Multi-vector sensing in cardiac devices using a hybrid approach
First Claim
1. A cardiac rhythm management device having operational circuitry for analyzing cardiac signals including a least first and second cardiac sensing vectors and first and second sensing channels, wherein the operational circuitry is configured to use the at least first and second sensing vectors as follows:
- comparing one or more sensing quality metrics of the at least first and second cardiac sensing vectors;
selecting one of the at least first and second cardiac sensing vectors as a preferred sensing configuration based on the comparison of the one or more sensing quality metrics;
implementing the preferred sensing configuration to analyze cardiac signals, detect cardiac cycles, and calculate cardiac rate;
identifying low sensing signal quality for the preferred sensing configuration and;
re-analyzing sensing quality metrics of the at least first and second cardiac sensing vectors;
identifying a better sensing configuration than the preferred sensing configuration based on the re-analysis of the sensing quality metrics, at least as assessed at the time of the low sensing quality of the preferred sensing configuration;
if one or more first preconditions are met, implementing the better sensing configuration to analyze cardiac signals, wherein the operational circuitry is configured to initialize the better sensing configuration before the better sensing configuration is implemented; and
monitoring signal quality of the preferred sensing configuration until the low sensing quality for the preferred sensing configuration improves and one or more second preconditions are met, at which time the operational circuitry is configured to return to using the preferred sensing configuration;
wherein;
the operational circuitry is configured to initialize the better sensing configuration at least by seeding a value for cardiac cycle amplitude from memory of the device, without reference to a signal detected using the better sensing configuration; and
the operational circuitry is configured to detect cardiac cycles using a detection profile defining a time varying detection threshold by applying the time varying detection threshold to cardiac signals and detecting a new cardiac cycle when the time varying detection threshold is crossed by the cardiac signal, the time varying detection threshold being defined in part by an estimate of cardiac cycle amplitude, such that seeding a value for cardiac cycle amplitude affects the detection threshold.
1 Assignment
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Accused Products
Abstract
Methods and devices for combining multiple signals from multiple sensing vectors for use in wearable or implantable cardiac devices. A preferred sensing configuration may be selected at a given point in time, for example under clinical conditions. Signal quality for the preferred sensing configuration is then monitored, and if the signal quality degrades under selected conditions, re-analysis may be performed to select a different sensing vector configuration for at least temporary use. If signal quality increases for the preferred sensing configuration, temporary use of the different sensing vector configuration may cease and reversion to the preferred sensing configuration takes place if certain conditions are met. The conditions for reversion may depend in part of a history of sensing signal quality for the preferred sensing configuration.
35 Citations
11 Claims
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1. A cardiac rhythm management device having operational circuitry for analyzing cardiac signals including a least first and second cardiac sensing vectors and first and second sensing channels, wherein the operational circuitry is configured to use the at least first and second sensing vectors as follows:
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comparing one or more sensing quality metrics of the at least first and second cardiac sensing vectors; selecting one of the at least first and second cardiac sensing vectors as a preferred sensing configuration based on the comparison of the one or more sensing quality metrics; implementing the preferred sensing configuration to analyze cardiac signals, detect cardiac cycles, and calculate cardiac rate; identifying low sensing signal quality for the preferred sensing configuration and; re-analyzing sensing quality metrics of the at least first and second cardiac sensing vectors; identifying a better sensing configuration than the preferred sensing configuration based on the re-analysis of the sensing quality metrics, at least as assessed at the time of the low sensing quality of the preferred sensing configuration; if one or more first preconditions are met, implementing the better sensing configuration to analyze cardiac signals, wherein the operational circuitry is configured to initialize the better sensing configuration before the better sensing configuration is implemented; and monitoring signal quality of the preferred sensing configuration until the low sensing quality for the preferred sensing configuration improves and one or more second preconditions are met, at which time the operational circuitry is configured to return to using the preferred sensing configuration;
wherein;the operational circuitry is configured to initialize the better sensing configuration at least by seeding a value for cardiac cycle amplitude from memory of the device, without reference to a signal detected using the better sensing configuration; and the operational circuitry is configured to detect cardiac cycles using a detection profile defining a time varying detection threshold by applying the time varying detection threshold to cardiac signals and detecting a new cardiac cycle when the time varying detection threshold is crossed by the cardiac signal, the time varying detection threshold being defined in part by an estimate of cardiac cycle amplitude, such that seeding a value for cardiac cycle amplitude affects the detection threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A cardiac rhythm management device having operational circuitry for analyzing cardiac signals including a least first and second cardiac sensing vectors and first and second sensing channels, wherein the operational circuitry is configured to use the at least first and second sensing vectors as follows:
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comparing one or more sensing quality metrics of the at least first and second cardiac sensing vectors; selecting one of the at least first and second cardiac sensing vectors as a preferred sensing configuration based on the comparison of the one or more sensing quality metrics; implementing the preferred sensing configuration to analyze cardiac signals, detect cardiac cycles, and calculate cardiac rate; identifying low sensing signal quality for the preferred sensing configuration and; re-analyzing sensing quality metrics of the at least first and second cardiac sensing vectors; identifying a better sensing configuration than the preferred sensing configuration based on the re-analysis of the sensing quality metrics, at least as assessed at the time of the low sensing quality of the preferred sensing configuration; if one or more first preconditions are met, implementing the better sensing configuration to analyze cardiac signals, wherein the operational circuitry is configured to initialize the better sensing configuration before the better sensing configuration is implemented; and monitoring signal quality of the preferred sensing configuration until the low sensing quality for the preferred sensing configuration improves and one or more second preconditions are met, at which time the operational circuitry is configured to return to using the preferred sensing configuration; further comprising a non-transitory device memory, wherein; the operational circuitry is configured to initialize the better sensing configuration at least by seeding a value for cardiac cycle rate from the device memory, without reference to a signal detected using the better sensing configuration; and the operational circuitry is configured to detect cardiac cycles using a detection profile defining a time varying detection threshold by applying the time varying detection threshold to cardiac signals and detecting a new cardiac cycle when the time varying detection threshold is crossed by the cardiac signal, wherein the time varying detection threshold of the detection profile changes in accordance with cardiac cycle rate, such that seeding a value for cardiac cycle rate affects the detection threshold.
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11. A cardiac rhythm management device having operational circuitry for analyzing cardiac signals including a least first and second cardiac sensing vectors and first and second sensing channels, wherein the operational circuitry is configured to use the at least first and second sensing vectors as follows:
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comparing one or more sensing quality metrics of the at least first and second cardiac sensing vectors; selecting one of the at least first and second cardiac sensing vectors as a preferred sensing configuration based on the comparison of the one or more sensing quality metrics; implementing the preferred sensing configuration to analyze cardiac signals, detect cardiac cycles, and calculate cardiac rate; identifying low sensing signal quality for the preferred sensing configuration and; re-analyzing sensing quality metrics of the at least first and second cardiac sensing vectors; identifying a better sensing configuration than the preferred sensing configuration based on the re-analysis of the sensing quality metrics, at least as assessed at the time of the low sensing quality of the preferred sensing configuration; if one or more first preconditions are met, implementing the better sensing configuration to analyze cardiac signals, wherein the operational circuitry is configured to initialize the better sensing configuration before the better sensing configuration is implemented; and monitoring signal quality of the preferred sensing configuration until the low sensing quality for the preferred sensing configuration improves and one or more second preconditions are met, at which time the operational circuitry is configured to return to using the preferred sensing configuration;
wherein;the operational circuitry is configured to initialize the better sensing configuration at least by determining a cardiac rate using an autocorrelation analysis and storing the cardiac rate; and the operational circuitry is configured to detect cardiac cycles using a detection profile defining a time varying detection threshold by applying the time varying detection threshold to cardiac signals and detecting a new cardiac cycle when the time varying detection threshold is crossed by the cardiac signal, wherein the time varying detection threshold of the detection profile changes in accordance with cardiac rate, such that storing a cardiac rate affects the detection threshold.
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Specification