Irrigated Catheter Uniform Cooling via Segmented Lumens
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Solution Overview
Problem
Existing irrigated ablation catheters face challenges in achieving uniform cooling of the catheter tip and surrounding tissues, leading to potential overheating and thrombus formation, especially when the tip is not perpendicular to the tissue, limiting the effectiveness of energy delivery and lesion creation.
Innovation Solution
The catheter design features an elongated tubular body with varying lumen diameters and tilted ducts to ensure uniform fluid outflow from elution holes, along with an optional inflatable balloon to enhance tissue contact, allowing for controlled and uniform cooling of the ablation electrodes and surrounding tissues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a typical irrigation system is used with a delivery lumen inside the catheter body, then cooling fluid can be supplied to the catheter tip, but uniform cooling of the catheter tip and surrounding tissues cannot be achieved, leading to potential overheating and thrombus formation
Solution Approach 1:
The irrigation system is segmented into multiple delivery lumens (first and second delivery lumens) with separate elution holes positioned at different locations on the catheter tip. This segmentation allows independent control of cooling fluid delivery to different regions, enabling uniform temperature distribution across the catheter tip and surrounding tissues, thereby preventing localized overheating and reducing thrombus formation risk.
Solution Approach 2:
The patent implements local quality by positioning elution holes at specific locations (distal end and lateral surface) to deliver cooling fluid precisely where needed. The first delivery lumen supplies cooling fluid to the distal end while the second delivery lumen supplies cooling fluid to the lateral surface, creating locally optimized cooling zones that address temperature variations across different regions of the catheter tip.
2Area of stationary object
If the catheter tip is positioned tangentially to increase tip/tissue contact area, then more tissue can be treated, but non-uniform cooling occurs because the temperature distribution along the catheter tip varies
Solution Approach 1:
The irrigation system divides cooling fluid delivery into segmented zones corresponding to different regions of the catheter tip. The first delivery lumen with elution holes at the distal end addresses cooling needs at the tip apex, while the second delivery lumen with elution holes on the lateral surface addresses cooling needs along the sides. This segmentation enables independent optimization of cooling for each region, maintaining temperature uniformity even when the catheter is positioned tangentially to maximize tissue contact area.
3Power
If RF energy is delivered to ablate tissue, then arrhythmogenic tissue can be destroyed, but temperature increases at the tissue/catheter interface limit energy delivery and cause thrombus formation
Solution Approach 1:
The irrigation system performs preliminary cooling action by delivering cooling fluid through the delivery lumens and elution holes before and during RF energy delivery. This preliminary cooling establishes a temperature gradient that protects the catheter tip and surrounding tissues from excessive heating, enabling sustained high-power RF energy delivery without reaching dangerous temperature thresholds that would cause thrombus formation.
Solution Approach 2:
Cooling fluid acts as an intermediary substance between the RF energy source and the tissue. The fluid absorbs excess thermal energy at the tissue/catheter interface, transferring heat away from the critical regions. This intermediary cooling mechanism allows higher RF power delivery by mediating the thermal interaction, preventing direct thermal damage and thrombus formation while maintaining effective ablation zones.
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
This design achieves uniform cooling of the catheter tip and surrounding tissues, reducing thrombus formation and enabling more efficient energy delivery for ablation, even when the tip is not perpendicular to the tissue, thereby improving lesion creation and minimizing overheating risks.
Implementation Method 1
a cooling fluid may be delivered from a pump, through the lumen, through the ducts, and out of the holes to the environment outside of the catheter
Implementation Method 2
The catheter may have an elongated tubular catheter body having a distal end, a proximal end, and a lumen extending longitudinally within the catheter body. A number of elution holes may be provided in the catheter tip region, and these holes are in fluid communication with the lumen through ducts. The lumen may have a diameter that is smaller at a distal end than at a proximal end.
Data Source
AI summary
An irrigated catheter with uniform cooling and/or uniform fluid distribution in longitudinally spaced apart elution holes by varying the diameter of a fluid delivery lumen. A number of elution holes are provided in a tip region of a catheter body, and these elution holes are in fluid communication with the lumen through ducts. The fluid delivery lumen may be provided with a flow constrictor to restrict flow of fluid towards the distal region.