Local Cardiac Propagation Velocity Mapping From Electrode Activation Times
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Solution Overview
Problem
Existing cardiac mapping technologies face challenges in accurately computing local activation times (LATs) and propagation velocities with sufficient spatial resolution, particularly due to issues with electrically-inactive tissue misclassification and the need for real-time visualization during electroanatomical mapping procedures.
Innovation Solution
The use of a processor to select suitable sets of measurement locations, perform Principal Component Analysis (PCA) on covariance matrices, and compute propagation velocities based on LATs, while excluding electrically-inactive tissue, and real-time display of propagation velocities using a probe with electrodes to facilitate accurate diagnosis and treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional methods are used to compute propagation velocities, then computation can be performed, but spatial resolution is insufficient and electrically-inactive tissue is misclassified
Solution Approach 1:
The patent replaces traditional mechanical/electrical measurement methods with a computational approach using Principal Component Analysis (PCA) on covariance matrices derived from electrogram signals. This substitution enables high spatial resolution velocity computation while properly distinguishing electrically-inactive tissue through statistical analysis of signal variations across multiple electrodes.
Solution Approach 2:
The patent transforms the problem from direct velocity measurement to computing propagation velocities as derivatives of activation time maps. By changing the computational parameters from raw signal analysis to derivative-based calculations on smoothed activation time surfaces, the system achieves both high spatial resolution and accurate tissue classification.
2Measurement precision
If high spatial resolution is achieved in propagation velocity computation, then diagnostic precision is improved, but computational complexity increases
Solution Approach 1:
The patent performs preliminary smoothing of the activation time map before computing propagation velocities as derivatives. This pre-processing step simplifies the subsequent differentiation operation and reduces computational complexity while maintaining high spatial resolution in the final velocity measurements.
Solution Approach 2:
The patent replaces complex direct differentiation methods with a smoothed activation time approach, where propagation velocities are computed as derivatives of the smoothed map. This substitution reduces computational complexity by avoiding direct numerical differentiation of noisy raw data while preserving high spatial resolution.
3Productivity
If real-time computation is implemented, then clinical utility is enhanced, but processing speed requirements increase
Solution Approach 1:
The patent computes propagation velocities as derivatives of smoothed activation time maps in real-time during the mapping procedure. The preliminary smoothing operation enables subsequent rapid differentiation, allowing real-time display of velocity information that enhances clinical workflow without requiring excessive processing speed.
Solution Approach 2:
The patent implements continuous real-time computation and display of propagation velocities as the catheter moves through the heart. This continuous updating provides immediate clinical feedback while the efficient mathematical approach (derivatives of smoothed maps) maintains processing speed requirements at manageable levels.
Data Source
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AI summary
A method includes, based on respective signals acquired by a plurality of electrodes on an anatomical surface of a heart, computing respective local activation times (LATs) at respective locations of the electrodes. The method further includes, based on the LATs, computing respective directions of electrical propagation at the locations. The method further includes selecting pairs of adjacent ones of the electrodes such that, for each of the pairs, a vector joining the pair is aligned, to within a predefined threshold degree of alignment, with the direction of electrical propagation at the location of one of the electrodes belonging to the pair. The method further includes associating respective bipolar voltages measured by the pairs of electrodes with a digital model of the anatomical surface. Other examples are also described.