Systems and methods for managing noise in implantable medical devices
First Claim
1. A method for processing atrial electrical signals obtained from a patient comprising:
- gathering a first set of atrial electrical signals within the patient using an implantable medical device during an atrial pacing threshold test, the first set of electrical signals comprising a set of samples of electrical activity from a discrete sample time window spanning a pacing event, wherein the sample time window starts in response to an electrical stimulation p acing pulse;
filtering the first set of atrial signals to provide a second set of electrical signals, the second set of electrical signals comprising frequencies above a cutoff frequency;
estimating the amount of noise present in the first set of atrial electrical signals based on the magnitude of the second set of electrical signals;
calculating a noise threshold value according to a capture detection threshold;
discarding the first set of atrial electrical signals if the estimated amount of noise exceeds the noise threshold value;
calculating an updated noise adjusted pace artifact threshold based on the estimated amount of noise if the noise does not exceed the noise threshold value;
comparing the updated noise adjusted pace artifact threshold to the noise threshold value; and
when the updated noise adjusted pace artifact threshold is less than the noise threshold value, classifying the electrical signal as loss of capture or fusion.
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Abstract
Embodiments of the invention are related to managing noise in sensed signals in implantable medical devices, amongst other things. In an embodiment the invention includes a method for processing electrical signals obtained from a patient including gathering a first set of electrical signals using an implantable medical device, filtering to provide a second set of electrical signals, the second set including frequencies above a threshold frequency, and estimating the amount of noise present in the first set of electrical signals based on the magnitude of the second set. In an embodiment, the invention includes a medical device configured to gather a first set of electrical signals, filter the first set to provide a second set of electrical signals including frequencies above a threshold frequency, and estimate the amount of noise present in the first set based on the magnitude of the second set. Other embodiments are also included herein.
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Citations
17 Claims
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1. A method for processing atrial electrical signals obtained from a patient comprising:
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gathering a first set of atrial electrical signals within the patient using an implantable medical device during an atrial pacing threshold test, the first set of electrical signals comprising a set of samples of electrical activity from a discrete sample time window spanning a pacing event, wherein the sample time window starts in response to an electrical stimulation p acing pulse; filtering the first set of atrial signals to provide a second set of electrical signals, the second set of electrical signals comprising frequencies above a cutoff frequency; estimating the amount of noise present in the first set of atrial electrical signals based on the magnitude of the second set of electrical signals; calculating a noise threshold value according to a capture detection threshold; discarding the first set of atrial electrical signals if the estimated amount of noise exceeds the noise threshold value; calculating an updated noise adjusted pace artifact threshold based on the estimated amount of noise if the noise does not exceed the noise threshold value; comparing the updated noise adjusted pace artifact threshold to the noise threshold value; and when the updated noise adjusted pace artifact threshold is less than the noise threshold value, classifying the electrical signal as loss of capture or fusion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A medical device comprising:
- a processor circuit; and
a memory circuit operatively connected to the processor circuit;
the medical device configured togather a first set of electrical signals from a patient, the first set of electrical signals comprising a set of samples of electrical activity from a discrete sample time window spanning a pacing event, wherein the sample time window starts in response to an electrical stimulation pacing pulse; filter the first set of electrical signals to provide a second set of electrical signals, the second set of electrical signals including frequencies above a cut off frequency; estimate the amount of noise present in the first set of electrical signals based on the magnitude of the second set of electrical signals, wherein one or more of the initial filtered results making up the second set of electrical signals are excluded from the noise estimate; calculate a noise threshold value according to a capture detection threshold; discard the first set of electrical signals if the estimated amount of noise exceeds the noise threshold value; calculate an updated noise adjusted pace artifact threshold based on the estimated amount of noise if the estimated amount of noise does not exceed the noise threshold value; compare the updated noise adjusted pace artifact threshold to the noise threshold value; and when the updated noise adjusted pace artifact threshold is less than the noise threshold value, classify the electrical signal as loss of capture or fusion. - View Dependent Claims (10, 11, 12, 13, 14, 15)
- a processor circuit; and
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16. A method for processing electrical signals obtained from a patient comprising:
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gathering a first set of electrical signals within the patient using an implantable medical device, the first set of electrical signals comprising a set of samples of electrical activity from a discrete sample time window spanning a p acing event, wherein the sample time window starts in response to an electrical stimulation pacing pulse; filtering the first set of signals to provide a second set of electrical signals, the second set of electrical signals comprising frequencies above a cutoff frequency; estimating the amount of noise present in the first set of electrical signals based on the magnitude of the second set of electrical signals; calculating a noise threshold value according to a capture detection threshold; discarding the first set of electrical signals if the estimated amount of noise exceeds a noise threshold value; calculating a noise adjusted pace artifact threshold based on the estimated amount of noise if the noise does not exceed the noise threshold value; comparing the updated noise adjusted pace artifact threshold to the noise threshold value; and when the up dated noise adjusted pace artifact threshold is less than the noise threshold value, classifying the electrical signal as loss of capture or fusion; wherein filtering the first set of signals is performed with a Chebyshev high pass filter. - View Dependent Claims (17)
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Specification