Implantable tissue perfusion sensing system and method
First Claim
1. A medical device system for sensing cardiac events, comprising:
- a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event;
a plurality of light sources capable of emitting light at a plurality of wavelengths;
a detector to detect the emitted light; and
a processor to determine a plurality of light measurements in response to the emitted light detected by the detector, determine changes in perfusion in response to first changes in the plurality of light measurements in a direction indicative of a decrease in blood oxygenation and second changes in a direction indicative of a decrease in blood volume, and adjusting delivery of therapy by the device in response to the determined loss of perfusion, wherein the processor determines an isobestic blood volume index in response to determined light measurements of the plurality of light measurements from a first light source of the plurality of light sources emitting light at an isobestic wavelength, determines an oxygen index associated with light measurements of light measurements of the plurality of light measurements from a light source of the plurality of light sources other than the first light source, and determines the first changes in response to the oxygen index.
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Abstract
A medical device system for sensing cardiac events that includes a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event, a plurality of light sources capable of emitting light at a plurality of wavelengths, and a detector to detect the emitted light. A processor determines a plurality of light measurements in response to the emitted light detected by the detector, determines changes in perfusion in response to first changes in the plurality of light measurements in a direction indicative of a decrease in blood oxygenation and second changes in a direction indicative of a decrease in blood volume, and adjusts delivery of therapy by the device in response to the determined loss of perfusion.
51 Citations
11 Claims
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1. A medical device system for sensing cardiac events, comprising:
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a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event; a plurality of light sources capable of emitting light at a plurality of wavelengths; a detector to detect the emitted light; and a processor to determine a plurality of light measurements in response to the emitted light detected by the detector, determine changes in perfusion in response to first changes in the plurality of light measurements in a direction indicative of a decrease in blood oxygenation and second changes in a direction indicative of a decrease in blood volume, and adjusting delivery of therapy by the device in response to the determined loss of perfusion, wherein the processor determines an isobestic blood volume index in response to determined light measurements of the plurality of light measurements from a first light source of the plurality of light sources emitting light at an isobestic wavelength, determines an oxygen index associated with light measurements of light measurements of the plurality of light measurements from a light source of the plurality of light sources other than the first light source, and determines the first changes in response to the oxygen index. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A medical device system for sensing cardiac events, comprising:
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a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event; a plurality of light sources capable of emitting light at a plurality of wavelengths; a detector to detect the emitted light; and a processor to determine a plurality of light measurements in response to the emitted light detected by the detector, determine changes in perfusion in response to first changes in the plurality of light measurements in a direction indicative of a decrease in blood oxygenation and second changes in a direction indicative of a decrease in blood volume, and adjusting delivery of therapy by the device in response to the determined loss of perfusion, wherein the processor determines a blood volume index in response to determined light measurements of the plurality of light measurements from a first light source of the plurality of light sources emitting light at an isobestic wavelength, and determines the second changes in response to the blood volume index. - View Dependent Claims (10, 11)
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Specification