Liquid dispensing apparatus and methods

• US 20040139963A1
• Filed: 09/05/2003
• Published: 07/22/2004
• Est. Priority Date: 04/05/1995
• Status: Active Grant

• Current Assignee: Novartis Pharma AG (Novartis Ag)
• Original Assignee: Aerogen, Inc. (Nektar Therapeutics)
• Inventors: Wu, Cheng H., Ivri, Yehuda
• Granted Patent: US 7,174,888 B2
• Time in Patent Office: Days
• US Class Current: 128/200.16
• CPC Class Codes: A61M 11/005 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: A61M 15/0085 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: A61M 15/009 using medicine packages with incorporated spraying means, e.g. aerosol cans pocket atomiser of the injector type A61M11/08
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: B05B 12/08 responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
• CPC Class Codes: B05B 17/0646 Vibrating plates, i.e. plates being directly subjected to the vibrations, e.g. having a piezoelectric transducer attached thereto
• CPC Class Codes: B05B 17/0684 Wicks or the like
• CPC Class Codes: B41J 2/025 by vibration

Abstract

The invention provides methods and apparatus for nebulizing liquids. In one exemplary embodiment, an apparatus is provided which comprises a thin shell member having a front surface, a rear surface, and a plurality of apertures extending therebetween. The apertures are tapered to narrow from the rear surface to the front surface. A liquid supplier is further provided which delivers a predetermined unit volume of liquid to the rear surface. A vibrator vibrates the thin shell member to eject liquid droplets from the front surface of the thin shell member.

Claims

1. An apparatus for nebulizing a liquid, the apparatus comprising:

a thin shell member comprising a front surface, a rear surface, and a plurality of apertures extending therebetween, said apertures being tapered to narrow from the rear surface to the front surface;

a liquid supplier which delivers a predetermined unit volume of liquid to the rear surface; and

a vibrator which vibrates the thin shell member to eject liquid droplets from the front surface of the thin shell member.

2. An apparatus as in claim 1, wherein the liquid supplier comprises a canister which holds the liquid under pressure.

3. An apparatus as in claim 2, wherein the canister comprises a storage reservoir and a valve which allows the predetermined unit volume of liquid to be delivered from the canister when the valve is in an open position.

4. An apparatus as in claim 3, wherein the valve comprises a chamber having a piston therein and a stem having a proximal end and a distal end, wherein the stem includes an elongate groove at the distal end which places the storage reservoir and the chamber in fluid communication when the valve is in a closed position so that the chamber may be filled with liquid from the storage reservoir.

5. An apparatus as in claim 4, wherein the stem further includes a lumen at the proximal end which is placed in fluid communication with the chamber when the valve is in the open position such that a unit volume of the liquid within the chamber is forced out of the lumen and onto the rear surface of the thin shell member upon translation of the piston.

6. An apparatus as in claim 5, further comprising a spring adjacent the piston, wherein the piston may be translated to force the unit volume of liquid from the chamber when the valve is in the open position.

7. An apparatus as in claim 6, wherein the pressure within the storage reservoir compresses the spring to allow the chamber to be filled with liquid from the storage reservoir when the valve is in the closed position.

8. An apparatus as in claim 1, further comprising an acoustical sensor which detects when the unit volume of liquid has been ejected from the thin shell member.

9. An apparatus as in claim 8, wherein the acoustical sensor comprises a piezoelectric element.

10. An apparatus as in claim 1, wherein the apparatus further comprises a mouthpiece and means for actuating the vibrator when a patient begins to inhale from the mouthpiece.

11. An apparatus as in claim 1, wherein the tapers have a size in the range from about 1 μ

m to 6 μ

m at their narrowest dimension.

12. An apparatus as in claim 1, wherein the liquid comprises a medicament.

13. An apparatus as in claim 12, wherein the unit volume is in the range from about 20 μ

l to about 100 μ

l.

14. A method for nebulizing a liquid, the method comprising:

providing a thin shell member comprising a front surface, a rear surface, and a plurality of apertures extending therebetween, said apertures being tapered to narrow from the rear surface to the front surface;

opening a valve of a container to deliver a unit volume of the liquid to the rear surface of the thin shell member; and

vibrating the thin shell member until substantially all of the unit volume of the liquid on the rear surface is ejected from the front surface.

15. A method as in claim 14, further comprising translating a piston within the container sufficient to expel the unit volume of the liquid from the container and onto the rear surface when the valve is opened.

16. A method as in claim 15, wherein the valve is spring biased so that the piston will translate upon opening of the valve.

17. A method as in claim 16, wherein the container holds the liquid under pressure, and wherein the piston is translated in an opposite direction by force of the liquid to compress the spring when the valve is closed.

18. A method as in claim 14, wherein the container comprises a canister which holds the liquid in a pressurized storage reservoir, wherein the valve comprises a chamber having a spring loaded piston therein and a stem having a proximal end and a distal end and an elongate groove at the distal end which places the storage reservoir and the chamber in fluid communication when the valve is in a closed position, and wherein opening of the valve comprises depressing the valve stem to place a lumen at the proximal end of the stem in fluid communication with the chamber so that a unit volume of the liquid within the chamber will be forced out the lumen upon translation of the piston.

19. A method as in claim 14, further comprising sensing when the unit volume of liquid has been ejected from the thin shell member.

20. A method as in claim 19, wherein the sensing step comprises detecting a change of an acoustical signal generated by the vibrating thin shell member to indicate when the unit volume has been ejected.

21. A method as in claim 20, wherein the acoustical signal is sensed with a piezoelectric element.

22. A method as in claim 14, further comprising a mouthpiece spaced-apart from the thin shell member, and further comprising sensing when a patient inhales from the mouthpiece and vibrating the thin shell member only during inhalation.

23. A method as in claim 14, wherein the tapers have a size in the range from about 1 μ

m to 6 μ

m at their narrowest dimension.

24. A method as in claim 14, wherein the liquid comprises a medicament.

25. A method as in claim 24, wherein the unit volume is in the range from about 20 μ

l to about 100 μ

l.

26. An apparatus for nebulizing a liquid, the apparatus comprising:

a thin shell member comprising a front surface, a rear surface, and a plurality of apertures extending therebetween, said apertures being tapered to narrow from the rear surface to the front surface;

a liquid reservoir; and

a capillary system in fluid communication with the liquid reservoir, said capillary system being disposed to draw liquid from the reservoir by capillary action for delivery to the rear surface of the thin shell member; and

a vibrator which vibrates the thin shell member to eject liquid droplets from the front surface of the thin shell member.

27. An apparatus as in claim 26, wherein the capillary system comprises a wicking member having a bottom end within the liquid reservoir and a delivery end near the rear surface of the thin shell member and an outer member spaced-apart from the wicking member by a capillary gap so that liquid from the reservoir may be drawn toward the delivery end by capillary action.

28. An apparatus as in claim 27, wherein the wicking member further includes at least one capillary channel at the delivery end so that liquid delivered from the capillary gap may continue its travel to the rear surface of the thin shell member through the capillary channel.

29. An apparatus as in claim 27, wherein a bottom portion of the wicking member is cylindrical in geometry and wherein the outer member includes an annular body which surrounds the wicking member.

30. An apparatus as in claim 27, further comprising a housing having a chamber and a mouthpiece, and wherein the outer member is attached to the housing.

31. An apparatus as in claim 30, wherein the wicking member is attached to the liquid reservoir, and wherein the liquid reservoir is detachably secured to the housing so that the liquid reservoir may be separated from the housing.

32. An apparatus as in claim 27, wherein the wicking member includes a flexible portion so that it may axially flex upon contact with the vibrating member.

33. An apparatus as in claim 27, wherein the liquid reservoir has a concave shape and includes capillary channels which move the liquid toward the capillary gap between the outer member and the wicking member.

34. An apparatus as in claim 26, further comprising a power supply which supplies power to the vibrator.

35. An apparatus as in claim 34, wherein the power supply comprises a rechargeable battery.

36. A method for nebulizing a liquid, the method comprising:

providing a thin shell member comprising a front surface, a rear surface, and a plurality of apertures extending therebetween, said apertures being tapered to narrow from the rear surface to the front surface;

drawing liquid from a liquid reservoir by capillary action to place the liquid in contact with the rear surface of the thin shell member; and

vibrating the thin shell member to eject the liquid on the rear surface from the front surface, wherein liquid is continuously supplied from the liquid reservoir to the rear surface as the thin shell member is vibrated.

37. A method as in claim 36, further comprising vibrating the thin shell member until substantially all of the liquid within the reservoir is depleted.

38. A method as in claim 37, wherein the liquid reservoir holds an amount of liquid equal to a unit dosage amount.

39. A method as in claim 36, wherein the capillary action is provided by a capillary gap between a wicking member and an outer member, with the wicking member having a bottom end within the liquid reservoir and a delivery end near the rear surface of the thin shell member.

40. A method as in claim 39, wherein the capillary action is further provided by at least one capillary channel at the delivery end of the wicking member, wherein liquid from the capillary gap may continue its travel through the capillary channel.

41. A method as in claim 39, further comprising providing a housing having a chamber, a mouthpiece, the outer member, and the vibratable member, and further comprising attaching the reservoir to the housing prior to vibrating the vibratable member.

42. A method as in claim 41, further comprising detaching the housing from the reservoir and washing the housing and reservoir.

43. A method as in claim 41, further comprising tilting the housing while nebulizing the liquid, wherein a patient may inhale from the mouthpiece while lying down.

44. A method as in claim 39, further comprising transferring liquid from the liquid reservoir and to the capillary gap by capillary action.

45. A device for dispensing a predetermined volume of liquid, the device comprising:

a source of pressurized liquid;

an expandable chamber;

an metering valve which may be moved between a first position and a second position, the metering valve including a discharge opening, wherein in the first position liquid flows from the source to the expandable chamber to expand and fill the chamber with a predetermined unit volume of liquid, and in the second position the unit volume of liquid flows from the chamber to the discharge opening.

46. The device of claim 45, wherein the expandable chamber defines an annular volume and includes a spring loaded ring piston which may be moved to expand the chamber volume.

47. The device of claim 45, further comprising a thin shell member which receives the unit volume of liquid from the discharge opening, the liquid being held to the thin shell member by surface tension.