US 6,809,807 B1 · Body fluid analyte measurement

Abstract

An analyte (e.g., glucose) is tested in a sample (e.g., blood or blood-free interstitial fluid) having both the analyte and other constituents (e.g., protein). The analyte has an absorption peak over a narrow bandwidth at a characteristic wavelength. The other constituents have an absorption over a broad bandwidth. The broad bandwidth includes and is broader than the narrow bandwidth. Radiant energy (e.g., IR radiation) is directed at the sample. The energy has a source bandwidth including the broad bandwidth. The sample absorbs a portion of the energy. A remainder of the energy is available for analysis. The remainder is analyzed by filtering the remainder into an analyte portion and a reference portion. The analyte portion contains substantially only the narrow bandwidth. The reference portion contains substantially only the broad bandwidth. The analyte portion and the reference portion are measured and compared to calculate an amount of the analyte in the sample.

Claims13

Dependent claims

A method for testing for an analyte in a sample having both the analyte and other constituents where the analyte has an absorption peak over a narrow bandwidth at a characteristic wavelength and where the other constituents have an absorption of a broad bandwidth and where the broad bandwidth includes and is broader than the narrow bandwidth, the method comprising:

directing a radiant energy at the sample with a source bandwidth broader than and including the broad bandwidth which includes the narrow bandwidth, wherein a portion of the energy is absorbed by the sample and wherein a remainder of the energy is available for analysis;
analyzing the remainder of the energy by optically filtering the remainder into an analyte portion containing substantially only the narrow bandwidth and a reference portion containing substantially the broad bandwidth and said narrow bandwidth;
and
measuring and comparing the analyte portion and the reference portion to calculate an amount of the analyte in the sample.

1 more element

providing a substrate onto which the sample is to be deposited;
directing a radiant energy at the substrate with a source bandwidth, wherein a portion of the energy is absorbed by the substrate and wherein a first remainder of the energy is available for analysis;
analyzing the first remainder of the energy by filtering the first remainder into a substrate portion containing substantially only the narrow bandwidth and a first reference portion containing substantially only the broad bandwidth;
measuring the substrate portion and the first reference portion;
determining the ratio of the substrate portion to the first reference portion;
depositing the sample onto the substrate;
directing the radiant energy at the sample with the source bandwidth including the broad bandwidth, wherein a portion of the energy is absorbed by the sample and wherein a second remainder of the energy is available for analysis;
analyzing the second remainder of the energy by filtering the second remainder into an analyte portion containing substantially only the narrow bandwidth and a second reference portion containing substantially only the broad bandwidth;
measuring the analyte portion and the second reference portion;
determining the ratio of the analyte portion to the second reference portion;
and
comparing the substrate portion and the first reference portion to the analyte portion and the second reference portion to calculate the amount of the analyte in the sample.

9 more elements

An apparatus for testing for an analyte in a sample having both the analyte and other constituents where the analyte has an absorption peak over a narrow bandwidth at a characteristic wavelength and where the other constituents have an absorption of a broad bandwidth and where the broad bandwidth includes and is broader than the narrow bandwidth, the apparatus comprising:

a chamber for receiving the sample;
a radiant energy source for directing a radiant energy at the chamber with a source bandwidth broader than and including the broad bandwidth which includes the narrow bandwidth;
a filter and energy detection system for analyzing radiant energy from the chamber by filtering the radiant energy from the chamber into an analyte portion containing substantially only the narrow bandwidth and a reference portion containing substantially the broad bandwidth and said narrow bandwidth;
and
a controller for measuring and comparing the analyte portion and the reference portion to calculate an amount of the analyte in the sample.

2 more elements

Dependencies are inferred from the claim text.

Body fluid analyte measurement

Life of this patent

Body fluid analyte measurement

Life of this patent

Abstract

Claims13