Shape-Memory Stylet Catheter for Pulmonary Vein Isolation
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Solution Overview
Problem
Existing ablation catheters face challenges in creating complete, durable, and safe electrical signal isolation in the heart due to incomplete lesion formation, pulmonary vein reconnection, and anatomical variations, leading to high recurrence rates of atrial fibrillation.
Innovation Solution
A cryoablation catheter with a shape-memory stylet and pulsed field ablation capabilities, featuring a shape-memory material stylet and electrodes for adjustable lesion formation, combined with cryoablation and pulsed field ablation to ensure continuous and efficient tissue ablation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional ablation catheters are used to create lesions in the heart, then the procedure can be performed, but incomplete lesion formation occurs leading to pulmonary vein reconnection and high recurrence rates
Solution Approach 1:
The catheter divides the ablation function into multiple independent modules: a cryoablation balloon for circumferential pulmonary vein isolation, a shape memory stylet for structural support and positioning, and electrodes for additional ablation points. This segmentation allows each component to optimize its specific function, ensuring complete and durable electrical isolation
Solution Approach 2:
The catheter employs composite construction combining a shape memory alloy stylet (Nitinol) with a flexible catheter shaft, and integrates both cryoablation and radiofrequency ablation capabilities in a single device. This composite approach enables the catheter to maintain structural integrity while achieving complete transmural lesions through multiple mechanisms
2Adaptability or versatility
If the catheter is made flexible to navigate heart anatomy, then anatomical variations can be accommodated, but the catheter cannot maintain stable positioning for complete lesion formation
Solution Approach 1:
The catheter incorporates a shape memory stylet that can dynamically change its rigidity. The stylet remains flexible during insertion to navigate anatomical variations, then transitions to a rigid state when deployed to maintain stable positioning against the pulmonary vein ostia, ensuring complete lesion formation without compromising adaptability
Solution Approach 2:
The stylet's physical state is changed from a compressed flexible configuration during delivery to an expanded rigid configuration during ablation. This parameter change allows the catheter to adapt to anatomical variations during insertion while maintaining stable positioning for complete lesion formation during the procedure
3Reliability
If multiple ablation points are created to ensure complete isolation, then pulmonary vein reconnection is reduced, but procedure time increases
Solution Approach 1:
The catheter merges cryoablation and radiofrequency ablation capabilities into a single integrated device. The cryoablation balloon provides circumferential isolation while electrodes create additional focal lesions, achieving complete pulmonary vein isolation in a single procedure without requiring multiple separate ablation points or extended procedure time
Solution Approach 2:
The cryoablation balloon applies continuous circumferential freezing around the pulmonary vein ostia, creating complete isolation in one continuous action. This eliminates the need for multiple discrete ablation points and reduces procedure time while ensuring complete electrical isolation
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 catheter reduces procedure time, minimizes adverse effects, and enhances lesion depth and completeness, providing effective electrical signal isolation with reduced risk of complications.
Implementation Method 1
the stylet is collapsible from an operational configuration in which the stylet extends longitudinally to support the catheter shaft to a delivery configuration in which the stylet is compressed within the catheter shaft
Implementation Method 2
Atrial fibrillation is one of the more prevalent types of heart conditions
Data Source
AI summary
A multimodality or hybrid ablation system includes an ablation apparatus for creating a lesion in target tissue. The ablation apparatus has an ablation shaft including a handle, a first portion, an ablation portion, distal tip, at least one ablation energy delivery lumen, at least one ablation energy return lumen, and a stylet lumen that extends substantially along a length of the ablation shaft from the handle to at least the ablation portion. The ablation apparatus also includes a stylet that is capable of being inserted into the stylet lumen where the stylet is made of a shape-memory material. A plurality of electrodes are arranged on the ablation portion for measuring or verifying tissue contact with the tissue and applying a pulsed electric field. Optionally, the pulsed electric field may be applied after, contemporaneously, or for only a portion that the cryo-modality is applied to the target tissue.