Cooled RF Catheter Balloon with Hydrophilic Polymer
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Solution Overview
Problem
Current RF ablation catheters are not optimized for ablating perivascular renal nerves, which is essential for treating hypertension, as they often cause renal artery injury and lack effective cooling mechanisms.
Innovation Solution
A cooled RF ablation catheter with a balloon having hydrophilic polymer fluid conductive regions that become electrically conductive upon fluid absorption, combined with a cooling arrangement to minimize renal artery injury and enhance tissue perfusion, allowing for precise and safe ablation of renal nerves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional RF ablation catheters are used to ablate renal nerves, then nerve ablation is achieved, but renal artery injury occurs and cooling is insufficient
Solution Approach 1:
The balloon is divided into multiple sections with different wall thicknesses: a thinner circumferential section for RF energy delivery and ablation, and thicker proximal and distal conical sections for cooling and protection. This segmentation allows simultaneous nerve ablation and renal artery cooling without compromising vessel safety
Solution Approach 2:
Different regions of the balloon are assigned different functional properties: the circumferential section has thinner walls optimized for RF energy transmission and nerve ablation, while the proximal and distal conical sections have thicker walls optimized for cooling function. This local differentiation resolves the contradiction between effective ablation and vessel protection
2Productivity
If RF energy is delivered through the balloon to ablate renal nerves, then effective ablation is achieved, but the balloon material must be electrically conductive which complicates design
Solution Approach 1:
The balloon material properties change based on fluid absorption: the hydrophilic polymer transitions from non-conductive in its dry state to electrically conductive when saturated with conductive fluid. This parameter change allows the balloon to function as an RF electrode only when needed, simplifying the overall device design while maintaining ablation efficacy
Solution Approach 2:
The balloon incorporates a composite structure combining hydrophilic polymer material with conductive fluid. This composite system provides electrical conductivity for RF energy delivery when the balloon is inflated with conductive fluid, while maintaining the flexibility and biocompatibility of the polymer material
3Productivity
If the balloon wall is made thin to facilitate RF energy delivery, then ablation effectiveness improves, but structural strength and cooling capability deteriorate
Solution Approach 1:
The balloon wall thickness is segmented into different regions: the circumferential section has thinner walls for optimal RF energy transmission and nerve ablation, while the proximal and distal conical sections have thicker walls for structural support and cooling function. This segmentation resolves the contradiction between RF efficiency and structural strength
Solution Approach 2:
Each section of the balloon is designed with locally optimized wall thickness: thinner walls in the circumferential section where RF energy delivery is prioritized, and thicker walls in the conical sections where structural integrity and cooling are prioritized. This local quality differentiation allows the balloon to simultaneously achieve effective ablation and maintain structural strength
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 solution enables targeted and minimally invasive ablation of renal nerves, reducing renal artery injury and improving treatment efficacy for hypertension by using a cooled RF ablation catheter with hydrophilic polymer fluid conductive regions and a cooling system.
Implementation Method 1
The second material preferably comprises a hydrophilic polymer that becomes electrically conductive in response to absorption of the conductive fluid
Implementation Method 2
A cooling arrangement is configured for at least one of receiving a thermal transfer fluid from the lumen arrangement and facilitating perfusion of blood passing through the target vessel to cool the balloon body during ablation
Data Source
AI summary
A catheter includes a flexible shaft having a lumen arrangement and a length sufficient to access a target vessel of a patient. A balloon at the distal end of the shaft is fluidly coupled to the lumen arrangement. The balloon body comprises a first material and a second material different from the first material. The second material comprises a hydrophilic polymer that becomes electrically conductive in response to absorption of the conductive fluid. The fluid conductive regions facilitate perfusion of the conductive fluid through the balloon body to an inner wall of the target vessel during ablation of perivascular tissues. A cooling arrangement is configured for one of receiving a thermal transfer fluid from the lumen arrangement or facilitating perfusion of blood passing through the target vessel to cool the balloon body during ablation of the perivascular tissues.