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Method and device for in vivo measuring the concentration of a substance in the blood

Assignee: Novo Nordisk AS
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Filing: 1993-09-24
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Granted: 1995-09-26
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Expires: 2013-09-24
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Abstract

Abstract In vivo measurement of the concentration of a substance in the blood, e.g. glucose, despite varying concentrations of interfering components, e.g. protein and fat, by measuring the absorption of infra red light at a pair of selected wavelengths in the range 1-40 μm for each of the substance and the components one being a measuring wavelength at which the substance or component show a specific absorption and another being a reference wavelength at which the substance or component shows a low absorption, at least one wavelength being selected from the range 1-10 μm. The absorption is measured using a detector providing a computable electric signal corresponding to the absorbed amount of infra red radiation at the respective wavelengths. The electric signals are used to calculate the concentration of the substance taking into account the absorption caused by the interfering components.

Inventors

  • 👤 Vaughan Clift

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 16:34
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/1459; A61B5/14532

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 216 words
A method for in vivo measurement of a substance's concentration in blood, despite varying concentrations of interfering components, by measuring absorption of selected wavelengths of infrared light, the method comprising, selecting for each of the substance and the components a pair of different wavelengths of infrared light from the range of 1-40 μm, one being a measuring wavelength at which the substance or component show a specific absorption and another being a reference wavelength at which the substance or component shows a low absorption, at least one wavelength being selected from a range of 3-10 μm; transmitting the selected wavelengths of infrared light to a surface part covering vascularized tissue of a person whose blood is being tested for its concentration of the substance; placing at said surface part a detector detecting for each selected wavelength the absorbed amount of infrared radiation and giving of a computable electric signal expressing the measured absorption; calculating the concentrations of the interfering components, and calculating the concentration of the substance using the absorption measurement at the substance measuring and reference wavelengths taking into account the absorption caused by the interfering components at the measuring and reference wavelengths for this substance, the interfering absorption being calculated taking into account the measured concentrations of the interfering components and experimentally derived constants.
Claim 2
Independent Claim 216 words
A method for in vivo measurement of a substance's concentration in blood, despite varying concentrations of interfering components, by measuring absorption of selected wavelengths of infrared light, the method comprising, selecting for each of the substance and the components a pair of different wavelengths of infrared light from the range of 1-40 μm, one being a measuring wavelength at which the substance or component show a specific absorption and another being a reference wavelength at which the substance or component shows a low absorption, at least one wavelength being selected from a range of 3-10 μm; transmitting the selected wavelengths of infrared light to a surface part covering vascularized tissue of a person whose blood is being tested for its concentration of the substance; placing at said surface part a detector detecting for each selected wavelength the absorbed amount of infrared radiation and giving of a computable electric signal expressing the measured absorption; calculating the concentrations of the interfering components, and calculating the concentration of the substance using the absorption measurement at the substance measuring and reference wavelengths taking into account the absorption caused by the interfering components at the measuring and reference wavelengths for this substance, the interfering absorption being calculated taking into account the measured concentrations of the interfering components and experimentally derived constants.
Claim 3
Dependent Claim 26 words
A method according to claim 1, wherein the substance the concentration of which is measured is glucose and the interfering components are fat, protein and water.
Claim 4
Dependent Claim 28 words
A method according to claim 1, wherein the substance the concentration of which is measured is CO 2 and the interfering components are glucose, fat, protein and water.
Claim 5
Dependent Claim 27 words
A method according to claim 1, wherein the substance the concentration of which is measured is ethanol and the interfering components are glucose, fat, protein and water.
Claim 6
Dependent Claim 26 words
A method according to claim 4, wherein the sample wavelength and the reference wavelength used for glucose are 9.5 ±0.5 μm and 7.7 ±0.5 μm, respectively.
Claim 7
Dependent Claim 25 words
A method according to claim 4, wherein the sample wavelength and the reference used for glucose are 3.47 ±0.5 μm and 2.96 ±0.5 μm, respectively.
Claim 8
Independent Claim 24 words
A method according to 4, wherein the sample wavelength and the reference wavelength for fat are 5.74 ±0.5 μm and 5.58 ±0.5 μm, respectively.
Claim 9
Independent Claim 24 words
A method according to 4, wherein the sample wavelength and the reference wavelength for fat are 5.74 ±0.5 μm and 5.58 ±0.5 μm, respectively.
Claim 10
Dependent Claim 25 words
A method according to claim 4, wherein the sample wavelength and the reference wavelength for fat are 3.513 ±0.5 μm and 3.57 ±0.5 μm, respectively.
Claim 11
Dependent Claim 25 words
A method according to claim 4, wherein the sample wavelength and the reference wavelength for protein are 6.5 ±0.5 μm and 6.7 ±0.5 μm, respectively.
Claim 12
Dependent Claim 29 words
A method according to claim 1, wherein the light is transmitted to the tissue and the light absorption is measured by attenuated total reflection transcutaneously, i.e. invasively or non-invasively.
Claim 13
Dependent Claim 35 words
A method according to claim 1, wherein the light is transmitted to the outer side of the surface part and the absorption is measured by detecting the heat generated in the tissue beneath the skin.
Claim 14
Independent Claim 148 words
An apparatus for measurement of the concentration of a substance in blood despite varying concentrations of interfering components by measuring the absorption of selected wavelengths of infrared light, this apparatus comprising a light aggregate able to provide selectable narrow bands of infrared light in the wavelength range of 1-40 μm; light transmitting means for transmitting selected narrow bands of light to a measuring spot; a detector detecting for each selected narrow band of infrared light the absorbed amount of infrared radiation at the measuring spot and giving of a computable electric signal expressing the measured absorption, a calculating unit for calculating the concentration of the substance measuring and reference wavelengths taking into account the absorption caused by the interfering components at the measuring and reference wavelengths for this substance, the interfering absorption being calculated taking into account the measured concentrations of the interfering components and experimentally derived constants.
Claim 15
Independent Claim 148 words
An apparatus for measurement of the concentration of a substance in blood despite varying concentrations of interfering components by measuring the absorption of selected wavelengths of infrared light, this apparatus comprising a light aggregate able to provide selectable narrow bands of infrared light in the wavelength range of 1-40 μm; light transmitting means for transmitting selected narrow bands of light to a measuring spot; a detector detecting for each selected narrow band of infrared light the absorbed amount of infrared radiation at the measuring spot and giving of a computable electric signal expressing the measured absorption, a calculating unit for calculating the concentration of the substance measuring and reference wavelengths taking into account the absorption caused by the interfering components at the measuring and reference wavelengths for this substance, the interfering absorption being calculated taking into account the measured concentrations of the interfering components and experimentally derived constants.
Claim 16
Dependent Claim 44 words
An apparatus according to claim 12 enclosed in a portable housing and comprising an ATR device with an external surface on which a sample may be placed, and focusing means for transmitting light into the device and from the device to a the detector.
Claim 17
Dependent Claim 29 words
An apparatus according to claim 13 where the light aggregate comprises a wide-banded light source and a number of filters each transmitting one of the selected narrow light bands.
Claim 18
Dependent Claim 26 words
An apparatus according to claim 13, wherein the light aggregate comprises a number of surface emitting light diodes each emitting infrared light of a chosen wavelength.
Claim 19
Dependent Claim 26 words
An apparatus according to claim 13, wherein the light aggregate comprises means for focusing the light on an optical coupling means for the light transmitting means.
Claim 20
Dependent Claim 25 words
An apparatus according to claim 16, wherein the chopper means is provided as an electronic circuit controlling the energizing of light diodes or semiconductor sources.
Claim 21
Dependent Claim 28 words
An apparatus according to claim 13, wherein the light aggregate comprises chopper means for chopping at preset chopping frequencies the light wave lengths transmitted from the light aggregate.
Claim 22
Dependent Claim 16 words
An apparatus according to claim 18, wherein the chopper means is a rotating diaphragm with cut-outs.
Claim 23
Dependent Claim 29 words
An apparatus according to claim 13, comprising an optical needle probe ATR cell having an input fibre and an output fibre, the detector being provided at the output fibre.
Claim 24
Dependent Claim 27 words
An apparatus according to claim 20, wherein the ATR needle probe cell is coated with a metal such that it acts as a surface plasma resonance device.
Claim 25
Dependent Claim 29 words
An apparatus according to claim 21, wherein the metal coated ATR needle probe is jacketed by a cellulose permeable membrane with a gap between the membrane and the probe.
Claim 26
Dependent Claim 35 words
An apparatus according to claim 22, wherein the membrane has a glucose specific enzyme or system of enzymes and the ATR prove is used to measure the product of enzymic reaction of the glucose molecule.
Claim 27
Dependent Claim 52 words
An apparatus according to claim 12, wherein the detector comprises a first and a second chamber each having an open side placed against the skin at the measuring spot, and a pressure transducer comprising a diaphragm and measuring the pressure difference between the chambers representing this differential pressure by an electric signal.
Claim 28
Dependent Claim 28 words
An apparatus according to claim 24, wherein the first chamber at a side opposite the open side has an inlet for infrared radiation transmitted from the light aggregate.
Claim 29
Dependent Claim 26 words
An apparatus according to claim 24, wherein both chambers have at a side opposite the open side inlets for infrared radiation transmitted for the light aggregate.
Claim 30
Dependent Claim 40 words
An apparatus according to claim 24, wherein a further transducer is added to each chamber at an end thereof and with a diaphragm lying in a plane parallel with the plane of the diaphragm of the transducer between the chambers.
Claim 31
Dependent Claim 22 words
An apparatus according to claim 27, wherein each chamber has an inlet for infrared radiation communicates with a compartment containing a desiccant.
Claim 32
Dependent Claim 26 words
An apparatus according to claim 27, wherein each chamber has an inlet for infrared radiation each chamber having a wall with a rigid water permeable membrane.

References Cited (Backward Citations)

US4169676A Cited
US4427889A Cited
US4655225A Cited
US4975581A Cited
US5137023A Cited
US5313941A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-09-25 1999-03-27 1999-09-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-09-25 2003-03-27 2003-09-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-09-25 2007-03-27 2007-09-26 $7700.00 Window Closed / Lapsed

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