Directionally controlled EHD aerosol sprayer

• US 6,302,331 B1
• Filed: 04/20/2000
• Issued: 10/16/2001
• Est. Priority Date: 04/23/1999
• Status: Expired due to Fees

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Ventaira Pharmaceuticals Inc. (Battelle Memorial Institute)
• Inventors: Chongsiriwatana, Songsdhit, Dvorsky, James E.
• Primary Examiner(s): Scherbel, David A.
• Assistant Examiner(s): Nguyen, Dinh Q.
• Application Number:
  US09/552,970
• Time in Patent Office: 544 Days
• Field of Search: 239/690, 239/690.1, 239/692, 239/695, 239/706, 239/708, 239/705, 239/696, 239/3, 361/227, 361/228, 128/200.14, 128/203.13, 128/204.13, 128/204.21
• US Class Current: 239/3
• CPC Class Codes: A61M 15/02 with activated or ionised fluids, e.g. electrohydrodynamic [EHD] or electrostatic devices; Ozone-inhalators with radioactive tagged particles
• CPC Class Codes: B05B 5/0255 spraying and depositing by electrostatic forces only
• CPC Class Codes: B05B 5/0533 Electrodes specially adapted therefor; Arrangements of electrodes

Abstract

The invention provides an aerosol delivery method and system for producing a charged electrohydrodynamic (EHD) aerosol, discharging the aerosol and moving the discharged aerosol in a desired direction without substantial wetting of the device. The delivery system may include a spray nozzle for dispensing the fluid to be aerosolized and negatively charging the aerosol droplets, a discharge electrode generally downstream of the spray nozzle for generating a positive ion stream which intercepts and electrically neutralizes the negative aerosol droplets while also imparting a desired movement on the aerosol in a direction generally away from the discharge electrode and a reference electrode between the spray nozzle and the discharge electrode for modifying the electric field between the spray nozzle and the discharge electrode.

Claims

1. A directionally controlled electrohydrodynamic aerosol sprayer comprising:

a spray nozzle in fluid communication with a source of fluid to be aerosolized, the spray nozzle having at least one spray tip near which the fluid exits the spray nozzle and is aerosolized;

a discharge electrode;

a reference electrode located between the spray nozzle and the discharge electrode and crossing a line connecting the spray tip and the discharge electrode;

a first voltage source maintaining the spray nozzle at a negative or positive potential relative to the potential of the reference electrode; and

a second voltage source maintaining the discharge electrode at the opposite potential relative to the potential of the reference electrode than is the spray nozzle.

2. The directionally controlled electrohydrodynamic aerosol sprayer of claim 1, wherein the reference electrode is positioned relative to the spray nozzle such that the electric field generated between the spray nozzle and the reference electrode is the highest between a spray tip of the spray nozzle and a spray end of the reference electrode, whereby the electric field minimizes the wetting of the exterior of the nozzle.

3. The directionally controlled electrohydrodynamic aerosol sprayer of claim 1, wherein the reference electrode is positioned relative to the discharge electrode, such that the electric field generated between the discharge electrode and the reference electrode is the highest between a discharge tip of the discharge electrode, and a spray end of the reference electrode.

4. A directionally controlled electrohydrodynamic aerosol sprayer comprising:

a spray nozzle in fluid communication with a source of fluid to be aerosolized, the spray nozzle having at least one spray tip near which the fluid exits the spray nozzle and is aerosolized generally along a selected aerosol spray path;

a discharge electrode for producing ions near an ionization site on the discharge electrode and a corona wind from the discharge electrode along a desired path, wherein the discharge electrode is oriented such that the desired path makes an angle of less than 90 degrees to the selected aerosol spray path;

a reference electrode located between the spray nozzle and the discharge electrode;

a first voltage source maintaining the spray nozzle at a negative or positive potential relative to the potential of the reference electrode; and

a second voltage source maintaining the discharge electrode at the opposite potential relative to the potential of the reference electrode than is the spray nozzle.

5. A directionally controlled electrohydrodynamic aerosol sprayer comprising:

a sprayer housing having an exit for communicating the aerosol to a user;

a spray nozzle within the housing and in fluid communication with a source of fluid to be aerosolized;

a discharge electrode capable of producing a positive ion stream from air molecules proximate the discharge electrode and oriented such that the positive ion stream may intercept the aerosol from the spray nozzle and move at least a portion of the aerosol generally in a direction toward the exit;

a first reference electrode located between the spray nozzle and the discharge electrode;

a first voltage source maintaining the spray nozzle at a negative potential relative to the potential of the reference electrode; and

a second voltage source maintaining the discharge electrode at a positive potential relative to the potential of the reference electrode.

6. The directionally controlled electrohydrodynamic aerosol sprayer of claim 5, wherein the spray nozzle has at least one spray tip near which the fluid exits the spray nozzle and is aerosolized and the first reference electrode is located between the spray nozzle and the discharge electrode and crossing a line connecting the spray tip and the discharge electrode.

7. The directionally controlled electrohydrodynamic aerosol sprayer of claim 5 wherein the discharge electrode has a configuration and an orientation to produce a positive ion stream which intercepts the aerosol along an aerosol path downstream of the spray nozzle to discharge the aerosol and to move at least a portion of the aerosol generally in a direction substantially parallel to the positive ion stream.

8. The directionally controlled electrohydrodynamic aerosol sprayer of claim 5, wherein the spray nozzle is positioned to dispense the aerosol generally along a path parallel to a selected aerosol spray direction and the discharge electrode is positioned such that the positive ion stream may intercept the aerosol spray direction at an angle of between about 0 and 120 degrees.

9. The directionally controlled electrohydrodynamic aerosol sprayer of claim 8, wherein the spray nozzle and the discharge electrode are positioned such that the positive ion stream may intercept the aerosol spray direction at an angle of between about 30 and 90 degrees.

10. The directionally controlled electrohydrodynamic aerosol sprayer of claim 5, which further comprises:

a second reference electrode located such that the discharge electrode is located between the first reference electrode and the second reference electrode and wherein the second reference electrode is at a potential which is positive with respect to the spray nozzle and negative with respect to the discharge electrode.

11. The directionally controlled electrohydrodynamic aerosol sprayer of claim 10, wherein the second reference electrode is positioned such that a line drawn from the spray nozzle to the discharge electrode passes through the second reference electrode.

12. The directionally controlled electrohydrodynamic aerosol sprayer of claim 10, which further comprises:

a third reference electrode located such that the spray nozzle is located between the first reference electrode and the third reference electrode and wherein the third reference electrode is at a potential which is positive with respect to the spray nozzle and negative with respect to the discharge electrode.

13. The directionally controlled electrohydrodynamic aerosol sprayer of claim 12, wherein the third reference electrode is positioned such that a line drawn from an end of the second reference electrode nearest the spray nozzle to an end of the third reference electrode nearest the spray nozzle does not pass through the spray nozzle.

14. A directionally controlled electrohydrodynamic aerosol sprayer comprising:

a sprayer housing having an exit for communicating aerosol to a user;

a plurality of spray nozzles within the housing and in fluid communication with a source of fluid to be aerosolized;

a plurality of discharge electrodes capable of producing positive ion streams from air molecules proximate the discharge electrodes and oriented such that the positive ion streams may intercept the aerosol from the spray nozzles and move at least a portion of the aerosol generally in a direction toward the exit;

at least one reference electrode located between the spray nozzles and the discharge electrodes;

a first voltage source maintaining the spray nozzles at a negative potential relative to the potential of the at least one reference electrode; and

a second voltage source maintaining the discharge electrodes at a positive potential relative to the potential of the at least one reference electrode.

15. The directionally controlled electrohydrodynamic aerosol sprayer of claim 14, wherein the at least one reference electrode crosses a line connecting the spray nozzles and the discharge electrodes, whereby the electric field created between the reference electrode and the spray nozzles is substantially de-coupled from the electric field created between the discharge electrodes and the at least one reference electrode.

16. The directionally controlled electrohydrodynamic aerosol sprayer of claim 14 wherein the discharge electrodes have a configuration and an orientation to produce a positive ion stream which intercepts the aerosol along an aerosol path downstream of the spray nozzles to discharge the aerosol and to move at least a portion of the aerosol generally in a direction substantially parallel to the positive ion stream.

17. The directionally controlled electrohydrodynamic aerosol sprayer of claim 14, wherein the spray nozzles are positioned to dispense the aerosol generally along a path parallel to a selected aerosol spray direction and the discharge electrodes are positioned such that the positive ion stream may intercept the aerosol spray direction at an angle of between about 0 and 120 degrees.

18. The directionally controlled electrohydrodynamic aerosol sprayer of claim 17, wherein the spray nozzles and the discharge electrodes are positioned such that the positive ion stream may intercept the aerosol spray direction at an angle of between about 30 and 90 degrees.

19. Device for delivering electrically neutral aerosol droplets substantially along a desired path comprising:

means for converting a fluid into aerosol droplets having a negative electrical charge with respect to a reference potential; and

discharge electrode means for producing ions positively charged with respect to the reference potential and a corona wind from the discharge electrode means in a direction along the desired path for intercepting the aerosol droplets and moving the droplets in the direction along the desired path away from the means for converting a fluid.

20. The device of claim 19 for delivering electrically neutral aerosol droplets substantially along a desired path further comprising a field modifying element located between the means for converting a fluid and the means for producing ions and comprising either a dielectric means or a reference electrode means at the reference potential.

21. A device for delivering electrically neutral aerosol droplets to a user comprising:

housing means including an exit communicating with the user;

electrohydrodynamic means for converting a fluid into aerosol droplets having a negative electrical charge; and

discharge electrode means for producing positively charged ions and a corona wind from the discharge electrode means in a direction intercepting the aerosol droplets and generally toward the exit.

22. The device of claim 21 for delivering electrically neutral aerosol droplets to a user further comprising first reference electrode means at the reference potential located between the electrohydrodynamic means and the discharge electrode means.

23. The device of claim 22 for delivering electrically neutral aerosol droplets to a user further comprising:

second reference electrode means located such that the discharge electrode means is between the first reference electrode means and the second reference electrode means, and

third reference electrode means located such that the electrohydrodynamic means is located between the first reference electrode means and the third reference electrode means, and wherein

the first, second and third reference electrode means are each at a potential which is positive with respect to the electrohydrodynamic means and negative with respect to the discharge electrode means.

24. Apparatus for delivering therapeutic aerosol droplets substantially along a desired path by EHD spraying comprising:

a EHD spray nozzle in communication with a source of therapeutic fluid to be aerosolized, the EHD spray nozzle having a spray tip and a central axis;

a discharge electrode having a sharp point or edge near an end thereof and a central axis, the discharge electrode being positioned and oriented with respect to the spray nozzle such that the spray tip and the sharp point or edge are proximate and such that the angle between the axis of the spray nozzle and the axis of the discharge electrode is between about 0 and 120 degrees;

a reference electrode at a reference potential located between the EHD spray nozzle and the discharge electrode;

first voltage source maintaining the EHD spray nozzle at a negative potential with respect to the reference potential; and

second voltage source maintaining the discharge electrode at a positive potential with respect to the reference potential.

25. The method of claim 24 for delivering therapeutic aerosol droplets substantially along a desired path by EHD spraying wherein the angle between the spray nozzle central axis and the discharge electrode central axis is between about 30 and 90 degrees.

26. A method for delivering aerosol droplets substantially along a desired path comprising:

providing an aerosol source and a discharge electrode;

providing a reference potential on a reference electrode located between the aerosol source and the discharge electrode;

producing aerosol droplets near the aerosol source, the aerosol droplets being charged with respect to the reference potential;

producing ions near an ionization site on a discharge electrode and a corona wind from the ionization site in a direction along the desired path, the ions having a charge that is opposite to the charge of the aerosol droplets; and

intercepting the aerosol droplets with the corona wind such that the aerosol droplets are electrically discharged and are moved along with the corona wind in the desired path.

27. The method of claim 26 for delivering aerosol droplets substantially along a desired path which further includes producing the aerosol droplets by electrohydrodynamic spraying.

28. The method of claim 26 for delivering aerosol droplets substantially along a desired path which further includes positioning and orienting the discharge electrode such that the corona wind moves in a direction away from the discharge electrode and away from the aerosol source.

29. The method of claim 26 for delivering aerosol droplets substantially along a desired path which further includes:

producing an aerosol stream from the aerosol droplets from the tip of a spray nozzle, the aerosol stream moving away from the aerosol source in a direction substantially parallel to the spray nozzle central axis; and

orienting the discharge electrode such that the corona wind intercepts the aerosol source central axis at an angle of between about 0 and 120 degrees.

30. The method of claim 26 for delivering aerosol droplets substantially along a desired path which further includes:

producing the aerosol droplets by electrohydrodynamic spraying;

producing an aerosol stream from the aerosol droplets near the tip of a spray nozzle, the aerosol stream moving away from the tip of the spray nozzle in a direction substantially parallel to the spray nozzle central axis;

orienting the discharge electrode such that the corona wind intercepts the aerosol source central axis at an angle of between about 0 and 120 degrees; and

positioning the reference electrode such that the end of the reference electrode substantially abuts the line of sight between the tip of the spray nozzle and the ionization site of the discharge electrode.

31. A method for delivering therapeutic aerosol droplets substantially along a desired path by EHD spraying comprising:

providing an EHD spray nozzle having a central axis;

providing a discharge electrode having a sharp point or edge;

providing a reference potential on a reference electrode located between the EHD spray nozzle and the discharge electrode;

producing aerosol droplets near the tip of the EHD spray nozzle, the aerosol droplets being negatively charged with respect to the reference potential;

producing ions near the sharp point or edge of the discharge electrode and a movement of ions away from the discharge electrode in a direction along the desired path, the ions being positively charged with respect to the reference potential; and

intercepting the aerosol droplets with the ions downstream of the tip of the spray nozzle and downstream of the sharp point or edge such that the aerosol droplets are electrically discharged and are moved along with the ions in the desired path.

32. The method of claim 31 for delivering therapeutic aerosol droplets substantially along a desired path by EHD spraying which further comprises orienting the discharge electrode such that the angle between the spray nozzle central axis and direction of movement of ions away from the discharge electrode is between about 0 and 120 degrees.

33. The method of claim 31 for delivering therapeutic aerosol droplets substantially along a desired path by EHD spraying which further comprises orienting the discharge electrode such that the angle between the spray nozzle central axis and direction of movement of ions away from the discharge electrode is between about 30 and 90 degrees.

34. Device for delivering aerosol substantially along a desired path comprising:

at least one aerosol source; and

at least one ionization electrode for producing a stream of ions therefrom in a direction along the desired path for intercepting and moving the aerosol in the direction along the desired path away from the aerosol source.

35. The device of claim 34 wherein the aerosol source is capable of delivering an aerosol with a positive charge, a negative charge or with substantially no charge with respect to ground.

36. The device of claim 35 which further comprises:

at least one dielectric device between the aerosol source and the ionization electrode.

37. The device of claim 35 which further comprises:

a reference electrode located between the aerosol source and the ionization electrode;

a first voltage source maintaining the aerosol source at a negative potential relative to the potential of the reference electrode; and

a second voltage source maintaining the ionization electrode at a positive potential relative to the potential of the reference electrode.

38. A method for delivering aerosol droplets substantially along a desired path comprising:

providing an aerosol source and an ionization electrode;

producing aerosol droplets near the aerosol source;

producing ions near an ionization site on the ionization electrode and a corona wind therefrom in a direction along the desired path; and

intercepting the aerosol droplets with the corona wind such that the aerosol droplets are moved along with the corona wind in the desired path.

39. The method for delivering aerosol droplets substantially along a desired path according to claim 38 and further comprising:

providing a reference potential on a reference electrode located between the aerosol source and the discharge electrode;

providing an electrical charge on the aerosol droplets; and

providing an electrical charge on the ionization electrode that is opposite to the charge on the aerosol droplets.