Abstract: An optical-based sensor for detecting the presence or amount of an analyte using both indicator and reference channels. The sensor has a sensor body with a source of radiation embedded therein. Radiation emitted by the source interacts with indicator membrane indicator molecules proximate the surface of the body. At least one optical characteristic of these indicator molecules varies with analyte concentration. For example, the level of fluorescence of fluorescent indicator molecules or the amount of light absorbed by light-absorbing indicator molecules can vary as a function of analyte concentration. In addition, radiation emitted by the source also interacts with reference membrane indicator molecules proximate the surface of the body. Radiation (e.g., light) emitted or reflected by these indicator molecules enters and is internally reflected in the sensor body.

Abstract: The present invention provides systems and methods for attenuating the effect of ambient light on optical sensors and for measuring and compensating quantitatively for the ambient light.

Abstract: An electro-optical sensing device for detecting the presence and concentration of an analyte in a liquid or gaseous medium includes a pair of indicator elements positioned to receive radiation from a radiation source and transmit radiation to a pair of photosensitive elements. The indicator elements each contain indicator molecules having an optical characteristic responsive to the presence of an analyte; however, one of the indicator elements is covered by an analyte-impermeable chamber that renders the indicator element insensitive to the presence of the analyte in the medium outside the chamber so that it can be used as a reference to cancel environmental and systemic variables that affect both indicator elements. The chamber preferably holds an analyte-containing fluid in contact with the reference indicator element so that the indicator elements operate under nominally identical conditions.

Abstract: In one aspect, the present invention relates to an implantable device for detecting the presence or concentration of an analyte in an aqueous environment in vivo. The device includes a macromolecule that comprises a copolymer of: a) one or more indicator component monomers which individually are not sufficiently water soluble to permit their use in an aqueous environment for detecting the presence or concentration of said analyte; b) one or more hydrophilic monomers; and c) one or more catalytic antioxidant monomers; such that the macromolecule is capable of detecting the presence or concentration of the analyte in an aqueous environment. The presence of the catalytic antioxidant reduces or prevents oxidative damage to the macromolecule.

Abstract: The invention relates to indicator molecules for detecting the presence or concentration of an analyte in a medium, such as a liquid, and to methods for achieving such detection. More particularly, the invention relates to copolymer macromolecules containing relatively hydrophobic indicator component monomers, and hydrophilic monomers, such that the macromolecule is capable of use in an aqueous environment.

Abstract: The present invention provides an electro-optical sensing device for detecting the presence or concentration of an analyte. More particularly, the invention relates to (but is not in all cases necessarily limited to) optical-based sensing devices which are characterized by being totally self-contained, with a smooth and rounded oblong, oval, or elliptical shape (e.g., a bean- or pharmaceutical capsule-shape) and a size which permits the device to be implanted in humans for in-situ detection of various analytes.

Abstract: An optical-based sensor for detecting the presence or amount of an analyte using both indicator and reference channels. The sensor has a sensor body with a source of radiation embedded therein. Radiation emitted by the source interacts with indicator membrane indicator molecules proximate the surface of the body. At least one optical characteristic of these indicator molecules varies with analyte concentration. For example, the level of fluorescence of fluorescent indicator molecules or the amount of light absorbed by light-absorbing indicator molecules can vary as a function of analyte concentration. In addition, radiation emitted by the source also interacts with reference membrane indicator molecules proximate the surface of the body. Radiation (e.g., light) emitted or reflected by these indicator molecules enters and is internally reflected in the sensor body.

Abstract: The present invention provides systems and methods for attenuating the effect of ambient light on optical sensors and for measuring and compensating quantitatively for the ambient light.

Abstract: The present invention provides, among other things, a sensor system, having (1) a sensor implanted in a body part of the subject, wherein the sensor has a first antenna, and (2) a sensor reader worn on the subject's body part, wherein the sensor reader has a band housing a second antenna, which is inductively coupled with the first antenna, for enabling the sensor reader to communicate with the sensor.

Abstract: The present invention provides a method for increasing the lifetime of an optical sensor. In one aspect, the method includes the step of configuring the optical sensor so that the duty cycle of sensor's radiant source is less than 100% over a continuous period amount of time when the sensor is periodically obtaining data regarding an analyte. By operating the sensor according to the above inventive method, the indicator molecules of the optical sensor are not excited during the entire continuous period of time during which the sensor is needed to provide data regarding the presence or concentration of a substance. Thus, the method increases the life of the indicator molecules.

Abstract: An optical sensor device for determining the presence or concentration of an analyte, contains a waveguide disposed over a light source and a light detector mounted on a surface of a substrate and separated by an internal baffle, wherein the waveguide has a thickness corresponding to a far field emission point of the light source as determined by a light shielding baffle between the light source and light detector. An analyte indicator matrix is disposed on the outer surface of the waveguide. The sensor device geometry takes advantage of only direct illumination of the indicator matrix, and direct collection of indicator matrix illumination, without any significant reflection by said waveguide. Undesirable light noise generated by the light source passes directly out of the device through the waveguide.

Abstract: The present invention provides a biocompatible circuit assembly that includes a circuit encased within a housing. In some embodiments, the housing is a PMMA housing and before the circuit is enclosed within the housing the circuit is encased within a brick of epoxy.

Abstract: The invention relates to immobilization methods, in particular for immobilizing indicator molecules on supports such as sensors and to sensors having those molecules immobilized to their surface. Non-covalent immobilization of macromolecular indicator molecules on those supports via mechanical interlacing with polymers at the surface of a support and via ionic bonding via charged moieties of indicator molecules and ionic groups on the surface of the support are disclosed.

Abstract: The present invention provides systems and methods for attenuating the effect of ambient light on optical sensors and for measuring and compensating quantitatively for the ambient light.

Abstract: Radiant energy is transmitted to a probe element including an interior conical reflecting surface and a fluid sample chamber. Portions of the light which have been transmitted, partially attenuated, or scattered by a fluid sample in the sample chamber are directed by at least a portion of the interior conical reflecting surface to means for collecting the transmitted, partially attenuated, or scattered light. A stilling valve incorporated into the probe element enables elimination of entrained gas bubbles from the chamber.