ICD Post-Stimulation Sensing Threshold Decay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current implantable cardioverter defibrillators (ICDs) face challenges in accurately sensing cardiac signals post-electrical stimulation, particularly in distinguishing between shockable and non-shockable arrhythmias, due to the need for rapid assessment of cardiac electrical activity after therapies like cardioversion or defibrillation shocks.
Innovation Solution
The ICD automatically adjusts the cardiac event sensing threshold using a post-stimulation decay sequence based on pre-stimulation cardiac event amplitude, enabling rapid detection of shockable rhythms and appropriate therapeutic responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the ICD uses a fixed cardiac event sensing threshold after electrical stimulation, then the device structure remains simple, but the accuracy of cardiac signal detection deteriorates due to residual electrical activity masking true cardiac events
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed sensing threshold to a dynamically adjusted threshold that automatically decays over time following electrical stimulation. The sensing threshold is modified based on the elapsed time since stimulation delivery, allowing the system to adapt to changing electrical conditions in the heart tissue without requiring complex manual intervention or overly complicated control mechanisms.
Solution Approach 2:
The patent implements parameter changes by systematically varying the sensing threshold parameter as a function of time after electrical stimulation. The threshold is initially elevated to avoid false detection of residual stimulation artifacts, then gradually reduced according to a predetermined decay sequence, enabling accurate cardiac event detection as the tissue recovers from stimulation effects.
2Speed
If the ICD implements rapid post-stimulation sensing, then the response time to detect shockable arrhythmias improves, but the reliability of sensing deteriorates due to residual electrical stimulation artifacts
Solution Approach 1:
The patent applies preliminary action by pre-modifying the sensing threshold before actual cardiac event detection begins. The threshold is adjusted in advance based on the timing relative to electrical stimulation delivery, creating a protective window that prevents false sensing of residual stimulation artifacts. This preliminary threshold modification enables rapid sensing to begin immediately while maintaining reliability through预先 established protection against artifacts.
3Measurement precision
If the ICD uses a high sensing threshold immediately after stimulation, then false detection of residual artifacts is reduced, but the detection of true low-amplitude cardiac events is delayed
Solution Approach 1:
The patent implements periodic action through a structured, time-based decay sequence that systematically reduces the sensing threshold in controlled stages following electrical stimulation. Rather than maintaining a constantly high threshold or using a single fixed value, the threshold progresses through predetermined decay phases that balance false detection prevention with timely true event detection, optimizing the trade-off between these competing requirements.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A medical device is configured to deliver an electrical stimulation pulse to a heart of a patient, determine a pre-stimulation cardiac event amplitude prior to delivering the electrical stimulation pulse and adjust a cardiac event sensing threshold according to a first post-stimulation decay sequence in response to the electrical stimulation pulse delivery. The first post-stimulation decay sequence is controlled by a sensing module of the medical device according to a first set of sensing control parameters including at least one sensing control parameter based on the pre-stimulation cardiac event amplitude.