Electrosurgical Cutting Device Thermal Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrosurgical devices face challenges in navigating narrow body passageways while maintaining sufficient thermal isolation to prevent self-destruction during RF-powered procedures, requiring a cutting device that can articulate effectively and manage heat generated during tissue coring and coagulation.
Innovation Solution
A cutting device with a cylindrical body and peripheral cutting edge powered by RF energy, mechanically supported by struts and thermally isolated from the catheter using air gaps and thermally insulating materials, along with features like slanted slots to enhance thermal resistance and facilitate tissue aspiration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the inner diameter of the cutting device is increased to permit navigation and delivery of RF energy, then the device can navigate narrow passageways and deliver sufficient electrical current, but the device becomes larger and more difficult to navigate tortuous pathways
Solution Approach 1:
The cutting device is segmented into distinct functional components: a cylindrical body for RF energy delivery, a cutting element for tissue coring, and an aspiration system for tissue removal. This segmentation allows each component to be optimized independently for its specific function while maintaining overall device compactness for navigation through narrow passageways
Solution Approach 2:
The cutting device is nested within the elongated medical device catheter system, with the cutting device fitting inside the catheter lumen. The aspiration channel is nested within the cylindrical body, allowing tissue to be drawn through the device interior. This nesting arrangement minimizes the overall device profile while maintaining functional capabilities
2Power
If RF power level is increased to improve cutting and coagulation effectiveness, then electrosurgical procedure performance is enhanced, but heat generated may deteriorate or cause self-destruction of the elongated medical device
Solution Approach 1:
A thermal barrier layer is introduced as an intermediary between the RF-powered cutting device and the elongated medical device catheter. This thermal barrier, positioned at the distal end of the catheter, mediates heat transfer by reflecting or absorbing thermal energy, thereby protecting the catheter from thermal damage while allowing high RF power to be delivered to the cutting device
Solution Approach 2:
The thermal barrier layer changes the thermal parameters of the system by introducing materials with specific thermal conductivity properties. The barrier layer is designed with thickness and material composition that optimize thermal resistance to protect the catheter while maintaining cutting device temperature for effective tissue coring and coagulation
3Length of moving object
If the outer diameter of the cutting device is reduced to access remote locations, then the device can navigate narrow passageways, but the structural support and mechanical strength are compromised
Solution Approach 1:
The cutting device utilizes composite material construction, combining materials with different mechanical properties to achieve both small outer diameter and sufficient structural strength. The cylindrical body may use materials with high strength-to-weight ratio, while the cutting element uses materials optimized for tissue interaction. This composite approach allows the device to maintain mechanical integrity despite reduced overall dimensions
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
Enables safe and effective navigation and operation within the body by preventing heat transfer to the catheter, ensuring the device's stability and integrity during electrosurgical procedures, while allowing efficient tissue separation and aspiration.
Implementation Method 1
Thermal isolation is provided by inserting between the substantially cylindrical body and the catheter a material (e.g., air) that has a thermal resistance that is higher than the thermal resistance of the material (e.g., stainless steel) from which the substantially cylindrical body is formed
Implementation Method 2
a peripheral cutting edge powered by electrical energy, such as RF energy
Data Source
AI summary
A cutting device for tissue separation includes a cutting edge using electrical energy such as RF power that is coupled to, but thermally insulated from, a catheter in an elongated medical device. Thermal insulation between a ring-type cutting device and the catheter is provided by a gap, slots within the ring, and/or slanted slots within the ring. In one embodiment, tissue separation occurs by rotation of a ring-type electrically-powered cutting edge having internal cross-bar elements. In an alternate embodiment, tissue separation occurs by longitudinal movement of an offset electrically-powered cutting edge that is pressed against tissue by an inflatable balloon. In a further alternate embodiment, a cutting edge is coupled longitudinally to a catheter, is provided electrical energy by wired connection to the braided catheter, but is thermally isolated from the catheter.