Abstract: Systems, methods, and devices for obtaining consistently reproducible diagnostic measurements with a photoplethysmographic sensor are provided. In one embodiment, a method for obtaining such a diagnostic measurement includes applying a pressure between a photoplethysmographic sensor and a patient, increasing the pressure until the photoplethysmographic sensor outputs a plethysmographic waveform of minimal amplitude, decreasing the pressure by a predetermined fraction, and obtaining a diagnostic measurement using the photoplethysmographic sensor. The pressure may be applied using a pressure device that includes, for example, a clip, a wrap, an inflatable balloon or bladder, or an inflatable cuff or any combination thereof.

Abstract: This invention provides methods and devices to measure particle suspension concentrations through the side wall of a container. Particle back-scatter readings are taken at light wavelengths that do not travel far through the medium. Detected scatter is related to actual particle concentration or standard O.D. values. The methods and devices allow particle concentration readings through containers not normally intended for use in such assays.

Abstract: A method is provided for determining the location of the sensor. The method comprises determining a physiological parameter based on detected light and determining the location of the sensor based on the physiological parameter. In addition, a method is provided for operating a sensor that includes calibrating a sensor based on a patient-specific physiological parameter, in which the patient-specific physiological parameter is skin color, age, gender, pooled blood, venous blood pulsation, or abnormal tissue.

Abstract: This invention provides methods and devices to measure particle suspension concentrations through the side wall of a container. Particle back-scatter readings are taken at light wavelengths that do not travel far through the medium. Detected scatter is related to actual particle concentration or standard O.D. values. The methods and devices allow particle concentration readings through containers not normally intended for use in such assays.

Abstract: A system and method are provided for determining tissue hydration. Specifically, in accordance with one aspect of the present invention there is provided a method for determining tissue hydration. The method includes detecting electromagnetic radiation scattered and reflected from the living tissue and using the detected electromagnetic radiation to determine spectral absorption bandwidth. The method also includes correlating the spectral absorption bandwidth to a tissue hydration index.

Abstract: A sensor for pulse oximeter systems is provided which comprises a first source of electromagnetic radiation configured to operate at a first wavelength, a second source of electromagnetic radiation configured to operate at a second wavelength and a third source of electromagnetic radiation configured to operate at a third wavelength. The first and third sources of electromagnetic radiation are symmetrically oriented about an axis.

Abstract: Methods and systems for calculating body fluid metrics are provided. In accordance with an exemplary embodiment of the present technique, there is provided a method for calculating body fluid metrics by acquiring an absorbance spectrum of a subject's tissue over a range of near-infrared light, performing a multi-linear regression of the absorbance spectrum of the subject's tissue in relation to absorbance spectra of tissue constituents, and calculating body fluid metrics based on the results of the multi-linear regression. A system is provided having a sensor for emitting the light into the subject's tissue and detecting reflected, scattered, or transmitted light, a spectrometer for processing the detected light and generating the absorbance spectrum of the subject's tissue, memory for storing absorbance spectra of the tissue constituents and a multi-linear regression model, and a processor for performing the multi-linear regression and calculating the body fluid metrics.

Abstract: The present invention comprises methods and systems/devices for non-invasively measuring and/or altering collagen structures before, during and after treatment, e.g., by the application of RF energy, of tissues that comprise such collagen structures.

Abstract: There is provided a sensor for pulse oximeter systems. The sensor comprises a first source of electromagnetic radiation configured to operate at a first wavelength, a second source of electromagnetic radiation configured to operate at a second wavelength, and a third source of electromagnetic radiation configured to operate at a third wavelength. The emission spectra of the first and third sources of electromagnetic radiation overlap at their half power level or greater and correspond to a center wavelength in the range of 650 to 670 nm.

Abstract: A sensor for carbon dioxide detection may be adapted to have reduced water permeability. A sensor is provided that is appropriate for use in an aqueous medium. The sensor has a barrier with reduced water permeability, but that is permeable to carbon dioxide, that separates the sensor components from the aqueous medium.

Abstract: The present invention comprises methods and systems/devices for non-invasively measuring birefringent tissues (e.g. collagen) and changes during treatment of tissue, e.g., denaturation by the application of RF energy, through linear dichroism, circular dichroism, or birefringence. The invention optionally uses polarization sensitive optical measurements to discriminate between denaturation of unidirectionally oriented strands of collagen, such as a ligament or tendon, and denaturation of planar collagen surfaces, such as the dermal layer of the skin or collagen in joint capsules.

Abstract: Systems, methods, and devices for obtaining consistently reproducible diagnostic measurements with a photoplethysmographic sensor are provided. In one embodiment, a method for obtaining such a diagnostic measurement includes applying a pressure between a photoplethysmographic sensor and a patient, increasing the pressure until the photoplethysmographic sensor outputs a plethysmographic waveform of minimal amplitude, decreasing the pressure by a predetermined fraction, and obtaining a diagnostic measurement using the photoplethysmographic sensor. The pressure may be applied using a pressure device that includes, for example, a clip, a wrap, an inflatable balloon or bladder, or an inflatable cuff or any combination thereof.

Abstract: The present invention comprises methods and systems/devices for non-invasively measuring baseline collagen and collagen changes during treatment of tissue, e.g., denaturation by the application of RF energy, through linear dichroism, circular dichroism, or birefringence. The invention optionally uses polarization sensitive optical measurements to discriminate between denaturation of unidirectionally oriented strands of collagen, such as a ligament or tendon, and denaturation of planar collagen surfaces, such as the dermal layer of the skin or collagen in joint capsules.

Abstract: Embodiments of the present invention relate to a system and method of detecting or monitoring brain edema in a patient. One embodiment of the present invention includes emitting a first light into the patient's brain tissue at a first wavelength, emitting a second light into the patient's brain tissue at a second wavelength, detecting the first and second lights after dispersion by the brain tissue at a detector, and determining an amount of water proximate the brain tissue based on the detected first and second lights.

Abstract: This invention provides a novel methods and devices for measurement of particle concentration or changes in particle concentration over a wide linear range. The invention comprises one or more radiation sources and one or more detectors contained in a housing which is interfaced to a medium containing particulate matter. The one or more radiation sources are directed into the medium, scattered or transmitted by the particulate matter, and then some portion of the radiation is detected by the one or more detectors. Methods for confining the measurement to a specific volume within the medium are described. Algorithms are provided for combining the signals generated by multiple source-detector pairs in a manner that results in a wide linear range of response to changes in particle concentration. In one embodiment the sensor provides non-invasive measurements of biomass in a bioreactor. In another embodiment an immersible probe design is described, which may be suited for one-time use.

Abstract: Methods and systems for calculating body fluid metrics are provided. In accordance with an exemplary embodiment of the present technique, there is provided a method for calculating body fluid metrics by acquiring an absorbance spectrum of a subject's tissue over a range of near-infrared light, performing a multi-linear regression of the absorbance spectrum of the subject's tissue in relation to absorbance spectra of tissue constituents, and calculating body fluid metrics based on the results of the multi-linear regression. A system is provided having a sensor for emitting the light into the subject's tissue and detecting reflected, scattered, or transmitted light, a spectrometer for processing the detected light and generating the absorbance spectrum of the subject's tissue, memory for storing absorbance spectra of the tissue constituents and a multi-linear regression model, and a processor for performing the multi-linear regression and calculating the body fluid metrics.

Abstract: A method is provided for determining the location of the sensor. The method comprises determining a physiological parameter based on detected light and determining the location of the sensor based on the physiological parameter. In addition, a method is provided for operating a sensor that includes calibrating a sensor based on a patient-specific physiological parameter, in which the patient-specific physiological parameter is skin color, age, gender, pooled blood, venous blood pulsation, or abnormal tissue.

Abstract: A sensor for pulse oximeter systems is provided which comprises a first source of electromagnetic radiation configured to operate at a first wavelength, a second source of electromagnetic radiation configured to operate at a second wavelength and a third source of electromagnetic radiation configured to operate at a third wavelength. The first and third sources of electromagnetic radiation are symmetrically oriented about an axis.

Abstract: Embodiments of the present invention relate to a system and method of detecting or monitoring brain edema in a patient. One embodiment of the present invention includes emitting a first light into the patient's brain tissue at a first wavelength, emitting a second light into the patient's brain tissue at a second wavelength, detecting the first and second lights after dispersion by the brain tissue at a detector, and determining an amount of water proximate the brain tissue based on the detected first and second lights.

Abstract: There is provided a sensor for pulse oximeter systems. The sensor comprises a first source of electromagnetic radiation configured to operate at a first wavelength, a second source of electromagnetic radiation configured to operate at a second wavelength, and a third source of electromagnetic radiation configured to operate at a third wavelength. The emission spectra of the first and third sources of electromagnetic radiation overlap at their half power level or greater and correspond to a center wavelength in the range of 650 to 670 nm.