Method and apparatus for substance delivery in system for supplying breathable gas

• US 7,779,834 B2
• Filed: 09/29/2005
• Issued: 08/24/2010
• Est. Priority Date: 12/12/1996
• Status: Expired due to Fees

• Current Assignee: Resmed Limited (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Calluaud, Michel, Yerbury, Victor
• Primary Examiner(s): Yu; Justine R
• Assistant Examiner(s): OSTRUP, CLINTON T
• Application Number:
  US11/237,830
• Publication Number:
  US 20060021620A1
• Time in Patent Office: 1,790 Days
• Field of Search: 128/203.12, 128/203.15, 128/203.16, 128/203.19, 128/200.24, 128/203.22, 128/203.25, 128/203.29, 128/204.18, 128/204.21, 128/204.22, 128/204.26, 128/205.11, 128/205.25, 128/200.21, 128/204.23
• US Class Current: 128/203.12
• CPC Class Codes: A61M 15/0065 Inhalators with dosage or measuring devices A61M15/0028 takes precedence; dosage devices incorporated in aerosol cans B65D83/52
• CPC Class Codes: A61M 15/0066 with means for varying the dose size
• CPC Class Codes: A61M 16/14 by mixing different fluids, one of them being in a liquid phase
• CPC Class Codes: A61M 16/147 the respiratory gas not passing through the liquid container
• 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 2016/0042 in the expiratory circuit

Abstract

A substance delivery apparatus for use with a system for supplying breathable gas to a human or animal includes a sensor to measure the pressure of the supplied breathable gas and to detect inhalation by the human or animal; and a reservoir, a conduit, a pump, and a diaphragm to deliver the substance to the human or animal during inhalation at a pressure higher than the supplied pressure of the breathable gas.

Claims

1. A substance delivery apparatus for use with a system for supplying breathable gas pressurized above atmospheric pressure to a human or animal, the apparatus including:

means for measuring the pressure of a supplied breathable gas; and

means for delivering a substance to the human or animal only during inhalation at a pressure that exceeds the measured pressure of a supplied pressure of the breathable gas by a predetermined pressure difference.

2. An apparatus as claimed in claim 1, wherein the substance is a medicinal substance.

3. An apparatus as claimed in claim 1, wherein the substance is in the form of a gas, mist, aerated suspension, jet, spray, or a gas mixture.

4. An apparatus as claimed in claim 1, further including means for measuring a volume of the substance to be delivered to the human or animal.

5. An apparatus as claimed in claim 1, wherein the pressure of the supplied breathable gas is typically between 4-32 cmH₂O.

6. An apparatus as claimed in claim 1, wherein the means for delivering the substance is adapted to deliver the substance to a respiratory system of the human or animal.

7. An apparatus as claimed in claim 6, wherein the means for delivering the substance is adapted to deliver the substance to nasal airways of the human or animal.

8. An apparatus as claimed in claim 1, wherein the means for measuring the pressure is a pressure transducer adapted to be connected to a conduit in fluid communication with a pressurized gas flow generator and a mask adapted to be worn by the human or animal, said transducer being adapted to generate a fourth input signal indicative of pressure of the breathable gas in the conduit.

9. An apparatus as claimed in claim 8, including an amplifier to amplify the fourth input signal into a fifth input signal also indicative of gas pressure in the conduit.

10. An apparatus as claimed in claim 1, further comprising means for detecting inhalation by the human or animal.

11. An apparatus as claimed in claim 10, wherein the means for detecting inhalation includes an airflow sensor adapted to measure a volumetric flow rate of the breathable gas passing through a flexible conduit in fluid communication with a pressurized gas flow generator and a mask adapted to be worn by the human or animal and being adapted to generate a first input signal indicative of the breathable gas flow rate.

12. An apparatus as claimed in claim 11, further including an amplifier to amplify the first input signal into a second input signal also indicative of the breathable gas flow rate.

13. An apparatus as claimed in claim 11, further including a differentiating filter to derive the first signal into a third input signal indicative of acceleration or deceleration of the breathable gas to thereby indicate inhalation or exhalation respectively.

14. An apparatus as claimed in claim 11, wherein the airflow sensor is adapted to be disposed downstream of a gas washout vent of the mask such that inhalation can be detected by sensing a reversal of direction of the breathable gas flow through the vent.

15. An apparatus as claimed in claim 14, wherein the airflow sensor is adapted to detect inhalation by sensing an interruption of the breathable gas flow through the vent.

16. An apparatus as claimed in claim 1, wherein the means for delivering a substance is a positive displacement pump.

17. An apparatus as claimed in claim 16, wherein the positive displacement pump is a diaphragm pump.

18. An apparatus as claimed in claim 17, wherein the diaphragm pump is in fluid communication with a substance reservoir via a one-way valve adapted to allow the substance to only pass from the reservoir to the diaphragm pump.

19. An apparatus as claimed in claim 17, wherein the diaphragm pump is adapted to be in fluid communication with the gas supply conduit via a one-way valve adapted to allow the substance to only pass from the diaphragm pump to the conduit.

20. An apparatus as claimed in claim 17, wherein the diaphragm pump is displaced by a linear drive.

21. An apparatus as claimed in claim 20, wherein the linear drive is an electromagnet.

22. An apparatus as claimed in claim 17, wherein a diaphragm of the diaphragm pump is displaced by a rotary to linear converter driven by a rotary drive.

23. An apparatus as claimed in claim 22, wherein the rotary drive is one of an electric DC motor, an electric AC motor, a stepper motor or a brushless motor.

24. A method of delivering a substance to a human or animal being supplied with breathable gas pressurized above atmospheric pressure, the method including:

measuring the pressure of a supplied breathable gas; and

delivering a substance to the human or animal only during inhalation at a pressure that exceeds the pressure of a supplied pressure of the breathable gas by a predetermined pressure difference.

25. A method as claimed in claim 24, wherein the delivery includes treatment of obstructive sleep apnea with continuous positive airway pressure (CPAP).

26. A method as claimed in claim 24, wherein the pressurized breathable gas is provided to the patient at a first treatment pressure during inhalation and a second treatment pressure during exhalation, wherein the first treatment pressure is higher than the second treatment pressure and the method further comprises delivering the substance to the patient only during the delivery of the first treatment pressure.

27. A method as claimed in claim 24, wherein the substance is a medicinal substance.

28. A method as claimed in claim 27, wherein the substance is in the form of a gas, mist, aerated suspension, jet, spray, or a gas mixture.

29. A method as claimed in claim 24, wherein the substance is delivered to a respiratory system of the human or animal.

30. A method as claimed in claim 29, wherein the substance is delivered to nasal airways of the human or animal.

31. A method as claimed in claim 24, including measuring volume of the substance to be delivered to the human or animal.

32. A method as claimed in claim 31, wherein the breathable gas pressure is measured with a pressure transducer adapted to generate a fourth input signal indicative of the breathable gas pressure.

33. A method as claimed in claim 32, including amplifying the fourth input signal into a fifth input signal also indicative of the breathable gas pressure.

34. A method as claimed in claim 24, including measuring the volumetric flow rate of the breathable gas with an airflow sensor and generating a first input signal indicative of the breathable gas flow rate.

35. A method as claimed in claim 34, including amplifying the first signal into a second signal also indicative of the breathable gas flow rate.

36. A method as claimed in claim 34, including differentiating the first signal into a third signal indicative of breathable gas acceleration or deceleration to indicate inhalation or exhalation respectively.

37. A method as claimed in claim 24, wherein the substance is delivered to the human or animal using a positive displacement pump.

38. A method as claimed in claim 37, wherein the positive displacement pump is a diaphragm pump.

39. A method as claimed in claim 38, wherein the diaphragm pump is in fluid communication with a substance reservoir via a one-way valve adapted to allow the substance to only pass from the reservoir to the diaphragm pump.

40. A method as claimed in claim 38, wherein the diaphragm pump is adapted to be in fluid communication with the gas supply conduit via a one-way valve adapted to allow the substance to only pass from the diaphragm pump to the conduit.

41. A method as claimed in claim 38, wherein the diaphragm pump is displaced by a linear drive.

42. A method as claimed in claim 41, wherein the linear drive is an electromagnet.

43. A method as claimed in claim 38, wherein the diaphragm pump is displaced by a rotary to linear converter driven by a rotary drive.

44. A method as claimed in claim 43, wherein the rotary drive is one of an electric DC motor, an electric AC motor, a stepper motor or a brushless motor.

45. A substance delivery apparatus for use with a system for supplying breathable gas pressurized above atmospheric pressure to a human or animal, the apparatus including:

a pressure transducer to measure pressure of a supplied breathable gas; and

a positive displacement pump to deliver a substance to the human or animal only during inhalation at a pressure that exceeds the measured pressure of the supplied breathable gas by a predetermined pressure difference.

46. An apparatus as claimed in claim 45, wherein the substance is a medicinal substance.

47. An apparatus as claimed in claim 45, wherein the substance is in the form of a gas, mist, aerated suspension, jet, spray, or a gas mixture.

48. An apparatus as claimed in claim 45, further including signals indicative of volume of the substance to be delivered to the human or animal.

49. An apparatus as claimed in claim 45, wherein the supplied breathable gas is provided to the patient at a first treatment pressuring during inhalation and a second treatment pressure during exhalation, wherein the first treatment pressure is higher than the second treatment pressure and the positive displacement pump is configured to deliver the substance to the patient only during the delivery of the first treatment pressure.

50. An apparatus as claimed in claim 45, wherein the substance is delivered to a respiratory system of the human or animal.

51. An apparatus as claimed in claim 50, wherein the substance is delivered to nasal airways of the human or animal.

52. An apparatus as claimed in claim 45, wherein the pressure transducer is connected to a conduit in fluid communication with a pressurized gas flow generator and a mask adapted to be worn by the human or animal of the system for supplying breathable gas, said transducer being adapted to generate a fourth input signal indicative of the pressure of the breathable gas in the conduit.

53. An apparatus as claimed in claim 52, including an amplifier to amplify the fourth input signal into a fifth input signal also indicative of the breathable gas pressure.

54. An apparatus as claimed in claim 45, further comprising an airflow sensor to detect inhalation by the human or animal.

55. An apparatus as claimed in claim 54, wherein the airflow sensor further measures a volumetric flow rate of the breathable gas passing through a flexible conduit in fluid communication with a pressurized gas flow generator and a mask adapted to be worn by the human or animal, and generates a first input signal indicative of the breathable gas flow rate.

56. An apparatus as claimed in claim 55, further including an amplifier adapted to amplify the first input signal into a second input signal also indicative of the breathable gas flow rate.

57. An apparatus as claimed in claim 55, further including a differentiating filter adapted to derive the first signal into a third input signal indicative of acceleration or deceleration of the breathable gas to thereby indicate inhalation or exhalation respectively.

58. An apparatus as claimed in claim 55, wherein the airflow sensor is disposed downstream of a gas washout vent of the mask such that inhalation can be detected by sensing a reversal of the direction of the breathable gas flow through the vent.

59. An apparatus as claimed in claim 58, wherein inhalation is detected by sensing an interruption of the breathable gas flow through the vent.

60. An apparatus as claimed in claim 45, wherein the positive displacement pump is a diaphragm pump.

61. An apparatus as claimed in claim 60, wherein the diaphragm pump is in fluid communication with a substance reservoir via a one-way valve adapted to allow the substance to only pass from the reservoir to the diaphragm pump.

62. An apparatus as claimed in claim 60, wherein the diaphragm pump is adapted to be in fluid communication with the gas supply conduit via a one-way valve adapted to allow the substance to only pass from the diaphragm pump to the conduit.

63. An apparatus as claimed in claim 60, wherein the diaphragm pump is displaced by a linear drive.

64. An apparatus as claimed in claim 63, wherein the linear drive is an electromagnet.

65. An apparatus as claimed in claim 60, wherein a diaphragm of the diaphragm pump is displaced by a rotary to linear converter driven by a rotary drive.

66. An apparatus as claimed in claim 65, wherein the rotary drive is one of an electric DC motor, an electric AC motor, a stepper motor and a brushless motor.

67. A substance delivery system for supplying breathable gas pressurized above atmospheric pressure to a human or animal, the system including:

a pressurized gas flow generator in fluid communication with a mask adapted to be worn by the human or animal via a flexible conduit;

a pressure transducer adapted to measure the pressure of a supplied breathable gas; and

a positive displacement pump adapted to deliver a substance within the flexible tube to the human or animal only during inhalation at a pressure that exceeds the measured pressure of the supplied breathable gas by a predetermined pressure difference.

68. An apparatus as claimed in claim 67, wherein the flow generator is configured to generate a first treatment pressure during patient inhalation and a second treatment pressure during patient exhalation, wherein the first treatment pressure is higher than the second treatment pressure and the positive displacement pump is adapted to deliver the substance to the patient only during the delivery of the first treatment pressure.

69. An apparatus as claimed in claim 67, further comprising an airflow sensor adapted to detect inhalation by the human or animal.

70. A system as claimed in claim 69, further including a substance reservoir to store the substance, wherein the airflow sensor is also configured to detect exhalation by the human or animal, wherein the substance reservoir is configured to provide the substance to the positive displacement pump during exhalation of the human or animal, and wherein the substance is delivered from the positive displacement pump to the human or animal during inhalation of the human or animal.