Abstract: The efficacy of tissue piercing elements in the area of transdermal drug delivery is well-documented. Multiple studies have shown that enhancement of skin permeation via creation of microscopic pores in the stratum corneum can greatly improve the delivery rates of drugs. However, skin perforation with tissue piercing elements is not the only factor affecting the rate of drug transport. Other factors including such as the formulation of the drug and rate of closure of the micropores closure also need to be considered. Similarly micro tissue piercing elements have been used with less success by several workers for continuous glucose monitoring.

Abstract: One aspect of the invention provides a glucose monitor having a plurality of tissue piercing elements, each tissue piercing element having a distal opening, a proximal opening and interior space extending between the distal and proximal openings; a sensing area in fluid communication with the proximal openings of the tissue piercing elements; sensing fluid extending from the sensing area into substantially the entire interior space of the tissue piercing elements; and a glucose sensor adapted to detect a concentration of glucose in the sensing fluid within the sensing area.

Abstract: An analyte monitor having a plurality of fluid paths, each fluid path having a distal opening adapted to be disposed on one side of a stratum corneum layer of a user's skin, a proximal opening adapted to be disposed on another side of the stratum corneum layer and an interior space extending between the distal and proximal openings; a sensing zone in fluid communication with the proximal openings of the fluid paths; sensing fluid extending from the sensing zone into substantially the entire interior space of the fluid paths; and an analyte sensor adapted to detect a concentration of analyte in the sensing fluid within the sensing zone, wherein at least one of the sensing fluid and the analyte sensor comprises a catalyst for mutarotation of glucose. The invention also includes a method of using the monitor.

Abstract: A method of monitoring an analyte (such as, e.g., glucose) including the following steps: diffusing the analyte from a sampling location into a sensing fluid within a sensing chamber; detecting a concentration of the analyte in the sensing fluid; moving flushing fluid into the sensing chamber and simultaneously removing sensing fluid from the sensing chamber; permitting the flushing fluid to remain in the sensing chamber without flowing for a dwell time; removing the flushing fluid from the sensing chamber after the dwell time expires; and, after removing the flushing fluid from the sensing chamber, moving sensing fluid into the sensing chamber. The invention also includes an analyte monitoring device performing this method.

Abstract: One aspect of the invention is a method of in vivo monitoring of an individual's interstitial fluid glucose concentration comprising inserting a plurality of tissue piercing elements through a stratum corneum layer of an area of the individual's skin. The tissue piercing elements each comprise a distal end in fluid communication with interstitial fluid of the individual, and a proximal end in fluid communication with a sensing zone located outside of the patient's body. An interior space extends between the distal and proximal ends of the tissue piercing elements. A sensing fluid fills substantially the entire interior space and the sensing fluid concentration comprises a concentration of citrate in a buffer solution. The concentration of citrate may range from 100 mM to 200 mM, preferably 135-165 mM.

Abstract: One aspect of the invention provides a glucose monitor having a plurality of tissue piercing elements, each tissue piercing element having a distal opening, a proximal opening and interior space extending between the distal and proximal openings; a sensing area in fluid communication with the proximal openings of the tissue piercing elements; sensing fluid extending from the sensing area into substantially the entire interior space of the tissue piercing elements; and a glucose sensor adapted to detect a concentration of glucose in the sensing fluid within the sensing area.

Abstract: One aspect of the invention provides a glucose monitor having a plurality of tissue piercing elements, each tissue piercing element having a distal opening, a proximal opening and interior space extending between the distal and proximal openings; a sensing area in fluid communication with the proximal openings of the tissue piercing elements; sensing fluid extending from the sensing area into substantially the entire interior space of the tissue piercing elements; and a glucose sensor adapted to detect a concentration of glucose in the sensing fluid within the sensing area.

Abstract: A system for treating a blood sample (700) having an analyte of interest comprises a strip (200) having a membrane (218), respective portions (216, 220 and 222, or 300) which are provided for receiving the sample, for lysing cells of the sample to liberate hemoglobin, and for capturing glycated hemoglobin. The latter two portions (220 and 222, or 300) of the membrane are treated with lysing and capture agents, respectively. A portion of the strip (214 or 230 or 240) is provided for holding an eluting agent and for releasing the agent upon a release condition. A system for detecting analyte comprises an optical subsystem (550) that is aligned with the strip to provide a signal corresponding to an amount of analyte, and an electronic subsystem (650) for processing the signal (560) to provide a result, such as an amount or percentage of glycated hemoglobin.

Abstract: A system for treating a blood sample (700) having an analyte of interest comprises a strip (200) having a membrane (218), respective portions (216, 220 and 222, or 300) which are provided for receiving the sample, for lysing cells of the sample to liberate hemoglobin, and for capturing glycated hemoglobin. The latter two portions (220 and 222, or 300) of the membrane are treated with lysing and capture agents, respectively. A portion of the strip (214 or 230 or 240) is provided for holding an eluting agent and for releasing the agent upon a release condition. A system for detecting analyte comprises an optical subsystem (550) that is aligned with the strip to provide a signal corresponding to an amount of analyte, and an electronic subsystem (650) for processing the signal (560) to provide a result, such as an amount or percentage of glycated hemoglobin.

Abstract: One aspect of the invention provides an analyte monitor including a sensing volume, an analyte extraction area in contact with the sensing volume adapted to extract an analyte into the sensing volume, and an analyte sensor adapted to detect a concentration of analyte in the sensing volume. The sensing volume is defined by a first face, a second face opposite to the first face, and a thickness equal to the distance between the two faces. The surface area of the first face is about equal to the surface area of the second face and the extraction area is about equal to the surface area of the first and second face of the sensing volume. The analyte sensor includes a working electrode in contact with the sensing volume, the working electrode having a surface area at least as large as the analyte extraction area, and a second electrode in fluid communication with the sensing volume.

Abstract: One aspect of the invention provides a glucose monitor having a plurality of tissue piercing elements, each tissue piercing element having a distal opening, a proximal opening and interior space extending between the distal and proximal openings; a sensing volume in fluid communication with the proximal openings of the tissue piercing elements; sensing fluid extending into the sensing volume; and a glucose sensor adapted to detect a concentration of glucose in the sensing fluid within the sensing volume.

Abstract: The invention relates to a surface penetration device, a method to use the device, and an analyte monitor. Embodiments of the surface penetration device include a substrate with first and second surfaces, and first and second tissue piercing elements, the elements differing in configuration, but each associated with the first surface of the substrate. At least some of the tissue piercing elements have a distal and a proximal opening and a lumen extending between the openings. The proximal openings are in fluid communication with an opening in the second surface of the substrate. Embodiments of the analyte monitor include the features of the penetration device plus an analyte sensor that detects an analyte in a fluid. Embodiments of the method of penetrating tissue include providing a surface penetration device and urging the surface penetration device against a tissue surface until some of the first and second tissue piercing elements penetrate the tissue surface.

Abstract: An analyte monitor is provided with a sensor unit body configured for mounting on tissue, a sensor configured to detect an analyte in a fluid in the sensing area, an output device configured to communicate a result from the sensor to a user; and a user input device coupled with the sensor and the output device, wherein the monitor is configured to communicate a result to the user through the output device only after the user input device is activated. Systems, sensors and methods associated with the monitor are also disclosed.

Abstract: Analyte monitors and their methods of use. The analyte monitors include multiple calibration fluids which may have different known concentrations of an analyte, such as glucose. The analyte monitors may also include sensing or washing fluids. The analyte monitors are configured to be calibrated with the multiple calibration fluids to potentially provide a more accurate determination of analyte concentrations. The analyte monitors can be adapted to be self-calibrating with the multiple calibration fluids.

Abstract: The present invention includes methods and apparatus for continuous glucose monitoring of a patient. In one aspect a glucose monitor includes a plurality of substantially cylindrical tissue piercing elements adapted to pierce the stratum corneum and enter the epidermis, allowing for the diffusion of glucose from the interstitial fluid into the glucose monitors described herein. In another aspect of the invention, a glucose monitor includes a deformed substrate layer defining a plurality of tissue piercing elements.

Abstract: The present invention provides a single-use electronic device and test card for use therein which performs a coagulation or lysis assay of a blood or plasma sample. The device includes a housing having an exterior surface and defining an interior area and means for receiving the sample through the housing into the interior space. A non-porous substrate is positioned within the interior space for receiving the sample thereon. Preferably, a reagent accelerates the coagulation of the sample and is positioned on the substrate and in contact with the sample. An electroactive species is added to the sample. The device also measures the impedance of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay. Optionally, the electrical signal is received and converted into a digital output corresponding to the coagulation/lysis assay using assay calibration information stored therein. The digital output can be displayed external to the housing.

Abstract: The present invention provides a single-use electronic device and test card for use therein which performs a coagulation or lysis assay of a blood sample. The device includes a housing having an exterior surface and defining an interior area and means for receiving the sample through the housing into the interior space. A non-porous substrate is positioned within the interior space for receiving the sample thereon. A reagent accelerates the coagulation of the sample and is positioned on the substrate and in contact with the sample. Optionally, an electroactive species may also be reacted with the sample. The device also includes means for measuring the viscosity of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay.

Abstract: The present invention provides a single-use electronic device and test card for use therein which performs a coagulation or lysis assay of a blood sample. The device includes a housing having an exterior surface and defining an interior area and means for receiving the sample through the housing into the interior space. A non-porous substrate is positioned within the interior space for receiving the sample thereon. A reagent accelerates the coagulation of the sample and is positioned on the substrate and in contact with the sample. Optionally, an electroactive species may also be reacted with the sample. The device also includes means for measuring the viscosity of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay.

Abstract: The present invention provides a single-use electronic device and test card for use therein which performs a coagulation or lysis assay of a blood sample. The device includes a housing having an exterior surface and defining an interior area and means for receiving the sample through the housing into the interior space. A non-porous substrate is positioned within the interior space for receiving the sample thereon. A reagent accelerates the coagulation of the sample and is positioned on the substrate and in contact with the sample. Optionally, an electroactive species may also be reacted with the sample. The device also includes means for measuring the viscosity of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay.

Abstract: The present invention provides a single-use electronic device and test card for use therein which performs a coagulation or lysis assay of a blood sample. The device includes a housing having an exterior surface and defining an interior area and means for receiving the sample through the housing into the interior space. A non-porous substrate is positioned within the interior space for receiving the sample thereon. A reagent accelerates the coagulation of the sample and is positioned on the substrate and in contact with the sample. Optionally, an electroactive species may also be reacted with the sample. The device also includes means for measuring the viscosity of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay.