Delivery of aerosol medications for inspiration

• US 5,404,871 A
• Filed: 03/05/1991
• Issued: 04/11/1995
• Est. Priority Date: 03/05/1991
• Status: Expired due to Term

• Current Assignee: Aradigm Corporation
• Original Assignee: Aradigm Corporation
• Inventors: Rubsamen, Reid M., Goodman, David E.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Lewis, Aaron J.
• Application Number:
  US07/664,758
• Time in Patent Office: 1,498 Days
• Field of Search: 128/200.14, 128/200.23, 128/203.12, 128/204.26, 128/204.23, 128/204.21, 128/205.23
• US Class Current: 128/200.14
• CPC Class Codes: A61J 7/0418 with electronic history memory
• CPC Class Codes: A61M 11/002 by flow deviation causing inertial separation of transported particles
• CPC Class Codes: A61M 15/00 Inhalators drug delivery in endotracheal tubes A61M16/04
• CPC Class Codes: A61M 15/0021 Mouthpieces therefor
• CPC Class Codes: A61M 15/0066 with means for varying the dose size
• CPC Class Codes: A61M 15/008 Electronic counters
• 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 15/0091 mechanically breath-triggered
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/60 with identification means
• CPC Class Codes: A61M 2205/6018 providing set-up signals for the apparatus configuration
• CPC Class Codes: A61M 2205/6027 Electric-conductive bridges closing detection circuits, with or without identifying elements, e.g. resistances, zener-diodes
• CPC Class Codes: A61M 2205/6036 characterised by physical shape, e.g. array of activating switches
• CPC Class Codes: A61M 2205/6045 having complementary physical shapes for indexing or registration purposes
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 2205/8212 : with means or measures taken for minimising energy consumption
• CPC Class Codes: B01F 23/2132 : using nozzles
• CPC Class Codes: B01F 35/71 : Feed mechanisms with proportioning B01F35/80
• CPC Class Codes: B01F 35/711 : for feeding a mixture of components, i.e. solids in liquid, solids in a gas stream
• CPC Class Codes: B01F 35/7179 : using sprayers, nozzles or jets
• CPC Class Codes: F16H 35/00 : Gearings or mechanisms with other special functional features
• CPC Class Codes: G01F 1/363 : with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/40 : Details of construction of the flow constriction devices
• CPC Class Codes: G01F 1/44 : Venturi tubes
• CPC Class Codes: G01F 1/50 : Correcting or compensating means
• CPC Class Codes: G01F 13/006 : measuring volume in function of time
• CPC Class Codes: G01F 15/002 : for gases
• CPC Class Codes: G01F 25/10 : of flowmeters
• CPC Class Codes: G01F 7/005 : by measuring pressure or differential pressure, created by the use of flow constriction

Abstract

Apparatus and methods for delivering an amount of aerosolized medicine for inspiration by a patient in response to the occurrence of appropriate delivery point or points in the patient'"'"'s detected breath flow. The aerosol medication may be administered as one or more pulses having a pulse width, shape, and frequency that will maximize the respirable fraction of the aerosolized compound being administered. The delivery point or points may be predetermined or determined from a prior inspiratory flow for depositing the selected medication at one or more desired locations in the patient'"'"'s airway. Determined delivery points are recursively lowered for each inspiratory flow that does not satisfy one of the predetermined and previously lowered threshold. Changes in the patient'"'"'s breath flow patterns during the course of an aerosolized medication inspiration therapy program may be detected and used to adjust the controlled amount of medication to be delivered in a given administration and/or to inform the patient of the patient'"'"'s condition or change in condition. The device also may contain a library of administration protocols or operating parameters for different medications and a means for identifying from the canister the medicinal contents of the canister for customizing operation of the apparatus.

Claims

1. A system for releasing an aerosol for inspiration by a patient comprising:

a flow sensor for measuring a patient'"'"'s breath flow in a non-linear flow path, at least a portion of said non-linear flow path being incorporated in a disposable unit,

means, including a look-up table Or an algorithm stored in a memory, for controlling flow of the selected medication in said non-linear flow path by compensating for non-linearity in said non-linear flow path;

a reservoir of a selected medication having thereon an electric circuit element identifying the selected medication, said reservoir being incorporated in said disposable unit;

a valve for releasing the selected medication from said reservoir, thereby to form an aerosol;

means for actuating the valve to release a controlled amount of the selected medication;

means responsive to the electronic circuit element for obtaining the identity of the selected medication;

means for containing the operating parameters for administering controlled amounts of the selected medication; and

means for controlling the actuating means to release a controlled amount of the selected medication in accordance with the operating parameters associated with the identified selected medication.

2. The apparatus of claim 1 wherein the containing means further comprises:

a library of operating parameters for a plurality of medications; and

means for selecting from the library the operating parameters corresponding to the identified selected medication and providing the selected operating parameters to the controlling means.

3. The apparatus of claim 2 further comprising means for receiving operating parameters for identified medications not contained in the library from an external source and means for providing the received operating parameters to the controlling means.

4. The apparatus of claim 1 wherein the means responsive to the electronic circuit element further comprises means for receiving the operating parameters for the selected medication from an external source and means for providing the received operating parameters to the controlling means.

5. The apparatus of claim 1 wherein the electronic circuit element further identifies the operating parameters for administering the selected medication and the means responsive to the electronic circuit element further comprises means for providing the identified operating parameters to the controlling means.

6. An apparatus for releasing an aerosol from a reservoir of aerosol generating material for inspiration by a person characterized by:

a valve associated with the reservoir for releasing an amount of aerosol generating material from the reservoir to form an aerosol;

a sensor for monitoring inspiratory flow through a flow path;

means for calculating a firing threshold parameter based on a sensed flow parameter of a detected inspiratory flow;

means for determining whether each detected inspiratory flow meets the firing threshold parameter and for decreasing a previous calculated firing threshold parameter from said means for calculating a firing threshold parameter in response to failure of a patient to meet said previous firing threshold parameter; and

means for operating the valve to deliver an amount of aerosol in response to the detected inspiratory flow satisfying the provided delivery threshold.

7. The apparatus of claim 6 characterized in that the calculating means is further characterized by:

means for obtaining the sensed flow parameter of the last detected inspiratory flow in response to the last detected inspiratory flow not satisfying the provided delivery threshold; and

means for adjusting the provided delivery threshold in response to the obtained flow parameter, thereby providing the calculated delivery threshold for the following detected inspiratory flow.

8. The apparatus of claim 6 characterized in that the delivery threshold further comprises a delivery schedule including the delivery threshold and one or more other delivery points in the detected inspiratory flow following the delivery threshold, and the adjusting means adjusts every delivery point in the delivery schedule and the second determining means determines whether or not the detected inspiratory flow satisfies each delivery point in the delivery schedule so that an amount of aerosol is delivered for each delivery point that is satisfied by the detected inspiratory flow.

9. The apparatus of claim 8 characterized in that the valve and the valve operating means are characterized by:

an electromechanical actuator that can be changed at a rate up to 100 cycles per second between a first state for releasing an amount of aerosol generating material and a second state for not releasing an amount of aerosol generating material, the electromechanical actuator being in the first state from a time in the range of from about 10 to about 1000 msecs, thereby to deliver pulses of aerosol having a maximized respirable fraction; and

means for operating the electromechanical actuator to change between the first and second states one or more times in response to the second detected inspiratory flow satisfying each delivery point in the delivery schedule.

10. The apparatus of claim 6 characterized in that the reservoir and the valve are characterized by a canister having a valve and valve stem and the valve operating means is characterized by an actuator for moving the valve stem relative to the canister to open and close the canister valve to release an amount of aerosol.

11. The apparatus of claim 6 further characterized by an aerosol flow path having a nozzle for releasing the contents of the reservoir into the inspiratory flow path, characterized in that the valve is interposed in the aerosol flow path for opening and closing the aerosol flow path;

and the valve controlling means is an electromechanical device.

12. The apparatus of claim 11 further characterized by a visual display of a measure of the amount of aerosol in the reservoir.

13. The apparatus of claim 11 characterized in that the sensor is a structure interposed in the inspiratory flow path, a means for measuring a differential pressure due to flow across the structure, and means for converting the measured differential pressure into an inspiratory flow rate.

14. The apparatus of claim 13 characterized in that the measuring means has a differential pressure sensitivity in the range of about ±

25.4 cm of water corresponding to a maximum flow rate up to about 800 liters per minute.

15. The apparatus of claim 14 characterized in that the structure is selected from among one of a venturi section having a first and second cross sectional areas and means for measuring a differential pressure due to flow across the first and second areas and a resistive flow screen and characterized in that the means for converting converts the measured differential pressure into a flow rate using an array of predetermined calibration constants.

16. The apparatus of claim 13 further characterized by means for providing a laminar air flow across the structure.

17. The apparatus of claim 16 characterized in that the structure and laminar air flow means are at least three flow resistive screens interposed in series across the inspiratory flow path and the differential pressure is measured across the middle screen.

18. The apparatus of claim 11 characterized in that the sensor is a hot wire anemometer disposed in the inspiratory flow path and means for converting the measured temperature changes into an inspiratory flow rate.

19. The apparatus of claim 6 characterized in that the determining means determines the delivery threshold as one of a selected flow rate, a selected flow volume, and a combination of a selected flow rate and flow volume, the selected flow rate being less than or at the sensed peak inspiratory flow rate of the first detected inspiratory flow, the selected flow volume being less than or at the peak flow volume of the first detected inspiratory flow.

20. The apparatus of claim 19 characterized in that the delivery threshold is determined to correspond to a selected location of deposition of the aerosol in the person.

21. The apparatus of claim 20 characterized in that the determined delivery schedule includes the delivery threshold and at least one other delivery point in the first detected inspiratory flow and the valve operating means is operated in response to the sensed second detected inspiratory flow satisfying the delivery threshold and each other delivery point.

22. The apparatus of claim 6 wherein the preselected delivery threshold is calculated by the delivery threshold calibrating means based on a sensed calibrating inspiratory flow, said calibrating inspiratory flow occurring prior to said first flow.

23. A method for delivering an aerosol to a person for inspiration using an apparatus for releasing from a reservoir an aerosol generating material for inspiration by a person, said apparatus having a supply of aerosol generating material, a valve associated with said reservoir for releasing an amount of aerosol generating material to form an aerosol and a sensor for detecting the inspiratory flow through a flow path, said method characterized by:

monitoring the inspiratory flow through a flow path;

calculating a firing threshold parameter based on the monitored inspiratory flow;

determining whether each detected inspiratory flow is one of a first flow detected following a reset flow event or a subsequent flow detected following a detected first flow that is not followed by a reset flow event, the reset flow event being any of a release of an amount of aerosol and initialization of operation of the apparatus;

selecting a delivery threshold corresponding to a point in the detected inspiratory flow at which an amount of aerosol is to be released characterized by selecting a preselected delivery threshold in response to the detected inspiratory flow being a determined first flow and selecting a calculated delivery threshold that is calculated based on a sensed flow parameter of the preceding detected inspiratory flow in response to the detected inspiratory flow being a determined subsequent flow; and

determining whether or not the detected inspiratory flow satisfies the selected delivery threshold and

(i) in response to the detected inspiratory flow satisfying the selected delivery threshold, operating the valve to release an amount of aerosol generating material to form an aerosol; and

(ii) in response to determining that the detected inspiratory flow did not satisfy the selected delivery threshold, calculating a new delivery threshold based on the detected inspiratory flow so that the selected delivery threshold for the next detected inspiratory flow determined to be a subsequent flow is the last calculated delivery threshold.

24. The method of claim 23 characterized in that calculating the delivery threshold is characterized by:

measuring a selected flow parameter of the monitored inspiratory flow in response to determining that the monitored inspiratory flow did not satisfy the selected delivery threshold; and

adjusting the selected delivery threshold in response to the obtained flow parameter, thereby providing the calculated delivery threshold.

25. The method of claim 24 characterized in that selecting the delivery threshold is further characterized by selecting a delivery schedule including the delivery threshold and one or more other delivery points in an inspiratory flow, and adjusting the provided threshold is further characterized by adjusting each point in the delivery schedule, and operating the valve is further characterized by operating the valve for each delivery point in the delivery schedule that is satisfied by the detected inspiratory flow.

26. The method of claim 25 further characterized by:

operating the valve to change between a first state for releasing an amount of aerosol and a second state for not releasing an amount of aerosol, one or more times in response to the detected inspiratory flow satisfying each delivery point in the provided delivery schedule, the valve cycling at a rate up to 100 cycles per second; and

controlling the period of time the valve is in the first state to be a time in the range of from about 10 to about 1000 msecs, thereby to release pulses of aerosol having a maximized respirable fraction.

27. The method of claim 24 further characterized by measuring the selected flow parameter to be one of a selected flow rate, a selected flow volume, and a combination of a selected flow rate and flow volume, the selected flow rate being less than or at the sensed peak inspiratory flow rate of the preceding detected inspiratory flow, the selected flow volume being less than or at the flow volume of the preceding detected inspiratory flow.

28. The method of claim 27 characterized in that determining a delivery threshold is characterized by selecting a delivery threshold that corresponds to a point that will deposit the aerosol at a selected location in the person.

29. The method of claim 23 characterized in that the supply and the valve are characterized by a canister having a valve and valve stem and operating the valve is characterized by moving the valve stem relative to the canister to open and close the canister valve to release a pulse of aerosol.

30. The method of claim 23 characterized by interposing the valve in an aerosol flow path connecting the contents of the reservoir with a nozzle for releasing the aerosol in the inspiratory flow.

31. The method of claim 30 characterized in that monitoring inspiratory flow is characterized by determining the temperature change of a hot wire anemometer in response to flow and converting the measured temperature change into an inspiratory flow rate.

32. The method of claim 23 further characterized by displaying a measure of the amount of aerosol in the supply.

33. The method of claim 23 characterized in that monitoring inspiratory flow is characterized by measuring a differential pressure due to flow across a structure in the inspiratory flow path and converting the measured differential pressure into an inspiratory flow rate.

34. The method of claim 33 characterized in that the structure is selected from among a venturi section having a first and second cross section areas and a resistive flow screen, and converting the measured differential pressure is characterized by converting the measured differential pressures into a flow rate using an array of predetermined calibration constants.

35. The method of claim 33 further characterized by providing a laminar air flow across the structure.

36. The method of claim 35 characterized in that the structure and laminar air flow are at least three flow resistive screens interposed in series across the inspiratory path and measuring the differential pressure across the middle screen.

37. The method of claim 23 further comprising determining the preselected delivery threshold based on a sensed flow parameter of a sensed calibrating inspiratory flow, said calibrating inspiratory flow occurring prior to said first flow.

38. An apparatus for releasing an aerosol from a reservoir of aerosol generating material for inspiration by a person characterized by:

a valve for releasing an amount of aerosol generating material from the reservoir to form an aerosol;

a sensor for monitoring the person'"'"'s inspiratory flow through an inspiratory flow path;

inspiration calibration means for automatically determining, based on a selected flow or volume parameter of a first monitored inspiration flow, a delivery threshold for releasing an amount of aerosol; and

means for controlling the valve in response to a second monitored inspiratory flow satisfying the delivery threshold, thereby to release the amount of aerosol during the second inspiratory flow, the second monitored inspiratory flow following the first monitored inspiratory flow.

39. The apparatus of claim 38 characterized in that the reservoir and the valve are characterized by a canister having a valve and a valve stem and the valve controlling means is characterized by an actuator for moving the valve stem relative to the canister to open and close the canister valve to release an amount of aerosol.

40. The apparatus of claim 38 further characterized by an aerosol flow path having a nozzle for releasing the contents of the reservoir into the inspiratory flow path, characterized in that the valve is interposed in the aerosol flow path for opening and closing the aerosol flow path;

and

the valve controlling means is an electromechanical device.

41. The apparatus of claim 38 characterized in that determining means determines automatically the delivery threshold as one of a selected flow rate, a combination of a selected flow volume, and a selected flow rate and flow volume, the selected flow rate being less than or at the sensed peak inspiratory flow rate of the first detected inspiratory flow, the selected flow volume being less than or at the peak flow volume of the first detected inspiratory flow.

42. The apparatus of claim 41 characterized in that the delivery threshold is determined to correspond to a selected location of deposition of the aerosol in the person.

43. The apparatus of claim 41 characterized in that the determined delivery threshold is further characterized by a delivery schedule including the delivery threshold and at least one other delivery point in the first detected inspiratory flow and the valve controlling means is controlled in response to the sensed second detected inspiratory flow satisfying the delivery threshold and each other delivery point.

44. The apparatus of claim 43 characterized in that the valve and the valve controlling means are characterized by:

an electromechanical actuator that can be changed at a rate up to 100 cycles per second between a first state for releasing an amount of aerosol generating material and a second state for not releasing an amount of aerosol generating material, the electromechanical actuator being in the first state from a time in the range of from about 10 to about 1000 msecs, thereby to deliver pulses of aerosol having a maximized respirable fraction; and

means for operating the electromechanical actuator to change between the first and second states one or more times in response to the second detected inspiratory flow satisfying each delivery point in the delivery schedule.

45. The apparatus of claim 38 further characterized by a visual display of a measure of the amount of aerosol in the reservoir.

46. The apparatus of claim 38 characterized in that the sensor is a structure interposed in the inspiratory flow path, a means for measuring a differential pressure generated by a flow across the structure, and means for converting the measured differential pressure into an inspiratory flow rate.

47. The apparatus of claim 46 characterized in that the measuring means has a differential pressure sensitivity in the range of about ±

25.4 cm of water corresponding to a maximum flow rate up to about 800 liters per minute.

48. The apparatus of claim 47 characterized in that the structure is selected from among one of a venturi section having a first and second cross sectional areas and means for measuring a differential pressure across the first and second areas and a resistive flow screen, and the apparatus is characterized in that the means for converting converts the measured differential pressure into a flow rate using an array of predetermined calibration constants.

49. The apparatus of claim 47 further characterized by means for providing a laminar air flow across the structure.

50. The apparatus of claim 47 characterized in that the structure is at least three flow resistive screens interposed in series across the inspiratory flow path and the differential pressure is measured across the middle screen.

51. The apparatus of claim 38 characterized in that the sensor is a hot wire anemometer disposed in the inspiratory flow path and means for converting the measured temperature changes into an inspiratory flow rate.

52. A method for administering an aerosol from a reservoir of aerosol generatinq material for inspiration by a person using an apparatus having a supply of aerosol generating material, a valve for releasing an amount of aerosol generating material to form an aerosol, and sensor for detecting an inspiratory flow of a person through an inspiratory flow path, said method characterized by:

(a) monitoring said inspiratory flow of said person through said inspiratory flow path;

(b) automatically determining, based on a selected flow or volume parameter of a first monitored inspiratory flow, a delivery threshold for the release of an amount of aerosol; and

(c) operating the valve in response to a second monitored inspiratory flow satisfying the determined delivery threshold to release an amount of aerosol for inspiration during the second monitored inspiratory flow, the second monitored inspiratory flow following the first monitored inspiratory flow.

53. The method of claim 52 characterized in that the supply and the valve are characterized by a canister having a valve and valve stem and operating the valve is characterized by moving the valve stem relative to the canister to open and close the canister valve to release a pulse of aerosol.

54. The method of claim 52 characterized by interposing the valve in an aerosol flow path connecting the contents of the reservoir with a nozzle for releasing the aerosol in the inspiratory flow.

55. The method of claim 54 characterized in that monitoring inspiratory flow is characterized by determining the temperature change of a hot wire anemometer in response to flow and converting the measured temperature changes into an inspiratory flow rate.

56. The method of claim 54 characterized in that monitoring inspiratory flow is characterized by measuring a differential pressure due to a flow across a structure in the inspiratory flow path and converting the measured differential pressure into an inspiratory flow rate.

57. The method of claim 56 characterized in that the structure is selected from among a venturi section having a first and second cross section areas and a resistive flow screen, and converting the measured differential pressure is characterized by converting the measured differential pressure into a flow rate using an array of predetermined calibration constants.

58. The method of claim 57 further characterized by providing a laminar air flow across the structure.

59. The method of claim 58 characterized in that the structure and laminar air flow are at least three flow resistive screens interposed in series across the inspiratory path and measuring the differential pressure across the middle screen.

60. The method of claim 52 further characterized by determining the delivery threshold to be one of a selected flow rate, a selected flow volume, and a combination of a selected flow rate and flow volume, the selected flow rate being less than or at the sensed peak inspiratory flow rate of the first detected inspiratory flow, the selected flow volume being less than or at the peak flow volume of the first detected inspiratory flow.

61. The method of claim 60 characterized in that the delivery threshold is further characterized by a delivery schedule including the delivery threshold and at least one other delivery point in the first detected inspiratory flow and operating the valve in response to the sensed second detected inspiratory flow satisfying the delivery threshold and each other delivery point.

62. The method of claim 60 further characterized by:

operating the electromechanical valve actuator to change between a first state for releasing an amount of aerosol and a second state for not releasing an amount of aerosol one or more times in response to the second detected inspiratory flow satisfying each delivery point in the delivery schedule; and

controlling the period of time the valve is in the first state to be a time in the range of from about 10 to about 1000 msecs, thereby to release pulses of aerosol having a maximized respirable fraction.

63. The method of claim 60 characterized in that determining a delivery threshold is characterized by selecting a delivery threshold that corresponds to a point that will deposit the aerosol in a selected location in the patient.

64. The method of claim 52 further characterized by displaying a measure of the amount of aerosol in the supply.

65. A system for dispensing aerosolized medication for inspiration by a patient from a reservoir of medication under pressure characterized by:

a valve in communication with the reservoir for releasing an amount of medication to form an aerosol;

a sensor for monitoring the patient'"'"'s inspiratory flow;

inspiration calibration means for automatically determining, based on a selected flow or volume parameter of a first monitored inspiration flow, a delivery threshold for releasing an amount of aerosol; and

means for actuating the valve more than one time to release more than one pulse of aerosol medication in response to sensed inspiratory flow satisfying a selected delivery threshold.

66. The system of claim 65 characterized in that the valve actuating means is an electromechanical actuator and the reservoir includes a source of energy for operating the electromechanical actuator.

67. The system of claim 66 characterized in that the electromechanical actuator is a solenoid and the source of energy is a battery.

68. The system of claim 65 further characterized by a means for processing signals and controlling the actuating means characterized in that the sensor is a differential pressure transducer and a circuit for providing a measure of the instantaneous flow based on the differential pressure signal corresponding to the sensed flow.

69. A hand held device for delivering aerosolized medications for inspiration characterized by:

a tube forming a flow path having a mouth end and an open end;

a nozzle disposed in the tube directed toward the mouth end;

a flow transducer for measuring a patient'"'"'s breath flow in a non-linear flow path, at least a portion of said non-linear flow path being incorporated in a disposable unit, said flow transducer being disposed in the inspiratory flow path;

a reservoir for a selected one of the medications incorporated in said disposable unit;

means, including a look-up table or an algorithm stored in a memory, for controlling flow of the selected one of the medications in said non-linear flow path by compensating for non-linearity in said non-linear flow path;

a receptacle having a valve seat for receiving a valve stem for a supply of aerosol generating material;

an aerosol flow path extending from the valve seat to the nozzle;

a valve interposed in the aerosol flow path for opening and closing the flow path; and

means for actuating the valve to open and close the flow path for delivering an amount of aerosol out the nozzle.

70. The apparatus of claim 69 characterized in that the valve actuating means opens and closes the valve a predetermined number of times to deliver the amount of aerosol as a predetermined number of pulses in response to each actuation.

71. The apparatus of claim 70 further characterized by a microprocessor and memory for recording a log history of the aerosol delivered and the sensed inspiratory flow of each valve actuation including the date, time and amount of aerosol delivered.

72. The apparatus of claim 69 further characterized by means for operating the valve actuating means in response to a detected inspiratory flow.

73. The apparatus of claim 72 further characterized by a filter disposed in the inspiratory flow path for minimizing contamination of the flow transducer.

74. The apparatus of claim 72 characterized in that the flow transducer and the means for operating are characterized by a differential pressure transducer disposed in the inspiratory flow path, means for measuring a differential pressure of a flow across the transducer, and means for converting the measured differential pressure into an inspiratory flow rate.

75. The apparatus of claim 74 characterized in that the tube and nozzle are disposable components of the device.

76. The apparatus of claim 74 characterized in that the differential pressure transducer has a pressure sensitivity in the range of about ±

25.4 cm of water corresponding to a maximum flow rate up to about 800 liters per minute.

77. The apparatus of claim 76 characterized in that the differential pressure transducer is selected from among one of a venturi section having a first and second cross sectional areas and a flow resistive screen, and the converting means is characterized by means for converting the differential pressure measured across the transducer into a flow rate using an array of predetermined calibration constants.

78. The apparatus of claim 76 characterized in that the inspiratory flow path further comprises means for providing a laminar air flow across the differential pressure transducer.

79. The apparatus of claim 78 characterized in that the differential pressure transducer and the laminar air flow means further comprise at least three flow resistive screens interposed in series across the air flow path characterized in that the differential pressure is measured across the middle screen.

80. The apparatus of claim 69 characterized in that the valve and valve actuating means are characterized by an electromechanical device having an open condition for a time selected from the range of from 10 to 1000 msecs and a closed condition.

81. The apparatus of claim 69 further characterized by means for enabling the device for delivering aerosolized medications when it is sufficiently agitated and disabling the device from delivering aerosolized medication when it is not sufficiently agitated.

82. The apparatus of claim 69 characterized in that the supply of aerosol generating material is in open communication with the aerosol flow path proximate to the supply when the supply valve stem is seated in the receptacle valve seat.

83. The apparatus of claim 69 further characterized by a visual display device for providing a measure of the supply of aerosol seated in the receptacle.

84. An apparatus for inhalation therapy of a patient characterized by:

a sensor for monitoring a patient'"'"'s breath flow including inspiratory flow through a flow path;

an inhaler device containing a supply of aerosol generating material including medication for releasing an amount of aerosol medication for inspiration in response to a detected inspiratory flow exceeding a delivery threshold;

means for determining a pulmonary function based on a measure of the detected breath flow, the determined pulmonary function being selected from among the group consisting of forced expiratory volume in one second, forced vital capacity, and peak expiratory flow rate;

means for comparing a first determined pulmonary function based on a first detected breath flow and a second determined pulmonary function based on a second detected breath flow and determining relative changes in the determined pulmonary function in response to released aerosol medication over time and

a display device for displaying a parameter corresponding to relative changes in the first and second determined pulmonary functions.

85. The apparatus of claim 84 further characterized by means for adjusting the amount of aerosol medication released from the reservoir in response to the determined relative change in the first and second determined pulmonary functions.

86. The apparatus of claim 85 characterized in that the inhaler device determines a delivery threshold in response to a first detected inspiratory flow and releases the adjusted amount of aerosol medication in response to a following detected inspiratory flow satisfying the determined delivery threshold.

87. The apparatus of claim 86 characterized in that the determined pulmonary function is adjusted based on the patient'"'"'s predetermined health characteristics.

88. The apparatus of claim 85 characterized in that the inhaler device determines whether a first detected inspiratory flow satisfies a preselected delivery threshold and releases the adjusted amount of aerosol in response to the first detected inspiratory flow satisfying the preselected delivery threshold;

and is further characterized by means for lowering the preselected delivery threshold in response to the first detected inspiratory flow not satisfying the preselected delivery threshold and the inhaler device releases the adjusted amount of aerosol medication if a subsequently detected inspiratory flow satisfies the lowered delivery threshold.

89. The apparatus of claim 88 characterized in that the inhaler device recursively lowers the lowered delivery threshold a predetermined amount in response to the last detected inspiratory flow not satisfying the previous lowered delivery threshold.

90. The apparatus of claim 89 characterized in that the determined pulmonary function is adjusted based on the patient'"'"'s predetermined health characteristics.

91. The apparatus of claim 84 in which the display device is further characterized by a display device for indicating whether the patient'"'"'s pulmonary function is improving, degrading or remaining nominally the same.

92. The apparatus of claim 91 characterized in that the display device includes a first visual display for indicating an improving pulmonary function and a second visual display for indicating a degrading pulmonary function.

93. The apparatus of claim 84 further characterized by signal generator for indicating a desired breath flow pattern for determining the pulmonary function to be determined.

94. A method for controlling inhalation therapy using an inhaler device including a supply of aerosol generating material including medication and having a valve for releasing an amount of aerosolized medication for inspiration by a patient in response to a sufficient inspiratory flow characterized by:

monitoring a patient'"'"'s breath flow including the inspiratory flow;

determining a pulmonary function based on a detected breath flow, the determined pulmonary function being selected from among the group consisting of forced expiratory volume in one second, forced vital capacity, and peak expiratory flow rate;

comparing a first determined pulmonary function based on a first detected breath flow and a second determined pulmonary function based on a second detected breath flow;

determining relative changes in the determined pulmonary function in response to aerosol medication released over time; and

displaying a parameter corresponding to the determined relative changes in the first and second determined pulmonary functions.

95. The method of claim 94 further characterized by adjusting the amount of medication to be released from the supply by the inhaler device in response to the determined relative change in the first and second pulmonary functions.

96. The method of claim 95 further characterized by displaying an indication of whether the determined pulmonary function is improving, degrading, or remaining nominally the same.

97. The method of claim 96 characterized in that an improving condition is displayed on a first visual display and a degrading condition is displayed on a second visual display.

98. The method of claim 94 further characterized by generating a signal for indicating a desired breath flow pattern for determining the pulmonary function to be determined.

99. The method of claim 94 characterized in that identifying a sufficient inspiratory flow for the release of an amount of aerosol medication is characterized by selecting a delivery schedule based on a first detected inspiratory flow and releasing the amount of aerosol when the following detected inspiratory flow satisfies the selected delivery schedule.

100. The method of claim 99 further characterized by adjusting the determined pulmonary function based on the patient'"'"'s predetermined health characteristics. canister having a valve and valve stem and the valve operating means is characterized by an actuator for moving the valve stem relative to the canister to open and close the canister valve to release an amount of aerosol.

101. The method of claim 94 characterized in that releasing the amount of aerosol medication is characterized by:

comparing a first detected inspiratory flow to a preselected delivery threshold;

releasing the amount of aerosol medication in accordance with a preselected delivery schedule in response to the detected inspiratory flow satisfying the delivery threshold;

lowering the preselected delivery schedule in response to the detected inspiratory flow not satisfying the preselected delivery threshold;

comparing a subsequently detected inspiratory flow to the lowered delivery threshold; and

releasing the amount of aerosol medication in accordance with the lowered delivery schedule in response to the subsequently detected inspiratory flow satisfying the lowered delivery threshold.

102. The method of claim 101 further characterized by recursively lowering the lowered delivery schedule a predetermined amount in response to the last detected inspiratory flow not satisfying the previous lowered delivery threshold.

103. The method of claim 102 further characterized by adjusting the determined pulmonary function based on the patient'"'"'s predetermined health characteristics.

104. Apparatus for displaying a measured pulmonary function of a person characterized by:

a flow path;

a sensor for monitoring a breath flow of the person through the flow path;

means for determining a pulmonary function of the person based on a measure of the sensed breath flow, the determined pulmonary function being selected from among the group consisting of forced expiratory volume in one second, forced vital capacity, and peak expiratory flow rate;

a first visual indicator corresponding to a first predetermined range of pulmonary functions having an on state and an off state;

a second visual indicator corresponding to a second predetermined range of pulmonary functions having an on state and an off state; and

means for turning on the visual indicator whose preselected range includes the determined pulmonary function.

105. The apparatus of claim 104 further characterized by a signal generator for indicating a desired breath flow pattern for determining the pulmonary function to be determined.

106. The apparatus of claim 104 further characterized by a third visual indicator corresponding to a third predetermined range of pulmonary functions having an on state and an off state, characterized in that the first, second, and third visual indicators respectively indicate predetermined ranges of acceptable pulmonary functions, marginal pulmonary functions, and unacceptable pulmonary functions.

107. The apparatus of claim 106 further characterized by:

means for comparing a first determined pulmonary function based on a first breath flow and a second determined pulmonary function based on a second breath flow and determining whether or not the person'"'"'s determined pulmonary function has changed over time; and

means for indicating that the determined pulmonary function has improved on one of the first, second, and third visual indicators, nominally remained the same on a second of the first, second and third visual indicators, and degenerated on a third of the first, second and third visual indicators in response to the determined change in the determined pulmonary function.

108. The apparatus of claim 104 characterized in that the sensor detects the expiratory flow rate and the determined pulmonary function is FEV1.

109. The apparatus of claim 104 further characterized by:

a canister of aerosol generating material;

a valve for releasing an amount of aerosol generating material from the canister to form an aerosol; and

means for operating the valve to deliver a selected amount of aerosol in response to the determined pulmonary function and a detected inspiratory flow occurring subsequent to the sensed breath flow so that the selected amount of aerosol is delivered for inspiration by the person during the detected inspiratory flow.

110. The apparatus of claim 104 further comprising:

means for comparing a first determined pulmonary function based on a first breath flow and a second determined pulmonary function based on a second breath flow and determining whether or not the person'"'"'s determined pulmonary function has changed from the first to the second determinations;

a supply of aerosol generating material;

a valve for releasing an amount of aerosol generating material from the supply to form an aerosol; and

means for operating the valve to release a selected amount of aerosol in response to the first and second determined pulmonary functions and a detected inspiratory flow occurring subsequent to the first and second breath flows characterized in that the selected amount of aerosol is adjusted in response to the determined change in pulmonary function and released for inspiration by the person during the detected inspiratory flow.

111. A method for displaying a measured pulmonary function of a person characterized by:

monitoring the breath flow of a person through a flow path;

measuring a breath parameter of the detected breath flow;

determining a pulmonary function of the person based on the measured breath parameter, the determined pulmonary function being selected from among the group consisting of forced expiratory volume in one second, forced vital capacity, and peak expiratory flow rate;

turning on a first visual indicator having an on state and an off state in response to the determined pulmonary function being in a first range of pulmonary functions; and

turning on a second visual indicator having an on state and an off state in response to the determined pulmonary function being in a second range of pulmonary functions.

112. The method of claim 111 further characterized by generating a signal indicating a desired breath flow pattern for measuring the breath parameter used for determining the pulmonary function to be determined.

113. The method of claim 111 further characterized by turning on a third visual indicator having an on state and an off state in response to the determined pulmonary function being in a third range of pulmonary functions, characterized in that the first, second, and third visual indicators correspond respectively to selected ranges of acceptable, marginal and unacceptable pulmonary functions.

114. The method of claim 113 further characterized by:

comparing a first determined pulmonary function based on a first breath flow to a second determined pulmonary function based on a second breath flow;

determining whether or not the person'"'"'s determined pulmonary function has changed from the first to the second determinations; and

indicating that the determined pulmonary function has improved on one of the first, second and third visual indicators, remained nominally the same on a second of the first, second and third visual indicators, and degenerated on a third of the first, second and third visual indicators in response to the determined change in pulmonary function.

115. The method of claim 111 characterized in that determining the pulmonary function is characterized by determining the FEV1 based on measuring the expiratory flow rate.

116. The method of claim 111 further characterized by:

selecting an amount of aerosol to be released from a canister of aerosol generating material in response to the determined pulmonary function;

detecting an inspiratory flow subsequent to the detected breath flow; and

releasing the selected amount of aerosol for inspiration by the person during the detected inspiratory flow.

117. The method of claim 111 further characterized by:

comparing a first determined pulmonary function based on a first breath flow to a second determined pulmonary function based on a second breath flow;

determining whether or not the person'"'"'s determined pulmonary function has changed from the first to the second determinations;

selecting an amount of aerosol to be released from a supply of aerosol generating material in response to the first and second determined pulmonary functions and any determined change in pulmonary function;

detecting an inspiratory flow subsequent to the first and second detected breath flows; and

releasing the selected amount of aerosol for inspiration by the person during the detected inspiratory flow.

118. A portable, hand held device for administering aerosolized medication for inhalation therapy of a patient characterized by:

a sensor for monitoring breath flow through a nonlinear flow path, at least a portion of said non-linear flow path being incorporated in a disposable unit;

a reservoir being incorporated in said disposable unit;

a means, including a look-up table or an algorithm stored in a memory, for controlling flow of the selected medication in said non-linear flow path by compensating for non-linearity in said non-linear flow path;

a clock for providing the date and time;

an inhaler device for releasing a selected amount of aerosol from a supply in response to a sensed inspiratory flow satisfying a delivery schedule; and

a battery operated microprocessor having memory for recording a log of the date, time and amount of each amount of aerosol released during any sensed inspiratory flow and a parameter corresponding to the sensed inspiratory flow at the time of release of each amount of aerosol;

an

a data port for transmitting the recorded log data to an external device.

119. The apparatus of claim 118 further characterized by means for determining a pulmonary function of the person based on a detected breath flow, characterized in that the microprocessor records a log of the time, date, determined pulmonary function and detected breath flow data for each determined pulmonary function.

120. The apparatus of claim 119 characterized in that the recorder is characterized by a microprocessor and memory, further characterized by a data port for transmitting the recorded log data to an external device.

121. The apparatus of claim 119 further characterized by a display device for displaying the determined pulmonary function.

122. The apparatus of claim 119 characterized by a display device for displaying relative changes over time of the determined pulmonary function.

123. The apparatus of claim 118 further characterized by a display device for indicating a measure of the amount of aerosol remaining in the inhaler device supply.

124. The apparatus of claim 118 further characterized by means for evaluating the recorded log and inhibiting the inhaler device from releasing medication if such release would result in a determined overdose of medication.

125. A method for administering aerosolized medication for inhalation therapy using an inhaler device for releasing an amount of aerosol from a supply into a sensed inspiratory flow, characterized by:

monitoring breath flow in a non-linear flow path at least a portion of said non-linear flow path being incorporated in a disposable unit;

monitoring the operation of a clock providing date and time information;

releasing a selected amount of aerosol in response to a monitored inspiratory flow satisfying a delivery threshold;

recording in memory a log of the date, time and amount of aerosol released each time an amount of aerosol is released, and a parameter corresponding to the inspiratory flow at the time of each release of an amount of aerosol; and

transferring the recorded contents of the memory to an external device.

126. The method of claim 125 further characterized by:

determining a pulmonary function of the detected breath flow; and

recording in the log the time, date, determined pulmonary function and determined breath flow data for each determined pulmonary function.

127. The method of claim 126 further characterized by displaying relative changes in the determined pulmonary function over time.

128. The method of claim 126 further characterized by displaying the determined pulmonary function.

129. The method of claim 125 further characterized by displaying a measure of the amount of aerosol remaining in the supply.

130. The method of claim 125 further characterized by evaluating the recorded log data over a selected recent time interval and inhibiting the release of an amount of aerosol if such release would result in a determined overdose of the medication.

131. A hand held device for delivering an aerosolized medication for inspiration characterized by:

a tube forming a flow path having a mouth end and an open end;

a nozzle disposed in the tube for insertion of the aerosolized medication into the tube;

a flow transducer for measuring a patient'"'"'s breath flow in a non-linear flow path, at least a portion of said non-linear flow path being incorporated in a disposable unit, said flow transducer being disposed in the inspiratory flow path;

a reservoir for the medication incorporated in said disposable unit;

means, including a look-up table or an algorithm stored in a memory, for controlling flow of the aerosolized medication in said non-linear flow path by compensating for non-linearity in said non-linear flow path;

an aerosolizer operatively coupled to said reservoir and positioned to deliver the aerosolized medication through the flow path out the nozzle.

132. The apparatus of claim 131 in which said aerosolizer comprises a volatile propellant in said reservoir with the medication, said device additionally including a valve for selectively blocking flow of the medication between the reservoir and the flow path.