750 results about "Sample volume" patented technology

The Laser Induced Fluorescence Attenuation Spectroscopy (LIFAS) method and apparatus preferably include a source adapted to emit radiation that is directed at a sample volume in a sample to produce return light from the sample, such return light including modulated return light resulting from modulation by the sample, a first sensor, displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor, displaced by a second distance from the sample volume, for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor associated with the first sensor and the second sensor and adapted to process the first and second signals so as to determine the modulation of the sample. The methods and devices of the inventions are particularly well-suited for determining the wavelength-dependent attenuation of a sample and using the attenuation to restore the intrinsic laser induced fluorescence of the sample. In turn, the attenuation and intrinsic laser induced fluorescence can be used to determined a characteristic of interest, such as the ischemic or hypoxic condition of biological tissue.

There is provided the reagent layer composition that can substantially reduce the measurement bias arising from hematocrits. The addition of fatty acid (4-20 carbons) and quaternary ammonium salt to a commonly used reagent layer composition composed of an enzyme, an electron transfer mediator, and several water soluble polymers not only reduce the hematocrit level-dependent bias but also provide very stable performance for an extended period of time. Disclosed are also various types of sub microliter sample volume electrochemical biosensors that are suitable to use with the reagent layer composition of present invention.

Systems and methods are provided for determining whether a volume of biological sample is adequate to produce an accurate analyte concentration measurement. Certain such systems and methods provide the additional function of compensating for a sample volume determined to be less than adequate in order to proceed with an accurate analyte concentration measurement. The present invention is employed with a biosensor, such as an electrochemical test strip to which the sample volume of biological solution is deposited, and a meter configured to receive such test strip and to measure the concentration of selected analytes within the biological sample.

The presence of a select analyte in the sample is evaluated in an an electrochemical system using a conduction cell-type apparatus. A potential or current is generated between the two electrodes of the cell sufficient to bring about oxidation or reduction of the analyte or of a mediator in an analyte-detection redox system, thereby forming a chemical potential gradient of the analyte or mediator between the two electrodes After the gradient is established, the applied potential or current is discontinued and an analyte-independent signal is obtained from the relaxation of the chemical potential gradient. The analyte-independent signal is used to correct the analyte-dependent signal obtained during application of the potential or current. This correction allows an improved measurement of analyte concentration because it corrects for device-specific and test specific factors such as transport (mobility) of analyte and/or mediator, effective electrode area, and electrode spacing (and as a result, sample volume), without need for separate calibration values. The analysis can be performed using disposable test strips in a hand held meter, for example for glucose testing.

A test strip for determining the concentration of an analyte in a body fluid includes a membrane in fluid communication with a porous layer. The membrane and the porous layer are divided into compressed portions, which restrict the capillary flow of the body fluid, and uncompressed portions. The uncompressed portions are adapted to absorb and retain body fluids in excess of the amount required for operation of the test strip. The test strip may be constructed with an internal relief chamber to accommodate the uncompressed portions. A method of making the test strip by pressure and/or heat sealing individual components on a shaping die is also provided.

A method for quantitatively measuring nucleic acid amplification reactions, especially the polymerase chain reaction, employing microparticles as hybridization solid phase, a probe sequence labeled with a fluorescent label and a fluorescence detection system which is based on two-photon fluorescence excitation, contacting all the amplification reaction components and the solid phase simultaneously in a closed cuvette, performing the amplification reactions in the same cuvette, focusing a two-photon exciting laser beam into the cuvette during the amplification cycles and measuring the fluorescence signal emitted by the microparticles from one particle at a time when they randomly float through the focal volume of the laser beam. The features of this invention allow a method and device for performing a fast quantitative nucleic acid amplification assay of single or multiple target sequences in a very small closed sample volume.

Embodiments of the present invention relate to methods and apparatuses for the discretization and manipulation of sample volumes that is simple, robust, and versatile. It is a fluidic device that partitions a sample by exploiting the interplay between fluidic forces, interfacial tension, channel geometry, and the final stability of the formed droplet and/or discretized volume. These compartmentalized volumes allow for isolation of samples and partitioning into a localized array that can subsequently be manipulated and analyzed. The isolation of the discretized volumes along with the device's inherent portability render our invention versatile for use in many areas, including but not limited to PCR, digital PCR, biological assays for diagnostics and prognostics, cancer diagnosis and prognosis, high throughput screening, single molecule and single cell reactions or assays, the study crystallization and other statistical processes, protein crystallization, drug screening, environmental testing, and the coupling to a wide range of analytical detection techniques for biomedical assays and measurements. The minimal fluid interconnects and simple flow geometry makes the device easy to use and implement, economical to fabricate and operate, and robust in its operations.

An air-filled pipette for accurately metering small and large volumes of fluid samples is provided. The pipette has dual resolution capability such that the pipette can accurately aspirate a wide range of sample volumes and deliver them contact-free (touchless). The pipette may include an extension mandrel that reduces air space in a disposable tip within the pipette. The dual resolution capability and/or the extension mandrel also minimize errors associated with the compressibility of air. Multiple pipettes may also be arranged to form a pipetting module for the metering of multiple sample volumes simultaneously and automatically. The pipette includes a channel block having at least one cylindrical passage, that slides up and down over a rod, and a cylinder, with an axially extending passage therethrough, that is sized, shaped and aligned to fit into the cylindrical passage in a dynamic sealing relationship. A method for mixing multiple fluid samples within a pipette tip is also provided.

A system is disclosed for detecting a signal field from a sample volume. The system includes a source system and an optical fiber system. The source system provides a first electromagnetic field at a first frequency and a second electromagnetic field at a second frequency that is different from the first frequency. The optical fiber system includes at least one optical fiber for guiding the first and second electromagnetic fields to the sample volume to generate coherent radiation characteristic of molecular vibrations by non-linear interaction of the first and second fields with the sample volume. The optical fiber system also receives the signal field resulting from the coherent radiation, and guides the signal field to a detector.

A method of extracting hormones from a biological sample using digital microfluidic arrays is provided. Biological samples containing hormones are dried on a digital microfluidic array, lysed by a lysing solvent, dried, subsequently dissolved in a polar solvent, and further purified in an extraction step in which droplets are transported through a volume of non-polar solvent. The method disclosed herein provides the distinct advantage of an automated sample preparation method that is capable of extracting hormones from low sample volumes with excellent precision and recovery.

Methods and apparatus for collecting a fluid sample using an integrated collection device are disclosed. The integrated collection device includes an analyte detector and a gradient means to actively and rapidly drive the transport of a sample fluid from the point of contact to the point of detection and reading. The analyte detector can include a visually-read colorimetric detector using a chemical or enzymatic detection process. The gradient means can include physical and/or chemical processes as described in more detail herein. In some embodiments, the device is provided as an occlusive patch. Preferably, the test device provides a reading immediately upon fluid contact with the analyte detector. Consequently, the time-to-result is sample volume and transport time dependent. By providing immediate or nearly immediate reading of results, the device is particularly useful in those applications in which immediate results are advantageous.

A device for quantitively collecting, preserving, storing and mailing a fresh and wet specimen of fecal or other biological matter for later analysis comprises a simple tubular vessel double sealed at one end by a machine manipulable plug having breakable hollow nib and cover, and that is engaged at the opposite end by a machine manipulable stopper from which a specimen carrying stick axially projects into the vessel through an internal sealable septum spanning a median section of the vessel. The cross-sectional profile of the stick is shaped to form a widened shoulder carrying a resilient washer. The shoulder matingly engages a correspondingly shaped passageway in the septum when the stopper engages the vessel which restricts the amount of specimen passing therethrough. The amount of specimen and preserving fluid are quantitatively balanced and remain so until part or all of the fluid is extracted for analysis either manually by breaking of the sealing nib or automatedly by machine removal of the plug or stopper. Collection by a patient or unskilled person is enhanced by providing the tubular vessel as part of a sample collection and return kit which further contains a disposable paper catch web which is made to be temporarily secured to a toilet droopingly spanning the seat to catch the feces for sampling. The kit also provides a sealable plastic bag and a crush resistant mailing carton. The above components of the kit are carried within a sterile bag until used.

An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

Methods, systems and kits for the simultaneous or sequential analysis of one or more hormones by mass spectrometry are disclosed. The methods require minimal sample size and minimal preparation time. The methods include ionizing the hormones and analyzing the hormones by mass spectrometry. In addition, methods, systems and kits for the simultaneous or sequential analysis of thyroid hormones are disclosed including ionization of the thyroid hormones in the negative mode using an electrospray source.

A method of initializing a spectral Doppler mode of operation for an ultrasonic system includes acquiring ultrasound-based data during a two-dimensional mode of operation for a particular examination session and includes automatically establishing settings for the Doppler mode operation parameters based upon the ultrasound-based data. That is, the ultrasound-based data is processed during the session to select spectral Doppler mode settings that are specific to the ongoing session. The session-specific settings are invoked when the system is switched to the spectral Doppler mode. If the two-dimensional mode is a colorflow mode, the Doppler sample volume can be based upon detecting the location of maximum velocity in the colorflow image, the angle correct setting can be based upon maximum velocities in colorflow vectors, the pulse repetition frequency setting can be based upon the maximum frequency shift detected in the colorflow data, and the gain setting can be based upon the amplitude of colorflow data. On the other hand, if the two-dimensional mode is a power mode, the Doppler sample volume is based upon detecting the region of the power mode image having the strongest signals, the angle correct setting can be based upon detecting the direction of flow, the Doppler pulse repetition frequency can be based upon a scale setting for the power mode data acquisition, and a gain setting can be based upon the amplitude of power mode data. Lastly, if the two-dimensional mode is the grey-scale imaging mode, the selection of a Doppler sample volume can be based upon identifying a dark region near the center of the grey-scale image, the angle correct setting can be based upon the orientation of the boundaries of the identified dark region, and the gain setting can be based upon the amplitude of image data.

The present invention is to present a sample analyzer, comprising: an imaging device for imaging a sample container which has translucency and contains a sample; a measuring device for aspirating the sample contained in the sample container and measuring the aspirated sample; a transporting device for transporting the sample container to a supply position for supplying the sample contained in the sample container to the measuring device; a sample volume obtainer for obtaining sample volume information relating to volume of the sample in the sample container, based on an image obtained by imaging the sample container by the imaging device; and a transport controller for controlling the transporting device to perform a transport operation in accordance with the sample volume information obtained by the sample volume obtainer.