EP Catheter Roll Angle Detection and MRI Artifact Filtering
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Solution Overview
Problem
Existing electrophysiology catheters have limited steering capabilities due to lack of direct roll angle information and are prone to gradient-induced artefacts in MRI environments, making precise navigation and signal filtering challenging.
Innovation Solution
The catheter system includes a bendable distal end with electrically isolated electrode segments arranged in bands, connected to a workstation that identifies electrode segments in contact with tissue to determine roll angle and provides filtering capabilities by determining a reference signal from electrical potential differences between segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional EP catheters are used with limited bending capabilities, then the catheter structure remains simple, but the operator cannot directly determine roll angle information which worsens steering precision
Solution Approach 1:
The catheter incorporates multiple electrode segments arranged in bands around the distal end portion, allowing the operator to identify which segments are in contact with tissue. This segmentation provides roll angle information without requiring complex mechanical sensors, thereby improving measurement precision while maintaining relatively simple device structure.
Solution Approach 2:
The patent uses electrical signals from electrode segments as an intermediary to indirectly determine roll angle information. Instead of directly measuring mechanical orientation, the system uses tissue contact detection through electrical signals to infer the catheter's rotational position, solving the measurement problem without adding complex mechanical measurement devices.
2Adaptability or versatility
If EP catheters are used in MRI environments, then comprehensive imaging capability is achieved, but gradient induced artefacts contaminate the electrophysiology signals making filtering difficult
Solution Approach 1:
The patent extracts the artefact signal from the composite signal by identifying components that are present during gradient switching. By separating the artefact portion from the physiological signal through signal processing that exploits the temporal correlation with gradient switching, the system removes the harmful artefact while preserving the useful electrophysiology data.
Solution Approach 2:
The system uses feedback from the known gradient waveform timing and morphology to guide the filtering process. By continuously referencing the gradient switching events and using this information to adjust the filtering parameters in real-time, the system effectively removes artefacts that correlate with gradient changes while preserving physiological signals that do not correlate.
3Reliability
If signal filtering is performed to remove gradient artefacts, then signal quality improves, but the complexity of signal processing increases due to the need for gradient waveform synchronization
Solution Approach 1:
The filtering system uses the already-acquired gradient waveform data from the MRI system without requiring additional external synchronization hardware. The EP catheter system independently processes the signal using the gradient timing information that is naturally available from the MRI sequence, making the complex filtering process self-sufficient and reducing overall system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables precise navigation and improved signal quality by providing operators with detailed orientation information and efficiently filtering gradient-induced artefacts, enhancing the safety and efficiency of catheter advancement.
Implementation Method 1
a plurality of electrically isolated electrode segments for detecting electrical signals
Implementation Method 2
The switched gradient fields induce signal artefacts which contain similar frequencies as the physiological EP signal
Data Source
AI summary
The invention relates to electrophysiology catheter systems and their use, such as in an MRI environment, and in particular to analysis of electric signals from such. An electrophysiology (EP) catheter with a plurality of electrically isolated electrode segments arranged in longitudinally spaced bands around the catheter is used to detect electric signals. A workstation receives the electrical signals which are then processed by a processing unit. Electric signals from electrode segments can be used to determine roll angle information of the catheter in relation to patient anatomy by determining signals from electrode segments in contact with tissue. Also, electric signals can be used to extract a reference signal that can be used to correct for gradient induced artifacts.