerosol generators338 and438 are delivered to the drug solution to form nebulized particles from the drug solution at corresponding ones ofbarriers334 and434.
• Method910 includes anoperation924, at which the temperature of the heater is sensed by the temperature sensor to determine if the temperature is between the first temperature and the second temperature. If the temperature of the heater is determined to be below the first temperature,method910 proceeds to anoperation926. Atoperation926, the flow of the drug solution from thedrug reservoir310 to thebarriers334 and434 are sealed (or substantially sealed), effectively stopping the delivery of the drug solution from thedrug reservoir310 to thebarriers334 and434. For example, the flow of the drug solution is sealed by closingvalve622. Atoperation926, theaerosol generators338 and438 are deactivated. Fromoperation926,method910 may return tooperation916.
• As is illustrated inFIG. 10, atoperation924, if the temperature of the heater is above the first threshold and the second threshold,method910 proceeds to anoperation928, at which the heater is deactivated. This causes the heater to stop producing heat. In some instances, the flow of the drug solution from thedrug reservoir310 to thebarriers338 and438 is sealed (or substantially sealed), effectively stopping the delivery of the drug solution from thedrug reservoir310 to thebarriers334 and434, and theaerosol generators338 and438 are deactivated. However, in other instances, the delivery of the drug solution from thedrug reservoir310 to thebarriers334 and434 is continued and theaerosol generators338 and438 are deactivated. Fromoperation928,method910 returns tooperation924.
• Atoperation924, if the temperature of the heater is between the first temperature threshold and the second temperature threshold,method910 proceeds to an operation930. At operation930, it is determined if a treatment session with thenebulizing device110 has been completed. The completion of a treatment session includes, among other things, receiving a deactivation command from the user, completing nebulization of a predetermined or threshold amount of the drug solution, nebulizing the drug solution for a predetermined or threshold amount of time, or otherwise completing the treatment session. If the treatment session is not completed,method910 returns tooperation924. If the treatment session is completed,method910 proceeds to anoperation932.
• Atoperation932, thenebulizing device110 is deactivated. Deactivating thenebulizing device110 includes, among other things, deactivating theaerosol generators338 and438, closing thevalve622, and/or otherwise deactivating thenebulizing device110.
• FIGS. 11A-11C and12 are exemplary illustrations of ahandheld nebulizing device1110 in accordance with another embodiment. In this embodiment,device1110 includes ahousing1112, aninlet1114, anoutlet1116, and auser control interface1118.
• Housing1112 includesmouthpiece module1120, anintermediate module1122, and abase module1124.Modules1120,1122, and1124 are selectively coupled to each other, and may be coupled and uncoupled to each other by the user.
• As is illustrated in the rear plan view ofFIG. 11C,inlet1114 includes aninlet port1121 formed inhousing1112, and particularly inmouthpiece module1120.
• As shown in the front plan view ofFIG. 11A,outlet1116 includes anoutlet port1126 formed inhousing1112 atmouthpiece module1120.Outlet port1126 is configured for engagement by the user's mouth.
• In some embodiments,user control interface1118 includes a control knob1128. Control knob1128 is located on the front ofhousing1112 atbase module1124.
• Intake gas, such as air from the atmosphere, is received intoinlet1114. Atoutlet1116, nebulized particles of the drug solution are communicated fromdevice1110 to the user. The user may control various aspects of operation ofdevice1110 viacontrol interface1118.
• As is illustrated inFIG. 11C,device1110 includes apower receiving connector1130.Power connector1130 is provided inhousing1112 atbase module1124. Power is provided todevice1110 viapower connection1130. Alternatively, power may be provided todevice1110 via an internal power source, such as a battery, a fuel cell, or other power source.
• FIG. 12 is a cross sectional view, taken along cross section line12-12 inFIG. 11B. In some instances,device1110 includes adrug solution reservoir1310, afirst nebulization section1312, asecond nebulization section1314, andcontrol electronics1316.
• Drug solution reservoir1310 includes a drugsolution receiving opening1320, adrug dispensing opening1322, areservoir wall1324, and areservoir floor1326.Drug solution reservoir1310 is generally cylindrical in shape, or may be otherwise shaped. Drugsolution receiving opening1322 is formed byreservoir wall1324, and is circular, or otherwise shaped.Reservoir floor1326 angles fromreservoir wall1324 in a downward slope todrug dispensing opening1322, which is formed byreservoir floor1322.
• First nebulization section1312 includes afirst reservoir channel1328, afirst valve1330, afirst barrier chamber1332, afirst barrier1334, a first fluid chamber1336, afirst aerosol generator1338, and afirst aerosol region1340.First reservoir channel1328 is formed withinhousing112 and runs fromdrug dispensing opening1322 tofirst valve1330.First valve1330 is positioned outwardly fromdrug dispensing opening1322 withinhousing112, betweenfirst reservoir channel1328 andfirst barrier channel1332.
• In some embodiments of the invention,first valve1330 includes afirst valve opening1342, and avalve seal1344.First valve opening1342 is formed withinhousing1112 as an outer opening offirst reservoir channel1328.First valve seal1344 is disposed atfirst valve opening1342 to selectively sealfirst valve opening1342.First valve seal1344, in one embodiment, may include afirst float1346 disposed withinfirst valve1330 at a firstfloat reception cavity1348.First float1346 is composed of a material that enablesfirst float1346 to float in the drug solution, such as a closed cell foam. Firstfloat reception cavity1348 is formed inhousing1112 betweenfirst reservoir channel1328 andfirst barrier chamber1332.First valve1344 includes a first float/cavity interface1350 that includes corresponding surfaces offirst float1346 and firstfloat reception cavity1348.First float1346 is forced againstfirst valve opening1342 asfirst float1346 rises to sealfirst valve opening1342.
• In the embodiment illustrated inFIG. 12,first float1346 includes a firstprotruding center portion1345 and firstsloping lateral portions1347. First protrudingcenter portion1345 protrudes from first slopinglateral portions1347, which slope away from firstprotruding center portion1345. Firstfloat reception cavity1348 includes a firstvertical channel1349 and firstlateral sloping surfaces1351, arranged such that firstprotruding center portion1345 is constantly positioned in firstvertical channel1349 even whenfirst float1346 is not sealingfirst valve opening1342 to maintain the orientation offirst float1346. Maintaining the orientation offirst float1346 ensures that firstsloping lateral portions1347 will contact slopinglateral surfaces1351 to sealfirst valve1330 when first float rises due to its buoyancy.
• According to an embodiment of the invention,first barrier chamber1332, which communicates withfirst reservoir channel1328 viafirst valve1330, is formed withinhousing1112 betweenfirst barrier1334 andfirst aerosol region1340.First barrier1334 is mounted withinhousing112 to afirst mounting surface1352 that is formed on an upper surface of first fluid chamber1336, betweenfirst barrier channel1332 and first fluid chamber1336. First barrier forms a physical separation (i.e., a seal) betweenfirst barrier channel1332 and first fluid chamber1336.First barrier1334 is composed of one or more materials designed to enablefirst barrier1334 to be capable of transmitting ultrasonic energy therethrough, even under high temperature conditions. For example, polyetheretherketone (PEEK), or other materials may be used.
• According to one embodiment of the invention, first fluid chamber1336 is formed withinhousing1112 betweenfirst barrier1334 andfirst aerosol generator1338. First fluid chamber1336 holds a fluid1339 in communication withfirst barrier1334 and first acousticwave aerosol generator1338.Fluid1339 includes one or more fluids capable of transmitting acoustic waves, such as, for example, water, or other fluids.Fluid1339 may include one or more sterilant, such as, alcohol, or other sterilants.
• In the embodiment of the invention illustrated inFIG. 12,first aerosol generator1338 is disposed at a first aerosolgenerator seating portion1354 formed withinhousing112. In some instances,first aerosol generator1338 includes a concave piezoelectric transducer with a silver electrode.First aerosol generator1338 generates acoustic waves at a generator frequency, such as, for example, 2.5 MHz, or another frequency. The acoustic waves are focused at a focal point, or focal band, that is a focal length fromfirst aerosol generator1338. First aerosolgenerator seating portion1354 is formed withinhousing112 such that the focal point will be withinfirst barrier chamber1332. Other embodiments offirst aerosol generator1338 exist.First aerosol generator1338 is operatively linked to controlelectronics1316 so thatcontrol electronics1316 can control various aspects of acoustic wave generation byfirst aerosol generator1338, such as, for instance, activation and deactivation, or other aspects.First aerosol generator1338 is operatively linked topower receiving connection1130 so that power can be provided tofirst aerosol generator1338 via this operative link.
• According to an embodiment of the invention,first aerosol region1340 includes afirst fountain region1356, one or more firstaerosol region inlets1358, afirst chimney1360, and a first drug return region1362.First fountain region1356 is formed withinhousing1112 betweenfirst barrier chamber1332 andfirst chimney1360.First fountain region1356 is open at a first end tofirst barrier chamber1332 and at a second end tofirst chimney1360.First fountain region1356 is formed as a funnel with a smaller opening at the first end and a larger opening at the second end, or may be otherwise shaped.
• The firstaerosol region inlet1358 is formed inhousing1112 atfirst fountain region1356. Firstaerosol region inlet1358 is in communication with inlet port1132.
• In one embodiment,first chimney1360 is formed inhousing1112, and opens at a first end tofirst fountain region1356. A firstaerosol region ceiling1374 is formed at a second end offirst chimney1360.First chimney1360 provides operable communication betweenfirst fountain region1356 andoutlet1116.
• In some embodiments of the invention, first drug return region1362 is formed inhousing1112. First drug return region1362 is open at a first end todrug reservoir1310. First drug return region1362 communicates withfirst chimney1360.
• In accordance with an embodiment of the invention shown inFIG. 12,second nebulization section1314 includes asecond reservoir channel1428, asecond valve1430, asecond barrier chamber1432, asecond barrier1434, asecond fluid chamber1436, asecond aerosol generator1438, and asecond aerosol region1440.Second reservoir channel1428 is formed withinhousing1112 and runs from drug dispensing opening1422 tosecond valve1430.Second valve1430 is positioned outwardly from drug dispensing opening1422 withinhousing1112, betweensecond reservoir channel1428 andsecond barrier chamber1432.
• In the embodiment shown,second valve1430 includes asecond valve opening1442, and avalve seal1444.Second valve opening1442 is formed withinhousing1112 as an outer opening ofsecond reservoir channel1428.Second valve seal1444 is disposed atsecond valve opening1442 to selectively sealsecond valve opening1442. In some instances,second valve seal1444 includes asecond float1446, disposed withinsecond valve1430 at a secondfloat reception cavity1448.Second float1446 is composed of materials that enablesecond float1446 to float in the drug solution. Secondfloat reception cavity1448 is formed inhousing1112 betweensecond reservoir channel1428 andsecond barrier chamber1432.Second valve1444 includes a second float/cavity interface1450 that includes corresponding surfaces ofsecond float1446 and secondfloat reception cavity1448, and is arranged to biassecond float1446 againstsecond valve opening1442 assecond float1446 rises to sealsecond valve opening1442. For example, second float/cavity interface1450 is structured similarly to first float/cavity interface1350.
• In other embodiments,valves1330 and1430 include, for example, one or more electrically operated solenoid valves that are actuated to open and/or closesecond valve1430.
• According to one embodiment of the invention,second barrier chamber1432, which communicates withsecond reservoir channel1428, viasecond valve1430 is formed withinhousing1112 betweensecond barrier1434 andsecond aerosol region1440.Second barrier1434 is mounted withinhousing1112 to asecond mounting surface1452 that is formed on an upper surface ofsecond fluid chamber1436, betweensecond barrier chamber1432 andsecond fluid chamber1436. Second barrier forms a physical separation (i.e., a seal) betweensecond barrier chamber1432 andsecond fluid chamber1436.Second barrier1434 is composed of one or more materials designed to enablesecond barrier1434 to be capable of transmitting ultrasonic energy therethrough, even under high temperature conditions. For example, polyetheretherketone (PEEK), or other materials may be used.
• Thesecond fluid1436 is formed withinhousing1112 betweensecond barrier1434 andsecond aerosol generator1438.Second fluid1436 holds an fluid1439 in communication withsecond barrier1434 andsecond aerosol generator1438.Fluid1439 includes one or more fluids capable of transmitting acoustic waves, such as, for example, water, or other fluids.Fluid1439 may include one or more sterilant, such as, alcohol, or other sterilants.
• Second aerosol generator1438 is disposed at a second aerosolgenerator seating portion1454 formed withinhousing1112. In one embodiment,second aerosol generator1438 includes a concave piezoelectric transducer with a silver electrode.Second aerosol generator1438 generates acoustic waves at a generator frequency, such as, for example, 2.5 MHz, or another frequency. The acoustic waves are focused at a focal point, or focal band, that is a focal length fromsecond aerosol generator1338. Second aerosolgenerator seating portion1454 is formed withinhousing1112 such that the focal point will be withinsecond barrier chamber1432.Second aerosol generator1438 is operatively linked to controlelectronics1316 so thatcontrol electronics1316 can control various aspects of acoustic wave generation bysecond aerosol generator1438, such as, for instance, activation and deactivation, or other aspects.Second aerosol generator1438 is operatively linked topower connection1130 so that power can be provided tosecond aerosol generator1438 via this operative link.
• Second aerosol region1440 includes asecond fountain region1456, one or more secondaerosol region inlets1458, asecond chimney1460, and a second drug return region1462.Second fountain region1456 is formed withinhousing1112 betweensecond barrier chamber1432 andsecond chimney1460.Second fountain region1456 is open at a first end tosecond barrier chamber1432 and at a second end tosecond chimney1460.Second fountain region1456 is formed as a funnel with a smaller opening at the first end and a larger opening at the second end, or may be otherwise shaped.
• In some embodiments of the invention, secondaerosol region inlet1458 is formed inhousing1112 atsecond fountain region1456. Secondaerosol region inlet1458 is in communication with inlet port1132.
• In the embodiment ofFIG. 12,second chimney1460 is formed inhousing1112, and opens at a first end tosecond fountain region1456. A secondaerosol region ceiling1474 is formed at a second end ofsecond chimney1460.Second chimney1460 provides operable communication betweensecond fountain region1456 andoutlet1116.
• In one embodiment of the invention, second drug return region1462 is formed inhousing1112. Second drug return region1462 is open at a first end todrug reservoir1310. Second drug return region1462 communicates withsecond chimney1460.
• Thebarrier chambers1332 and1432 hold an amount of the drug solution at each ofbarriers1334 and1434. Nebulized particles of the drug solution are formed by the fountains and are delivered toaerosol regions1340 and1440. The fountains are formed by acoustic waves within the drug solution held inbarrier chambers1332 and1432 atbarriers1334 and1434. The acoustic waves are generated byaerosol generators1338 and1438. The acoustic waves transmitted fromaerosol generators1338 and1438 tobarrier chambers1332 and1432 via the fluid held influid chambers1336 and1436. The transmitted acoustic waves pass fromfluid chambers1336 and1436 tobarrier chambers1332 and1432 viabarriers1334 and1434.
• According to various embodiments of the invention, the acoustic waves transmitted tobarrier chambers1332 and1432 are focused at the focal point. The drug solution inbarrier chambers1332 and1432 absorbs the ultrasonic energy provided by the focused acoustic waves to create a fountain within each ofbarrier chambers1332 and1432. The ultrasonic energy delivered by the acoustic waves has a maximum density at or near the focal point of the acoustic waves. The fountains shed a portion of the drug solution as particles. Some of these particles are so large they immediately fall out. Some are small enough to pass into drug return regions1362,1462 before falling out. The remaining particles which are appropriately sized, pass out through first tosecond outlet1116. In this manner, substantially consistent particle size is achieved.
• In one embodiment of the invention, the nebulized particles are communicated frombarrier chambers1332 and1432, throughaerosol regions1340 and1440, and to the user viaoutlet1116. More particularly, the nebulized particles and the larger droplets of the drug solution formed at the fountains are received byaerosol regions1340 and1440 at fluid chambers1364 and1464, and pass intochimneys1360 and1460. Fromchimneys1360 and1460, the nebulized particles are communicated to the user viaoutlet1116. In contrast, due to size and/or weight, the larger droplets may not be communicated to the user, but instead may contact a surface ofaerosol regions1340 and1440, such asaerosol region ceilings1374 and1474, or other surfaces. The larger droplets then condense on the contacted surface(s), thereby separating the larger droplets from the nebulized particles prior to delivery to the user. The drug solution contained in the condensed larger droplets are passed back todrug solution reservoir1310 via drug return regions1362 and1462.
• The nebulization of the drug solution by the fountains is enhanced when the focal point of the acoustic waves coincides (exactly or substantially) with an upper surface of the drug solution infirst barrier chamber1332. This requires a level of the upper surface to be controlled with some particularity to enhance the operation of the fountains. To maintain the level of the upper surface, an amount of the drug solution atbarriers334 and434 is controlled by manipulating a flow of the drug solution fromdrug reservoir1310 tobarrier chambers1332 and1432 viareservoir channels1328 and1428 are controlled viavalves1330 and1430 by independently sealing and unsealingvalve openings1342 and1442 withvalve seals1344 and1444. For example, when the level of the upper surface of the drug solution on either ofbarriers1334 and/or1434 reaches a threshold level at or near the focal point of the acoustic waves that corresponds to a threshold amount of the drug solution being present on one ofbarriers1334 and1434, corresponding one offloats1346 and/or1446 are positioned to sealvalve openings1342 and/or1442 by virtue of the buoyancy offloats1346 and1446 with respect to the drug solution. However, as particles are formed by the fountains, the level of the upper surface in one or both ofbarrier chambers1332 and1432 may drop below the threshold level, which in turn lowers one or both offloats1346 and1446 fromvalve openings1342 and1442, thereby openingvalves1330 and/or1430. This functionality is illustrated with respect tovalves330, and430 inFIGS. 3, and4.
• Referring toFIG. 12, activation ofaerosol generators1338 and1438 enable generation of particles of the drug solution to be propelled by the fountains intoaerosol regions1340 and1440. As particles are propelled by the fountain intoaerosol regions1340 and1440, the atmosphere withinaerosol regions1340 and1440 is disturbed such that intake gas is pulled into particle receiving regions1366 and1466 viaaerosol region inlets1358 and1458. Pulling air into particle receiving regions1366 and1466 may initiate the flow of intake gas throughaerosol regions1340 and1440 tooutlet1116, which may in turn motivate the nebulized particles formed at the fountains towardoutlet1116. Thus, the atmospheric disturbances that may be caused by the nebulized particles from the fountains, and the resulting flow of intake gas throughaerosol regions1340 and1440 may function in a cooperative manner to “drive” the delivery of nebulized particles from the fountains to the user without requiring additional active moving parts.
• FIG. 13 is an exemplary cross sectional view of thehandheld nebulizing device1110, taken along cross section line13-13, in accordance with another embodiment of the invention. In the embodiment illustrated inFIG. 13, device1610 includes afirst nebulization section1612, asecond nebulization section1614, andcontrol electronics1616.
• In the embodiment ofFIG. 13,first nebulization section1612 includes a first aerosol generator1618, afirst fluid1620, afirst barrier1622, afirst barrier chamber1624, afirst guide tube1626, and a first separator structure1628. First aerosol generator1618 may include a concave piezoelectric transducer with a silver electrode. First aerosol generator1618 generates acoustic waves at a generator frequency, such as, for example, 2.5 MHz, or another frequency. The acoustic waves are focused at a focal point that is a focal length from first aerosol generator1618.Device1110 is arranged such that the focal point is withinfirst barrier chamber1624. Other embodiments of aerosol generator1618 exist. The inventors contemplate that various other aerosol generators could be employed with the teachings of the present invention. For instance, the aerosol generator may be a jet type nebulizer, a vibrating mesh nebulizer, a vibratory plate nebulizer, a traditional planar ultrasonic nebulizer, or an electrospray nebulizer.
• According to one embodiment of the invention, first aerosol generator1618 is seated in a first aerosolgenerator seating portion1630 withinintermediate module1122. First aerosolgenerator seating portion1630 is defined by an upper surface of a first seating portion wall1632 that extends upward from a bottom plane ofintermediate module1122.
• In this embodiment of the invention,first fluid1620 is formed adjacent to aerosolgenerator seating portion1630 such that first aerosol generator1618 forms a portion of a lower surface offirst fluid1620.
• A firstbarrier mounting surface1634 is located at an upper surface offirst fluid1620. Firstbarrier mounting surface1634 defines afirst barrier opening1636.First barrier opening1636 enable communication between first fluid1620 andfirst barrier chamber1624.First barrier1622 is mounted to firstbarrier mounting surface1634, effectively sealing first fluid1620 fromfirst barrier chamber1624.
• According to the embodiment illustrated inFIG. 13,first barrier chamber1624 is formed by a firstbarrier chamber wall1638 and a firstbarrier chamber floor1640. Firstbarrier chamber floor1640 is sloped such thatfirst barrier opening1636 is a lowest point withinfirst barrier chamber1624.
• In one embodiment of the invention,first guide tube1626 is provided overfirst barrier1622 such that a first end offirst guide tube1626 extends down intofirst barrier chamber1624 and a second end offirst guide tube1626 extends out offirst barrier chamber1624.First guide tube1626 is held in position overfirst barrier1622 by a firstguide tube collar1638 associated with first separator structure1628. Firstguide tube collar1638 holdsfirst guide tube1626 in position such that the second end offirst guide tube1626 extends up into first separator structure1628. First separator structure1628 provides communication between the second end offirst guide tube1626 andoutlet1116.
• According to an embodiment of the invention, first aerosol generator1618 may be activated bycontrol electronics1616 to generate acoustic waves that are introduced intofirst fluid1620. First fluid1620 contains a fluid1629 that is capable of transmitting the received acoustic waves. For example, the transmitting fluid1629 may include water, or other fluids. In some instances, a sterilant, such as alcohol, or another sterilant, may be added to the transmitting fluid.
• Thesecond nebulization section1614 includes asecond aerosol generator1718, asecond fluid1720, a second barrier1722, asecond barrier chamber1724, asecond guide tube1726, and asecond separator structure1728.Second aerosol generator1718 may include a concave piezoelectric transducer with a silver electrode.Second aerosol generator1718 generates acoustic waves at a generator frequency, such as, for example, 2.5 MHz, or another frequency. The acoustic waves are focused at a focal point that is a focal length fromsecond aerosol generator1718.Device1110 is arranged such that the focal point is withinsecond barrier chamber1724. Other embodiments ofaerosol generator1718 exist.
• According to one embodiment of the invention,second aerosol generator1718 is seated in a second aerosolgenerator seating portion1630 withinintermediate module1122. Second aerosolgenerator seating portion1630 is defined by an upper surface of a second seating portion wall1632 that extends upward from a bottom plane ofintermediate module1122.
• In the embodiment of the invention shown inFIG. 13,second fluid1720 is formed adjacent to aerosolgenerator seating portion1630 such thatsecond aerosol generator1718 forms a portion of a lower surface ofsecond fluid1720.
• In this embodiment, a secondbarrier mounting surface1634 is located at an upper surface ofsecond fluid1720. Secondbarrier mounting surface1634 defines asecond barrier opening1636.Second barrier opening1636 enable communication between second fluid1720 andsecond barrier chamber1724. Second barrier1722 is mounted to secondbarrier mounting surface1634, effectively sealing second fluid1720 fromsecond barrier chamber1724.
• Thesecond barrier chamber1724 is formed by a secondbarrier chamber wall1638 and a second barrier chamber floor1740. Second barrier chamber floor1740 is sloped such thatsecond barrier opening1636 is a lowest point withinsecond barrier chamber1724.
• In accordance with one embodiment of the invention,second guide tube1726 is provided over second barrier1722 such that a first end ofsecond guide tube1726 extends down intosecond barrier chamber1724 and a second end ofsecond guide tube1726 extends out ofsecond barrier chamber1724.Second guide tube1726 is held in position over second barrier1722 by a second guide tube collar1738 associated withsecond separator structure1728. Secondguide tube collar1728 holdssecond guide tube1726 in position such that the second end ofsecond guide tube1726 extends up intosecond separator structure1728.Second separator structure1728 provides communication between the second end ofsecond guide tube1726 andoutlet1116.
• According to an embodiment of the invention, second acousticwave aerosol generator1718 may be activated by control electronics1716 to generate acoustic waves that are introduced intosecond fluid1720.Second fluid1720 contains a fluid1729 that is capable of transmitting the received acoustic waves. For example, the fluid1729 may include water, or other fluids. In some instances, a sterilant, such as alcohol, or another sterilant, may be added to the transmitting fluid.
• In one embodiment, the acoustic waves introduced tofluids1620 and1720 are transmitted fromfluids1620 and1720 tobarrier chambers1624 and1724 viabarriers1622 and1722. The acoustic waves transmitted tobarrier chambers1624 and1724 are focused at the focal points ofaerosol generators1618 and1718. Pools of drug solution held withinbarrier chambers1624 and1724 absorb the ultrasonic energy provided by the focused acoustic waves, thereby energizing the drug solution to create a fountain at the top ofguide tubes1626,1726. The fountains shed a portion of the drug solution as particles. Some of these particles are so large they immediately fall out. The remaining particles, which are appropriately sized, pass out ofbarrier chambers1624,1724. In this manner, a substantially consistent particle size is achieved.
• In the embodiment ofFIG. 13, the nebulization of the drug solution by the fountains is enhanced when the focal point of the acoustic waves coincides (exactly or substantially) with a surface of the drug solution inbarrier chambers1624 and1724. This may require a level of the surface to be controlled with some particularity to enhance the operation of the fountain.
• In the illustrated embodiment, the fountains are formed at the top ofguide tubes1626 and1726. The drug solution withinguide tubes1626 and1726 is propelled toward the second ends ofguide tubes1626 and1726 by the ultrasonic energy from the acoustic waves. At the second ends ofguide tubes1626 and1726, ultrasonic energy received byguide tubes1626 and1726 from the acoustic waves are transmitted to the drug solution propelled up from first ends ofguide tubes1626 and1726, and is delivered to the drug solution at the second ends ofguide tubes1626 and1726 to form the nebulized particles of the drug solution. Thus, guidetubes1626 and1726 enhance the formation of the nebulized particles of the drug solution within the fountains by energizing the drug solution withinguide tubes1626 and1726 to nebulize drug solution that is not located at the respective focal points of the acoustic waves. Preferably the guide tubes are 2 mm-3 mm in diameter. One of ordinary skill in the art can best appreciate that the particles discharged fromguide tubes1626,1726 can be adjusted by adjusting the size of theguide tubes1626,1726.
• The above described systems are particularly well suited for delivering drugs to patients that have previously been difficult to administer. For instance, one such drug that has been difficult to deliver in an aerosolized form is pulmonary surfactants. Surfactants mainly consist of phosphelipids and surfactants proteins that are used to replace deficient endogenous surfactants in patient's lungs. There are a variety of surfactant medications available such as natural human surfactants (obtained from amniotic fluid or a bio-synthetic material), natural animal surfactants (obtained from bovine lung extracts, porcine lung extracts, or a bio-synthetic material), or synthetic preparations. What makes pulmonary surfactants particularly difficult to delivery in aerosol form is that they are highly viscous. Accordingly using one or more of the above described features of the present invention permits high speed delivery of viscous drugs such as pulmonary surfactants. Of course, the novel aspects of the present invention can also be used with a variety of other drug formulations.
• Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims.

Claims (10)

1. A nebulizing drug delivery device, comprising:

a housing having an inlet and an outlet;

an aerosol generator in communication with a fluid;

a temperature sensor that senses a temperature of the drug solution; and

a heater in functional communication with the temperature sensor, the heater being operable in response to the temperature sensor to maintain the temperature of the drug solution above a threshold temperature.

2. A nebulizing drug device according toclaim 1, wherein the threshold temperature can be adjusted.

3. A nebulizing device according toclaim 1, wherein the heater is positioned to heat the drug solution.

4. A nebulizing device according toclaim 1, further comprising a drug solution reservoir in the housing, and a valve that can be opened to supply the drug solution from the reservoir, wherein the heater is positioned to heat the drug solution in the reservoir.

5. A nebulizing device according toclaim 4, wherein the valve comprises an electrically operated solenoid, the solenoid being in communication with the temperature sensor, the solenoid being operated to open the valve and enable the drug solution to flow from the reservoir to the barrier in response to the temperature sensor indicating that the temperature of the drug solution is above the threshold level.

6. A nebulizing device according toclaim 5, wherein the solenoid remains open until the device is turned off.

7. A nebulizing device according toclaim 1, wherein the temperature sensor turns the heater on and off to maintain the drug solution with a range.

8. A nebulizing device according toclaim 1, wherein the heater is turned off in response to the temperature sensor determining that the drug solution is above an upper threshold level, and wherein the heater is turned off and on to maintain the drug solution within a temperature range.

9. A nebulizing device comprising:

a housing having an inlet and an outlet;

an aerosol generator;

a temperature sensor that senses a temperature of the drug solution; and

a heater in functional communication with the temperature sensor, the heater being operable in response to the temperature sensor to maintain the drug above a threshold temperature; wherein the drug solution is a surfactant.

10. The nebulizing device as recited inclaim 9 wherein the threshold temperature is approximately about 37 degrees Celsius.

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