Laser Ablation Catheter Expanded Distal Tip for Tissue Removal
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Solution Overview
Problem
Current pulsed laser energy transmitting catheters for ablating blockages in human arteries face inefficiencies due to significant dead space at the ablation tip, leading to more tissue damage and less effective ablation, as shown by Hamburger's research on multiple fiber optic bundle catheters compared to single fiber optic systems.
Innovation Solution
The development of a liquid filled waveguide laser ablation catheter with an ultraviolet grade elongated distal optical window featuring an insert segment and an expanded segment, where the expanded segment has no cladding and a larger outer diameter than the insert segment, allowing for increased optical beam expansion and reduced dead space, thereby enhancing ablation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple smaller diameter fiber optics are used to improve catheter flexibility, then catheter flexibility is improved, but dead space at the ablation tip increases leading to reduced ablation efficiency
Solution Approach 1:
The catheter divides the ablation function into two segments: a flexible distal section with multiple smaller fiber optics for navigation, and a rigid proximal section with a single large diameter fiber optic for efficient ablation. This segmentation allows the catheter to achieve both flexibility for delivery and ablation efficiency for treatment.
Solution Approach 2:
The distal flexible section with multiple fiber optics is nested within or transitions to the proximal rigid section with the single large fiber optic. This nested configuration allows the flexible delivery catheter to house or connect to the rigid ablation tip, combining both functionalities in one device.
2Productivity
If a single large diameter fiber optic is used to improve ablation efficiency, then ablation efficiency is improved, but catheter flexibility deteriorates
Solution Approach 1:
The catheter is divided into functional segments where the proximal portion uses a single large diameter fiber optic for optimal ablation efficiency, while the distal portion uses multiple smaller fiber optics for flexibility. This segmentation resolves the contradiction by assigning different structural characteristics to different functional zones.
Solution Approach 2:
Different sections of the catheter are given different structural qualities: the distal section has smaller diameter fibers for flexibility where navigation is critical, while the proximal section has larger diameter fibers for ablation efficiency where energy delivery is critical. Each local region is optimized for its specific function.
3Reliability
If higher energy densities and repetition rates are used to compensate for dead space, then ablation effectiveness is maintained, but energy consumption increases
Solution Approach 1:
The patent converts the harmful effect of dead space into a beneficial design feature by intentionally creating a transition zone where the fiber bundle transitions from multiple small fibers to a single large fiber. This transition zone manages the dead space problem while maintaining ablation effectiveness, eliminating the need for compensatory high energy densities.
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 configuration reduces the need for higher energy densities and repetition rates, increases the active ablation area, and allows for easier passage through tight lesions with less pulse energy, improving the efficiency and effectiveness of tissue ablation.
Implementation Method 1
a liquid filled waveguide including an elongate catheter body tube having an inner surface with a first index of refraction and a biocompatible ultraviolet transparent optical fluid disposed within and completely filling a core liquid volume of the elongate catheter body tube which is at least partially bounded by the inner surface, with the optical fluid having a second index of refraction which is greater than the first index of refraction
Implementation Method 2
the distal optical window may also have an expanded segment which is disposed distally of the insert segment, which does not have a core and cladding configured to act as a waveguide, which has an outer diameter which is greater than an outer diameter of the insert segment, which has an output surface that has an area which is equal to or greater than an area of a transverse section of the elongate catheter body tube proximally adjacent the distal optical window and which has an axial length sufficient to allow optical energy expansion within the expanded segment
Implementation Method 3
Laser ablation catheters having expanded distal tip windows for efficient tissue ablation
Data Source
AI summary
Laser ablation catheters and methods of using same for efficient tissue ablation are disclosed. In some cases, laser ablation catheter embodiments may include expanded distal tips that allow for beam energy expansion and reduce dead space at the distal cutting surface of the laser ablation catheter.