Needle Swaging with Offset Indentations for Suture Attachment
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Solution Overview
Problem
Conventional methods for attaching surgical needles to sutures using swaging processes face challenges such as material failure, precision requirements, and increased complexity and cost, particularly when dealing with sensitive suture materials like polypropylene, which are prone to deformation or clipping due to excessive pressure.
Innovation Solution
A swaging apparatus with a die assembly and swaging elements that converge to exert pressure and diverge to release pressure, creating offset indentations in the needle to securely attach the suture without deforming the needle excessively, allowing for a more efficient and precise attachment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional swaging processes are used to attach needles to sutures, then secure attachment is achieved, but material failure occurs due to excessive pressure on sensitive suture materials like polypropylene
Solution Approach 1:
The swaging process is divided into multiple sequential compression stages rather than a single high-pressure operation. The first compression applies a predetermined amount of pressure to initially attach the suture, and subsequent compressions apply additional pressure in steps, allowing the suture material to gradually deform without exceeding its elastic limit and causing failure.
Solution Approach 2:
The swaging apparatus employs periodic compression cycles with predetermined intervals. Between compressions, the system allows for pressure release and stabilization, creating a rhythmic process that prevents continuous excessive stress on the suture material while progressively achieving secure attachment.
2Manufacturing precision
If multiple hit swaging is used to provide good suture attachment and smooth outer surfaces, then attachment quality improves, but device complexity and cost increase
Solution Approach 1:
Multiple swaging operations that would traditionally require separate dies and multiple positioning steps are merged into a single integrated die assembly. The die includes multiple compression surfaces that can apply sequential compressions to the needle-suture assembly in one continuous operation, eliminating the need for complex repositioning mechanisms and multiple dies.
Solution Approach 2:
The swaging die assembly is designed with universal applicability to handle various needle and suture combinations. The die structure incorporates adjustable and interchangeable components that can accommodate different suture materials, needle sizes, and attachment requirements, replacing the need for specialized dies for each application.
3Device complexity
If single hit swaging is used to simplify the apparatus, then device complexity is reduced, but manufacturing precision and attachment quality deteriorate
Solution Approach 1:
The swaging die incorporates dynamic elements including resilient members and movable compression surfaces that can adapt during the swaging process. The die transitions from a static single-compression design to a dynamic multi-stage compression system where pressure is applied, released, and reapplied in controlled sequences, all within a single apparatus configuration.
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 reduces material failure and increases efficiency by distributing shear force evenly, allowing for secure attachment of sutures to needles with reduced precision requirements, enabling the use of a common swaging process for various suture and needle combinations, thus lowering production costs and improving attachment quality.
Implementation Method 1
a swage die impinges upon the outer peripheral surface of the needle receptacle (the outer surface of the cylinder), collapsing some or all of the cylinder radialy inwardly
Implementation Method 2
collapsing some or all of the cylinder radialy inwardly, such that the interior dimensions of the suture receptacle are reduced
Implementation Method 3
The reduced interior dimensions of the needle receptacle grasp the inserted suture end via mechanical interference and by surface contact (friction)
Data Source
AI summary
A method and apparatus for making armed sutures has a pair of opposed die assemblies that may be driven by actuating surfaces of a swaging machine to hold and swage a needle on a suture. The dies grip and confine the needle in the area of the suture receptacle. A pair of opposed swaging elements with offset stakes insert through passageways in the dies and impinge on the captured needle making a plurality of indentations in the needle barrel and gripping the suture in the suture receptacle. The indentations are offset and aligned generally in alternating peak-to-valley relationship, causing the suture receptacle and the contained suture to assume a serpentine configuration. The stakes and the resulting indentations can be dimensioned to result in a converging suture receptacle, which exhibits increasing shear force being exerted on the suture with increasing depth into the suture receptacle. The apparatus and method permit reliable suture-needle attachment over a larger range of tolerances, such that a single die setup can be used on a plurality of needle and suture materials. The resulting product exhibits a serpentine suture/needle attachment interface with reliable attachment and smooth outer dimensions.