Irrigated Catheter Temperature Control via Delayed Flow

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Solution Overview

Problem

Open irrigated catheter ablation systems face challenges in accurately controlling electrode temperature during RF ablation procedures, leading to potential tissue damage and uneven ablation due to direct fluid irrigation, which can result in excessive cooling and increased ablation in target areas.

Innovation Solution

An open irrigated catheter ablation system with a temperature control mechanism that regulates irrigation fluid flow based on predetermined temperature thresholds, using a saline pump and RF generator, and a processor to manage irrigation flow through intermitted or delayed methods, ensuring optimal cooling and ablation control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct fluid irrigation is used during RF ablation, then blood coagulation is prevented and tissue damage is reduced, but electrode temperature is dramatically cooled which may result in increased ablation in target area and make temperature control challenging

Engineering Contradiction:
Improveprevention of blood coagulationVSAvoidelectrode temperature control
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The system delays the initiation of irrigation fluid flow until a predetermined time period has elapsed since the start of RF energy delivery. This preliminary action allows the electrode temperature to rise to the desired ablation temperature before cooling begins, thereby preventing blood coagulation during the critical initial phase while maintaining temperature control during sustained ablation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts irrigation fluid flow based on elapsed time and temperature feedback. The controller modulates the irrigation flow rate to vary over time, providing minimal or no irrigation initially when temperature control is critical, then increasing irrigation as the procedure progresses to prevent coagulation, thereby adapting to changing thermal conditions throughout the ablation process.

Inventive Principle:
Principle #15Dynamics

2Reliability

If irrigation fluid flow is increased to prevent blood coagulation, then safety is improved, but electrode temperature rises become cut off which may result in increased ablation beyond desirable levels

Engineering Contradiction:
Improvesafety of ablation procedureVSAvoidablation precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system continuously monitors electrode temperature and uses this feedback to control irrigation fluid flow rate. The controller adjusts irrigation in real-time based on temperature measurements, ensuring that cooling is applied only when and where needed to maintain precise temperature control and prevent over-ablation, while still providing sufficient cooling to prevent blood coagulation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system establishes a predetermined time delay before initiating irrigation, allowing the ablation process to begin without cooling interference. This preliminary phase enables precise temperature control during the critical early ablation stage, after which irrigation is introduced to maintain safety without compromising the already-established ablation zone precision.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If irrigation is delayed to improve temperature control, then ablation precision is improved, but blood coagulation risk increases during the delay period

Engineering Contradiction:
Improveablation precisionVSAvoidblood coagulation risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The system applies partial irrigation during the delayed period rather than complete cooling suppression. By providing minimal or reduced irrigation flow during the initial phase, the system maintains enough cooling to prevent blood coagulation while allowing sufficient heat accumulation to achieve precise ablation temperatures, thereby balancing both requirements through partial application of the cooling effect.

Inventive Principle:
Principle #16Partial or excessive action

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 minimizes blood coagulation and maintains precise temperature control during ablation procedures, ensuring accurate and controlled tissue ablation by adjusting irrigation fluid flow in response to temperature measurements, thereby improving the safety and efficacy of the ablation process.

Implementation Method 1

provide fluid to the site during the ablation procedure... the saline thus flows directly through the outlets of the passageways onto or about the distal electrode member. This direct flow through the distal electrode tip lowers the temperature of the distal tip during operation

Methodology Applied
Scientific EffectHeat dissipation through fluid irrigation: Convection

Implementation Method 2

RF ablation is accomplished by transmission of radiofrequency energy to a desired target area through an electrode assembly to ablate tissue at a target site. Because RF ablation may generate significant heat

Methodology Applied
Scientific EffectRadiofrequency energy transmission and tissue heating: Dielectric Heating

Data Source

PatentEP2740431B1Controlled irrigated catheter ablation systems
Publication Date: 2020.05.06 ST JUDE MEDICAL ATRIAL FIBRILLATION DIVISION INC
  • EP2740431B1 patent drawingFigure 1~3
  • EP2740431B1 patent drawingFigure 4
  • EP2740431B1 patent drawingFigure 5

AI summary

The present invention relates to open irrigated catheter ablation systems and methods used in connection with open irrigated catheter systems. The systems and related methods can control irrigation fluid flow to obtain temperature responses indicative of temperatures associated with an ablation procedure. Embodiments of the present invention provide irrigated catheter ablation systems having controlled irrigation fluid flow that can be directed at target areas where coagulation is more likely to occur to help minimize blood coagulation and associated problems. The irrigated fluid flow may be regulated in connection with an established or predetermined temperature threshold to improve or better optimize cooling and ablation properties of the system. In embodiments, irrigation flow may be either delayed or intermitted.