Nebulizer vibrating aperture plate drive frequency control and monitoring

Patent metadata

Field	Value
Publication number	US-11065399-B2
Application number	US-201916572298-A
Country	US
Kind code	B2
Filing date	Sep 16, 2019
Priority date	Jul 24, 2013
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A nebulizer has an aperture plate, a mounting, an actuator, and an aperture plate drive circuit ( 2 - 4 ). A controller measures an electrical drive parameter at each of a plurality of measuring points, each measuring point having a drive frequency; and based on the values of the parameter at the measuring points makes a determination of optimum drive frequency and also an end-of-dose prediction. The controller performs a short scan at regular sub-second intervals at which drive current is measured at two measuring points with different drive frequencies. According to drive parameter measurements at these points the controller determines if a full scan sweeping across a larger number of measuring points should be performed. The full scan provides the optimum drive frequency for the device and also an end of dose indication.

First claim

The invention claimed is:

1. A nebulizer, comprising:
a vibrating aperture plate mounted within the nebulizer and driven by an actuator; and
an aperture plate drive circuit coupled to the actuator and having a controller, wherein the controller is configured to:
perform a short scan measuring drive current to the aperture plate; and
initiate a full scan of the drive current if the short scan measures a change in the drive current outside a predetermined tolerance.

2. A nebulizer as claimed in claim 1 , wherein the short scan has fewer than five measuring points.

3. A nebulizer as claimed in claim 1 , wherein the predetermined tolerance includes a tolerance range, and if the short scan measures a change in the drive current outside the tolerance range, the full scan is initiated.

4. A nebulizer as claimed in claim 1 , wherein the short scan is performed at regular intervals.

5. A nebulizer as claimed in claim 4 , wherein the regular intervals are sub-second intervals.

6. A nebulizer as claimed in claim 1 , wherein the full scan has five to three-hundred measuring points.

7. A nebulizer as claimed in claim 6 , wherein the full scan has one-hundred to three-hundred measuring points.

8. A nebulizer as claimed in claim 1 , wherein the controller is configured to dynamically determine, from the full scan, a frequency associated with a measuring point of the short scan.

9. A nebulizer as claimed in claim 8 , wherein the controller is configured to select a frequency value corresponding to lowest drive current as a frequency for a measuring point of the short scan.

10. A nebulizer as claimed in claim 9 , wherein said lowest drive current is determined to correspond to a resonant frequency, and a frequency value for a measuring point of the full scan with lowest drive current is stored for use as a measuring point frequency for the short scan.

11. A nebulizer as claimed in claim 1 , wherein the controller is configured to, during the full scan:
dynamically perform a plurality of iterations, and
in each iteration, compare the measured drive current against a measurement at a previous measuring point to determine an end-of-dose indication and/or a selected drive frequency, wherein the end-of-dose indication is indicative of an end of an aerosolization cycle of the nebulizer, and wherein the selected drive frequency is a frequency between a resonant frequency and a non-resonant frequency.

12. A nebulizer as claimed in claim 11 , wherein the controller is further configured to determine a slope value from the comparison and identify the end-of-dose when the slope value is above a threshold that indicates end of dose.

13. A method of operation of a nebulizer comprising a vibrating aperture plate mounted in the nebulizer and driven by an actuator, the actuator being coupled to an aperture plate drive circuit having a controller, wherein the method comprises:
performing a short scan measuring drive current to the aperture plate; and
initiating a full scan of the drive current if the short scan measures a change in the drive current outside a predetermined tolerance.

14. A method as claimed in claim 13 , wherein the short scan has fewer than five measuring points and the full scan has five to three-hundred measuring points.

15. A method as claimed in claim 13 , wherein the controller compares measurements with tolerance ranges, and if a measurement falls outside its associated range, a full scan is initiated.

16. A method as claimed in claim 13 , wherein the short scan is performed at regular intervals.

17. A method as claimed in claim 13 , wherein the controller dynamically determines, from the full scan, a frequency associated with a measuring point of the short scan, and selects a frequency value corresponding to lowest drive current as a frequency for a measuring point of the short scan.

18. A method as claimed in claim 17 , wherein said lowest drive current is determined to correspond to a resonant frequency, and a frequency value for a measuring point of the full scan with lowest drive current is stored for use as a measuring point frequency for the short scan.

19. A method as claimed in claim 13 , further comprising:
dynamically performing a plurality of iterations during the full scan, and
in each iteration, compare the measured drive current against a measurement at a previous measuring point to determine an end-of-dose indication and/or a selected drive frequency, wherein the end-of-dose indication is indicative of an end of an aerosolization cycle of the nebulizer, and wherein the selected drive frequency is a frequency between a resonant frequency and a non-resonant frequency.

20. A nebulizer, comprising:
a vibrating aperture plate mounted within the nebulizer and driven by an actuator; and
an aperture plate drive circuit coupled to the actuator and having a controller, wherein the controller is configured to:
perform a short scan at regular intervals measuring drive current to the aperture plate;
initiate a full scan of the drive current if the short scan measures a change in the drive current outside a predetermined tolerance range; and
dynamically determine, from the full scan, a frequency associated with a measuring point of the short scan.

Assignees

• Stamford Devices Ltd

Inventors

• Grehan Joseph
• Smith Niall

Classifications

• B05B17/0669

  Excitation frequencies · CPC title

• A61M2205/33

  Controlling, regulating or measuring · CPC title

• A61M11/001

  Particle size control · CPC title

• B05B12/004

  comprising sensors for monitoring the delivery, e.g. by displaying the sensed value or generating an alarm (B05B12/08 takes precedence; registering or indicating the condition or the working of machines or other apparatus in general G07C3/00) · CPC title

• B05B15/14

  Arrangements for preventing or controlling structural damage to spraying apparatus or its outlets, e.g. for breaking at desired places; Arrangements for handling or replacing damaged parts · CPC title