Labsystems Oy

Vivascan Corporation

Other

Worcester Polytechnic Institute

Biohit Oy

Grove Instruments, Inc.

Biosensors Technology, Inc.

Harjunmaa, Hannu

Harjunmaa, Sinikka

Hannu Harjunmaa

Yitzhak Mendelson

Robert A Peura

Yi Wang

Stevan Kun

Osmo A Suovaniemi

Pertti Ekholm

Paul Partanen

Juhani E Luotola

Rebecca Burrell

Helena Seppanen

John A Rolls

Esko Kaukanen

Brian D Gross

Jukka Savonlahti

Enni Harjunmaa

Sinikka Harjunmaa

Georg Leuenberger

A nephelometer for determining the turbidity of a body of fluid in which a light beam is directed as an angled beam through the body and two light detectors measure the intensity of light scatter at two points in the beam. The two measurements are divided and scaled, and then the result is logarithmically amplified and displayed as the turbidity.

Nephelometer

A noninvasive method for estimating a concentration of a target analyte in a sample comprises generating a first and second (reference) radiation, a principal radiation and a target analyte carrier detection radiation; directing the first, second, principal and the target analyte carrier detection radiations at the sample which includes the target analyte; and detecting a first, second, principal and target analyte carrier detection amount of the radiation that leaves the sample. The method further comprises modulating the sample thickness in order to achieve time-wise or spatial target analyte concentration variation within the sample. The method further comprises generating first, second, principal and target analyte carrier detection measurement data based respectively on the first, second, the principal and the target analyte carrier detected amounts of radiation; numerically processing the first, second, principal and target analyte carrier detection measurement data to obtain a weighted combination of the first measurement data and the second measurement data that balances the principal measurement data with respect to a sample background; and estimating the concentration of the target analyte based on the difference between the balanced weighted combination of the first measurement data and the second measurement data vs. the principal measurement data.

Noninvasive measurement of analyte concentration using methods and systems of post-balancing

The present invention pertains to the measurement of the refractive index of a medium, such as a fluid, through the wall of its container. The essential characteristic of the invention is that, by using at least two separate light paths that are of unequal length and that reflect from the wall/medium interface, it is possible to perform the measurement of the refractive index of the medium so that the result is insensitive to the color and thickness of the wall.

Noninvasive refractometer

An improved method for non-invasively measuring a concentration of a target analyte dissolved in a fluid flowing through a sample is presented. It includes directing a probe beam of electromagnetic radiation, having time multiplexed components of different wavelengths, where at least one of the time-multiplexed components consists of two different simultaneous wavelengths through the sample and measuring the difference of the absorption of the radiation of the time-multiplexed components at different sample states. During sample state changes, the amount of fluid containing the target analyte within the sample is changing, varying the total amount of target analyte in the sample, and the absorption properties of the sample. The sample states may be produced by compressing and uncompressing the tissue sample. The method is useful in measuring the concentration of a target analyte, such as glucose, in tissue containing blood.

Three diode optical bridge system

An improved method for non-invasively measuring a concentration of a target analyte dissolved in a fluid flowing through a sample is presented. It includes directing a probe beam of electromagnetic radiation, consisting of time multiplexed components of different wavelengths, through the sample and measuring the difference of the absorption of the radiation at at least one wavelength pair at different sample states. During sample state changes, the amount of fluid containing the target analyte within the sample is changing, which varies the total amount of target analyte in the sample, as well as the absorption properties of the sample. The sample states are produced, for instance, by compressing and uncompressing the tissue sample. The accuracy of the presented method is enhanced by including continuous estimation of the amount of the fluid containing the target analyte within the sample, and measurement of the variations of the absorption at a wavelength at which the target analyte absorbs significantly. The method is particularly useful in measuring the concentration of a target analyte, such as glucose, in tissue containing blood. An apparatus for performing this method also is disclosed.

Non-invasive substance concentration measurement using and optical bridge

Method for correcting a liquid dispensing error, and a liquid dispensing

The present invention relates to the determination of an analyte or multiple analytes in blood using information derived from the differential optical absorption spectra of blood. Specifically, the information is derived from the differential spectra of tissue before and immediately after the volume of blood in the tissue has been changed.

Blood constituent determination based on differential spectral analysis

To deterine glucose or other constituents of the human or animal body, near-infrared radiation containing two alternating wavelengths that have equal extinction coefficients in the tissue is directed onto a sample area of the body. The intensity relation of the two different wavelengths is adjusted so as to balance the two wavelength detected signals. The extracellular-to-intracellular fluid ratio of the tissue is changed or is allowed to change, and the alternating component of the transmitted beam power is measured. The amplitude of the alternating-current (AC) signal given by the detector represents glucose concentration or the difference from a preset reference concentration.

Electromagnetic method and apparatus to measure constituents of human or

To determine glucose or other constituents of the human or animal body, a stabilized near-infrared radiation beam containing two alternating wavelengths that have approximately equal extinction coefficients in the tissue, is directed onto the sample area, the transmitted signal alternating component is zeroed by tuning one of the wavelengths, the extracellular-to-intracellular fluid ratio of the tissue is changed by exerting varying mechanical pressure on the tissue, or the ratio is allowed to change as a result of the natural pulsation. The alternating component of the transmitted beam power is measured in the changed fluid ratio state. The amplitude of the alternating-current (AC) signal given by the detector, is taken to represent glucose concentration or the difference from a preset reference concentration.

A non-invasive system for measuring the concentration of an analyte, such as glucose, in an absorbing matrix is described. The system directs beams of light at the matrix using an analyte sensitive wavelength and an analyte insensitive wavelength. The principles of photoplethysmography are applied to measure the change in light intensity caused by matrix absorption before and after the blood volume change caused by the systolic phase of the cardiac cycle. The change in light intensity is converted to an electrical signal which is used to adjust the light intensity and as a measure of analyte concentration.

Method and apparatus for monitoring blood analytes noninvasively by

A non-invasive system for measuring the concentration of an analyte in an absorbing matrix is described. The system directs a beam of radiation at the matrix. The beam consists of a series of successive alternate pulses of electro-magnetic radiation, one of which is highly absorbed by the analyte and the other of which is non-absorbed. The transmitted or reflected beam is optically detected and an electrical signal proportional to beam intensity is used to adjust the beam intensity and as a measure of analyte concentration.

Method and apparatus for measuring the concentration of absorbing

A method and apparatus for non-invasively testing analytical substances in turbid matrices i.e. body fluids and tissues. In this method a sample is irradiated with a beam of electromagnetic energy at two alternating wavelenths, .lambda..sub.1 and .lambda..sub.2, at which the absorption by the background is the same but at one of which the radiation is absorbed by the analyte and at the other it is not. The apparatus comprises means which enable to control the input energy at .lambda..sub.1 and .lambda..sub.2 so that at the output from the sample the electric signals issuing after detection cancel in the absence of the analyte in the sample. When analyte is present cancellation no longer occurs and a signal proportional to the analyte concentration in the sample is produced. The apparatus is also designed for shifting the response back to zero when a calibrating known concentration of analyte is used as standard, thus providing a controllable zeroing base line.

Method for determining by absorption of radiations the concentration of

The invention concerns an immunological assay system, wherein the inner face of the cuvettes is used as the solid phase. The equipment includes a displaceable carriage (8) for the cuvette set as well as, above the carriage, a dosage head (9), to which the liquid dosimeter (11) and the measurement device (19) are attached. All the operations take place automatically.

Combined incubator and cuvette holding apparatus

Method and apparatus for immunological determinations

Immunological fluorometric assay method, wherein an antigen (1) attached to magnetic particles (3) reacts in a liquid with an antibody (2) present in the sample and with an antibody (4) marked with a fluorescent substance. After the reaction, the particles are pulled by means of a magnetic field through a second (6) liquid layer onto the bottom of the measurement vessel, whereupon the particles are excited, and emitted radiation is collected through the wall of the vessel.

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Holden, MA, United States of America

Hannu Harjunmaa