Catheter ECG Noise Reduction via Conductive Fluid Grounding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During medical catheterization procedures, controlling local heating of tissue during radiofrequency energy application for cardiac tissue ablation is challenging, as it involves tradeoffs between lesion size and excessive heating, which can lead to ineffective procedures or tissue charring.
Innovation Solution
A catheterization system that includes a flexible catheter with a lumen for passing an electrically conductive fluid, connected to an irrigation pump and an electrocardiogram circuitry for monitoring, with an electrically conductive cable linking the fluid reservoir to a body surface electrode, significantly reduces electrical interference noise by connecting the conductive fluid to an isolated ground.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiofrequency energy is applied to create a larger lesion for effective ablation, then the effectiveness of the procedure is improved, but excessive local heating occurs causing tissue charring and high impedance
Solution Approach 1:
An electrically conductive fluid (intermediary substance) is introduced between the radiofrequency energy source and the tissue to act as a heat sink and temperature regulator. The fluid absorbs excess heat through convection and conduction, preventing direct overheating of the tissue while allowing effective ablation to occur.
Solution Approach 2:
A hydraulic system using electrically conductive fluid circulation is implemented to control thermal effects. The fluid is pumped through the catheter lumen to the treatment site, where it absorbs heat and carries it away, enabling temperature control during radiofrequency ablation through fluid dynamics rather than direct thermal contact.
2Temperature
If slower heating is used to provide better control of ablation, then temperature control is improved, but the procedure time is unduly prolonged
Solution Approach 1:
The electrically conductive fluid circulates continuously throughout the ablation procedure, providing ongoing heat removal and temperature control. This continuous action allows faster heating rates to be used while maintaining temperature control, as the fluid constantly removes excess heat rather than relying on slow, controlled heating.
Solution Approach 2:
The conductive fluid serves as a thermal intermediary that enables faster energy delivery by immediately absorbing and removing excess heat. This mediator allows the system to operate at higher power levels without sacrificing temperature control, thereby reducing procedure time while maintaining safety.
3Temperature
If the catheter system uses electrically conductive fluid for irrigation, then cooling control is improved, but electrical interference noise increases in ECG monitoring
Solution Approach 1:
The harmful electrical interference is extracted and separated from the ECG monitoring system by providing an alternative ground path through the conductive fluid. The fluid acts as a dedicated electrical reference that isolates the irrigation system's electrical noise from the sensitive ECG amplifiers, allowing both functions to operate simultaneously without mutual interference.
Solution Approach 2:
The electrically conductive fluid serves as an electrical intermediary and reference potential between the irrigation system and the ECG monitoring system. By establishing a common electrical reference through the conductive fluid, the system eliminates potential differences that cause noise, while the fluid continues to perform its thermal cooling function.
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
The system effectively reduces electrocardiogram noise interference, allowing for more controlled and efficient cardiac tissue ablation procedures by minimizing the impact of equipment emissions on signal clarity and preventing overheating.
Implementation Method 1
an electrically conductive cable links the electrically conductive fluid of the fluid reservoir to a body surface electrode on the subject
Implementation Method 2
a lumen for passing an electrically conductive fluid therethrough to exit the catheter at its distal portion
Implementation Method 3
controlling local heating of tissue during radiofrequency energy application for cardiac tissue ablation
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Methods and systems of catheterization include a flexible catheter adapted for insertion into a heart of a living subject. The catheter has a lumen for passing an electrically conductive fluid therethrough with the fluid exiting the catheter at the distal portion. The lumen is connectable to an irrigation pump to form a fluid communication therewith. A fluid reservoir connected to the lumen supplies the fluid to the catheter. Electrocardiogram circuitry is connectable to the subject for monitoring electrical activity in the heart. An electrically conductive cable diverts induced charges in the fluid from the catheter electrodes, for example by connection to an isolated ground of the electrocardiogram.