Intracardiac Pacemaker P-Wave Sensing via Adjustable Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current implantable cardiac pacemakers often require transvenous leads, which can lead to complications such as infection, lead fracture, and poor connection, and are not capable of providing reliable atrial-synchronized ventricular pacing, essential for maintaining a regular heart rhythm in patients with AV conduction defects.
Innovation Solution
An intracardiac pacemaker system that filters cardiac signals to distinguish P-waves from R-waves and T-waves, allowing for atrial-synchronized ventricular pacing without transvenous leads, using an adjustable filter to enhance P-wave sensing and set a ventricular pacing escape interval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If transvenous leads are used for pacemaker implantation, then dual chamber pacing capability is achieved, but complications such as infection, lead fracture, and poor connection occur
Solution Approach 1:
The invention extracts and eliminates the transvenous lead component from the pacemaker system. By developing an intracardiac pacemaker that can be implanted directly in the ventricle without transvenous leads, the patent removes the source of lead-related complications while maintaining essential pacing functions through alternative sensing and pacing mechanisms
Solution Approach 2:
The intracardiac pacemaker housing serves multiple functions: it acts as both the pacemaker generator and the sensing electrode for detecting P-waves and R-waves, and as the pacing electrode for delivering ventricular pacing pulses. This multi-functionality eliminates the need for separate transvenous leads while achieving dual chamber pacing capability
2Reliability
If intracardiac pacemaker is used without transvenous leads, then lead-related complications are reduced, but reliable P-wave sensing becomes difficult due to signal interference from T-waves and R-waves
Solution Approach 1:
The sensing system dynamically adjusts its operation based on the detected cardiac cycle phase. The pacemaker identifies P-waves by analyzing signal characteristics within specific time windows relative to the R-wave, and adapts its sensing thresholds and filtering parameters to distinguish P-waves from T-waves and R-waves, ensuring reliable atrial event detection despite the challenging electrical environment
Solution Approach 2:
The pacemaker uses feedback from the sensed cardiac signals to continuously refine P-wave detection. By monitoring the relationship between P-waves, R-waves, and T-waves, the system adjusts sensing parameters and confirms P-wave identity based on expected timing and morphology, improving measurement precision in the intracardiac environment
3Measurement precision
If filter is adjusted to enhance P-wave sensing, then P-wave detection accuracy is improved, but distinction between T-waves and P-waves may be reduced
Solution Approach 1:
The pacemaker establishes a T-wave sensing window in advance, positioned after the expected P-wave occurrence time and before the expected T-wave occurrence time. This preliminary temporal separation allows the system to confidently detect P-waves without confusion from T-waves, as the T-wave window is set to begin only after the P-wave detection period has concluded
Solution Approach 2:
The sensing system dynamically adjusts its parameters based on the detected cardiac cycle phase. By adapting filtering and threshold settings according to the timing relative to the R-wave and expected P-wave and T-wave occurrences, the system optimizes P-wave detection while maintaining the ability to distinguish T-waves when they occur
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
A pacemaker implantable in a chamber of a patient's heart is configured to produce a filtered cardiac electrical signal by filtering a raw cardiac signal by an adjustable filter of a sensing module of the pacemaker. The sensing module is configured to receive the raw cardiac electrical signal comprising R-waves, T-waves and P-waves via electrodes coupled to the sensing module. The pacemaker is further configured to determine if the T-waves are distinct from the P-waves in the filtered cardiac electrical signal and adjust the filter to increase a difference between a feature of the P-waves and a feature of the T-waves in the filtered cardiac signal when the T-waves are not distinct from the P-waves.