US6049728A
Expired / Lapsed
US
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Method and apparatus for noninvasive measurement of blood glucose by photoacoustics
Assignee: Northrop Grumman Systems Corp
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Filing: 1998-11-12
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Granted: 2000-04-11
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Expires: 2018-11-12
Abstract
Abstract A method and apparatus for noninvasively measuring blood glucose levels provides an indirect, reagentless, differential, photoacoustic technique which responds to absorption in a thin surface layer. An excitation source provides electromagnetic energy which is utilized to irradiate the tissue, such as skin. The output of the radiation of the excitation source at the desired wavelength is coupled through a transmission device, such as a fiber optic bundle, which irradiates the electromagnetic energy onto the body surface. Upon irradiation, acoustic energy is generated by the absorption of the electromagnetic energy in a relatively thin layer of the sample to be measured, characterized by a heat-diffusing length. The acoustic energy is detected by the probe which includes a measuring cell, reference cell, window and differential microphone. Absorption of the light beam results in periodic heating of the tissue, at and near the tissue surface. The air in contact with the tissue surface in the measuring cell is in turn heated, and produces an acoustic emission in the measuring cell. This acoustic emission is detected with the differential microphone, one end of which is positioned in the measuring cell and the other end of which is positioned in the reference cell. A processor determines the concentration of the substance based upon the detected acoustic signal.
Inventors
- 👤 Mau-Song Chou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:54
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/1702; A; A61; A61B; A61B5/00; A61B5/0093; A61B5/0095; A61B5/145; A61B5/14532; A61B5/1455
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
101 words
An apparatus for determining a concentration of a component in a subcutaneous bodily fluid, comprising: a source for irradiating a portion of a subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said irradiation; a detector comprising a measuring cell and a reference cell for detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy; and a processor for determining a concentration of a component in said subcutaneous bodily fluid in response to said acoustic signal and characteristics of said component.
Claim 2
Independent Claim
101 words
An apparatus for determining a concentration of a component in a subcutaneous bodily fluid, comprising: a source for irradiating a portion of a subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said irradiation; a detector comprising a measuring cell and a reference cell for detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy; and a processor for determining a concentration of a component in said subcutaneous bodily fluid in response to said acoustic signal and characteristics of said component.
Claim 3
Dependent Claim
12 words
The apparatus claimed in claim 1 wherein said component comprises blood glucose.
Claim 4
Dependent Claim
15 words
The apparatus claimed in claim 1 wherein said bodily fluid exists within an inner lip.
Claim 5
Dependent Claim
12 words
The apparatus claimed in claim 1, wherein said second medium comprises air.
Claim 6
Dependent Claim
13 words
The apparatus claimed in claim 1, wherein said source further comprises a laser.
Claim 7
Dependent Claim
22 words
The apparatus claimed in claim 1, wherein said source provides electromagnetic energy at wavelengths corresponding to the absorption characteristics of said component.
Claim 8
Dependent Claim
11 words
The apparatus claimed in claim 6, wherein said component comprises glucose.
Claim 9
Dependent Claim
18 words
The apparatus claimed in claim 7, wherein said range of wavelengths is between about 1520 and 1850 nanometers.
Claim 10
Dependent Claim
18 words
The apparatus claimed in claim 7, wherein said range of wavelengths is between about 2050 to 2340 nanometers.
Claim 11
Dependent Claim
57 words
The apparatus claimed in claim 1, wherein said detector for detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy, further comprises: a device for converting said acoustic energy to said acoustic signal disposed externally of said first medium and in contact relation with said second medium for detecting said acoustic energy.
Claim 12
Dependent Claim
12 words
The apparatus claimed in claim 10, wherein said device comprises a microphone.
Claim 13
Dependent Claim
25 words
The apparatus claimed in claim 1, further comprising: a device for recording and averaging said acoustic signal and generating a photoacoustic spectrum of said component.
Claim 14
Dependent Claim
40 words
The apparatus claimed in claim 1, wherein said processor for determining the concentration of said component in response to said acoustic signal and characteristics of said component, further comprises: an analyzer for analyzing a photoacoustic spectrum of said acoustic signal.
Claim 15
Dependent Claim
21 words
The apparatus claimed in claim 1, further comprising: a guide for transmitting said irradiation from said source to said first medium.
Claim 16
Dependent Claim
14 words
The apparatus claimed in claim 14, wherein said guide further comprises a fiber-optic guide.
Claim 17
Independent Claim
133 words
A method for determining a concentration of a component in a subcutaneous bodily fluid, comprising the steps of: irradiating a portion of subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said irradiation; measuring said acoustic energy generated in response to said irradiating step and providing a measured acoustic signal in response to said measured acoustic energy; detecting reference acoustic energy and providing a reference acoustic signal in response to said reference acoustic energy: measuring a difference in acoustic response between said measured acoustic signal and said reference acoustic signal; and determining a concentration of a component in said subcutaneous bodily fluid in response to said measuring and reference acoustic signals, said difference, and characteristics of said component.
Claim 18
Independent Claim
133 words
A method for determining a concentration of a component in a subcutaneous bodily fluid, comprising the steps of: irradiating a portion of subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said irradiation; measuring said acoustic energy generated in response to said irradiating step and providing a measured acoustic signal in response to said measured acoustic energy; detecting reference acoustic energy and providing a reference acoustic signal in response to said reference acoustic energy: measuring a difference in acoustic response between said measured acoustic signal and said reference acoustic signal; and determining a concentration of a component in said subcutaneous bodily fluid in response to said measuring and reference acoustic signals, said difference, and characteristics of said component.
Claim 19
Dependent Claim
12 words
The method claimed in claim 16, wherein said component comprises blood glucose.
Claim 20
Dependent Claim
15 words
The method claim in claim 16, wherein said bodily fluid exists within an inner lip.
Claim 21
Dependent Claim
12 words
The method claimed in claim 16, wherein said second medium comprises air.
Claim 22
Dependent Claim
51 words
The method claimed in claim 16, wherein said step of irradiating a portion of said bodily fluid by heat-diffusion to generate acoustic energy propagating in said second medium in response to said irradiation, further comprises the step of: providing electromagnetic energy at wavelengths corresponding to the absorption characteristics of said component.
Claim 23
Dependent Claim
11 words
The method claimed in claim 20, wherein said component comprises glucose.
Claim 24
Dependent Claim
18 words
The method claimed in claim 21, wherein said range of wavelengths is between about 1520 and 1850 nanometers.
Claim 25
Dependent Claim
18 words
The method claimed in claim 21, wherein said range of wavelengths is between about 2050 to 2340 nanometers.
Claim 26
Dependent Claim
60 words
The method claimed in claim 16, wherein said step of detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy, further comprises the step of: converting said acoustic energy to said acoustic signal utilizing a device disposed externally of said bodily fluid and in contact relation with said second medium for detecting said acoustic energy.
Claim 27
Dependent Claim
25 words
The method claimed in claim 16, further comprising the step of: recording and averaging said acoustic signal and generating a photoacoustic spectrum of said component.
Claim 28
Dependent Claim
40 words
The method claimed in claim 16, wherein said step of determining the concentration of said component in response to said acoustic signal and characteristics of said component, further comprises the step of: analyzing a photoacoustic spectrum of said acoustic signal.
Claim 29
Independent Claim
24 words
The method claimed in 16, filler comprising the step of: transmitting said irradiation from said source to said subcutaneous bodily fluid utilizing a guide.
Claim 30
Dependent Claim
13 words
The method claimed in claim 27, wherein said guide comprises a fiber-optic guide.
Claim 31
Independent Claim
145 words
An apparatus for measuring a concentration of an analyte in a subcutaneous bodily fluid, comprising: means for providing electromagnetic energy at wavelengths corresponding to the absorption characteristics of an analyte to excite a portion of subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said excitation; first detecting means for detecting said acoustic energy and providing a first acoustic signal in response to said acoustic energy; second detecting means for detecting noise and providing a second acoustic signal in response to said noise; means for measuring the difference in acoustic response of said first detecting means and said second detecting means; and means for determining a concentration of said analyte in response to said first acoustic signal, said second acoustic signal, said difference, and an absorption spectrum of said analyte.
Claim 32
Independent Claim
145 words
An apparatus for measuring a concentration of an analyte in a subcutaneous bodily fluid, comprising: means for providing electromagnetic energy at wavelengths corresponding to the absorption characteristics of an analyte to excite a portion of subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said excitation; first detecting means for detecting said acoustic energy and providing a first acoustic signal in response to said acoustic energy; second detecting means for detecting noise and providing a second acoustic signal in response to said noise; means for measuring the difference in acoustic response of said first detecting means and said second detecting means; and means for determining a concentration of said analyte in response to said first acoustic signal, said second acoustic signal, said difference, and an absorption spectrum of said analyte.
Claim 33
Dependent Claim
12 words
The apparatus claimed in claim 29, wherein said analyte comprises blood glucose.
Claim 34
Dependent Claim
12 words
The apparatus claimed in claim 29, wherein said second medium comprises air.
Claim 35
Independent Claim
158 words
A method of measuring a concentration of an analyte in a subcutaneous bodily fluid, comprising the steps of: providing electromagnetic energy at wavelengths corresponding to the absorption characteristics of an analyte to excite a portion of subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said excitation; detecting said acoustic energy by a measuring cell and providing a first acoustic signal in response to said acoustic energy; detecting noise by a reference cell and providing a second acoustic signal in response to said noise; receiving said first acoustic signal from said measuring cell; receiving said second acoustic signal from said reference cell; measuring the difference in acoustic response from said measuring cell and said reference cell; and determining a concentration of said analyte in response to said first acoustic signal said second acoustic signal, said difference, and an absorption spectrum of said analyte.
Claim 36
Independent Claim
158 words
A method of measuring a concentration of an analyte in a subcutaneous bodily fluid, comprising the steps of: providing electromagnetic energy at wavelengths corresponding to the absorption characteristics of an analyte to excite a portion of subcutaneous bodily fluid by heat-diffusion to generate acoustic energy propagating in a medium over a surface of said subcutaneous bodily fluid in response to said excitation; detecting said acoustic energy by a measuring cell and providing a first acoustic signal in response to said acoustic energy; detecting noise by a reference cell and providing a second acoustic signal in response to said noise; receiving said first acoustic signal from said measuring cell; receiving said second acoustic signal from said reference cell; measuring the difference in acoustic response from said measuring cell and said reference cell; and determining a concentration of said analyte in response to said first acoustic signal said second acoustic signal, said difference, and an absorption spectrum of said analyte.
Claim 37
Dependent Claim
12 words
The method claimed in claim 32, wherein said analyte comprises blood glucose.
Claim 38
Dependent Claim
12 words
The method claimed in claim 32, wherein said second medium comprises air.
Claim 39
Dependent Claim
37 words
The method claimed in claim 32, wherein said step of determining said concentration in response to said acoustic signal and absorption spectrum of said analyte, further comprises the step of: generating a photoacoustic spectrum of said analyte.
Claim 40
Independent Claim
98 words
An apparatus for determining a concentration of glucose in a subcutaneous body part, comprising: a source for irradiating a portion of a subcutaneous body part by heat diffusion to generate acoustic energy propagating in air over a surface of said subcutaneous body part in response to said irradiation; a detector comprising a measuring cell and a reference cell for detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy; and a processor for determining a concentration of glucose in said subcutaneous body art in response to said acoustic signal and characteristics of glucose.
Claim 41
Independent Claim
98 words
An apparatus for determining a concentration of glucose in a subcutaneous body part, comprising: a source for irradiating a portion of a subcutaneous body part by heat diffusion to generate acoustic energy propagating in air over a surface of said subcutaneous body part in response to said irradiation; a detector comprising a measuring cell and a reference cell for detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy; and a processor for determining a concentration of glucose in said subcutaneous body art in response to said acoustic signal and characteristics of glucose.
Claim 42
Dependent Claim
14 words
The apparatus claimed in claim 36, wherein said body part comprises an inner lip.
Claim 43
Dependent Claim
13 words
The apparatus claimed in claim 36, wherein said source further comprises a laser.
Claim 44
Dependent Claim
23 words
The apparatus claimed in claim 36, wherein said source provides electromagnetic energy at wavelength ranges corresponding to the absorption characteristics of said glucose.
Claim 45
Dependent Claim
18 words
The apparatus claimed in claim 39, wherein said range of wavelengths is between about 1520 and 1850 nanometers.
Claim 46
Dependent Claim
18 words
The apparatus claimed in claim 39, wherein said range of wavelengths is between about 2050 to 2340 nanometers.
Claim 47
Dependent Claim
56 words
The apparatus claimed in claim 36, wherein said detector for detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy, further comprises: a device for converting said acoustic energy to said acoustic signal disposed externally of said body part and in contact relation with said air for detecting said acoustic energy.
Claim 48
Dependent Claim
12 words
The apparatus claimed in claim 42, wherein said device comprises a microphone.
Claim 49
Dependent Claim
25 words
The apparatus claimed in claim 36, further comprising: a device for recording and averaging said acoustic signal and generating a photoacoustic spectrum of said glucose.
Claim 50
Dependent Claim
43 words
The apparatus claimed in claim 36, wherein said processor for determining the concentration of glucose in said subcutaneous body part in response to said acoustic signal and characteristics of glucose, further comprises: an analyzer for analyzing a photoacoustic spectrum of said acoustic signal.
Claim 51
Dependent Claim
21 words
The apparatus claimed in claim 36, further comprising: a guide for transmitting said irradiation from said source to said body part.
Claim 52
Dependent Claim
14 words
The apparatus claimed in claim 46, wherein said guide further comprises a fiber-optic guide.
Claim 53
Independent Claim
143 words
A method for determining a concentration of glucose in a subcutaneous body part, comprising the steps of: irradiating a portion of a subcutaneous body part by heat-diffusion to generate acoustic energy propagating in air over a surface of said body part in response to said irradiation; detecting said acoustic energy by a measuring cell and providing a first acoustic signal in response to said acoustic energy; detecting noise by a reference cell and providing a second acoustic signal in response to said noise; receiving said first acoustic signal from said measuring cell; receiving said second acoustic signal from said reference cell; measuring the difference in acoustic response from said measuring cell and said reference cell; and determining a concentration of glucose in said subcutaneous body part in response to said first acoustic signal, said second acoustic signal, said difference, and characteristics of glucose.
Claim 54
Independent Claim
143 words
A method for determining a concentration of glucose in a subcutaneous body part, comprising the steps of: irradiating a portion of a subcutaneous body part by heat-diffusion to generate acoustic energy propagating in air over a surface of said body part in response to said irradiation; detecting said acoustic energy by a measuring cell and providing a first acoustic signal in response to said acoustic energy; detecting noise by a reference cell and providing a second acoustic signal in response to said noise; receiving said first acoustic signal from said measuring cell; receiving said second acoustic signal from said reference cell; measuring the difference in acoustic response from said measuring cell and said reference cell; and determining a concentration of glucose in said subcutaneous body part in response to said first acoustic signal, said second acoustic signal, said difference, and characteristics of glucose.
Claim 55
Dependent Claim
14 words
The method claimed in claim 48, wherein said body part comprises an inner lip.
Claim 56
Dependent Claim
56 words
The method claimed in claim 48, wherein said step of irradiating a portion of said body part by heat-diffusion to generate acoustic energy propagating in air over a surface of said body part in response to said irradiation, further comprises the step of: providing electromagnetic energy at wavelengths corresponding to the absorption characteristics of said glucose.
Claim 57
Dependent Claim
18 words
The method claimed in claim 50, wherein said range of wavelengths is between about 1520 and 1850 nanometers.
Claim 58
Dependent Claim
18 words
The method claimed in claim 50, wherein said range of wavelengths is between about 2050 to 2340 nanometers.
Claim 59
Dependent Claim
60 words
The method claimed in claim 48, wherein said step of detecting said acoustic energy and providing an acoustic signal in response to said acoustic energy, further comprises the step of: converting said acoustic energy to said acoustic signal utilizing a device disposed externally of said subcutaneous body part and in contact relation with said air for detecting said acoustic energy.
Claim 60
Dependent Claim
25 words
The method claimed in claim 48, further comprising the step of: recording and averaging said acoustic signal and generating a photoacoustic spectrum of said glucose.
Claim 61
Dependent Claim
40 words
The method claimed in claim 48, wherein said step of determining the concentration of said glucose in response to said acoustic signal and characteristics of said glucose, further comprises the step of: analyzing a photoacoustic spectrum of said acoustic signal.
Claim 62
Dependent Claim
24 words
The method claimed in claim 48, further comprising the step of: transmitting said irradiation from said source to said body part utilizing a guide.
Claim 63
Dependent Claim
13 words
The method claimed in claim 56, wherein said guide comprises a fiber-optic guide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-04-11 | 2003-10-11 | 2004-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-04-11 | 2007-10-11 | 2008-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-04-11 | 2011-10-11 | 2012-04-11 | $7700.00 | Window Closed / Lapsed |