ANALYSIS AND CONTROL OF AEROSOL FLOW

• US 20150020804A1
• Filed: 10/23/2012
• Published: 01/22/2015
• Est. Priority Date: 10/28/2011
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Van Der Mark, Martinus Bernardus, Lammers, Jeroen Herman, Verschueren, Alwin Rogier Martijn, Boots, Henri Marie Joseph, Bentvelsen, Petrus Henricus Cornelius, Huijgen, Hendrik, Van Der Sluis, Paul, Schipper, Alphonsus Tarcisius Jozef Maria
• Granted Patent: US 9,599,550 B2
• Time in Patent Office: Days
• US Class Current: 128/203.14
• CPC Class Codes: A61M 11/00 Sprayers or atomisers specially adapted for therapeutic purposes in general B05B; aerosol containers B65D83/14
• CPC Class Codes: A61M 11/001 Particle size control
• CPC Class Codes: A61M 11/005 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: A61M 16/0003 Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 16/14 by mixing different fluids, one of them being in a liquid phase
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3327 Measuring
• CPC Class Codes: A61M 2209/02 Equipment for testing the apparatus
• CPC Class Codes: B05B 12/082 responsive to a condition of the discharged jet or spray, e.g. to jet shape, spray pattern or droplet size
• CPC Class Codes: B05B 17/0646 Vibrating plates, i.e. plates being directly subjected to the vibrations, e.g. having a piezoelectric transducer attached thereto
• CPC Class Codes: G01N 15/0205 by optical means
• CPC Class Codes: G01N 15/0211 Investigating a scatter or diffraction pattern
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01N 21/532 with measurement of scattering and transmission
• CPC Class Codes: G01N 21/534 by measuring transmission alone, i.e. determining opacity
• CPC Class Codes: G01N 21/6445 Measuring fluorescence polarisation
• CPC Class Codes: G01N 9/00 Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity

Abstract

An aerosol generation system has a light source arrangement which provides signals at first and second wavelengths, and the detected light signals are recorded. The detected signals are processed to derive at least a measure of the aerosol particle size. This can be used in combination with the other parameters which are conventionally measured, namely the aerosol density and flow velocity. Thus, optical measurement (possibly in combination with an air flow measurement) can be used to estimate the aerosol output rate as well as the particle size.

Claims

1. An aerosol generation system, comprising:

a flow device (1) for generating an aerosol flow;

a light source arrangement (6) and a light detector (3) for detecting light which has interacted with the aerosol flow;

a controller (9) for controlling the light source arrangement and for interpreting the detected light signals;

wherein the controller is adapted to;

control the light source arrangement to provide a first signal at a first wavelength and to record a first detected light signal;

control the light source arrangement to provide a second signal at a second wavelength and to record a second detected light signal;

process the first and second detected signals to derive a measure of the aerosol particle size by;

processing the first and second detected signals to determine measurements of the obscuration at each of the first and second wavelengths;

comparing the measurements of the obscuration at each of the first and second wavelengths to a function relating the modulation on the amount of light scattering by an aerosol flow to particle size variation; and

deriving a measure of the aerosol particle size from the result of the comparison.

2. A system as claimed in claim 1, wherein the light detector (3) is for detecting light which has passed through the aerosol flow.

3. A system as claimed in claim 2, further comprising a dye added to an aerosol liquid.

4. A system as claimed in claim 1, wherein the light detector (8) is for detecting light which has been reflected or scattered by the aerosol flow.

5. A system as claimed in claim 4, further comprising a fluorescent additive added to an aerosol liquid.

6. A system as claimed in claim 1, wherein the controller (9) is further adapted to derive the aerosol density from the detected light signals.

7. A system as claimed in claim 6, wherein the light source arrangement comprises light sources at different positions along the aerosol flow, and a detector is provided for each light source, wherein the controller is adapted to derive the aerosol velocity from the detected light signals at the different positions along the aerosol flow.

8. A system as claimed in claim 7, wherein the controller is adapted to determine a time delay of the aerosol flow between different positions along the aerosol flow by applying a cross correlation to the signals received at the different positions with a variable time delay.

9. A system as claimed in any preceding claim, wherein the light detector is adapted to separate polarized and depolarized light contributions to determine an amount of scattering.

10. A system as claimed in any preceding claim, further comprising a flow device controller for controlling the flow device, wherein the system comprises a feedback loop such that the flow device controller takes account of monitored parameters of the aerosol flow.

11. A method of generating an aerosol, comprising:

generating an aerosol flow;

controlling a light source arrangement to provide a first signal at a first wavelength and recording a first detected light signal;

controlling the light source arrangement to provide a second signal at a second wavelength and recording a second detected light signal;

processing the first and second detected signals to derive a measure of the aerosol particle size;

processing the first and second detected signals to determine measurements of the obscuration and each of the first and second wavelengths;

comparing the measurements of the obscuration at each of the first and second wavelengths to function relating the modulation and the amount of light scattering to particle size variation; and

deriving a measure of the aerosol particle size from the result of the comparison.

12. A method as claimed in claim 11, comprising detecting light which has passed through the aerosol flow, or detecting light which has been reflected or scattered by the aerosol flow.

13. A method as claimed in claim 11 comprising deriving the aerosol density from the detected light signals.

14. A method as claimed in claim 13, comprising deriving the aerosol velocity from the light signals at different positions along the aerosol flow, by applying a cross correlation to the signals received at the different positions along the aerosol flow with a variable time delay, thereby to determine a time delay of the aerosol flow between the different positions.

15. A method as claimed in claim 11, further comprising controlling the flow device using a feedback loop which takes account of monitored parameters of the aerosol flow.