Abstract: An analyte indicator may include a porous base and may be included in an analyte sensor. The analyte indicator may retain its physical, chemical, and optical properties in the presence of compression. The porous base may not vary in opacity. The analyte indicator may include (i) a polymer unit attached or polymerized onto or out of the porous base and (ii) an analyte sensing element attached to the polymer unit or copolymerized with the polymer unit. The analyte sensing element may include one or more indicator molecule. The analyte sensing element may include one or more indicator polymer chains. The analyte indicator may include (i) an indicator polymer chain attached or polymerized onto or out of the porous base and (ii) indicator molecules attached to the indicator polymer chain.

Abstract: An analyte indicator may include a porous base and may be included in an analyte sensor. The analyte indicator may retain its physical, chemical, and optical properties in the presence of compression. The porous base may not vary in opacity. The analyte indicator may include (i) a polymer unit attached or polymerized onto or out of the porous base and (ii) an analyte sensing element attached to the polymer unit or copolymerized with the polymer unit. The analyte sensing element may include one or more indicator molecule. The analyte sensing element may include one or more indicator polymer chains. The analyte indicator may include (i) an indicator polymer chain attached or polymerized onto or out of the porous base and (ii) indicator molecules attached to the indicator polymer chain.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.

Abstract: A sensor (e.g., an optical sensor) that may be placed within a living animal (e.g., a human) and may be used to measure an analyte (e.g., glucose or oxygen) in a medium (e.g., interstitial fluid) within the animal. The sensor may include a sensor housing and a polymer graft including indicator molecules and covering at least a portion of the sensor housing. The opacity of the polymer graft may remain substantially the same (i.e., may have little or no variation) over time. The sensor may include a photodetector, and variation in the opacity of the polymer graft does not cause a significant change in a measurement signal output by the photodetector. The polymer hydrogel may be made of polymers including acrylic acid and/or polyethylene glycol.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.

Abstract: An analyte indicator may include a porous base and may be included in an analyte sensor. The analyte indicator may retain its physical, chemical, and optical properties in the presence of compression. The porous base may not vary in opacity. The analyte indicator may include (i) a polymer unit attached or polymerized onto or out of the porous base and (ii) an analyte sensing element attached to the polymer unit or copolymerized with the polymer unit. The analyte sensing element may include one or more indicator molecule. The analyte sensing element may include one or more indicator polymer chains. The analyte indicator may include (i) an indicator polymer chain attached or polymerized onto or out of the porous base and (ii) indicator molecules attached to the indicator polymer chain.

Abstract: A system, method, and apparatus for implanting a sensor or other item into tissue of an animal includes the use of a tapered tip, which may be made from a bioresorbable material. The tapered tip may be removably attached to the distal end of a sleeve or cannula within which the item to be implanted is positioned. The tapered tip may facilitate advancement of the sleeve into the tissue to form a pocket within the tissue. Retraction of the sleeve may remove the item from the sleeve and separate the tip from the sleeve, thereby depositing the tip and the item in the pocket formed in the tissue.

Abstract: A system including a sensor and a transceiver and configured to determine a concentration of an analyte in a medium of a living animal. The sensor may include first and second signal photodetectors and first and second reference photodetectors, which may each be covered by an associate filter. The first photodetector may receive light emitted from first and second grafts, respectively. The grafts may receive excitation light from one or more light sources. The transceiver may receive signals from the photodetectors of the sensor and may determine the analyte concentration based on the received signals.

Abstract: Methods, sensors, and systems that prevent or reduce data loss when more than one external sensor transceiver is used with a sensor. A sensor may receive a transceiver identification (ID) of an external transceiver conveyed from the external transceiver and determine whether the received transceiver ID is a new transceiver ID. If sensor determines the received transceiver ID to be a new transceiver ID, the sensor may store the received transceiver ID in a nonvolatile storage medium of the sensor and convey, using the sensor, measurement information stored in the nonvolatile storage medium to the external transceiver.

Abstract: A hydrogel is dried by a critical point drying technique. The hydrogel may include indicator molecules embedded therein and may be part of a hydrogel-based device, such as, for example, an analyte sensor.

Abstract: A sensor (e.g., an optical sensor) that may be implanted within a living animal (e.g., a human) and may be used to measure an analyte (e.g., glucose or oxygen) in a medium (e.g., interstitial fluid, blood, or intraperitoneal fluid) within the animal. The sensor may include a sensor housing, an analyte indicator covering at least a portion of the sensor housing, and one or more therapeutic agents. The one or more therapeutic agents may reduce deterioration of the analyte indicator. The one or more therapeutic agents may be incorporated within the analyte indicator, a membrane covering at least a portion of the analyte indicator, and/or one or more drug eluting polymer matrices, which may be external to or within the sensor housing.

Abstract: A sensor (e.g., an optical sensor) that may be placed within a living animal (e.g., a human) and may be used to measure an analyte (e.g., glucose or oxygen) in a medium (e.g., interstitial fluid) within the animal. The sensor may include a sensor housing and a polymer graft including indicator molecules and covering at least a portion of the sensor housing. The opacity of the polymer graft may remain substantially the same (i.e., may have little or no variation) over time. The sensor may include a photodetector, and variation in the opacity of the polymer graft does not cause a significant change in a measurement signal output by the photodetector. The polymer hydrogel may be made of polymers including acrylic acid and/or polyethylene glycol.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.

Abstract: A sensor that may be used to detect the presence, amount, and/or concentration of an analyte in a medium within an animal. The sensor may include a sensor housing, an indicator element embedded within and/or covering at least a portion of the sensor housing, and a membrane over the indicator element. The membrane may reduce indicator element deterioration by preventing immune cells, such as white blood cells, from contacting the indicator element, substantially prevent transmission of light of at least a specified wavelength or range of wavelengths through the membrane, and/or permit the analyte to pass through to the indicator element. The membrane may be an opaque diffusion membrane. The sensor may include a foil. The foil may block light and/or reduce indicator element deterioration. The membrane may reduce oxidation of the indicator element.