Localized-Bending Suture Needle for Small Trocar Access
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Solution Overview
Problem
Conventional suture needles are limited by their size, making it difficult to pass larger needles through smaller trocars used in minimally invasive surgeries, leading to longer surgical procedures and increased risk of wound dehiscence due to smaller bite sizes and cheese wire effects.
Innovation Solution
A suture needle with a bendable region is created by heat treating a martensitic alloy to harden the proximal and distal sections while softening the bendable region, allowing for a seagull or folded configuration that reduces the needle's profile, enabling it to be passed through smaller trocars while maintaining strength and stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If larger suture needles are used, then suturing effectiveness is improved, but the ability to pass through small trocars deteriorates
Solution Approach 1:
The needle is divided into distinct functional segments: a rigid proximal section for strength, a bendable intermediate section for flexibility, and a rigid distal section for piercing. This segmentation allows the needle to maintain overall strength while enabling the intermediate section to bend for passing through small trocars.
Solution Approach 2:
Different sections of the needle have different mechanical properties. The proximal and distal sections are heat-treated to maintain high strength and stiffness, while the intermediate section is left softer and more bendable. This local differentiation of material properties resolves the contradiction between needing strength for suturing and flexibility for insertion.
2Ease of operation
If smaller suture needles are used, then the ability to pass through small trocars is improved, but surgical procedure duration increases
Solution Approach 1:
The segmented structure with a bendable intermediate section allows the use of larger needle sizes (e.g., 5mm or larger) while still being able to pass through small 5mm trocars. This eliminates the need to use smaller needles that would require multiple passes and extend surgical time.
Solution Approach 2:
The heat treatment process changes the material parameters of different needle sections, creating a gradient of stiffness that enables larger needles to be inserted through small trocars in a single pass, thereby reducing surgical procedure duration.
3Ease of operation
If smaller suture needles are used, then the ability to pass through small trocars is improved, but tissue damage increases
Solution Approach 1:
The proximal and distal sections are heat-treated to maintain high strength and stiffness, ensuring that the needle maintains its structural integrity and does not cause tissue damage during insertion and suturing, while the intermediate section's bendability facilitates passage through small trocars.
Solution Approach 2:
The segmented structure allows the critical piercing and suturing portions of the needle to maintain optimal strength characteristics, preventing tissue damage from needle flexure or breakage, while the intermediate section provides the necessary flexibility for insertion.
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 solution allows for the use of larger suture needles through smaller trocars, reducing surgical time and minimizing tissue damage, while maintaining the strength and stiffness required for effective suturing.
Implementation Method 1
austenitic transition temperature of the martensitic alloy
Implementation Method 2
quenching the suture needle to room temperature to harden the martensitic alloy
Implementation Method 3
locally heating the bendable region to a second temperature that is above 800 degrees Celsius, but below the austenitic transition temperature of the martensitic alloy so that the bendable region is softened
Data Source
AI summary
A method of making a suture needle having a bendable region includes obtaining a suture needle made of a martensitic alloy having an austenitic transition temperature. The suture needle has a proximal section, a distal section with a sharpened tip, and a bendable region located between the proximal and distal sections. The method includes heating the suture needle to a first temperature that is greater than the austenitic transition temperature of the martensitic alloy and quenching the suture needle to room temperature to harden the martensitic alloy, After heating and quenching, the bendable region of the suture needle is heated locally to a second temperature that is above 800 degrees Celsius, but below the austenitic transition temperature of the martensitic alloy so that the bendable region is softened and made more flexible relative to the proximal and distal sections of the suture needle.