Subcutaneous Device Oversensing Detection via Adaptive Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Subcutaneous implantable devices face challenges in reliably sensing arrhythmias due to muscle artifact, respiration, and other physiological signals, particularly because they rely on far-field sensing without intracardial or epicardial electrodes, and can be affected by noise from existing pacemakers when combined with them.
Innovation Solution
A subcutaneous device with a housing-based electrode array and signal processing algorithms that include adaptive auto-adjusting thresholds and noise rejection techniques to differentiate between cardiac signals and noise, allowing for accurate detection of arrhythmias and rejection of non-cardiac signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If subcutaneous device uses far-field sensing without intracardial electrodes, then lead-related complications are eliminated, but sensing reliability deteriorates due to muscle artifact and physiological noise
Solution Approach 1:
The patent uses an intermediary filtering mechanism (signal processing algorithms and noise rejection techniques) to separate cardiac signals from physiological noise. The device implements adaptive filtering that acts as a mediator between the noisy far-field sensing output and the arrhythmia detection decision, allowing reliable detection without intracardial electrodes.
Solution Approach 2:
The patent dynamically changes sensing parameters including adaptive threshold adjustment and variable filtering characteristics based on detected signal conditions. The device modifies detection criteria and sensitivity parameters in real-time to maintain reliable arrhythmia detection despite the noisy far-field sensing environment.
2Adaptability or versatility
If subcutaneous device combines with existing pacemaker, then comprehensive cardiac management is achieved, but false arrhythmia detection increases due to pacemaker spike interference
Solution Approach 1:
The patent extracts and removes pacemaker spike artifacts from the sensed signal before arrhythmia analysis. The device identifies characteristic pacemaker spike patterns and selectively eliminates them from the signal stream, separating the harmful interference from the useful cardiac information for accurate arrhythmia detection.
Solution Approach 2:
The patent converts the pacemaker spike interference into a beneficial feature by using the known pacemaker timing and spike characteristics to improve detection algorithms. The device leverages the predictable nature of pacemaker spikes to enhance discrimination between paced beats and true arrhythmias, turning the interference source into a reference signal.
3Measurement precision
If subcutaneous device uses adaptive threshold adjustment, then signal detection sensitivity is improved, but false detection from noise increases
Solution Approach 1:
The patent implements feedback mechanisms where detection results and signal characteristics continuously inform threshold adjustment. The device uses closed-loop control where arrhythmia detection outcomes feed back to modify sensing parameters, preventing runaway sensitivity that would cause false positives while maintaining high detection capability for true arrhythmias.
Data Source
AI summary
A method and apparatus for determining oversensing of cardiac signals that includes a housing containing electronic circuitry, an electrode coupled to the electronic circuitry to sense cardiac signals, and a processor, positioned within the housing, to determine an oversensing characteristic associated with the cardiac signals sensed over a predetermined sensing window, and to identify oversensing in response to the determined oversensing characteristic.