Claims for Patent: 5,662,271

Summary for Patent: 5,662,271

Title:	Atomizing devices and methods
Abstract:	A metered dose inhaler comprises a piston which is mounted in a cavity within a body, and is urged by a pre-loaded spring into a reduced cross-section pressure chamber. The piston may be loaded by means of an actuating rod having a handle, and may be latched in a loaded position by a latching means. A liquid drug (e.g. in aqueous solution) is contained in a collapsible bag. Metered quantities of the drug are successively presented in the pressure chamber, and then subjected to a sudden and great increase in pressure, to eject the liquid drug through an atomising head, to reduce it to fine atomised spray of small mean particle size--for example less than 30 micrometers. Non-return valves control the flow of liquid through the device. The sudden pressure pulse is caused be releasing the spring loaded piston, upon depressing an actuating button connected by the latching means.
Inventor(s):	Weston; Terence Edward (Woodbridge, GB2), Dunne; Stephen Terence (Ipswich, GB2)
Assignee:	Boehringer Ingelheim International GmbH (DE)
Application Number:	08/459,458
Patent Claims:	1. A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; a piston for pressurizing and discharging the fluid in said chamber, wherein said piston is reciprocable between a loaded position and a discharge position; resilient biasing means for urging said piston from the loaded position to the discharge position thereby subjecting the fluid in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid from said chamber at said second pressure, wherein said resilient biasing means is in a loaded state when said piston is in the loaded position; latching means for holding said resilient biasing means in the loaded state; actuating means for releasing said latching means, wherein release of said latching means releases said resilient biasing means from the loaded state and said resilient biasing means urges said piston from the loaded position to the discharge position thereby initiating discharge of the fluid from said chamber at said second pressure; and atomising means for atomising the fluid discharged from said chamber. 2. A device according to claim 1, wherein said piston comprises a channel in fluid communication with said chamber. 3. A device according to claim 2, further comprising: a non-return inlet valve for said chamber disposed within said channel. 4. A device according to claim 3, further comprising: a conduit connecting said chamber and said atomising means; and a valve mechanism for regulating the flow of fluid between said chamber and said atomising means. 5. A device according to claim 2, further comprising: a fluid reservoir in fluid communication with said channel, wherein said piston extends from said fluid reservoir. 6. A device according to claim 3, wherein a metered quantity of fluid is drawn into said chamber from said fluid reservoir when said piston is moved to the loaded position. 7. A device according to claim 2, further comprising: a fluid reservoir in fluid communication with said channel, wherein said piston is integrally formed with said fluid reservoir. 8. A device according to claim 7, wherein said fluid reservoir is collapsible. 9. A device according to claim 8, wherein said fluid reservoir is removable. 10. A device according to claim 9, wherein said fluid reservoir comprises fluid medicament. 11. A device according to claim 7, wherein a metered quantity of fluid is drawn into said chamber from said fluid reservoir when said piston is moved to the loaded position. 12. A device according to claim 7, wherein said fluid reservoir is removable. 13. A device according to claim 12, wherein said fluid reservoir comprises fluid medicament. 14. A device according to claim 1, further comprising: a conduit connecting said chamber and said atomising means; and a valve mechanism for regulating the flow of fluid between said chamber and said atomising means. 15. A device according to claim 1, wherein said second pressure is in the range of approximately 300 bar to approximately 500 bar. 16. A device according to claim 1, wherein said piston is configured to have a variable stroke. 17. A device according to claim 1, wherein said resilient biasing means comprises a spring. 18. A device according to claim 17, wherein said spring is a compression spring. 19. A device according to claim 17, wherein said spring is a tension spring. 20. A device according to claim 1, wherein said atomising means comprises: a first outlet aperture for discharging a first jet of fluid; and a second outlet aperture for discharging a second jet of fluid, said first jet and said second jet impinging upon one another to form a spray of droplets. 21. A device according to claim 1, wherein said atomising means comprises: a nozzle having an orifice with a hydraulic diameter of from approximately 1 to approximately 12 micrometers. 22. A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; a piston for pressurizing and discharging the fluid in said chamber, wherein said piston is reciprocable between a loaded position and a discharge position; resilient biasing means for urging said piston from the loaded position to the discharge position thereby subjecting the fluid in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid from said chamber at said second pressure, wherein said resilient biasing means is in a loaded state when said piston is in the loaded position; latching means for holding said resilient biasing means in the loaded state; a fluid reservoir in fluid communication with said chamber, wherein the fluid is drawn into said chamber from said fluid reservoir when said piston is moved to the loaded position; and atomising means for atomising the fluid discharged from said chamber. 23. A device according to claim 22, further comprising: actuating means for releasing said latching means, wherein release of said latching means releases said resilient biasing means from the loaded state and said resilient biasing means urges said piston from the loaded position to the discharge position thereby initiating discharge of the fluid from said chamber at said second pressure. 24. A device according to claim 22, wherein said piston comprises a channel in fluid communication with said chamber. 25. A device according to claim 24, wherein said piston extends from said fluid reservoir. 26. A device according to claim 24, wherein said piston is integrally formed with said fluid reservoir. 27. A device according to claim 24, further comprising: a non-return inlet valve for said chamber disposed within said channel. 28. A device according to claim 24, further comprising: a conduit connecting said chamber and said atomising means; and a valve mechanism for regulating the flow of fluid between said chamber and said atomising means. 29. A device according to claim 22, wherein said resilient biasing means comprises a spring. 30. A device according to claim 29, wherein said spring is a compression spring. 31. A device according to claim 29, wherein said spring is a tension spring. 32. A device according to claim 22, wherein said atomising means comprises: a first outlet aperture for discharging a first jet of fluid; and a second outlet aperture for discharging a second jet of fluid, said first jet and said second jet impinging upon one another to form a spray of droplets. 33. A device according to claim 22, wherein said atomising means comprises: a nozzle having an orifice with a hydraulic diameter of from approximately 1 to approximately 12 micrometers. 34. A device according to claim 22, wherein said fluid reservoir is removable. 35. A device according to claim 34, wherein said fluid reservoir is collapsible. 36. A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; a piston for pressurizing and discharging the fluid in said chamber, wherein said piston comprises a channel in fluid communication with said chamber and is reciprocable between a loaded position and a discharge position; resilient biasing means for urging said piston from the loaded position to the discharge position thereby subjecting the fluid in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid from said chamber at said second pressure; latching means for holding said resilient biasing means so that said piston is in the loaded position; actuating means for releasing said latching means so that said resilient biasing means urges said piston from the loaded position to the discharge position thereby initiating discharge of the fluid from said chamber at said second pressure; and atomising means for atomising the fluid discharged from said chamber. 37. A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; a piston for pressurizing and discharging the fluid in said chamber, wherein said piston comprises a channel in fluid communication with said chamber and is reciprocable between a loaded position and a discharge position; resilient biasing means for urging said piston from the loaded position to the discharge position thereby subjecting the fluid in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid from said chamber at said second pressure; a fluid reservoir in fluid communication with said chamber, wherein fluid is drawn into said chamber from said fluid reservoir when said piston is moved to the loaded position; latching means for holding said resilient biasing means so that said piston is in the loaded position; actuating means for releasing said latching means so that said resilient biasing means urges said piston from the loaded position to the discharge position thereby initiating discharge of the fluid from said chamber at said second pressure; and atomising means for atomising the fluid discharged from said chamber. 38. A metered dose inhaler for dispensing fluid medicament as a spray of droplets, comprising: a chamber for containing fluid medicament at a first pressure; a piston for pressurizing and discharging the fluid medicament in said chamber, wherein said piston comprises a channel in fluid communication with said chamber and is reciprocable between a loaded position and a discharge position; a non-return valve for said chamber disposed within said channel; resilient biasing means for urging said piston from the loaded position to the discharge position thereby subjecting the fluid medicament in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid medicament from said chamber at said second pressure; a removable fluid reservoir in fluid communication with said chamber, wherein the fluid medicament is drawn into said chamber from said removable fluid reservoir when said piston is moved to the loaded position, wherein said piston extends from said removable fluid reservoir; latching means for holding said resilient biasing means so that said piston is in the loaded position; actuating means for releasing said latching means so that said resilient biasing means urges said piston from the loaded position to the discharge position thereby initiating discharge of the fluid medicament from said chamber at said second pressure; and atomising means for atomising the fluid medicament discharged from said chamber, wherein said atomising means comprises a first outlet aperture for discharging a first jet of fluid medicament, and a second outlet aperture for discharging a second jet of fluid medicament, said first jet and said second jet impinging upon one another to form a spray of droplets. 39. A metered dose inhaler according to claim 38, further comprising: means operable by a user for moving said piston to the loaded position and for loading said resilient biasing means to a loaded state. 40. A metered dose inhaler according to claim 38, further comprising: a non-return valve disposed between said chamber and said atomising means. 41. A metered dose inhaler according to claim 40, wherein said non-return valve prevents air from being sucked into said chamber from said atomising means. 42. A metered dose inhaler according to claim 38, further comprising: means for preventing air from being sucked into said chamber from said atomising means. 43. A metered dose inhaler according to claim 38, wherein said removable fluid reservoir is collapsible. 44. A metered dose inhaler according to claim 38, wherein said second pressure is in the range of approximately 300 bar to approximately 500 bar. 45. A metered dose inhaler according to claim 38, wherein said piston is integrally formed with said removable fluid reservoir. 46. A device for dispensing fluid as a spray of droplets, comprising: a chamber for containing fluid at a first pressure; pressurizing and discharging means for pressurizing and discharging the fluid in said chamber; resilient biasing means for urging said pressurizing and discharging means from a loaded position to a discharge position thereby subjecting the fluid in said chamber to a predetermined increase in pressure from said first pressure to a second pressure of at least 50 bar to permit discharge of the fluid from said chamber at said second pressure, wherein said resilient biasing means is in a loaded state when said pressurizing and discharging means is in the loaded position; latching means for holding said resilient biasing means in the loaded state; actuating means for releasing said latching means, wherein release of said latching means releases said resilient biasing means from the loaded state and said resilient biasing means urges said pressurizing and discharging means to move from the loaded position to the discharge position thereby initiating discharge of the fluid from said chamber at said second pressure; and atomising means for atomising the fluid discharged from said chamber. 47. A device according to claim 46, wherein said pressurizing and discharging means comprises a channel in fluid communication with said chamber. 48. A device according to claim 47, further comprising: a fluid reservoir in fluid communication with said channel, wherein said pressurizing and discharging means extends from said fluid reservoir. 49. A device according to claim 47, further comprising: a fluid reservoir in fluid communication with said channel, wherein said pressurizing and discharging means is integrally formed with said fluid reservoir.