IN VIVO BLOOD SPECTROMETRY
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Accused Products
Abstract
A process and apparatus for determining the arterial and venous oxygenation of blood in vivo with improved precision. The optical properties of tissue are measured by determination of differential and total attenuations of light at a set of wavelengths. By choosing distinct wavelengths and using the measured attenuations, the influence of variables such as light scattering, absorption and other optical tissue properties is canceled out or minimized.
5 Citations
46 Claims
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1-25. -25. (canceled)
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26. An apparatus for measuring tissue oxygenation comprising:
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a sensor interface including at least one emitter configured to emit light into tissue with at least three wavelengths and at least one detector configured to receive light scattered by the tissue; and a processor coupled to the sensor interface and configured to calculate tissue oxygenation using the at least three wavelengths, the tissue oxygenation corresponding to venous blood oxygenation, the processor further configured to compensate for influence of varying optical tissue properties which are exponentially decreasing with increasing wavelength. - View Dependent Claims (27)
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28. An apparatus comprising:
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a sensor interface configured for coupling to a forehead of a person, the sensor interface including at least one light emitter configured to emit at least three different wavelengths of light into tissue, the sensor interface including at least two detectors configured to detect scattered light, the sensor interface having an emitter-detector distance of at least 2 cm; a processor coupled to the sensor interface and configured to calculate at least two light attenuations LAwsj which depend on detected light for selected wavelength wsj for the at least two detectors; and a display device coupled to the processor and configured for displaying tissue oxygenation corresponding to venous blood and for displaying arterial blood oxygenation based on pulse oximetry, the tissue oxygenation based on the least two light attenuations LAwsj. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
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41. An apparatus for measuring tissue oxygenation comprising:
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a sensor interface adapted to be coupled to the forehead of a person and including at least one light emitter and configured to emit light into tissue at at least three different wavelengths and having at least two detectors configured for detecting scattered light, wherein a detector-emitter distance is at least 2 cm, the sensor interface having an electrode configured for contacting a skin of the person; a processor coupled to the sensor interface and configured to calculate at least two light attenuations LAwsj which depend on detected light for selected wavelength wsj for the two detectors; and a display device coupled to the processor and configured for displaying an output for tissue oxygenation corresponding to venous blood, the output based on the light attenuations LAwsj. - View Dependent Claims (42, 43)
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44. An apparatus for measuring tissue oxygenation comprising:
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a sensor interface including at least one emitter and at least one detector, the at least one emitter configured to emit light into tissue with at least three wavelengths and the at least one detector to receive light scattered by the tissue; a processor configured to calculate tissue oxygenation corresponding to venous oxygenation; a sensor encoder configured to store coded information about a wavelength of the sensor interface; and wherein the processor is configured to reduce an error associated with varying sensor hardware. - View Dependent Claims (45)
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46. An apparatus for measuring tissue oxygenation comprising:
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a sensor interface including at least one emitter configured to emit light into tissue with at least three wavelengths and at least one detector to receive light scattered by the tissue; a processor configured to calculate tissue oxygenation corresponding to venous oxygenation; a sensor encoder configured to store coded information about calibration of sensor geometry; and wherein the processor is configured to reduce an error associated with varying sensor hardware.
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Specification