2537results about "Sampling" patented technology

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.

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.

A device for sampling body fluid, the device comprising, a main body, a lancet disposed within the main body, a carrier disposed within the main body fixedly attached to the lancet, a biasing means in communication with the lancet and the carrier, an annular space disposed within the main body adjacent the lancet, and a means for measuring a body fluid. Wherein the means for measuring the body fluid may include micro-porous test strips, an electronic testing device, an optical/reflectance testing measuring device, or a visual inspection.

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.

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.

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.

Rapid characterization and screening of polymer samples to determine average molecular weight, molecular weight distribution and other properties is disclosed. Rapid flow characterization systems and methods, including liquid chromatography and flow-injection analysis systems and methods are preferably employed. High throughput, automated sampling systems and methods, high-temperature characterization systems and methods, and rapid, indirect calibration compositions and methods are also disclosed. The described methods, systems, and devices have primary applications in combinatorial polymer research and in industrial process control.

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.

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.

A dual sensor for the simultaneous amperometric monitoring of glucose and insulin, wherein the glucose probe is based on the biocatalytic action of glucose oxidase, and the insulin probe is based on the electrocatalytic activity of metal oxide. Further provided is an oxidase enzyme composite electrode with an internal oxygen-rich binder. The present invention also optionally includes metallizing components within the carbon paste to eliminate signals from interfering compounds. The present invention includes embodiments for both in vitro and in vivo uses.

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 hydrophilic electrode domain and/or a cellulosic-based interference domain.

An in vivo biosensor disposed upon a subject comprising an electrochemical cell having a plurality of electrodes and a computer-controlled voltage source incorporating a potentiostat that is generative of a poise potential regime, which computer-controlled voltage source is operationally coupled to a computing device that: computes an output current whose magnitude is proportional to an amount of an analyte in a bodily fluid of the subject; and, adjusts the output current for drift due to biofouling at points in time greater than or equal to an induction period; and, outputs the amount of the analyte by transducing the adjusted output current. Methods and algorithms for adjusting the output current for drift due to biofouling are provided.

Disclosed herein are systems and methods for a continuous analyte sensor, such as a continuous glucose sensor. One such system utilizes first and second working electrodes to measure analyte or non-analyte related signal, both of which electrode include an interference domain.

Abstract of Disclosure Devices, systems and methods are provided for piercing the skin, accessing and collecting physiological sample therein, and measuring a characteristic, e.g., an analyte concentration, of the sampled physiological sample. The subject devices are in the form of a test strip which include a biosensor and at least one skin-piercing element which is a planar extension of a portion of the biosensor. At least one fluid pathway resides within a portion of the biosensor and within the skin-piercing element. The skin-piercing element has a space-defining configuration therein which acts as a sample fluid pooling area upon penetration into the skin. Systems are provided which include one or more test strip devices and a meter for making analyte concentration measurements. Methods for using the devices and systems are also provided.

In vitro electrochemical sensors that provide accurate and repeatable analysis of a sample of biological fluid are provided. Embodiments include sensors that include a sample chambers having overhangs extending therefrom.

An analyte sensor including an antiglycolytic agent or a precursor thereof and a chelating agent that stabilizes the antiglycolytic agent positioned proximate to the working electrode of the sensor. Also provided are systems and methods of using the electrochemical analyte sensors in analyte monitoring.

Embodiments of the invention provide electrochemical analyte sensors having elements designed to modulate their electrochemical reactions as well as methods for making and using such sensors.

An analyte test device is constructed as an integrated, single-use, disposable cartridge which can be releasably installed into a compatible analyte test monitor. In use, the device can be used in conjunction with the monitor to lance the skin of a patient to create a blood sample, express the blood sample from the wound site using vacuum forces and calculate the concentration of a particular analyte in the expressed blood sample. In one embodiment, the device includes a base which includes a top surface and a bottom surface. The base is also shaped to define an aperture which extends transversely through its top and bottom surfaces. An electrochemical test sensor is affixed to the base in such a manner so that a vacuum path is at least partially defined between the base and the test sensor, the vacuum path being in fluid communication with the aperture. A cover is affixed to the top surface of the base over the aperture, the cover comprising a flexible dome-shaped member and a lancet coupled to the member, the lancet being orientated such that its longitudinal axis extends at an approximate right angle relative to the longitudinal axis of the test sensor. The bottom surface of the base is shaped to include a skin receiving surface which at least partially defines the aperture in the base, the skin receiving surface having a steep inward contour to distend the skin of the patient when pressed thereagainst.

A method of measuring an analyte concentration in body fluid in an animal body having skin and subcutaneous soft tissue that includes body fluid. The method comprises, introducing a portion of an analyte-measuring device into the subcutaneous soft tissue. The analyte-measuring device includes an analyte sensing element, having a sharpened distal end to facilitate introduction into the animal body. Additionally the sensing element has an indicating electrode that is adapted to be activated by electric power and to form a raw analyte measurement, when it is activated and in contact with the body fluid, in less than two minutes. The sensing device further has a reference electrode and an electric power and display device that is adapted to mate to the analyte-sensing element. The power and display device activates the analyte-sensing element by applying electric power to it. The analyte-sensing element is introduced into the animal body and is activated by the electric power and display device, thereby causing the analyte-sensing element to form a raw analyte measurement. The power and display device forms and displays a second analyte measurement that is related to the raw analyte measurement, within two minutes of the analyte sensing element being introduced into the body.

An analyte-measuring device, particularly an electrochemical sensor, is provided for measuring current values at multiple bias potential settings to assess the quality of the analyte measurement, identify interference in the signal, and calculate substantially interference-free analyte concentration measurements. The device and method are suitable for calculating substantially interference-free analyte concentration measurements when glucose is the analyte and acetaminophen is an interfering species.

Described herein are methods to diagnose or prognose cancer in a subject by enriching, detecting, and analyzing individual rare cells, e.g., epithelial cells, in a sample from the subject. Also described are methods for labeling regions of genomic DNA in individual cells in said mixed sample with different labels wherein each label is specific to each cell and quantifying the labeled regions of genomic DNA from each cell in the mixed sample. More particularly the method includes detecting the presence of gene mutations in individual rare cells in a subsample.

A biosensor in the form of a strip. In one embodiment, the biosensor strip comprises an electrode support, a first electrode, i.e., a working electrode, a second electrode, i.e., a counter electrode, and a third electrode, i.e., a reference electrode. Each of the electrodes is disposed on and supported by the electrode support. Each of the electrodes is spaced apart from the other two electrodes. The biosensor strip can include a covering layer, which defines an enclosed space over the electrodes. This enclosed space includes a zone where an analyte in the sample reacts with reagent(s) deposited at the working electrode. This zone is referred to as the reaction zone. The covering layer has an aperture for receiving a sample for introduction into the reaction zone. The biosensor strip can also include at least one layer of mesh interposed in the enclosed space between the covering layer and the electrodes in the reaction zone. This layer of mesh facilitates transporting of the sample to the electrodes in the reaction zone. In another embodiment, a biosensor strip can be constructed to provide a configuration that will allow the sample to be introduced to the reaction zone by action of capillary force. In this embodiment, the layer of mesh can be omitted. The invention also provides a method for determining the concentration of glucose in a sample of whole blood by using the biosensor of this invention.