Some embodiments described herein relate to a sensor that includes an analyte-sensing dye and a reference dye. The analyte-sensing dye can be configured to emit an analyte-dependent optical signal in the presence of an analyte. Similarly stated, the intensity and/or duration of the analyte-dependent optical signal can be modulated by a quantity and/or concentration of the analyte in the environment of the sensor. The reference dye can be configured to emit an analyte-independent optical signal. The analyte-dependent optical signal and the analyte-independent optical signal have an analyte-dependent spectrum and an analyte-independent spectrum, respectfully. The analyte-dependent optical spectrum and the analyte-independent spectrum can be the same, substantially the same, and/or overlapping. The analyte-dependent optical signal can have a duration of lifetime that is shorter than a duration or lifetime of the analyte-independent optical signal.

Method and system embodiments for operating a device implantable in a subject using ultrasonic waves are described. In some embodiments, a method is performed at the implantable device to receive ultrasonic waves including an operating mode command. Then, the implantable device sets an operating mode of the implantable device to one operating mode from a plurality of predetermined operating modes based on the operating mode command.

Wearable apparatus for monitoring various physiological and environmental factors are provided. Real-time, noninvasive health and environmental monitors include a plurality of compact sensors integrated within small, low-profile devices, such as earpiece modules. Physiological and environmental data is collected and wirelessly transmitted into a wireless network, where the data is stored and/or processed.

An oxygen measurement device includes a catheter including a flexible hollow shaft, the flexible shaft having an open port configured to allow urine from a bladder to flow into the open port, and a urinary passage in communication with the open port configured to discharge the urine; and an oxygen sensor including an oxygen sensor main body capable of detecting oxygen in the urine, the oxygen sensor being disposed in the catheter and configured such that the oxygen sensor main body is in contact with the urine flowing in the urinary passage.

A non-invasive measurement of biological tissue reveals information about the function of that tissue. Polarized light is directed onto the tissue, stimulating the emission of fluorescence, due to one or more endogenous fluorophors in the tissue. Fluorescence anisotropy is then calculated. Such measurements of fluorescence anisotropy are then used to assess the functional status of the tissue, and to identify the existence and severity of disease states. Such assessment can be made by comparing a fluorescence anisotropy profile with a known profile of a control.

There is provided a method of calibrating a sensor comprising a luminescent compound having a luminescence that depends on the concentration of an analyte, and a detector configured to detect light emitted by the luminescent compound, the method comprising providing a component comprising the luminescent compound in a package that maintains exposure of the luminescent compound to the analyte at a known first concentration, assembling the component into the sensor and measuring a first value of a characteristic of the luminescence of the luminescent compound while exposed to the analyte at the first concentration, measuring a second value of the characteristic of the luminescence of the luminescent compound while exposed to the analyte at a known second concentration different from the first concentration, and determining parameters representing the dependence of the characteristic of the luminescence on concentration of the analyte using the first value and the second value.

Methods and systems for sensor calibration and sensor glucose (SG) fusion are used advantageously to improve the accuracy and reliability of orthogonally redundant glucose sensor devices, which may include optical and electrochemical glucose sensors. Calibration for both sensors may be achieved via fixed-offset and/or dynamic regression methodologies, depending, e.g., on sensor stability and Isig-Ratio pair correlation. For SG fusion, respective integrity checks may be performed for SG values from the optical and electrochemical sensors, and the SG values calibrated if the integrity checks are passed. Integrity checks may include checking for sensitivity loss, noise, and drift. If the integrity checks are failed, in-line sensor mapping between the electrochemical and optical sensors may be performed prior to calibration. The electrochemical and optical SG values may be weighted (as a function of the respective sensor's overall reliability index (RI)) and the weighted SGs combined to obtain a single, fused SG value.

A continuous glucose monitoring system may include a hand-held monitor, a transmitter, an insulin pump, and an orthogonally redundant glucose sensor, which may comprise an optical glucose sensor and a non-optical glucose sensor. The former may be a fiber optical sensor, including a competitive glucose binding affinity assay with a glucose analog and a fluorophore-labeled glucose receptor, which is interrogated by an optical interrogating system, e.g., a stacked planar integrated optical system. The non-optical sensor may be an electrochemical sensor having a plurality of electrodes distributed along the length thereof. Proximal portions of the optical and electrochemical sensors may be housed inside the transmitter and operationally coupled with instrumentation for, e.g., receiving signals from the sensors, converting to respective glucose values, and communicating the glucose values. The sensors' distal portions may be inserted into a user's body via a single delivery needle and may be co-located inside the user's body.

An ingestible device is disclosed which can produce spectral data of one or more analytes, as well as associated methods for characterizing the gastrointestinal tract of a subject which contains such analytes. Related kits and systems are also disclosed.

A sensor system includes a probe, and a photon source configured to direct photons at the probe. The probe can emit light in response to receiving photons. The sensor system can include a photodetector configured to detect the light emitted from the probe, and a configured to cause the photon source to emit photons according to a first time-varying intensity profile having a first frequency. The controller can be configured to receive optical data from the photodetector based on the interaction between the light emitted from the probe and the photodetector. The optical data can include a second time-varying intensity profile having a second frequency. The second frequency can be substantially the same as the first frequency. The controller can be configured to determine a difference in phase between the first time-varying intensity profile and the second time-varying intensity profile, and generate a report based on the difference in phase.