Absolute calibrated tissue oxygen saturation and total hemoglobin volume fraction
First Claim
1. A method for monitoring a patient condition in a medical device having an optical sensor, the method comprising:
- advancing the sensor intravascularly to position the sensor along a volume of tissue;
positioning the sensor along a renal vein, the volume of tissue comprising kidney tissue;
controlling the optical sensor to emit light comprising at least four spaced-apart light wavelengths;
detecting light scattered by the volume of tissue, wherein detecting light comprises measuring an optical sensor output signal corresponding to an intensity of the scattered light;
computing a measure of tissue oxygenation in response to the detected light; and
detecting hypoxia in the kidney tissue in response to the measurement of tissue oxygenation.
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Accused Products
Abstract
A medical device for monitoring a patient condition includes a sensor capable of being advanced transvascularly to be positioned along a volume of tissue, the sensor including a first combination of a light source and a light detector to emit light into a volume of tissue and to detect light scattered by the volume of tissue and to generate a first output signal corresponding to an intensity of the detected light. A control module is coupled to the light source to control the light source to emit light at least four spaced-apart light wavelengths, and a monitoring module is coupled to the light detector to receive the output signal and compute a measure of tissue oxygenation using the light detector output signal.
126 Citations
26 Claims
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1. A method for monitoring a patient condition in a medical device having an optical sensor, the method comprising:
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advancing the sensor intravascularly to position the sensor along a volume of tissue; positioning the sensor along a renal vein, the volume of tissue comprising kidney tissue; controlling the optical sensor to emit light comprising at least four spaced-apart light wavelengths; detecting light scattered by the volume of tissue, wherein detecting light comprises measuring an optical sensor output signal corresponding to an intensity of the scattered light; computing a measure of tissue oxygenation in response to the detected light; and detecting hypoxia in the kidney tissue in response to the measurement of tissue oxygenation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A medical device system, comprising:
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a sensor capable of being advanced transvascularly to be positioned along a volume of tissue, the sensor comprising a first combination of a light source and a light detector to emit light into a volume of tissue, to detect light scattered by the volume of tissue, and to generate a first output signal corresponding to an intensity of the detected light, wherein the first combination of a light source and a light detector is capable of being positioned adjacent to kidney tissue, and wherein the monitoring module detects kidney hypoxia in response to the measurement of tissue oxygenation; and a control module coupled to the light source to control the light source to emit light comprising at least four spaced-apart light wavelengths; and a monitoring module coupled to the light detector to receive the output signal and compute a measure of tissue oxygenation in response to the light detector output signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A medical device system, comprising:
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a sensor capable of being advanced transvascularly to be positioned along a volume of tissue, the sensor comprising a first combination of a light source and a light detector to emit light into a volume of tissue, to detect light scattered by the volume of tissue, and to generate a first output signal corresponding to an intensity of the detected light, wherein the first combination of the light source and the light detector are positioned along a patient'"'"'s skin; and a control module coupled to the light source to control the light source to emit light comprising at least four spaced-apart light wavelengths; and a monitoring module coupled to the light detector to receive the output signal and compute a measure of tissue oxygenation in response to the light detector output signal.
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26. A non-transitory computer readable medium having computer executable instructions for performing a method for monitoring a patient condition in a medical device having an optical sensor, the method comprising:
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advancing the sensor intravascularly to position the sensor along a volume of tissue; positioning the sensor along a renal vein, the volume of tissue comprising kidney tissue; controlling the optical sensor to emit light comprising at least four spaced-apart light wavelengths; detecting light scattered by the volume of tissue, wherein detecting light comprises measuring an optical sensor output signal corresponding to an intensity of the scattered light; computing a measure of tissue oxygenation in response to the detected light, wherein computing the measure of tissue oxygen saturation by the monitoring module comprises; computing an attenuation for each of the at least four wavelengths of detected light; computing a second derivative with respect to wavelength for at least two intermediate wavelengths of the at least four wavelengths; and computing a scaled second derivative of one of the intermediate wavelengths as a ratio of the at least two intermediate wavelengths; and detecting hypoxia in the kidney tissue in response to the measurement of tissue oxygenation.
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Specification