Methods and devices for accurately classifying cardiac activity
First Claim
Patent Images
1. An implantable cardiac stimulus (ICS) system comprising:
- a canister;
a plurality of electrodes exposed external to the canister configured for implantation in a patient;
operational circuitry disposed within the canister, operatively coupled to the plurality of electrodes, and configured to;
capture cardiac signals occurring within a patient using one or more of the plurality of electrodes;
detect electrical events in the captured cardiac signals;
identify an event representation for one of the detected electrical events;
compare the event representation to a template having a template fiducial point by identifying an event fiducial point of the event representation and aligning the template fiducial point and the event fiducial point to one another and calculating a first correlation between the event representation and the template when so aligned;
again compare the event representation to the template, this time by selecting a misalignment of the template fiducial point and the event fiducial point to yield a second correlation;
select a correlation result for the one of the detected electrical events from at least the first correlation or the second correlation whichever indicates greater correlation; and
use the correlation result to determine whether the patient has a cardiac condition which requires therapy; and
a power source disposed within the canister and configured to power the operational circuitry;
wherein the event fiducial point is a selected sample of the event representation, and the template fiducial point is a selected sample of the template.
0 Assignments
0 Petitions
Accused Products
Abstract
Methods, systems, and devices for signal analysis in an implanted cardiac monitoring and treatment device such as an implantable cardioverter defibrillator. In some examples, captured data including detected events is analyzed to identify likely overdetection of cardiac events. In some illustrative examples, when overdetection is identified, data may be modified to correct for overdetection, to reduce the impact of overdetection, or to ignore overdetected data. Several examples emphasize the use of morphology analysis using correlation to static templates and/or inter-event correlation analysis.
282 Citations
20 Claims
-
1. An implantable cardiac stimulus (ICS) system comprising:
-
a canister; a plurality of electrodes exposed external to the canister configured for implantation in a patient; operational circuitry disposed within the canister, operatively coupled to the plurality of electrodes, and configured to; capture cardiac signals occurring within a patient using one or more of the plurality of electrodes; detect electrical events in the captured cardiac signals; identify an event representation for one of the detected electrical events; compare the event representation to a template having a template fiducial point by identifying an event fiducial point of the event representation and aligning the template fiducial point and the event fiducial point to one another and calculating a first correlation between the event representation and the template when so aligned; again compare the event representation to the template, this time by selecting a misalignment of the template fiducial point and the event fiducial point to yield a second correlation; select a correlation result for the one of the detected electrical events from at least the first correlation or the second correlation whichever indicates greater correlation; and use the correlation result to determine whether the patient has a cardiac condition which requires therapy; and a power source disposed within the canister and configured to power the operational circuitry; wherein the event fiducial point is a selected sample of the event representation, and the template fiducial point is a selected sample of the template. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method of operation in an implantable cardiac device system comprising a canister housing operational circuitry and a plurality of electrodes exposed external to the canister and coupled to the operational circuitry, the method comprising:
-
capturing cardiac signals occurring within a patient using one or more of the plurality of electrodes; detecting electrical events in the captured cardiac signals using the operational circuitry; identifying an event representation for one of the detected electrical events using the operational circuitry; comparing, using the operational circuitry, the event representation to a template having a template fiducial point by identifying an event fiducial point of the event representation and aligning the template fiducial point and the event fiducial point to one another and calculating a first correlation between the event representation and the template when so aligned; again comparing, using the operational circuitry, the event representation to the template, this time by selecting a misalignment of the template fiducial point and the event fiducial point to yield a second correlation; selecting, using the operational circuitry, a correlation result for the one of the detected electrical events from at least the first correlation or the second correlation whichever indicates greater correlation; and using the correlation result to determine, using the operational circuitry, whether the patient has a cardiac condition which requires therapy; wherein the event fiducial point is a selected sample of the event representation, and the template fiducial point is a selected sample of the template. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification