Mist GeneratorSlide 2OverviewProblem StatementClient RequirementBackgroundUltrasonic NebulizerUltrasonic Nebulizer Advantages/DisadvantagesMicropumpsPressure Activated DevicesSlide 11Slide 12Particle measurement techniquesSlide 14Design AlternativesSlide 16Design/Decision MatrixFinal Design ChoiceFuture WorkReferencesMist GeneratorMist GeneratorKelly Toy Jon CappelKelly Toy Jon CappelJoe Bothwell Abdikarim MahamudJoe Bothwell Abdikarim Mahamud Advisor – John WebsterClient – Jack Jiang, MD, PhDhttp://www.rcjournal.com/conhttp://www.rcjournal.com/contents/06.00/06.00.0609.asp.tents/06.00/06.00.0609.asp.OverviewOverviewProblem StatementProblem StatementBackground MaterialBackground MaterialSummary of product design specificationsSummary of product design specificationsDesign Alternatives consideredDesign Alternatives consideredFuture WorkFuture WorkProblem StatementProblem StatementResearch being conducted on the larynx Research being conducted on the larynx can be benefited by the specific targeting of can be benefited by the specific targeting of medication in the respiratory systemmedication in the respiratory systemSpecific targeting of medication is difficult to Specific targeting of medication is difficult to complete accuratelycomplete accuratelyThe process of atomizing particles is The process of atomizing particles is complexcomplexClient RequirementClient Requirement-Product is needed that can:-Product is needed that can:Generate a mist of different densitiesGenerate a mist of different densitiesGenerate particle sizes in the range of 0.5-50 Generate particle sizes in the range of 0.5-50 micronsmicronsAdaptable as inhalerAdaptable as inhalerGenerate mist such that different areas of the Generate mist such that different areas of the respiratory system can be targetedrespiratory system can be targetedBackgroundBackgroundDifferent ways to generate mist:Different ways to generate mist:–Ultrasonic NebulizerUltrasonic Nebulizer–MicropumpsMicropumps–Pressure activated devicesPressure activated devicesParticle measurement techniquesParticle measurement techniquesUltrasonic NebulizerUltrasonic NebulizerConverts electricity into Converts electricity into ultrasonic waves ultrasonic waves Transducer vibrates at Transducer vibrates at frequency of waves (1-3 frequency of waves (1-3 MHz)MHz)Higher the frequency, Higher the frequency, smaller dropletssmaller dropletsTransducer generates Transducer generates ultrasonic fountain of liquidultrasonic fountain of liquidAerosol delivered by fan or Aerosol delivered by fan or inspirationinspirationCreates particles ~1-6 Creates particles ~1-6 micronsmicronsDennis J, Hendrick DDennis J, Hendrick DUltrasonic NebulizerUltrasonic NebulizerAdvantages/DisadvantagesAdvantages/DisadvantagesAdvantagesAdvantagesStable particle sizeStable particle sizeSmall dead volumeSmall dead volumeHigh aerosol outputHigh aerosol outputQuietQuietFast drug deliveryFast drug deliveryDisadvant agesDisadvant agesAerosol solution can become Aerosol solution can become heatedheatedExpensiveExpensiveShort cycle life (600-1000 Short cycle life (600-1000 uses)uses)http://www.mabis.net/40-270-Open/MicropumpsMicropumpsOnQ is one of the micropumps OnQ is one of the micropumps used in the market for used in the market for nebulizers. nebulizers. contains over a thousand contains over a thousand precision-formed tapered precision-formed tapered holes, surrounded by a holes, surrounded by a vibrational element. vibrational element. plate vibrates over 100,000 plate vibrates over 100,000 times per second.times per second.It draws liquid through the It draws liquid through the holes to form consistently holes to form consistently sized droplets. sized droplets. Problems Problems How to adjust the frequency.How to adjust the frequency.http://www.aerogen.comhttp://www.aerogen.comPressure Activated DevicesPressure Activated DevicesDevices that create mist by using pressure–Inhalers use a similar principlehand-held portable devices that deliver medication directly to the lungsUses pressurized canister with chemical propellanthttp://www.aaaai.org/patients/allergic_conditions/metered_dose_inhalers.stmPressure Activated DevicesPressure Activated DevicesDevices similar to hairspray Devices similar to hairspray bottlesbottles–Use pressure to compress liquidUse pressure to compress liquid–Liquid is compressed through tiny Liquid is compressed through tiny opening creating mistopening creating misthttp://www.atomization.de/basic.htm#Physicalhttp://www.drugstore.com/Pressure Activated DevicesPressure Activated DevicesAdvantagesAdvantages–InexpensiveInexpensive–SimpleSimpleDisadvantagesDisadvantages–Comparatively, very large mist particlesComparatively, very large mist particles–Different nozzles needed for different Different nozzles needed for different densitiesdensitiesParticle measurement techniquesParticle measurement techniquesLaser DiffractionLaser Diffraction–Method is absolute, no need to calibrate instrumentsMethod is absolute, no need to calibrate instruments–Wide range .01-2000 micronsWide range .01-2000 microns–Flexibility, paint nozzle sprays to dry powderFlexibility, paint nozzle sprays to dry powder–Can measure circulating liquid particles.Can measure circulating liquid particles.–Requires expensive equipmentRequires expensive equipment–Engine research lab has a Malvern laser diffraction Engine research lab has a Malvern laser diffraction instrument instrument MicroscopyMicroscopy–Relies on microscope, and precision measuring Relies on microscope, and precision measuring devices.devices.–Somewhat prone to error due to the judgment of the Somewhat prone to error due to the judgment of the operator. operator.Particle measurement techniquesParticle measurement techniquesCascade impactorCascade impactor–Progressively filters out smaller particles through a Progressively filters out smaller particles through a series of tubes.series of tubes.–Particles accumulate according to their size, and Particles accumulate according to their size, and the concentrations are analyzed after the the concentrations are analyzed after the experimentexperiment–Can take a relatively long time to completeCan take a relatively long time to completeElectrozone sensingElectrozone sensing–Changes in capacitance are measured as a Changes in capacitance are measured as a charged
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