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US 7,243,648 B2Granted
Thermal drop generator
AssigneeHewlett-Packard Development Company, L.P.
InventorsXiaofeng Yang, Kenneth E. Trueba, Rod Alley, Winthrop Childers, David Tyvoll, Douglas A. Sexton
Life of this patent
Estimating the term…
Abstract
A silicon die having an orifice layer with plural openings formed therein defines a drop ejection device for use in a handheld inhaler. An underlying control layer defines fluid chambers, each carrying a heat transducer. A control system energizes selected heat transducers to heat fluid in the chambers, vaporizing the fluid, which is ejected through the orifices in small droplets.
Claims24
A medication delivery apparatus, comprising:
- a drop ejection device including at least 1000 drop generators;
- circuitry electrically coupled to the drop generators and configured to deliver drop ejection pulses to the drop generators at a frequency of at least 25 KHz;
- and
- a fluid delivery system configured to deliver fluid to the drop generators with a gauge pressure within a range of gauge pressures, wherein the drop generators provide stable drop ejection at gauge pressures below −45 inches of water.
1 more element
A method of operating a metered dose inhaler having an ejector device, comprising the steps of:
- (a) supplying fluid medication to drop generators at an operating pressure range that includes a gauge pressure of less than −15 inches of water;
- and
- (b) applying firing pulses to at least about 4000 of the drop generators at a frequency of at least 100 KHz;
- and
- (c) operating the ejector device at a flux rate sufficient to generate drops expelled from said ejector device at a rate of at least about 1×109 drops per second.
2 more elements
A handheld inhaler, comprising:
- a drop ejection device including a multiplicity of fluid drop generators disposed at a density of at least about 100 drop generators/mm2;
- and
- circuitry electrically coupled to the drop generators and configured to simultaneously provide fire pulses to at least about 300 heat transducers;
- and
- a fluid delivery system configured to provide a fluid to the drop generators at a controlled pressure level, wherein the drop generators provide stable drop ejection when the pressure level is below a gauge pressure of about −10 inches of water, and wherein the ejector device outputs a flux of at least about 1×109 drops per second.
2 more elements
A medication delivery apparatus, comprising:
- a drop ejection device including a multiplicity of fluid drop generators for generating an aerosol formed from individual drops of less than about 50 femtoliters in size, each drop generator having a heat transducer associated therewith, wherein the drop ejection device outputs a flux of at least about 1×109 drops per second;
- a controller including circuitry electrically coupled to the drop generators and configured to provide drop ejection pulses to the drop generators and capable of energizing at least about 300 heat transducers simultaneously;
- and
- a fluid delivery system configured to deliver a fluid to the drop generators with a controlled gauge pressure within a range of gauge pressures, wherein the drop generators provide stable drop ejection at gauge pressures below −10 inches of water.
1 more element
A medication delivery apparatus, comprising:
- a drop ejection device including at least 1000 drop generators, wherein the drop ejection device outputs a flux of at least about 1×109 drops per second;
- circuitry electrically coupled to the drop generators and configured to deliver drop ejection pulses to the drop generators at a frequency of at least 25 KHz;
- and
- a fluid delivery system configured to deliver fluid to the drop generators with a gauge pressure within a range of gauge pressures, wherein the drop generators provide stable drop ejection at gauge pressures below −10 inches of water, and wherein the fluid has a surface tension of at least about 20 dynes/cm2.
1 more element
A medication delivery apparatus, comprising:
- a drop ejection device including at least 1000 drop generators, each drop generator including an orifice overlying a heat transducer, wherein the drop ejection device outputs a flux of at least about 1×109 drops per second;
- circuitry electrically coupled to the drop generators and configured to deliver drop ejection pulses to the drop generators at a frequency of at least 25 KHz;
- a fluid delivery system configured to deliver fluid to the drop generators with a gauge pressure within a range of gauge pressures, wherein the drop generators provide stable drop ejection at gauge pressures below −10 inches of water;
- and
- a controller capable of energizing at least about 300 heat transducers simultaneously.
2 more elements
Dependencies are inferred from the claim text.