Ventricular Pacemaker Atrial Tracking via Motion Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Intracardiac ventricular pacemakers face challenges in reliably detecting atrial events due to the low amplitude of P-waves in cardiac electrical signals, which can lead to unreliable atrial-synchronized ventricular pacing.
Innovation Solution
Incorporating a motion sensor, such as an accelerometer, within the pacemaker to detect atrial events based on mechanical activation or atrial systole, allowing for synchronized ventricular pacing through a programmable AV interval, and using a flow disturbance structure to enhance atrial event detection by inducing vibrations in response to blood flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical sensing is used to detect atrial events, then the pacemaker can provide atrial-synchronized ventricular pacing, but the low amplitude of P-waves leads to unreliable detection
Solution Approach 1:
The patent replaces electrical sensing (measuring electrical P-wave signals) with mechanical sensing (detecting mechanical vibrations and motions associated with atrial contraction). The motion sensor detects mechanical events such as atrial wall movement and blood flow changes, which produce detectable vibrations that are much stronger than electrical P-wave signals, thereby resolving the reliability issue.
Solution Approach 2:
The patent introduces a motion sensor as an intermediary device that indirectly detects atrial events by sensing mechanical vibrations and motions produced by atrial contraction. This intermediary approach converts the difficult-to-detect electrical P-wave problem into an easily detectable mechanical vibration problem, improving detection reliability.
2Reliability
If a motion sensor is added to detect atrial events, then detection reliability improves, but device complexity increases
Solution Approach 1:
The motion sensor serves multiple functions: it detects atrial contraction events for synchronization, characterizes blood flow patterns, and provides information about cardiac mechanics. This multi-functionality justifies the addition of the sensor by providing several benefits from a single component, thereby mitigating the complexity increase.
Solution Approach 2:
The motion sensor utilizes the natural mechanical vibrations and motions produced by the heart's own contraction and blood flow to generate detection signals. The system serves itself by using the heart's intrinsic mechanical energy rather than requiring external power or complex signal amplification circuits, 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
Enables reliable atrial-synchronized ventricular pacing by accurately detecting atrial events through motion sensor signals, improving heart rhythm synchronization and maintaining a target AV interval, thus addressing the limitations of relying solely on cardiac electrical signals.
Implementation Method 1
using a flow disturbance structure to enhance atrial event detection by inducing vibrations in response to blood flow
Data Source
Figure 1
Figure 2A~2C
Figure 2D~2F
AI summary
An intracardiac ventricular pacemaker is configured to detect an atrial mechanical event from a motion sensor signal received by an atrial event detector circuit of the pacemaker. The motion sensor signal is responsive the motion of blood flowing in the ventricle. A pacing pulse is scheduled at an expiration of a pacing interval set by a pace timing circuit in response to detecting the atrial mechanical event. An atrial-synchronized ventricular pacing pulse is delivered upon expiration of the pacing interval.