Abstract: A method and system that enables a user to maintain a sensor in real time. The present invention involves performing a diagnostic Electrochemical Impedance Spectroscopy (EIS) procedure to measure sensor impedance value in order to determine if the sensor is operating at an optimal level. If the sensor is not operating at an optimal level, the present invention may further involve performing a sensor remedial action. The sensor remedial action involves reversing the DC voltage being applied between the working electrode and the reference electrode. The reversed DC voltage may be coupled with an AC voltage to extend its reach.

Abstract: A multilayer substrate device formed from a base substrate and alternating metalization layers and dielectric layers. Each layer is formed without firing. Vias may extend through one of the dielectric layers such that two metalization layers surrounding the dielectric layers make. contact with each other. The vias may be formed by placing pillars on top of a metalization layer, forming a dielectric layer on top of the metalization layer and surrounding the pillars, and removing the pillars. Dielectric layers may be followed by other dielectric layers and metalization layers may be followed by other metalization layers. Vias in the substrate may be filled by forming an assembly around the substrate, the assembly including printing sheets containing a conductive ink and pressure plates for applying pressure. A vacuum may be applied to remove air in the ink. Pressure may then be applied to the printing sheets through the pressure plates.

Abstract: A system is provided for sensing blood glucose data of a patient. The system includes a sensor, user interface, and an optional auxiliary device. If the connection between the sensor and user interface is by a wire, the sensor remains powered when the wire is disconnected. The communication between the sensor and the user interface may be wireless. The auxiliary device can be a patient monitor or other display or signal device, which displays information about the blood glucose data collected by the sensor. The sensor is connected to sensor electronics, which include a sensor power supply, a voltage regulator, and optionally a memory and processor.

Abstract: 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.

Abstract: A sensor system includes a sensor and a sensor electronics device. The sensor includes a plurality of electrodes. The sensor electronics device includes a connection detection device, a power source, and a delay circuit. The connection detection device determines if the sensor electronics device is connected to the sensor and transmits a connection signal. The delay circuit receives the connection signal, waits a preset hydration time, and couples the regulated voltage from the power source to an electrode in the sensor after the preset hydration time has elapsed. Alternatively, the sensor electronics device may include an electrical detection circuit and a microcontroller. The electrical detection circuit determines if the plurality of electrodes are hydrated and generates an interrupt if the electrodes are hydrated. A microcontroller receives the interrupt and transmits a signal representative of a voltage to an electrode of the plurality of electrodes.

Abstract: A blood glucose sensing system includes a sensor and a sensor electronics device. The sensor includes a plurality of electrodes. The sensor electronics device includes stabilization circuitry. The stabilization circuitry cases a first voltage to be applied to one of the electrodes for a first timeframe and causes a second voltage to be applied to one of the electrodes for a second timeframe. The stabilization circuitry repeats the application of the first voltage and the second voltage to continue the anodic-cathodic cycle. The sensor electronics device may include a power supply, a regulator, and a voltage application device, where the voltage application device receives a regulator voltage from the regulator, applies a first voltage to an electrode for the first timeframe, and applies a second voltage to an electrode for the second timeframe.

Abstract: A method and program prevents a user from bypassing a limit placed on a specified operating life of a sensor by disconnecting and reconnecting the sensor. The present invention checks a characteristic of the sensor to see if the sensor is used prior to the connection of the sensor, and rejects the sensor if the sensor is determined to have been used before. The process of checking the characteristic of the sensor involves performing an Electrochemical Impedance Spectroscopy (EIS) procedure and calculating an impedance value. The impedance value can be compared to various threshold values for a variety of purposes including the determination of age, condition, hydration, and stabilization of the sensor.

Abstract: A thin film sensor, such as a glucose sensor, is provided for transcutaneous placement at a selected site within the body of a patient. The sensor includes several sensor layers that include conductive layers and includes a proximal segment defining conductive contacts adapted for electrical connection to a suitable monitor, and a distal segment with sensor electrodes for transcutaneous placement. The sensor electrode layers are disposed generally above each other, for example with the reference electrode above the working electrode and the working electrode above the counter electrode. The electrode layers are separated by dielectric layer.

Abstract: A reusable analyte sensor site for use with a replaceable analyte sensor for determining a level of an analyte includes a site housing material and a resealable insertion site coupled to one end of the site housing material. Preferably, the site housing material is formed to have an interior cavity with an opening. The site housing material is selected to promote tissue ingrowth and vascularization, and yet be free of tissue ingress. Also, the site housing material permits the analyte to pass through the site housing material to the interior cavity to permit measurement by the replaceable analyte sensor. The resealable insertion site provides a for inserting the replaceable analyte sensor into the interior cavity of the site housing material.

Abstract: A system and method for calibrating a sensor of a characteristic monitoring system in real time utilizes a self-calibration module for periodic determination of, and compensation for, the IR drop across unwanted resistances in a cell. A current-interrupt switch is used to open the self-calibration module circuit and either measure the IR drop using a high-frequency (MHz) ADC module, or estimate it through linear regression of acquired samples of the voltage across the sensor's working and reference electrodes (Vmeasured) over time. The IR drop is then subtracted from the closed-circuit value of Vmeasured to calculate the overpotential that exists in the cell (Vimportant). Vimportant may be further optimized by subtracting the value of the open-circuit voltage (Voc) across the sensor's working and reference electrodes. The values of Vmeasured and Vimportant are then controlled by respective first and second control units to compensate for the IR drop.

Abstract: A protective, biocompatible coating or encapsulation material protects and insulates a component or device intended to be implanted in living tissue. The coating or encapsulation material comprises a thin layer or layers of alumina, zirconia or other ceramic, less than 25 microns thick, e.g., 5-10 microns thick. The alumina layer(s) may be applied at a relatively low temperature. Once applied, the layer provides excellent hermeticity, and prevents electrical leakage. Even though very thin, the alumina layer retains excellent insulating characteristics. In one embodiment, an alumina layer less than about 6 microns thick provides an insulative coating that exhibits less than 10 pA of leakage current over an area 75 mils by 25 mils area while soaking in a saline solution at temperatures up to 80° C. over a three month period.

Abstract: Embodiments of the invention provide analyte sensors having optimized permselective membranes and methods for making and using such sensors. Embodiments of the invention also provide analyte sensors such as those having porous matrices coated with an analyte sensing composition and methods for making and using such sensors. Illustrative embodiments include electrochemical glucose sensors having glucose oxidase coatings.

Abstract: A system is provided for monitoring blood glucose data of a patient. The system includes a sensing device and hospital monitor. The sensing device includes a sensor and sensor electronics and is adapted to transmit information to the hospital monitor while continuing to sense blood glucose data. The communication between the sensing device and the hospital monitor may be wireless. The sensor electronics may include a sensor power supply, a voltage regulator, and optionally a memory and processor.

Abstract: A reusable analyte sensor site for use with a replaceable analyte sensor for determining a level of an analyte includes a site housing and a resealable insertion site coupled to one end of the site housing. Preferably, the site housing is formed to have an interior cavity, and includes an outer membrane made of a material selected to promote vascularization and having a first pore size, and an inner membrane made of a material selected to be free of tissue ingress. Also, the site housing permits the analyte to pass through the site housing to the interior cavity to permit measurement by the replaceable analyte sensor. The resealable insertion site is provided for inserting the replaceable analyte sensor into the interior cavity of the site housing.

Abstract: A method and apparatus for enhancing the integrity of an implantable sensor. Voids formed between an outer tubing and a sensor substrate or spacing element may be back-filled with a curable, implantable material, minimizing the extent to which unwanted fluids diffuse within the sensor. An enzyme or protein matrix pellet below the sensor window may be pre-treated with a reducing agent to enhance its bond stability, and to reduce undesired swelling that may cause the sensor window to detach or leak. The bonding between the enzyme pellet and a hydrogel layer may be reinforced by application of an intervening bonding layer of a protein material, such as human serum albumin (HSA). The size of the window may be minimized by minimizing the size of an underlying electrode, providing reduced flux and lengthening sensor. A coating may be deposited on the surface of the sensor leads, providing stiffening and lubrication.

Abstract: A flexible mounting base to hold a sensor at an infusion site, the sensor being a removable in vivo sensor for monitoring analyte concentration level in a patient, such as blood glucose (BG) level. The mounting base comprises a flexible adhesive that anchors the flexible sensor set at an infusion site to provide stability for the sensor set in a convenient and comfortable manner. Placement of the mounting base onto the patient's skin causes the insertion needle to pierce the skin for transcutaneous placement of the cannula with the sensor therein. The insertion needle can then be withdrawn to leave the cannula and sensor at the selected insertion position, with the distal segment of the sensor being exposed to patient extracellular fluid via apertures formed in the cannula.

Abstract: A method for formulating and immobilizing a protein and a protein matrix formed by the method. The protein matrix preparation method results in a physically and chemically stable protein matrix that has low swelling, non-leaching, high activity, and high mechanical strength properties. The method includes cross-linking and hardening the protein mixture and using a mold to form a protein into a desired shape and size.

Abstract: A reusable analyte sensor site for use with a replaceable analyte sensor for determining a level of an analyte includes a site housing and a resealable insertion site coupled to one end of the site housing. Preferably, the site housing is formed to have an interior cavity, and includes an outer membrane made of a material selected to promote vascularization and having a first pore size, and an inner membrane made of a material selected to be free of tissue ingress. Also, the site housing permits the analyte to pass through the site housing to the interior cavity to permit measurement by the replaceable analyte sensor. The resealable insertion site is provided for inserting the replaceable analyte sensor into the interior cavity of the site housing.

Abstract: A method and apparatus for enhancing the integrity of an implantable sensor. Voids formed between an outer tubing and a sensor substrate or spacing element may be back-filled with a curable, implantable material, minimizing the extent to which unwanted fluids diffuse within the sensor. An enzyme or protein matrix pellet below the sensor window may be pre-treated with a reducing agent to enhance its bond stability, and to reduce undesired swelling that may cause the sensor window to detach or leak. The bonding between the enzyme pellet and a hydrogel layer may be reinforced by application of an intervening bonding layer of a protein material, such as human serum albumin (HSA). The size of the window may be minimized by minimizing the size of an underlying electrode, providing reduced flux and lengthening sensor. A coating may be deposited on the surface of the sensor leads, providing stiffening and lubrication.

Abstract: A protective, biocompatible coating or encapsulation material protects and insulates a component or device intended to be implanted in living tissue. The coating or encapsulation material comprises a thin layer or layers of alumina, zerconia, or other ceramic, less than 25 microns thick, e.g., 5–10 microns thick. The alumina layer(s) may be applied at relatively low temperature. Once applied, the layer provides excellent hermeticity, and prevents electrical leakage. Even though very thin, the alumina layer retains excellent insulating characteristics. In one embodiment, an alumina layer less than about 6 microns thick provides an insulative coating that exhibits less than 10 pA of leakage current over an area 75 mils by 25 mils area while soaking in a saline solution at temperatures up to 80° C. over a three month period.