Disclosed are systems and methods for detecting analyte levels. These systems and methods may include a sensor configured for at least partial placement in an analyte-containing medium. The sensor may include one or more transducers and one or more diffusion barriers. The diffusion barriers may be arranged to delay diffusion of analyte to one transducer relative to another transducer. This delay may be used for purposes such as calculating and/or compensating for lag between a measured analyte level and a physiological analyte level of interest.

Compounds, systems, and methods are provided for the design and assembly of a non-invasive, analyte sensing dressing. The dressing can be therapeutic. The dressing includes a sensor and a matrix. The sensor is capable of detecting analytes such as molecular oxygen, carbon dioxide, nitric oxides, dissolved analytes in plasma, and hydrogen ions. The matrix is at least partially permeable to the analyte. The device emits a detectable signal when the sensor is excited in the presence of the analyte. In one version of the dressing, the sensor includes a meso-unsubstituted metallated porphyrin that is sensitive towards oxygen. The metallated porphyrin can be excited when illuminated at a first wavelength, followed by emission of phosphorescence at a second wavelength whose intensity can be used as an indicator for oxygen concentration.

Disclosed is a system for real-time detection and annunciation of blood associated with menstruation and surgical wounds. The system comprises a real-time, wide area blood detector, communication means for relay of blood detection information, and annunciation means to inform the user of the emanation of blood. Various system embodiments include local and remote as well as covert and non-covert annunciation to users or medical personnel, various forms of real-time blood detection sensors, blood analysis capability, and smart bandage telemetry.

The disclosure relates to methods and devices for monitoring the concentration of a substance, preferably oxygen, in a cell or tissue, e.g., in cells of the human skin. In particular, it provides a method for determining the concentration of a quencher, such as oxygen and/or the concentration of a probe, e.g., a heme precursor such as protoporphyrin IX (PpIX), wherein the probe is capable of exhibiting luminescence (delayed fluorescence (DF) or phosphorescence) and or transient triplet absorption, preferably, deDF, in a living cell. The method comprises steps of exciting the probe, measuring the lifetime of the luminescence exhibited by said probe, herein, in the presence of the quencher, the lifetime is shortened as compared to the lifetime in the absence of the quencher, and correlating said lifetime with said concentration. The disclosed method leads to more precise results than conventional methods, because of adaptations based on the understanding of the influence of the concentration of the probe and its excitation fluence rate (intensity) on the analysis. For example, the simultaneous time-resolved detection of the probe excimer and monomer DF allows estimation of the probe concentration and compensation of the probe self-quenching effect in the quencher concentration calculation, increasing the measurement precision. Taking into account second order triplet interactions also permits the interpretation of non-exponential decays and further improvement of the quencher and probe concentration estimation. Disclosed methods rely, e.g., on measurement at different emission wavelengths and application of an adaptive Stern-Volmer relationship, the decay central fitting method and/or a mixed orders approach. Said method can be applied, e.g., for bedside monitoring of patients. Also disclosed is the use of the PpIX precursor 5-aminolevulinic acid (5-ALA), or derivatives thereof, in this method, and a device suitable therefor.

The disclosed techniques include obtaining a first signal generated by an electrochemical glucose sensor and a second signal generated by an optical glucose sensor, and obtaining a glucose value indicative of a user's blood glucose level, where the glucose value and the second signal are obtained at different times. The disclosed techniques further cause calculating a mapped value for the second signal based on the first signal, and calibrating the mapped value of the second signal based on the glucose value.

An implantable unit includes fluorescent sensor molecules, each of which includes a binding site for an analyte, a donor fluorophore, and an acceptor fluorophore; and a first light source. An external system includes an external reading unit, which includes a light sensor; and a processor, which is configured to (i) during a first time period: (a) drive the first light source to generate light having a first illumination peak wavelength appropriate for excitation of the donor fluorophore, and (b) receive, from the light sensor, a first measurement of the fluorescent light emitted from the acceptor fluorophore, (ii) during a second time period: (a) drive a second light source to generate light having a second illumination peak wavelength appropriate for direct excitation of the acceptor fluorophore, and (b) receive, from the light sensor, a second measurement of the fluorescent light emitted from the acceptor fluorophore, and (iii) calculate the concentration of the analyte based on the measurements.

Compounds, systems, and methods are provided for the design and assembly of a non-invasive, analyte sensing dressing that includes a sensor and a matrix. The sensor is capable of detecting analytes such as molecular oxygen. The matrix is at least partially permeable to the analyte. In one version of the dressing, the sensor includes a meso-unsubstituted metallated porphyrin that is sensitive towards oxygen. The metallated porphyrin can be excited when illuminated at a first wavelength, followed by emission of phosphorescence at a second wavelength whose intensity can be used as an indicator for oxygen concentration. The metallated porphyrin can be prepared from a phosphorescent meso-unsubstituted porphyrin having the Formula (I): ##STR00001##
wherein M is a metal, wherein each R is independently an atom or a group of atoms, and wherein at least one R is —O(C)OR′, wherein R′ is optionally substituted alkyl.

Compounds, systems, and methods are provided for a non-invasive, analyte sensing dressing. The dressing includes a sensor and a matrix. The sensor is capable of detecting analytes such as molecular oxygen, carbon dioxide, nitric oxides, dissolved analytes in plasma, and hydrogen ions. The device emits a detectable signal when the sensor is excited in the presence of the analyte. The sensor may include a meso-unsubstituted metallated porphyrin that is sensitive towards oxygen. The porphyrin can be excited when illuminated at a first wavelength, followed by emission of phosphorescence at a second wavelength whose intensity is an indicator for oxygen concentration. An example metallated porphyrin has the Formula(I): ##STR00001## wherein M is a metal, each R is independently an atom or a group of atoms, and at least one R is —OR.sup.1, wherein R.sup.1 is an atom or a group of atoms.

Disclosed herein are embodiments of a continuous analyte sensor that can be used to measure glucose or lactate levels in a patient, along with other analytes. In some embodiments, the sensor can be located in the tissue or a blood vessel of a patient, and a probe can be located on the skin of the patient generally adjacent to the sensor. The probe can detect luminescent signals that originate from the sensor and that are dependent on analyte levels.

The invention provides systems for characterizing a biological sample by analyzing emission of fluorescent light from the biological sample upon excitation and methods for using the same. The system includes a laser source, collection fibers, a demultiplexer and an optical delay device. All references cited herein are incorporated by reference in their entirety as though fully set forth. Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of-ordinary skill in the art in which this invention belongs.