Cryo-Catheter Segmented Cross-Section for Refrigerant Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cryo-catheters face challenges in optimizing outer diameter and internal refrigerant flow path size, leading to inefficient refrigeration and potential operation in refrigerant-limited conditions, which hinders effective cryoablation of tissues, especially in navigating through tortuous vascular paths and maintaining low temperatures.
Innovation Solution
A cryo-catheter configuration with a two-part refrigerant supply line, including a high-pressure supply tube and a capillary tube, along with a braided and articulation segment, which maintains refrigerant in a liquid state and ensures efficient vaporization at the distal tip, avoiding refrigerant-limited conditions by managing pressure and flow rates through carefully designed cross-sectional areas and void spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the catheter outer diameter is reduced to improve navigation through tortuous vasculature, then the catheter can be advanced through peripheral arteries more easily, but the internal refrigerant flow path size is reduced leading to refrigerant-limited conditions
Solution Approach 1:
The catheter body is divided into two distinct segments: a flexible distal segment for navigation through tortuous vasculature and a proximal segment with larger cross-sectional area for adequate refrigerant flow. This segmentation allows each portion to be optimized for its specific function without compromising the other.
Solution Approach 2:
The invention transitions from a uniform catheter design to a variable cross-sectional area design along the catheter length. The cross-sectional area increases from the distal to proximal end, creating a dimensional variation that accommodates both navigation requirements and refrigerant flow requirements.
2Volume of moving object
If the catheter outer diameter is reduced to minimize profile for vascular navigation, then the catheter is less invasive, but the internal flow paths become insufficient for delivering adequate refrigerant quantity
Solution Approach 1:
The catheter is segmented into regions with different cross-sectional areas. The distal portion maintains a small profile for vascular navigation, while the proximal portion expands to provide adequate flow path dimensions for efficient refrigerant delivery to the treatment site.
Solution Approach 2:
The catheter design incorporates variation in the cross-sectional dimension along its length, allowing the internal flow path area to increase in the proximal region while maintaining a compact distal profile, thus resolving the conflict between miniminvasive profile and refrigerant delivery capacity.
3Adaptability or versatility
If sophisticated internal systems are added to the catheter for monitoring and articulation, then the catheter functionality is enhanced, but the available space for refrigerant flow paths is reduced
Solution Approach 1:
The catheter body is segmented such that the distal portion contains monitoring and articulation systems with minimal impact on flow paths, while the proximal portion provides expanded cross-sectional area dedicated to adequate refrigerant flow, accommodating both functional requirements.
Solution Approach 2:
The invention utilizes variation in the cross-sectional dimension along the catheter length to accommodate multiple systems. The proximal segment has larger area to house monitoring systems and maintain adequate refrigerant flow paths, while the distal segment is optimized for its specific functions.
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 allows for efficient delivery and evacuation of refrigerant, maintaining low temperatures and preventing refrigerant-limited conditions, thereby enhancing the cryoablation process by optimizing refrigerant flow and pressure management within the catheter.
Implementation Method 1
a refrigerant traverses the supply tube, passes through the capillary tube and then outflows into an expansion chamber at the cryo-catheter's distal tip
Implementation Method 2
ensures efficient vaporization at the distal tip
Implementation Method 3
A two-part refrigerant supply line is disposed in the central lumen. In this regard, the supply line includes a high pressure supply tube and a flow restricting tube (e.g. capillary tube)
Data Source
AI summary
A configuration for a cryo-catheter which optimizes both the catheter's outer diameter and the size of the catheter's internal refrigerant flow path is described. Specifically, the inner dimensions of the cryo-catheter are configured to accommodate a pre-selected flow of refrigerant into the catheter's distal tip, and a return flow of refrigerant from the distal tip. The return flow is established in the void spaces between a refrigerant supply line and the inner wall of the catheter body. The available void space varies along the catheter length and depends on the presence/absence of various catheter accessories (i.e. pull wires, pressure tubes, etc.) which typically only extend through a portion of the catheter length. The disclosed configuration ensures that the cryo-catheter does not operate in a refrigerant limited condition, maintains the refrigerant as a liquid in the supply tube, and maintains the return line pressure at about 1 atmosphere.