Abstract: Methods, devices and systems for one or both of two- or three-dimensional location of the disposition of a sensor coil in a subject including: an array of electromagnetic drive coil sets, each set having two or three dimensionally oriented drive coils; a sensor coil being electromagnetically communicative with the array of electromagnetic drive coil sets; and, a system controller communicative with and adapted to energize one or more of the electromagnetic coils in the array of electromagnetic drive coil sets, the energizing of the one or more of the electromagnetic coils including one or more of energizing the coils singly, or in pairs of x-y and y-z or x-z coils, or in triplets of x-y-z coils while measuring the response of the sensor coil; whereby the system uses the measurements of the responses of the sensor coil to calculate the location and orientation of the sensor coil relative to said drive coil sets.

Abstract: Methods, devices and systems for one or both of two- or three-dimensional location of the disposition of a sensor coil in a subject including: an array of electromagnetic drive coil sets, each set having two or three dimensionally oriented drive coils; a sensor coil being electromagnetically communicative with the array of electromagnetic drive coil sets; and, a system controller communicative with and adapted to energize one or more of the electromagnetic coils in the array of electromagnetic drive coil sets, the energizing of the one or more of the electromagnetic coils including one or more of energizing the coils singly, or in pairs of x-y and y-z or x-z coils, or in triplets of x-y-z coils while measuring the response of the sensor coil; whereby the system uses the measurements of the responses of the sensor coil to calculate the location and orientation of the sensor coil relative to said drive coil sets.

Abstract: Glucose concentration is noninvasively measured by measuring a plurality of absorption values using at least one emitter operating at a corresponding plurality of emission wavelengths through a common optical sample volume and deriving glucose concentration from the absorption measurement values.

Abstract: Glucose concentration is noninvasively measured by measuring a plurality of absorption values using at least one emitter operating at a corresponding plurality of emission wavelengths through a common optical sample volume and deriving glucose concentration from the absorption measurement values.

Abstract: An optical sensor includes an optical source capable of being positioned on a tissue and emitting near infrared light into the tissue at a plurality of selected wavelengths, and a photodetector capable of detecting reflected light from the tissue. The photodetector being positioned on the tissue removed from the optical source but sufficiently close in proximity to the optical source to contact the same general tissue. The optical sensor further includes an oscillator coupled to the optical source and capable of activating the optical source to emit the near infrared light, and a modulator coupled to the oscillator and capable of controlling radio frequency modulation of the optical source to emit a radio frequency component that is used to measure the optical path length and absorbance of an analyte of interest within the tissue.

Abstract: A diagnostic apparatus includes a near infrared spectrophotometer (NIRS) and an ultrasound transducer that operate in combination to improve diagnostic measurements. The diagnostic apparatus includes a near infrared spectrophotometer that measures an analyte, for example tissue oxygenation, in an optical sample volume and an ultrasound imager to accurately position the optical sample volume in biological tissue or vessels. In one example, the diagnostic apparatus includes an optical source, a linear array of ultrasound transducers, and an optical photodetector arranged in the same plane so that the ultrasound sample volume interrogated by the ultrasound transducers intersects the optical sample volume formed by the optical source and detector.