Variable Flexibility Stent Delivery Guiding Body
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Solution Overview
Problem
Current stent delivery devices are inefficient in rapidly transporting and indwelling stents during procedures like endoscopic ultrasound-guided transduodenal biliary drainage, requiring complex procedures and often damaging body lumens due to the need for multiple tools and sharp tips.
Innovation Solution
A stent delivery device with a guiding elongated body featuring a variable tip area that can change flexibility between a first state with high flexibility and a second state with increased stiffness, allowing for rapid stent transportation and indwelling by adjusting the tip's exposure length and shape to suit the procedure and patient conditions, and incorporating a puncturing portion with an electrode for cauterizing without a sharp needle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a catheter with high modulus material on the distal side is used to improve piercing ability, then pushability and piercing ability are improved, but flexibility deteriorates and risk of damaging body lumen increases
Solution Approach 1:
The catheter is divided into multiple sections with different material properties: a distal tip section with high modulus material for piercing, a proximal section with low modulus material for flexibility, and an intermediate transition section. This segmentation allows each part to perform its specific function optimally without compromising the whole system.
Solution Approach 2:
Different parts of the catheter are assigned different material qualities - the distal tip uses high modulus material for strength and piercing ability, while the proximal part uses low modulus material for flexibility and ease of insertion. This local differentiation resolves the contradiction between needing strength at the tip and flexibility along the catheter body.
2Reliability
If a complex procedure with multiple tools is used to ensure safety and precision, then reliability is improved, but procedure time and complexity increase
Solution Approach 1:
The catheter integrates multiple functions into a single device: the distal tip combines piercing function with cauterization capability through an embedded electrode, and the variable flexibility design incorporates both stiff and flexible sections in one structure. This merging eliminates the need for separate guide wires and multiple manipulation steps, reducing procedure time while maintaining safety through integrated design.
Solution Approach 2:
The catheter is designed as a multi-functional universal tool that can perform piercing, navigation, and cauterization within a single device. The distal tip serves multiple purposes: mechanical piercing, structural support during insertion, and electrical cauterization, making the catheter a universal instrument that replaces multiple specialized tools.
3Strength
If a sharp needle tip is used to improve piercing ability, then pushability is improved, but risk of damaging body lumen increases
Solution Approach 1:
The catheter converts the potential harm of a sharp needle tip into a beneficial cauterization function. The distal tip is designed with an electrode that provides cauterization capability, allowing the tip to pierce tissue with controlled thermal energy rather than purely mechanical force, reducing trauma while maintaining piercing effectiveness.
Solution Approach 2:
The catheter replaces purely mechanical piercing with a combination of mechanical and thermal methods. Instead of relying solely on a sharp mechanical needle tip, the design incorporates an electrode that uses electrical current to generate heat for cauterization, substituting part of the mechanical action with a thermal field approach that reduces tissue damage.
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 rapid and precise stent delivery with reduced risk of damaging body lumens, omitting the need for guide wires and simplifying procedures by using a single tool with adjustable flexibility and a cauterizing electrode, thereby shortening procedure time and improving operational safety.
Implementation Method 1
incorporating a puncturing portion with an electrode for cauterizing without a sharp needle
Data Source
Figure 1
Figure 2~3
Figure 4(a)~4(B)
AI summary
Provided is a stent delivery device capable of rapidly transporting a stent to an indwelling site. A stent delivery device includes: a catheter which includes an inner sheath and an outer sheath allowing the inner sheath to be slidably inserted therethrough; a stent which is provided between the inner sheath and the outer sheath in the vicinity of a distal end of the catheter; and a guiding elongated body which is inserted through an inner lumen of the inner sheath and is partially exposed from the distal end of the catheter so as to guide the insertion of the catheter, in which the guiding elongated body has a variable tip area provided in the vicinity of a distal end of the guiding elongated body so as to change flexibility between a first state in which the variable tip area has predetermined flexibility and a second state in which the variable tip area is hardly bent as compared with the first state.