21101results about "Biological substance pretreatments" patented technology

A small diameter flexible electrode designed for subcutaneous in vivo amperometric monitoring of glucose is described. The electrode is designed to allow “one-point” in vivo calibration, i.e., to have zero output current at zero glucose concentration, even in the presence of other electroreactive species of serum or blood. The electrode is preferably three or four-layered, with the layers serially deposited within a recess upon the tip of a polyamide insulated gold wire. A first glucose concentration-to-current transducing layer is overcoated with an electrically insulating and glucose flux limiting layer (second layer) on which, optionally, an immobilized interference-eliminating horseradish peroxidase based film is deposited (third layer). An outer (fourth) layer is biocompatible.

An apparatus and system are provided for simultaneously analyzing a plurality of analytes anchored to microparticles. Microparticles each having a uniform population of a single kind of analyte attached are disposed as a substantially immobilized planar array inside of a flow chamber where steps of an analytical process are carried out by delivering a sequence of processing reagents to the microparticles by a fluidic system under microprocessor control. In response to such process steps, an optical signal is generated at the surface of each microparticle which is characteristic of the interaction between the analyte carried by the microparticle and the delivered processing reagent. The plurality of analytes are simultaneously analyzed by collecting and recording images of the optical signals generated by all the microparticles in the planar array. A key feature of the invention is the correlation of the sequence of optical signals generated by each microparticle in the planar array during the analytical process.

Novel membranes comprising various polymers containing heterocyclic nitrogen groups are described. These membranes are usefully employed in electrochemical sensors, such as amperometric biosensors. More particularly, these membranes effectively regulate a flux of analyte to a measurement electrode in an electrochemical sensor, thereby improving the functioning of the electrochemical sensor over a significant range of analyte concentrations. Electrochemical sensors equipped with such membranes are also described.

Abstract of the Disclosure

An implantable analyte sensor including a sensing region for measuring the analyte and a non-sensing region for immobilizing the sensor body in the host. The sensor is implanted in a precisely dimensioned pocket to stabilize the analyte sensor in vivo and enable measurement of the concentration of the analyte in the host before and after formation of a foreign body capsule around the sensor. The sensor further provides a transmitter for RF transmission through the sensor body, electronic circuitry, and a power source optimized for long-term use in the miniaturized sensor body.

The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous measurement of glucose in a host.

Systems and methods of use for continuous analyte measurement of a host's vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host's circulatory system.

Systems, including apparatus and methods, for performing assays. These systems may involve separating sample components by partitioning them into droplets or other partitions, amplifying or otherwise reacting the components within the droplets, detecting the amplified components, or characteristics thereof, and/or analyzing the resulting data, among others.

Materials and methods are provided for producing patterned multi-array, multi-specific surfaces which are electronically excited for use in electrochemiluminescence based tests. Materials and methods are provided for the chemical and/or physical control of conducting domains and reagent deposition for use in flat panel displays and multiply specific testing procedures.

The present invention comprises systems and devices for sequencing of nucleic acid, such as short DNA sequences from clonally amplified single-molecule arrays.

The present invention provides a biointerface membrane for use with an implantable device that interferes with the formation of a barrier cell layer including; a first domain distal to the implantable device wherein the first domain supports tissue attachment and interferes with barrier cell layer formation and a second domain proximal to the implantable device wherein the second domain is resistant to cellular attachment and is impermeable to cells. In addition, the present invention provides sensors including the biointerface membrane, implantable devices including these sensors or biointerface membranes, and methods of monitoring glucose levels in a host utilizing the analyte detection implantable device of the invention. Other implantable devices which include the biointerface membrane of the present invention, such as devices for cell transplantation, drug delivery devices, and electrical signal delivery or measuring devices are also provided.

An electrochemical assay includes a method for determining with great accuracy the time at which an applied sample bridges a gap between the electrodes of an electrochemical cell. The method involves applying a constant small current across the gap, while monitoring the potential difference between the electrodes. The time at which the sample bridges the gap is marked by a sharp drop in the potential. A constant voltage is applied after the sample is detected, and the current and/or charge through the sample is monitored over a period of time. From the measured current or charge, the analyte concentration of interest can be calculated.

The present invention relates generally to systems and methods for increasing oxygen availability to implantable devices. The preferred embodiments provide a membrane system configured to provide protection of the device from the biological environment and/or a catalyst for enabling an enzymatic reaction, wherein the membrane system includes a polymer formed from a high oxygen soluble material. The high oxygen soluble polymer material is disposed adjacent to an oxygen-utilizing source on the implantable device so as to dynamically retain high oxygen availability to the oxygen-utilizing source during oxygen deficits. Membrane systems of the preferred embodiments are useful for implantable devices with oxygen-utilizing sources and/or that function in low oxygen environments, such as enzyme-based electrochemical sensors and cell transplantation devices.

A method for determining the concentration of a reduced (or oxidised) form of a redox species in an electrochemical cell of the kind comprising a working electrode and a counter electrode spaced from the working electrode by a predetermined distance, said method comprising the steps of: (1) applying an electric potential difference between the electrodes; (2) selecting the potential of the working electrode such that the rate of electro-oxidation of the reduced form (or electro-reduction of the oxidised form) of the species is diffusion controlled, (3) selecting the spacing between the working electrode and the counter electrode so that reaction products from the counter electrode arrive at the working electrode; (4) determining current as a function of time after application of the potential and prior to achievement of a steady state; (5) estimating the magnitude of the steady state current, and (6) obtaining from the change in current with time and the magnitude of the steady state current, a value indicative of the diffusion coefficient and/or of the concentration of the reduced form (or the oxidised form) of the species. Also disclosed is an apparatus for determining the concentration of a redox species in an electrochemical cell comprising: an electrochemical cell having a working electrode and a counter (or counter/reference) electrode, means for applying and electric potential difference between said electrodes, means for measuring the change in current with time, and characterised in that the working electrode is spaced from the counter electrode by less than 500 mum.

Disclosed are bioluminescent bioreporter integrated circuit devices that detect selected analytes in fluids when implanted in the body of an animal. The device comprises a bioreporter that has been genetically engineered to contain a nucleic acid segment that comprises a cis-activating response element that is responsive to the selected substance operably linked to a gene encoding a bioluminescent reporter polypeptide. In preferred embodiments, the target analyte is glucose, glucagons, or insulin. Exposure of the bioreporter to the target substance causes the response element to up-regulate the nucleic acid sequence encoding the reporter polypeptide to produce a luminescent response that is detected and quantitated. In illustrative embodiments, the bioreporter device is encapsulated on an integrated circuit that is capable of detecting the emitted light, processing the resultant signal, and then remotely reporting the results. Also disclosed are controlled drug delivery systems capable of being directly or indirectly controlled by the detection device that provide drugs such as insulin to the animal in reponse to the amount of target analyte present in the body fluids.

The present invention discloses devices and methods of performing high throughput screening of the physiological response of cells to biologically active compounds and methods of combining high-throughput with high-content spatial information at the cellular and subcellular level as well as temporal information about changes in physiological, biochemical and molecular activities. The present invention allows multiple types of cell interactions to be studied simultaneously by combining multicolor luminescence reading, microfluidic delivery, and environmental control of living cells in non-uniform micro-patterned arrays.

The present invention relates generally to systems and methods for improved electrochemical measurement of analytes. The preferred embodiments employ electrode systems including an analyte-measuring electrode for measuring the analyte or the product of an enzyme reaction with the analyte and an auxiliary electrode configured to generate oxygen and/or reduce electrochemical interferants. Oxygen generation by the auxiliary electrode advantageously improves oxygen availability to the enzyme and/or counter electrode; thereby enabling the electrochemical sensors of the preferred embodiments to function even during ischemic conditions. Interferant modification by the auxiliary electrode advantageously renders them substantially non-reactive at the analyte-measuring electrode, thereby reducing or eliminating inaccuracies in the analyte signal due to electrochemical interferants.

A system and method employing at least one semiconductor device, or an arrangement of insulating and metal layers, having at least one detecting region which can include, for example, a recess or opening therein, for detecting a charge representative of a component of a polymer, such as a nucleic acid strand, proximate to the detecting region, and a method for manufacturing such a semiconductor device. The system and method can thus be used for sequencing individual nucleotides or bases of ribonucleic acid (RNA) or deoxyribonucleic acid (DNA). The semiconductor device includes at least two doped regions, such as two n-typed regions implanted in a p-typed semiconductor layer or two p-typed regions implanted in an n-typed semiconductor layer. The detecting region permits a current to pass between the two doped regions in response to the presence of the component of the polymer, such as a base of a DNA or RNA strand. The current has characteristics representative of the component of the polymer, such as characteristics representative of the detected base of the DNA or RNA strand.

The present invention relates generally to devices for measuring an analyte in a host. More particularly, the present invention relates to devices for measurement of glucose in a host that incorporate a cellulosic-based interference domain.

A fluidic device holder configured to orient a fluidic device. The device holder includes a support structure configured to receive a fluidic device. The support structure includes a base surface that faces in a direction along the Z-axis and is configured to have the fluidic device positioned thereon. The device holder also includes a plurality of reference surfaces facing in respective directions along an XY-plane. The device holder also includes an alignment assembly having an actuator and a movable locator arm that is operatively coupled to the actuator. The locator arm has an engagement end. The actuator moves the locator arm between retracted and biased positions to move the engagement end away from and toward the reference surfaces. The locator arm is configured to hold the fluidic device against the reference surfaces when the locator arm is in the biased position.

An apparatus for detection and quantitation of an electrochemically-detect- able analyte, such as glucose, in blood or interstitial fluid includes a meter unit, a lancet and an electrochemical sensor. Of these components, the meter is preferably reusable, while the lancet and the electrochemical sensor are preferably incorporated in assemblies intended for single-use. The meter unit has a housing, within which a lancet is engaged with a mechanism for moving then lancet; a connector disposed within the housing for engaging an electrochemical sensor specific for the analyte and transmitting a signal indicative of the amount of analyte, and a display operatively-associated with a connector for displaying the amount of the analyte to user. The electrochemical sensor is adapted for detection of a particular analyte. In addition, the electrochemical sensor has an absorptive member for uptake of a sample of blood or interstitial fluid. In one version, the lancet moves from a initial position to a piercing position in which skin of the user is pierced and optionally back to a retracted position. The electrochemical sensor is disposed such that the absorptive member takes up a sample from the pierced skin of the user when it is pierced by the lancet without movement of the apparatus. In an alternative version, the lancet is a hollow cannula through which blood or interstitial fluid is transported from the puncture site to an absorbent portion of the electrochemical sensor. In either version, the apparatus provides single-step operation in which sample acquisition and analysis occur as a result of the single action of pressing the apparatus against the users skin.

A sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector.

A multifunctional membrane is provided. The multifunctional membrane is suitable for use in an analyte sensor. In a particular application, the multifunctional membrane may be used in connection with an amperometric biosensor, such as a transcutaneous amperometric biosensor. Some functions of the membrane are associated with properties of membrane itself, which is comprised of crosslinked polymers containing heterocyclic nitrogen groups. For example, the membrane, by virtue of its polymeric composition, may regulate the flux of an analyte to a sensor. Such regulation generally improves the kinetic performance of the sensor over a broad range of analyte concentration. Other functions of the membrane are associated with functional components, such as a superoxide-dismutating/catalase catalyst, either in the form of an enzyme or an enzyme mimic, that can be bound to the scaffold provided by the membrane. The effect of any such enzyme or enzyme mimic is to lower the concentration of a metabolite, such as superoxide and/or hydrogen peroxide, in the immediate vicinity of the sensing layer of the biosensor. Lowering the concentrations of such metabolites, which are generally deleterious to the function of the sensor, generally protects or enhances biosensor integrity and performance. The membrane is thus an important tool for use in connection with analyte sensors, amperometric sensors, biosensors, and particularly, transcutaneous biosensors. A membrane-covered sensor and a method for making same are also provided.

Abstract of the Disclosure

An implantable analyte sensor including a sensing region for measuring the analyte and a non-sensing region for immobilizing the sensor body in the host. The sensor is implanted in a precisely dimensioned pocket to stabilize the analyte sensor in vivo and enable measurement of the concentration of the analyte in the host before and after formation of a foreign body capsule around the sensor. The sensor further provides a transmitter for RF transmission through the sensor body, electronic circuitry, and a power source optimized for long-term use in the miniaturized sensor body.

A method for delivering a therapeutic agent to a predetermined location in a host is disclosed, wherein a liposome-encapsulated therapeutic agent is administered to the host, and an electrical field which encompasses a predetermined region within the host is established, such that as the liposome-encapsulated agent is exposed to the electrical field the release of the agent from the liposome to the predetermined region is enhanced.

An analyte sensor for use in connection with a biofluid is described. The analyte sensor may comprise any suitable interface between the biofluid and a derivative of the biofluid and any suitable transducer of information concerning an analyte. At least one catalytic agent is provided in a locale or vicinity of the interface. The catalytic agent, such as a proteinaceous agent or a non-proteinaceous, organic-metal agent, is sufficient to catalyze the degradation of reactive oxygen and/or nitrogen species that may be present in the vicinity of the interface. An analyte-sensing kit and a method of sensing an analyte are also described.

The present invention relates generally to systems and methods for increasing oxygen generation in electrochemical sensors in order to overcome the oxygen limitations. The preferred embodiments employ electrode systems with at least two electrodes in relatively close proximity to each other; wherein at least one electrode is configured to generate oxygen and at least one other electrode is configured to sense an analyte or a product of a reaction indicative of the concentration of analyte. The oxygen generated by the oxygen-generating electrode is available to the catalyst within a membrane system and/or the counter electrode, thereby enabling the electrochemical sensors of the preferred embodiments to function even during ischemic conditions.

The present invention relates to an apparatus for conducting a variety of assays for the determination of analytes in liquid samples, and relates to the methods for such assays. In particular, the invention relates to a single-use cartridge designed to be adaptable to a variety of real-time assay protocols, preferably assays for the determination of analytes in biological samples using immunosensors or other ligand/ligand receptor-based biosensor embodiments. The cartridge provides novel features for processing a metered portion of a sample, for precise and flexible control of the movement of a sample or second fluid within the cartridge, for the amending of solutions with additional compounds during an assay, and for the construction of immunosensors capable of adaptation to diverse analyte measurements. The disclosed device and methods of use enjoy substantial benefits over the prior art, including simplicity of use by an operator, rapid in situ determinations of one or more analytes, and single-use methodology that minimizes the risk of contamination of both operator and patient. The disclosed invention is adaptable to the point-of-care clinical diagnostic field, including use in accident sites, emergency rooms, surgery, nursing homes, intensive care units, and non-medical environments.

Devices and methods are provided for continuous measurement of an analyte concentration. The device can include a sensor having a plurality of sensor elements, each having at least one characteristic that is different from other sensor(s) of the device. In some embodiments, the plurality of sensor elements are each tuned to measure a different range of analyte concentration, thereby providing the device with the capability of achieving a substantially consistent level of measurement accuracy across a physiologically relevant range. In other embodiments, the device includes a plurality of sensor elements each tuned to measure during different time periods after insertion or implantation, thereby providing the sensor with the capability to continuously and accurately measure analyte concentrations across a wide range of time periods. For example, a sensor system 180 is provided having a first working electrode 150 comprising a first sensor element 102 and a second working electrode 160 comprising a second sensor element 104, and a reference electrode 108 for providing a reference value for measuring the working electrode potential of the sensor elements 102, 104.

An analytical test device useful for example in pregnancy testing, comprises a hollow casing (500) constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier (510) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member (506) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating means, such as an aperture (508) in the casing, enabling the extent (if any) to which the labelled reagent becomes bound in the second zone to be observed. Preferably the device includes a removable cap for the protruding bibulous member.

Luminescence test measurements are conducted using an assay module having integrated electrodes with a reader apparatus adapted to receive assay modules, induce luminescence, preferably electrode induced luminescence, in the wells or assay regions of the assay modules and measure the induced luminescence.