Metering system and method for fluid delivery

• US 9,550,033 B2
• Filed: 07/14/2015
• Issued: 01/24/2017
• Est. Priority Date: 09/25/2003
• Status: Expired due to Term

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Beavis, Russell H., Gray, Larry B., Kane, Derek G.
• Primary Examiner(s): DOUGLAS, STEVEN O
• Application Number:
  US14/799,054
• Publication Number:
  US 20150316405A1
• Time in Patent Office: 560 Days
• Field of Search: 128/200.14, 128/200.18, 128/200.21, 128/200.22, 128/203.12, 128/203.14, 128/205.23, 128/205.24, 128/203.26, 128/200.16, 731/49, 736/49, 732/90.B, 137/565.01, 137/565.34, 261/27
• US Class Current: 1/1
• CPC Class Codes: A61M 15/0003 with means for dispensing more than one drug
• CPC Class Codes: A61M 15/002 with air flow regulating means
• CPC Class Codes: A61M 15/0045 using multiple prepacked dosages on a same carrier, e.g. blisters
• CPC Class Codes: A61M 15/0048 the dosages being arranged in a plane, e.g. on diskettes
• 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 15/0068 Indicating or counting the number of dispensed doses or of remaining doses
• CPC Class Codes: A61M 15/008 Electronic counters
• 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 2202/03 Gases in liquid phase, e.g. cryogenic liquids
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 2205/3379 Masses, volumes, levels of fluids in reservoirs, flow rates
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: B05B 12/006 Pressure or flow rate sensors
• CPC Class Codes: B05B 12/085 : responsive to flow or pressure of liquid or other fluent material to be discharged B05B1/3006, B05B1/323, B05B7/1254 take precedence
• CPC Class Codes: G01F 1/007 : by measuring the level variations of storage tanks relative to the time
• CPC Class Codes: G01F 17/00 : Methods or apparatus for determining the capacity of containers or cavities, or the volume of solid bodies measuring linear dimensions to determine volume G01B
• CPC Class Codes: G01F 22/00 : Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for
• CPC Class Codes: G01F 23/14 : by measurement of pressure
• CPC Class Codes: G01H 3/00 : Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G10K 9/04 : by compressed gases, e.g. compressed air

Abstract

An apparatus for metering the delivery of an aerosol. The apparatus has a variable acoustic source and a microphone, both acoustically coupled to a volume having a fluid region and an air region. The apparatus may also include a processor to determine a volume of the air region based on signals received from the microphone and the variable acoustic source. A fluid valve is coupled to the processor, and is configured to allow an amount of fluid to exit the fluid region associated with the volume of the air region. An atomizer, coupled to the fluid region, is configured to aerosolize at least a portion of the fluid.

Claims

1. An apparatus for determining the fluid volume output from a fluid region, the apparatus comprising:

a housing containing a first volume and a second volume, the second volume including an air region, the air region containing an air volume and a fluid region containing a fluid volume, the first volume and the air region form at least part of an acoustic system;

a printed circuit board disposed within the housing, the printed circuit board defining the first volume within the housing and the printed circuit board including;

an acoustic source acoustically exciting the acoustic system,

a first microphone acoustically coupled to the first volume, the first microphone producing a first signal based on a response of the first volume to excitement by the acoustic source, and

a second microphone acoustically coupled to the air region, the second microphone producing a first signal based on a response of the air region to excitement by the acoustic source;

a processor in communication with the acoustic source, the first microphone and the second microphone, the processor comprising;

determining a first air volume associated with the first signal and second signal at a first instance,

determining a second air volume associated with the first signal and second signal at a second instance,

determining the fluid volume output from a fluid region associated with the difference between the first air volume and the second air volume.

2. The apparatus of claim 1, wherein the printed circuit board comprising the processor.

3. The apparatus of claim 1, wherein at least one of the first microphone and the second microphone is attached to the printed circuit board.

4. The apparatus of claim 1, wherein the air region is separated from the fluid region by a diaphragm, and wherein the air region and the fluid region form a fixed volume.

5. The apparatus of claim 4, further comprising a detachable cassette defining the fluid region of the second volume.

6. The apparatus of claim 1, wherein the housing further comprises a valve, the valve is in fluid communication with the fluid region.

7. The apparatus of claim 6, wherein the processor comprises:

driving the acoustic source at fixed frequency;

receiving a first signal from the first microphone;

receiving a second signal from the second microphone; and

outputting a control signal to the valve, the control signal being associated with the first signal and the second signal.

8. The apparatus of claim 7, wherein the control signal comprises information associated with releasing the fluid volume.

9. The apparatus of claim 1, wherein the printed circuit board comprises a hole for pressure equalization between the first volume and the second volume.

10. The apparatus of claim 1, wherein the acoustic source comprises a piezoelectric speaker.

11. The apparatus of claim 1, wherein the printed circuit board forms an air-tight seal with the housing.

12. The apparatus of claim 1, wherein the printed circuit board further comprises a temperature sensor, the temperature sensor being in communication with the processor.

13. An apparatus for determining the chamber volume of a variable-volume chamber, the apparatus comprising:

a housing including are fixed volume and the variable-volume chamber, the variable-volume chamber having a chamber volume, the variable-volume chamber being defined at least in part by the housing, the variable-volume chamber and fixed volume form at least part of an acoustic system;

an acoustic source exciting the acoustic system;

a printed circuit board disposed within the housing, the printed circuit board defining the fixed volume within the housing, the printed circuit board including;

a first microphone acoustically coupled to the fixed volume, the first microphone producing a first signal associated with a acoustic response of the fixed volume to excitement by the acoustic source,

a second microphone acoustically coupled to the variable-volume chamber, the second microphone producing a second signal associated with an acoustic response of the variable-volume chamber to excitement by the acoustic source; and

a processor including;

driving the acoustic source,

receiving the first signal and the second signal, and

determining the chamber volume associated with the first signal and second signal.

14. The apparatus of claim 13, wherein the printed circuit board separates the fixed volume from the variable-volume chamber.

15. The apparatus of claim 13, wherein the processor comprises determining the chamber volume associated with a resonant frequency of the acoustic system.

16. The apparatus of claim 13, wherein either of the first microphone or the second microphone is attached to the printed circuit board.

17. The apparatus of claim 13, wherein the printed circuit board forms an air-tight seal with the housing.

18. The apparatus of claim 13, wherein the printed circuit board further comprises a temperature sensor, the temperature sensor being in communication with the processor.

19. The apparatus of claim 18, wherein the processor comprises:

receiving a third signal from the temperature sensor, and

determining the chamber volume associated with the first signal, second signal and third signal.

20. The apparatus of claim 13, wherein the acoustic source comprises a piezoelectric speaker.

21. The apparatus claim 13, further comprising a detachable cassette mounted to the housing, the detachable cassette comprising a fluid region that is separated from the variable-volume chamber by a diaphragm.

22. The apparatus of claim 21, wherein the variable-volume chamber and the fluid region form a constant volume.

23. The apparatus of claim 21 further comprising a valve in communication with the fluid region.

24. The apparatus of claim 23, wherein the valve is in communication with the processor.

25. The apparatus of claim 24, wherein the processor outputs a control signal to the valve, the control signal being associated with the chamber volume.

26. The apparatus of claim 25, wherein the control signal comprises information associated with releasing a fluid volume from the fluid region.

27. An apparatus to control the flow of liquid, the apparatus comprising:

a housing containing a valve, a first volume and a second volume, the second volume including a gas region, the gas region containing a gas volume and a liquid region containing a liquid volume, the valve being in fluid communication with the liquid region, the first volume and gas-region form at least part of an acoustic system;

an acoustic source exciting the acoustic system;

a printed circuit board disposed within the housing, the printed circuit board and housing defining the first volume and the printed circuit board including;

a first microphone acoustically coupled to the first volume, the first microphone producing a first signal associated with a response of the first volume to excitement by the acoustic source, and

a second microphone acoustically coupled to the gas region, the second microphone producing a first signal associated with a response of the gas region to excitement by the acoustic source; and

a processor including;

driving the acoustic source;

receiving the first signal,

receiving the second signal,

determining the gas volume associated with the first signal and second signal, and

controlling the valve to allow a liquid volume to exit the liquid region based on the gas volume.

28. The apparatus of claim 27, wherein the processor is arranged to determine the gas volume associated with a resonant frequency of the acoustic system.

29. The apparatus of claim 27, wherein the processor is arranged to determine a resonant frequency of the acoustic system based on an underdamped second-order model of the acoustic system.

30. The apparatus of claim 27, wherein the printed circuit board comprises the processor.

31. The apparatus of claim 27, wherein the gas region is separated from the liquid region by a diaphragm, and the gas region and the liquid region form a constant volume.

32. The apparatus of claim 27, wherein the control signal comprises information associated with releasing a volume of liquid.

33. The apparatus of claim 27, wherein the printed circuit board includes a hole for pressure equalization between the first volume and the second volume.

34. The apparatus of claim 27, wherein the acoustic source comprises a piezoelectric speaker.

35. The apparatus of claim 27, wherein the printed circuit board comprises a temperature sensor.

36. The apparatus of claim 35, wherein the processor comprises:

receiving a third signal from the temperature sensor, and

calculating the gas volume of the gas-region based on the received first signal, second signal and third signal.