US5465608A
Expired / Lapsed
US
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Saw vapor sensor apparatus and multicomponent signal processing
Assignee: Hamilton Sundstrand Corp
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Filing: 1993-06-30
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Granted: 1995-11-14
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Expires: 2013-06-30
Abstract
Abstract A method and apparatus for the identification and quantification of a vapor, or a number of vapors, in air mixtures is discussed. The method includes calibration of a vapor responsive sensor, or a plurality of vapor responsive sensors, to known concentrations of the vapors of interest or to known concentrations of potential interfering vapors. The calibrations result in sensor response vectors which are derived from the transient signals observed as the vapors are sorbed and desorbed on the sensors. Detection of vapors in complex mixtures is effected by subjecting the apparatus to the mixture and measuring the sensor response, or plurality of sensor responses, and then applying multidimensional statistical analysis or filtering methods to this data, using the precalibrated response vectors as the basis set for deconvolution. The sensors disclosed are Surface Acoustic Wave sensors (SAWs), and include variations of temperature programmed SAWs, SAWs with various combinations of chemically selective coatings, and arrays of temperature programmed and coated SAWs.
Inventors
- 👤 Anatole Lokshin
- 👤 David E. Burchfield
- 👤 David H. Tracy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:40
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/32; G01N29/326; G01N29/02; G01N29/022; G01N29/30; G01N2291/00; G01N2291/02; G01N2291/025; G01N2291/0256; G01N2291/028; G01N2291/02845; G01N2291/04; G01N2291/042; G01N2291/0423
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
107 words
A method for detecting and determining the concentration of at least one target compound in a vapor mixture of compounds of unknown concentrations comprising the steps of: providing a pair of vapor responsive sensors whose average one cycle frequency response to a unit concentration of a selected vapor is known; subjecting said vapor responsive sensors to a mixture of compounds of unknown concentrations which provide a frequency shift from said average frequency response to a second frequency response as a result of said mixture on said vapor responsive sensors; and processing this frequency shift by multidimensional statistical methods to detect the target compound and determine its concentration.
Claim 2
Independent Claim
107 words
A method for detecting and determining the concentration of at least one target compound in a vapor mixture of compounds of unknown concentrations comprising the steps of: providing a pair of vapor responsive sensors whose average one cycle frequency response to a unit concentration of a selected vapor is known; subjecting said vapor responsive sensors to a mixture of compounds of unknown concentrations which provide a frequency shift from said average frequency response to a second frequency response as a result of said mixture on said vapor responsive sensors; and processing this frequency shift by multidimensional statistical methods to detect the target compound and determine its concentration.
Claim 3
Dependent Claim
77 words
The method of claim 1 wherein the step of processing the frequency shift comprises: constructing a calibration matrix comprising vectors that represent the average one cycle frequency response of said vapor responsive sensor per unit concentration of each target compound; constructing a response matrix comprising the one cycle frequency shift of said vapor responsive sensor to said vapor mixture; and operating on said response matrix by said calibration matrix to calculate the concentration of each target compound.
Claim 4
Dependent Claim
27 words
The method of claim 2 wherein the step of operating on said response matrix comprises multiplying said response matrix by the pseudo inverse of said calibration matrix.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein the step of providing a pair of vapor responsive sensors comprises providing a surface acoustic wave sensor.
Claim 6
Independent Claim
87 words
A method of detecting and determining the concentration of a target compound in a vapor mixture containing unknown concentration of the target compound and interferants, comprising the steps of: providing a surface acoustic wave sensor which has been calibrated to produce a signal which is an average one cycle response per unit concentration of the target compound; exposing this calibrated sensor to said vapor mixture to produce an output signal; and mathematically processing this output signal to identify the target compound and its concentration in the mixture.
Claim 7
Independent Claim
87 words
A method of detecting and determining the concentration of a target compound in a vapor mixture containing unknown concentration of the target compound and interferants, comprising the steps of: providing a surface acoustic wave sensor which has been calibrated to produce a signal which is an average one cycle response per unit concentration of the target compound; exposing this calibrated sensor to said vapor mixture to produce an output signal; and mathematically processing this output signal to identify the target compound and its concentration in the mixture.
Claim 8
Dependent Claim
65 words
The method of claim 5 wherein the step of mathematically processing the output signal of said sensor comprises: constructing a calibration matrix comprising vectors that represent the average one cycle response of the sensor per unit concentration of the target compound; processing the output signal of said sensor and said calibration matrix by multidimensional statistical methods to detect the target compound and determine its concentration.
Claim 9
Dependent Claim
52 words
The method of claim 6 wherein the step of processing the output signal of said sensor and said calibration matrix includes forming weighting vectors from said calibration matrix and multiplying said weighting vectors by said output signal to obtain a vector representing the concentrations of said target compound in said vapor mixture.
Claim 10
Independent Claim
137 words
A method of detecting at least one target compound and its respective concentration in a vapor mixture having one or more target compounds and interferants, comprising the steps of: directing sample mixtures containing known concentrations of said target compounds through each of an array of surface acoustic wave sensors to produce output signals which are each processed to provide a set of vectors representing the average one cycle response per unit concentration for each of the target compounds; constructing a matrix with each of the vectors of target compound response forming the columns of the matrix; exposing said sensor array to a mixture containing unknown concentrations of one or more of said target compounds to produce an output signal; mathematically processing this output signal to identify any one or more of the target compounds and their concentrations.
Claim 11
Independent Claim
137 words
A method of detecting at least one target compound and its respective concentration in a vapor mixture having one or more target compounds and interferants, comprising the steps of: directing sample mixtures containing known concentrations of said target compounds through each of an array of surface acoustic wave sensors to produce output signals which are each processed to provide a set of vectors representing the average one cycle response per unit concentration for each of the target compounds; constructing a matrix with each of the vectors of target compound response forming the columns of the matrix; exposing said sensor array to a mixture containing unknown concentrations of one or more of said target compounds to produce an output signal; mathematically processing this output signal to identify any one or more of the target compounds and their concentrations.
Claim 12
Dependent Claim
35 words
The method as claimed in claim 8 wherein the last mentioned step includes forming weighting vectors from the target compound response matrix and using this vector to extract the concentrations of the identified target compounds.
Claim 13
Dependent Claim
42 words
The method of claim 9 wherein the step of processing the output signal of said sensor array further comprises multiplying said weighting vectors by said output signal to obtain a vector representing the concentrations of said target compounds in said vapor mixture.
Claim 14
Dependent Claim
89 words
The method of claim 8 wherein the step of mathematically processing the output signal of said sensor array to identify target compounds comprises: processing the output signal of said sensor array to obtain a vapor mixture response matrix comprising a vector for each sensor in said sensor array representing the response of said sensor to the exposure of said vapor mixture; and determining the presence and concentration of target compounds in said vapor mixture by mathematical operations on said vapor mixture response matrix by said target compound response matrix.
Claim 15
Dependent Claim
32 words
The method of claim 11 wherein determining the presence and concentrations of said target compounds comprises multiplying said vapor mixture response matrix by the pseudo inverse of said target compound response matrix.
Claim 16
Dependent Claim
66 words
The method of claim 8 wherein the step of directing known concentrations of said target compounds through each sensor of said sensor array comprises: recording the response of each sensor to the known concentration of said target compound; and scaling this response data to obtain a set of vectors representing the average one cycle response of said sensor to a unit concentration of said target compound.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |