Tapered Optical Fiber Assembly for Intravascular Lithotripsy Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vascular lesions within and adjacent to vessels in the body are difficult to treat effectively, posing a risk for major adverse events such as myocardial infarction, embolism, and stroke, and existing interventions may not always be ideal or require subsequent treatment.
Innovation Solution
A catheter system with an inflatable balloon and optical fiber configuration, including a tapered optical fiber and energy source, generates plasma pulses to create therapeutic pressure waves for treating vascular lesions by inducing fractures in the lesions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a standard optical fiber is used to deliver laser energy, then the fiber can transmit energy, but the coupling efficiency is insufficient and energy loss occurs
Solution Approach 1:
The optical fiber is tapered to change its geometric parameters along its length, creating a gradual transition from a larger proximal diameter to a smaller distal diameter. This parameter change optimizes the mode field distribution and improves coupling efficiency between the laser source and the fiber, reducing energy loss while maintaining effective energy delivery to the treatment site
Solution Approach 2:
The optical fiber has non-uniform properties along its length, with different diameters at different locations. The proximal portion has a larger diameter for efficient coupling with the laser source, while the distal portion has a smaller diameter for effective energy delivery and plasma generation at the treatment site, creating local optimization at each position
2Loss of energy
If the optical fiber diameter is reduced to improve coupling, then coupling efficiency improves, but the fiber becomes more susceptible to bending losses and damage
Solution Approach 1:
The fiber diameter is changed gradually along its length rather than being uniformly small throughout. The proximal portion maintains a larger diameter to reduce bending losses and improve mechanical durability, while the distal portion tapers to a smaller diameter for optimal coupling and energy delivery, achieving both reliability and efficiency
Solution Approach 2:
The optical fiber is effectively segmented into different functional regions along its length: a proximal section with larger diameter for mechanical strength and low bending loss, and a distal section with smaller diameter for efficient energy coupling and plasma generation, allowing each segment to optimize for its specific function
3Power
If high energy is delivered to generate plasma, then therapeutic effect is achieved, but the risk of damaging surrounding tissue increases
Solution Approach 1:
The optical fiber creates a localized high-energy density region at its distal tip where plasma generation is needed, while the proximal portion maintains lower energy density for safe handling and coupling. The tapered geometry concentrates the laser energy into a small focal volume at the treatment site, enabling high power plasma generation without damaging surrounding tissues through precise spatial localization
Solution Approach 2:
The tapered optical fiber acts as an intermediary that transforms the laser energy from the proximal source into a concentrated plasma pulse at the distal tip. It mediates the energy transfer by gradually focusing the light modes into a small volume where plasma forms, acting as a buffer between the high-power laser source and the sensitive surrounding tissues
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 system effectively treats vascular lesions by generating plasma-induced pressure waves that fracture the lesions, reducing the risk of adverse events and improving treatment efficacy.
Implementation Method 1
The creation of plasma via optical breakdown of an aqueous solution typically requires a significant amount of energy in a short amount of time upon which it is converted into a therapeutic bubble and/or a therapeutic pressure wave
Implementation Method 2
it is converted into a therapeutic bubble and/or a therapeutic pressure wave
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A catheter system (100) for treating a treatment site (106) within or adjacent to a vessel wall (108) or a heart valve includes an inflatable balloon (104), an optical fiber (122), and an energy source (124). The optical fiber (122) has a fiber proximal end (122P), and a fiber distal end (122D) positioned within the inflatable balloon (104). The optical fiber (122) is configured to receive an energy pulse so that the optical fiber (122) emits light energy in a direction away from the optical fiber (122) to generate a plasma pulse within the inflatable balloon (104). The optical fiber (122) can be tapered from the fiber proximal end (122P) toward the fiber distal end (122D). The energy source (124) in optical communication with the fiber proximal end (122P) of the optical fiber (122), and can include a laser. The optical fiber (122) includes a first fiber member (250) and a second fiber member (258) that is coupled to the first fiber member (250). The first fiber member (250) can be fused to the second fiber member (258) in a fused region (256). The first fiber member (250) and the second fiber member (258) can be formed as a unitary structure. The catheter system (100) can also include a ferrule (248) that encircles the fused region (256).