US5459317A
Expired / Lapsed
US
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Method and apparatus for non-invasive detection of physiological chemicals, particularly glucose
Assignee: University of Iowa Research Foundation
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Filing: 1994-02-14
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Granted: 1995-10-17
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Expires: 2014-02-14
Abstract
Abstract Non-invasive measurements of physiological chemicals such as glucose are made using infrared radiation and a signal processing system that permits the construction of a device suited for home use. The level of a selected physiological chemical in a test subject is determined in a non-invasive and quantitative manner by a method comprising the steps of: (a) irradiating a portion of the test subject with near-infrared radiation such that the radiation is transmitted through or reflected from the test subject; (b) collecting data concerning the transmitted or reflected infrared radiation using a detector; (c) digitally filtering the collected data to isolate a portion of the data indicative of the physiological chemical; and (d) determining the amount of physiological chemical in the test subject by applying a defined mathematical model to the digitally filtered data. The data collected may be in the form of an absorbance spectrum, i.e., a representation of the variation in absorbance as a function of wavelength; or in the form of an interferogram, i.e., a representation of infrared light intensity as a function of the retardation of the moving mirror in the interferometer, and thus of time.
Inventors
- 👤 Gary W. Small
- 👤 Mark Arnold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:53
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/45; A; A61; A61B; A61B5/00; A61B5/145; A61B5/14532; A61B5/1455; A61B5/72; A61B5/7235; A61B5/7253; A61B5/7257; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/359
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
96 words
A method for non-invasive quantitative detection of a physiological chemical in a test subject comprising the steps of: (a) irradiating a portion of the test subject with near-infrared radiation such that the radiation is transmitted through or reflected from the test subject; (b) collecting data concerning the transmitted or reflected infrared radiation using a detector; (c) digitally filtering the collected data to isolate a portion of the data indicative of the physiological chemical; and (d) determining the amount of physiological chemical in the test subject by applying a defined mathematical model to the digitally filtered data.
Claim 2
Independent Claim
96 words
A method for non-invasive quantitative detection of a physiological chemical in a test subject comprising the steps of: (a) irradiating a portion of the test subject with near-infrared radiation such that the radiation is transmitted through or reflected from the test subject; (b) collecting data concerning the transmitted or reflected infrared radiation using a detector; (c) digitally filtering the collected data to isolate a portion of the data indicative of the physiological chemical; and (d) determining the amount of physiological chemical in the test subject by applying a defined mathematical model to the digitally filtered data.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein the digital filtering is performed by a Fourier filtering process.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein the collected data is in the form of an absorbance spectrum.
Claim 5
Dependent Claim
40 words
A method according to claim 3, wherein the spectrum is digitally filtered by performing a Fourier transform on the absorbance spectrum; multiplying the transformed spectrum by a Gaussian function; and applying an inverse Fourier transformation to the multiplied transformed spectrum.
Claim 6
Dependent Claim
28 words
A method according to claim 4, wherein the mathematical model applied to the digitally filtered spectrum applies coefficients developed using a partial least squares regression multivariate calibration procedure.
Claim 7
Dependent Claim
40 words
A method according to claim 5, wherein the spectrum is digitally filtered by performing a Fourier transform on the absorbance spectrum; multiplying the transformed spectrum by a Gaussian function; and applying an inverse Fourier transformation to the multiplied transformed spectrum.
Claim 8
Dependent Claim
11 words
A method according to claim 1, wherein the chemical is glucose.
Claim 9
Dependent Claim
40 words
A method according to claim 7, wherein the spectrum is digitally filtered by performing a Fourier transform on the absorbance spectrum; multiplying the transformed spectrum by a Gaussian function; and applying an inverse Fourier transformation to the multiplied transformed spectrum.
Claim 10
Dependent Claim
23 words
A method according to claim 8, wherein the spectrum that is digitally filtered spans the region from 6500 to 5800 cm -1 .
Claim 11
Dependent Claim
36 words
A method according to claim 8, wherein the magnitude of the digitally filtered spectrum is compared to a standard value using a series of regression coefficients developed using a partial least squares regression multivariate calibration procedure.
Claim 12
Dependent Claim
17 words
A method according to claim 1, wherein the collected data is in the form of an interferogram.
Claim 13
Dependent Claim
17 words
A method according to claim 11, wherein only a short segment of an entire interferogram is analyzed.
Claim 14
Dependent Claim
57 words
A method according to claim 11, wherein the digital filtering step comprises the steps of performing a fast Fourier transform on the interferogram to obtain a transformed spectrum; multiplying the transformed spectrum with a Gaussian function to select for a peak diagnostic for the physiological chemical; and applying an inverse Fourier transform to the multiplied, transformed spectrum.
Claim 15
Dependent Claim
12 words
A method according to claim 11, wherein the physiological chemical is glucose.
Claim 16
Dependent Claim
57 words
A method according to claim 14, wherein the digital filtering step comprises the steps of performing a fast Fourier transform on the interferogram to obtain a transformed spectrum; multiplying the transformed spectrum with a Gaussian function to select for a peak diagnostic for the physiological chemical; and applying an inverse Fourier transform to the multiplied, transformed spectrum.
Claim 17
Dependent Claim
22 words
A method according to claim 15, wherein the Gaussian function is selected to isolate the glucose-associated absorbance at 4400 cm -1 .
Claim 18
Dependent Claim
14 words
A method according to claim 14, wherein the interferogram is a short segment interferogram.
Claim 19
Dependent Claim
73 words
A method according to claim 1, wherein the collected spectrum is an interferogram and the digital filtering is performed directly on the interferogram to select out waveforms within the interferogram having a frequency equal to 2 X wavenumber of X mirror velocity radiation where the wavenumber has units of cm -1 , mirror velocity is the velocity of mirror travel in the interferometer used to generate the interferogram expressed in units of cm/sec.
Claim 20
Independent Claim
85 words
A device for measurement of glucose concentration in a sample being irradiated with near infrared radiation comprising: (a) means for collecting data concerning near-infrared radiation transmitted through or reflected from the sample; (b) means for digitally filtering the collected data to isolate a portion of data indicative of glucose; (c) means for applying a defined mathematical model to the digitally filtered data, whereby the amount of glucose in the test subject is determined; and (d) means for reporting the amount of glucose in the sample.
Claim 21
Independent Claim
85 words
A device for measurement of glucose concentration in a sample being irradiated with near infrared radiation comprising: (a) means for collecting data concerning near-infrared radiation transmitted through or reflected from the sample; (b) means for digitally filtering the collected data to isolate a portion of data indicative of glucose; (c) means for applying a defined mathematical model to the digitally filtered data, whereby the amount of glucose in the test subject is determined; and (d) means for reporting the amount of glucose in the sample.
Claim 22
Independent Claim
111 words
An apparatus for the non-invasive measurement of one or more physiological chemicals in a test subject, comprising, (a) means for irradiating a portion of the surface of the test subject with near-infrared radiation such that transmitted or reflected near-infrared radiation is available for collection; (b) means for collecting data concerning the transmitted or reflected near-infrared radiation; (c) means for digitally filtering the collected data to isolate a portion of data indicative of the physiological chemical; (d) means for applying a defined mathematical model to the digitally filtered data, whereby the amount of chemical in the test subject is determined; and (e) means for reporting the amount of chemical in the sample.
Claim 23
Independent Claim
111 words
An apparatus for the non-invasive measurement of one or more physiological chemicals in a test subject, comprising, (a) means for irradiating a portion of the surface of the test subject with near-infrared radiation such that transmitted or reflected near-infrared radiation is available for collection; (b) means for collecting data concerning the transmitted or reflected near-infrared radiation; (c) means for digitally filtering the collected data to isolate a portion of data indicative of the physiological chemical; (d) means for applying a defined mathematical model to the digitally filtered data, whereby the amount of chemical in the test subject is determined; and (e) means for reporting the amount of chemical in the sample.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-10-16 | 1999-04-17 | 1999-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-16 | 2003-04-17 | 2003-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-16 | 2007-04-17 | 2007-10-17 | $7700.00 | Window Closed / Lapsed |