Abstract: A system and a method for creating a stable and reproducible interface of an optical sensor system for measuring blood glucose levels in biological tissue include a dual wedge prism sensor attached to a disposable optic that comprises a focusing lens and an optical window. The disposable optic adheres to the skin to allow a patient to take multiple readings or scans at the same location. The disposable optic includes a Petzval surface placed flush against the skin to maintain the focal point of the optical beam on the surface of the skin. Additionally, the integrity of the sensor signal is maximized by varying the rotation rates of the dual wedge prisms over time in relation to the depth scan rate of the sensor. Optimally, a medium may be injected between the disposable and the skin to match the respective refractive indices and optimize the signal collection of the sensor.

Abstract: In accordance with the invention, a low coherence interferometer is used to non-invasively monitor the concentration of glucose in blood by shining a light over a surface area of human or animal tissue, continuously scanning the light over a two dimensional area of the surface, collecting the reflected light from within the tissue and constructively interfering this reflected light with light reflected along a reference path to scan the tissue in depth. Since the reflection spectrum is sensitive to glucose concentration at particular wavelengths, measurement and analysis of the reflected light provides a measure of the level of glucose in the blood. The measurement of glucose is taken from multiple depths within blood-profused tissue, and sensitivity is preferably enhanced by the use of multiple wavelengths. Noise or speckle associated with this technique is minimized by continuously scanning the illuminated tissue in area and depth.

Abstract: A method for noninvasively measuring analytes such as blood glucose levels includes using a non-imaging OCT-based system to scan a two-dimensional area of biological tissue and gather data continuously during the scanning. Structures within the tissue where measured-analyte-induced changes to the OCT data dominate over changes induced by other analytes are identified by focusing on highly localized regions of the data curve produced from the OCT scan which correspond to discontinuities in the OCT data curve. The data from these localized regions then can be related to measured analyte levels.

Abstract: A method for noninvasively measuring analytes such as blood glucose levels includes using a non-imaging OCT-based system to scan a two-dimensional area of biological tissue and gather data continuously during the scanning. Structures within the tissue where measured-analyte-induced changes to the OCT data dominate over changes induced by other analytes are identified by focusing on highly localized regions of the data curve produced from the OCT scan which correspond to discontinuities in the OCT data curve. The data from these localized regions then can be related to measured analyte levels.

Abstract: The present invention relates to a method and system for estimating blood analyte levels using a noninvasive optical coherence tomography (OCT) based physiological monitor. An algorithm correlates OCT-based estimated blood analyte data with actual blood analyte data determined by other methods, such as invasively. OCT-based data is fit to the obtained blood analyte measurements to achieve the best correlation. Once the algorithm has generated sets of estimated blood analyte levels, it may refine the number of sets by applying one or more mathematical filters. The OCT-based physiological monitor can be calibrated using an Intensity Difference plot or the Pearson Product Moment Correlation method.

Abstract: The present invention relates to a method for estimating blood glucose levels using a noninvasive optical coherence tomography- (OCT-) based blood glucose monitor. An algorithm correlates OCT-based estimated blood glucose data with actual blood glucose data determined by invasive methods. OCT-based data is fit to the obtained blood glucose measurements to achieve the best correlation. Once the algorithm has generated sets of estimated blood glucose levels, it may refine the number of sets by applying one or more mathematical filters. The OCT-based blood glucose monitor is calibrated using an Intensity Difference plot or the Pearson Product Moment Correlation method.

Abstract: Optical coherence tomography (herein “OCT”) based analyte monitoring systems are disclosed. In one aspect, techniques are disclosed that can identify fluid flow in vivo (e.g., blood flow), which can act as a metric for gauging the extent of blood perfusion in tissue. For instance, if OCT is to be used to estimate the level of an analyte (e.g., glucose) in tissue, a measure of the extent of blood flow can potentially indicate the presence of an analyte correlating region, which would be suitable for analyte level estimation with OCT. Another aspect is related to systems and methods for scanning multiple regions. An optical beam is moved across the surface of the tissue in two distinct manners. The first can be a coarse scan, moving the beam to provide distinct scanning positions on the skin. The second can be a fine scan where the beam is applied for more detailed analysis.

Abstract: Optical coherence tomography (herein “OCT”) based analyte monitoring systems are disclosed. In one aspect, techniques are disclosed that can identify fluid flow in vivo (e.g., blood flow), which can act as a metric for gauging the extent of blood perfusion in tissue. For instance, if OCT is to be used to estimate the level of an analyte (e.g., glucose) in tissue, a measure of the extent of blood flow can potentially indicate the presence of an analyte correlating region, which would be suitable for analyte level estimation with OCT. Another aspect is related to systems and methods for scanning multiple regions. An optical beam is moved across the surface of the tissue in two distinct manners. The first can be a coarse scan, moving the beam to provide distinct scanning positions on the skin. The second can be a fine scan where the beam is applied for more detailed analysis.

Abstract: In accordance with the invention, a low coherence interferometer is used to non-invasively monitor the concentration of glucose in blood by shining a light over a surface area of human or animal tissue, continuously scanning the light over a two dimensional area of the surface, collecting the reflected light from within the tissue and constructively interfering this reflected light with light reflected along a reference path to scan the tissue in depth. Since the reflection spectrum is sensitive to glucose concentration at particular wavelengths, measurement and analysis of the reflected light provides a measure of the level of glucose in the blood. The measurement of glucose is taken from multiple depths within blood-profused tissue, and sensitivity is preferably enhanced by the use of multiple wavelengths. Noise or speckle associated with this technique is minimized by continuously scanning the illuminated tissue in area and depth.

Abstract: Optical components, such as optical semi-isolators, are placed in a fixture that exposes at least a portion of the mounting surface of each optical component when a plasma or ion beam is directed at one side of the fixture, while shielding sensitive surfaces of the optical components (e.g., an optical element mounted within the frame of the optical component) from direct exposure to the plasma or ion beam. Exposure to the plasma or ion beam removes contaminants (e.g., metal oxide) that form on the mounting surface during the fabrication of the optical components when the optical element is mounted within its frame using glass solder in a heated oxygenated environment (e.g., air). By removing enough of the contaminants, the plasma or ion beam cleaning step produces optical components that can be reliably mounted onto substrates, such as the ceramic substrates used in encapsulated laser packages, using flux-less auto-bonding techniques.

Abstract: Relatively dust-free air to cool electronic equipment, for example, is provided by apparatus which includes at least first and second rows of filamentary electrodes disposed in an air stream and aligned with its direction of flow. Alternate rows of electrodes are connected to respective electric potentials, the potentials and the electrodes being such as to create a net positive space charge between the rows. This causes dust particles in the air stream to acquire a positive charge and thus to move toward the more negative row(s) under the influence of the electric field set up by the potential difference between the rows. This, in turn, results in the creation of streams of clean and dirty air. These are then separated by a baffle having channels which are substantially aligned with the rows of electrodes. The clean air is directed into an enclosure housing the equipment to be cooled. The dirty air is discharged back into the atmosphere, e.g., back into the room in which the equipment is located.