Method and device for in vivo measuring the concentration of a substance in the blood
First Claim
1. 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 μ
- m, 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 μ
m;
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.
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Accused Products
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.
154 Citations
29 Claims
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1. 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 μ - m, 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 μ
m;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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- m, 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 μ
-
12. 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 μ - m;
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. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
- m;
Specification