System and method for reconstructing cardiac activation information
Inventors
Narayan, Sanjiv • Briggs, Carey Robert
Assignees
US Department of Veterans Affairs • Topera Inc • University of California San Diego UCSD
Publication Number
US-9107600-B2
Publication Date
2015-08-18
Expiration Date
2031-08-24
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
An example method of representing cardiac information associated with a heart rhythm disorder is disclosed. The method includes accessing a plurality of neighboring cardiac signals obtained from a patient. The method also includes eliminating far-field activations from the plurality of neighboring cardiac signals using one or more divergence criteria that define local activations in the plurality of neighboring cardiac signals, the divergence criteria being associated with divergence among the plurality of neighboring cardiac signals. The method further includes constructing a clinical representation of local activations in the plurality of neighboring cardiac signals.
Core Innovation
The invention discloses a method and system for reconstructing cardiac activation information associated with heart rhythm disorders, particularly complex rhythm disorders such as atrial fibrillation (AF), ventricular tachycardia (VT), and ventricular fibrillation (VF). It involves accessing a plurality of neighboring cardiac signals obtained from a patient, eliminating far-field activations from these signals using divergence criteria that define local activations based on divergence among the signals, and constructing a clinical representation of these local activations.
The problem addressed is the difficulty in identifying and treating complex heart rhythm disorders due to the inability of prior systems to reliably distinguish local from far-field activations within cardiac signals, especially in complex rhythm disorders where activation onset patterns vary from beat to beat and are superimposed with far-field signals and noise. This impedes locating the source of the disorder and hinders targeted treatment such as ablation.
The invention improves cardiac activation reconstruction by processing pairs of cardiac signals to detect points of change in derivatives of the signals that exceed a threshold, thereby identifying local activation onsets while eliminating far-field activations. It iteratively processes multiple neighboring signals to assign activation onset times, enabling the construction of clinical representations—such as activation maps or rotor patterns—that locate sources of the rhythm disorder for more accurate and expedient treatment.
Claims Coverage
The claims include one independent claim regarding a method of representing cardiac information and several dependent claims detailing specific steps and features. The inventive features focus on elimination of far-field activations, processing of cardiac signals using derivative divergence and ratio criteria, and constructing clinical representations to facilitate treatment.
Eliminating far-field activations using divergence criteria
Accessing multiple neighboring cardiac signals from a patient and eliminating far-field activations by identifying points where derivatives of a first cardiac signal diverge from derivatives of a second cardiac signal above a threshold; defining local activations based on these divergence criteria.
Determining activation onset times by processing pairs of cardiac signals
Processing a first 'analysis' cardiac signal and a second 'reference' cardiac signal to detect points of change where derivatives differ significantly, assigning activation onset times in the first signal at these points to define local activations; processing iterative pairs of cardiac signals to define multiple local activations.
Using composite cardiac signals and ratio values for point of change determination
Forming a composite signal from the first and second cardiac signals and determining ratio values at multiple points representing differences in derivatives; selecting points with largest ratio values as points of change to identify local activations more reliably.
Constructing clinical representations based on local activations
After processing pairs of neighboring cardiac signals and assigning activation onsets, constructing a clinical representation that indicates sources of cardiac rhythm disorders such as rotors or focal sources, facilitating targeted treatment.
Matching signals to a catalog of reference signals when no point of change is detected
If no significant point of change is detected, matching characteristics of the first cardiac signal to characteristics of reference signals in a catalog and assigning activation onset times based on matched reference signals to define local activations.
The claims collectively cover methods for analyzing multiple neighboring cardiac signals by processing their derivatives and composite signals to detect local cardiac activations, eliminating far-field signal interference, constructing clinical activation maps, and assisting in treatment of heart rhythm disorders.
Stated Advantages
Enables reliable identification and representation of local cardiac activations by eliminating far-field activations from clinical signals.
Facilitates accurate detection of sources such as rotors and focal points in complex heart rhythm disorders, which were previously difficult or impossible to identify.
Allows rapid reconstruction of cardiac activation information, enabling treatment to occur immediately during sensing procedures.
Simplifies processing steps compared to prior methods, reducing complexity while effectively reconstructing activation onset times in complex cardiac signals.
Documented Applications
Detection and reconstruction of cardiac activation information in complex heart rhythm disorders such as atrial fibrillation (AF), ventricular tachycardia (VT), and ventricular fibrillation (VF).
Generating clinical activation maps and representations that help locate the source or cause of cardiac rhythm disorders.
Facilitating targeted treatment of cardiac tissue, such as ablation, gene therapy, stem cell therapy, pacing stimulation, or drug therapy to suppress or eliminate heart rhythm disorders.
Interested in licensing this patent?