Cryoablation Catheter With Multilumen Flow Paths for Bent Anatomy
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Solution Overview
Problem
Conventional cryoablation catheters face issues with fluid flow stability and diameter reduction when navigating through bent body cavities, leading to incomplete treatment due to lumens closing during bending.
Innovation Solution
A cryoablation catheter design featuring an inner tube with an irregular shape and multiple supply lumens, allowing fluid to pass through varying distances between the outer and inner tube surfaces, ensuring stable fluid flow even in bends, and a discharge flow path between the tubes for efficient cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If only one lumen for supplying fluid is formed to decrease catheter diameter, then the catheter diameter is reduced enabling insertion into narrower body cavities, but the lumen closes when the catheter is bent, preventing stable fluid delivery
Solution Approach 1:
The single lumen is divided into multiple separate lumens within the inner tube. This segmentation allows the catheter to maintain its flexibility and bendability while providing multiple independent fluid delivery pathways, preventing the complete closure of all lumens when the catheter is bent. The discharge flow path remains separate and functional.
Solution Approach 2:
The inner tube with multiple lumens is nested within the outer tube, creating a layered structure. This nested configuration allows the inner tube to be positioned optimally within the outer tube's lumen, maintaining fluid delivery stability while preserving the flexibility needed for navigation through bent body cavities.
2Adaptability or versatility
If the catheter is bent to navigate through body cavities, then the catheter can reach target tissues in complex anatomical pathways, but the single lumen closes, preventing stable fluid supply
Solution Approach 1:
By segmenting the single lumen into multiple independent lumens, the system maintains adaptability for navigating bent body cavities while ensuring that at least some lumens remain open and functional during bending, thus preserving fluid delivery reliability.
Solution Approach 2:
The inner tube is designed with non-circular cross-section and irregular shape to optimize fluid flow characteristics in specific regions. This local optimization ensures that certain areas of the inner tube maintain open pathways for fluid delivery even when the catheter is bent, while still allowing overall navigation flexibility.
3Length of moving object
If the outer diameter of the outer tube is decreased to improve passage capability, then the catheter can navigate through narrower pathways, but the distance between inner and outer tube surfaces is shortened, potentially affecting cooling efficiency
Solution Approach 1:
The inner tube is designed with a non-circular cross-section and irregular shape, creating varying radial distances between the inner tube surface and outer tube surface at different locations. This local variation allows optimization of cooling efficiency in critical regions while maintaining overall small diameter for improved passage capability through narrow body cavities.
Solution Approach 2:
The inner tube employs an asymmetric, non-circular cross-sectional design rather than a symmetric circular shape. This asymmetry creates different radial distances in different directions, allowing the catheter to maintain small overall diameter for navigation while preserving adequate cooling contact area between the inner tube and outer tube surfaces in specific orientations.
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 design enables stable fluid delivery and improved passage capability, facilitating effective cooling of lesions even in complex anatomical pathways while maintaining catheter position stability.
Implementation Method 1
in a cross section perpendicular to the longitudinal direction, an external shape of the inner tube is an irregular shape... the discharge flow path is located between an inner surface of the outer tube and an outer surface of the inner tube and allows the fluid to pass therethrough
Implementation Method 2
Cryoablation techniques are medical techniques that involve bringing a device having been set to have a low temperature into contact with a target tissue so as to freeze and necrose cells forming the target tissue
Implementation Method 3
As methods for setting a device to have a low temperature, there are a method in which liquid nitrogen is used and a method in which the Joule-Thomson effect based on high-pressure gas is utilized
Implementation Method 4
The fluid that has come to have an increased temperature as a result of cooling the lesion is carried from the distal side to the proximal side of the catheter through the discharge flow path
Data Source
AI summary
A cryoablation catheter including an outer tube, an inner tube whose external shape is an irregular shape and a discharge flow path, is provided. The inner tube includes a guide wire lumen and a plurality of supply lumens. The discharge flow path is located between an inner surface of the outer tube and an outer surface of the inner tube, and allows the fluid to pass therethrough from a distal side to a proximal side of the outer tube. The inner tube includes a hole located in a distal portion of the inner tube. Any of the supply lumens and the discharge flow path are in communication with each other through the hole.