Method and device for determining the concentration of a substance in body liquid
First Claim
1. A method for determining the concentration of a substance in a in-vitro or in-vivo specimen containing body liquid comprising the steps of arranging a first electrode (18) at said specimen, wherein said first electrode is electrically insulated from the specimen, applying a modulated electrical voltage to the first electrode for generating a modulated field in the specimen and measuring at least one parameter (A, phi) depending on a response of the specimen to the field and determining the concentration therefrom.
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Accused Products
Abstract
For measuring the concentration of a substance in body fluid, such as the glucose level in blood or tissue, a strip electrode (18) and a ring electrode (19) are arranged at the specimen. The ring electrode (19) is in direct electrical contact with the specimen while the strip electrode (18) is electrically insulated therefrom. The strip electrode (18) is arranged parallel to an arm or a leg for obtaining a large interaction length. The electrodes (18, 19) form a capacitor in a resonant circuit. A modulated voltage in the MHz range close to or at the resonance frequency is applied to the electrodes and the response of the body fluid is measured. This design allows a measurement of high accuracy.
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Citations
28 Claims
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1. A method for determining the concentration of a substance in a in-vitro or in-vivo specimen containing body liquid comprising the steps of
arranging a first electrode (18) at said specimen, wherein said first electrode is electrically insulated from the specimen, applying a modulated electrical voltage to the first electrode for generating a modulated field in the specimen and measuring at least one parameter (A, phi) depending on a response of the specimen to the field and determining the concentration therefrom.
Specification