Parylene-Coated Sphincterotome Wire for Precise Tissue Cutting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sphincterotomes often inadvertently cut adjacent tissue during procedures due to the exposure of cutting wires, and existing coatings are prone to damage, increasing the risk of electrical arcs and wire breakage, which can lead to injury from fragments.
Innovation Solution
A sphincterotome with a cutting wire coated using parylene-based polymeric coatings, such as poly-p-xylylene, providing a thin, durable, and electroinsulative layer that reduces the risk of tissue damage and wire exposure, while maintaining a targeted cutting capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the cutting wire is exposed to enable targeted cutting, then cutting precision is improved, but the risk of inadvertent tissue cutting and electrical arcing increases
Solution Approach 1:
The cutting wire is coated with electroinsulative material along its length, creating zones of different electrical properties. The distal portion remains uncoated or has reduced coating to enable cutting, while proximal portions have full coating for electrical isolation. This local differentiation allows the wire to provide targeted cutting precision where needed while maintaining safety through electrical insulation elsewhere.
2Reliability
If a polymer sleeve coating is applied to the cutting wire, then electroinsulation is improved, but the coating is prone to damage and migration
Solution Approach 1:
Instead of a thick polymer sleeve that can be nicked or split, the invention applies a thin film coating of electroinsulative material directly to the cutting wire surface. This thin film approach maintains electrical insulation while being more resistant to mechanical damage and migration during device manipulation and use.
3Strength
If the cutting wire diameter is increased to provide structural integrity, then wire strength is improved, but the outer diameter increases which may affect device flexibility
Solution Approach 1:
The cutting wire is constructed as a composite structure with a core wire providing mechanical strength and flexibility, and an electroinsulative coating layer providing electrical isolation. This composite approach allows the wire to maintain adequate strength for cutting while preserving flexibility for device navigation, with the coating thickness optimized to provide electroinsulation without significantly increasing outer diameter.
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 parylene coating enhances electroinsulation, durability, and reduces the risk of tissue damage and wire breakage, allowing for precise cutting with minimal exposure, thus improving safety and effectiveness during sphincterotomy procedures.
Implementation Method 1
A sphincterotome with a cutting wire coated using parylene-based polymeric coatings, such as poly-p-xylylene, providing a thin, durable, and electroinsulative layer
Implementation Method 2
A sphincterotome with a cutting wire coated using parylene-based polymeric coatings, such as poly-p-xylylene, providing a thin, durable, and electroinsulative layer
Data Source
Figure 1
Figure 2~2A
Figure 3A~3C
AI summary
A sphincterotome having a portion of its drive wire coated with a material selected from poly-p-xylylene, 2-chloro-p-xylylene, 2, 4-dichloro-p-xylylene, poly(tetraflouro-p-xylylene), poly(carboxyl-p-xylylene-co-p-xylylene), fluorinated parylene, parylene HT, and any combination thereof. The coating preferably provides an electro insulated coating on a portion of the drive wire exposed outside the sphincter tome shaft such that a non-electro insulated portion of the exposed drive wire may be targeted more specifically to tissue desired to be cut.