Non-contact Mapping System Electrode Position Correction

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Solution Overview

Problem

Conventional non-contact mapping systems for cardiac structures assume electrodes are within the boundary surface of the three-dimensional model, leading to erroneous reconstructions when they are exterior, due to factors like distance and surface movement during signal detection.

Innovation Solution

A computer-implemented method that determines the spatial position of electrodes relative to a three-dimensional model, compares this position to a tolerance criterion, and adjusts either the electrode position or the model's boundary surface to ensure accurate mapping, even when electrodes are exterior to the model, by translating the boundary surface towards the electrode position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional non-contact mapping systems assume electrodes are within the boundary surface of the three-dimensional model, then the mapping process is simplified, but erroneous reconstructions occur when electrodes are actually exterior to the model

Engineering Contradiction:
Improvemapping process complexityVSAvoidreconstruction accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system performs preliminary determination of electrode positions relative to the boundary surface before proceeding with the mapping reconstruction. By checking whether electrodes are interior or exterior to the boundary surface in advance, the system can select appropriate processing paths and avoid erroneous reconstructions, thus resolving the contradiction between simplified processing and accurate results

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of assuming electrodes are within the boundary surface and correcting when they are not, the invention inverts the approach by first determining the actual relative positions and then adapting the mapping process accordingly. This inversion allows the system to handle both interior and exterior electrode positions accurately without relying on incorrect assumptions

Inventive Principle:
Principle #13The other way round (Inversion)

2Adaptability or versatility

If the distance between electrodes and the endocardial surface varies, then non-contact mapping can be performed, but the determined electrode positions may be exterior to the model boundary

Engineering Contradiction:
Improvemapping flexibilityVSAvoidelectrode position accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts its processing based on the determined relative positions of electrodes. When electrodes are found to be exterior to the boundary surface, the system modifies the mapping approach accordingly. This dynamic adaptation allows the system to maintain precision across varying distances while preserving the flexibility of non-contact mapping

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback by continuously determining the relative positions of electrodes and using this information to guide subsequent mapping steps. The feedback loop ensures that variations in electrode distance are accounted for, maintaining position accuracy while allowing mapping flexibility

Inventive Principle:
Principle #23Feedback

3Reliability

If the endocardial surface moves during signal detection, then realistic physiological conditions are captured, but electrode positions become exterior to the static model boundary

Engineering Contradiction:
Improvephysiological accuracyVSAvoidposition correlation accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system performs preliminary determination of electrode positions relative to the boundary surface at multiple time points during the detection process. By establishing these relative positions in advance, the system can account for surface movement and maintain accurate correlation between electrode data and the anatomical model throughout the physiological cycle

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2943120B1Non-contact mapping system
Publication Date: 2020.05.20 ST JUDE MEDICAL ATRIAL FIBRILLATION DIVISION INC
  • EP2943120B1 patent drawingFigure 1
  • EP2943120B1 patent drawingFigure 2
  • EP2943120B1 patent drawingFigure 3

AI summary

In a system and method for non-contact mapping of an anatomic structure, the spatial position of an electrode is determined independent of a previously generated three-dimensional model of the anatomic structure. A position of the electrode relative to a boundary surface of the model is determined, along with a corresponding point on the boundary surface of the three-dimensional model that is closest to the relative electrode position. A signed distance (d) of the relative electrode position from the corresponding closest point on the boundary surface is determined, wherein a positive signed distance indicates the relative electrode position is exterior to the model. In such an instance, the boundary surface is perturbed (e.g., expanded outward) at least in part as a function of the signed distance (d) until the relative electrode position lies interior to the model.