Needle Swaging Press With On-Press Pull Strength Testing
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Solution Overview
Problem
Current swaging systems for attaching surgical needles to sutures are inefficient and unreliable, often leading to material failure and inconsistent attachment strength, especially with harder alloys, and lack a reliable method for testing the pull-out force of the needle-suture attachment.
Innovation Solution
A combined needle swaging and testing system that includes a swaging press with a die for both swaging and pull testing, utilizing a hinge mechanism with a load cell and microprocessor for real-time feedback to ensure proper force and duration during testing, providing visual and audible cues to the operator to prevent overstressing or prolonged force application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If manual or semi-automated swaging procedures are used to attach sutures to needles, then flexibility in handling different suture materials is maintained, but attachment strength consistency and productivity are poor
Solution Approach 1:
The patent combines multiple swaging operations into a single automated swaging head assembly that performs sequential compressions on the needle-suture interface. The automated system integrates positioning, swaging, and testing functions into one unified apparatus, eliminating manual intervention while maintaining adaptability through programmable control sequences that can accommodate different suture and needle combinations.
Solution Approach 2:
The automated swaging system allows dynamic adjustment of swaging parameters including compression force, duration, and number of compression cycles based on the specific suture material properties. The system modifies these parameters automatically to optimize attachment strength for different suture types while maintaining consistent results through precise control.
2Reliability
If multiple indentation swaging is performed to create pressure points on the needle wall, then suture retention is improved, but the risk of suture fracturing due to sheer stress increases
Solution Approach 1:
The automated swaging system performs multiple periodic compression cycles on the needle-suture interface rather than a single continuous compression. Each cycle applies controlled force followed by a brief pause, allowing the materials to settle and distribute stresses evenly. This periodic action creates multiple pressure points that enhance retention while preventing excessive sheer stress that could cause suture fracturing.
Solution Approach 2:
The swaging system dynamically adjusts compression force and timing during the swaging process based on real-time feedback from load cells and sensors. The system monitors the forces applied and automatically modulates the compression profile to optimize retention while preventing harmful stress concentrations that could lead to suture failure.
3Strength
If aligned depressions are created on opposing sides of the needle to grasp the suture, then attachment strength is improved, but the complexity of the swaging apparatus increases
Solution Approach 1:
The automated swaging head assembly is designed as a universal multi-functional device that can create various swaging patterns including aligned depressions, offset indentations, and distributed pressure points by repositioning its swaging elements. This single apparatus performs multiple swaging functions that would otherwise require separate dedicated devices, reducing overall system complexity while maintaining the capability to create high-strength attachments.
Solution Approach 2:
The swaging apparatus divides the needle-suture attachment process into discrete segmented operations performed by independently controllable swaging elements. Each element can be positioned and actuated separately to create the required depression pattern, allowing complex attachment geometries to be achieved through coordinated simple actions rather than requiring a monolithic complex mechanism.
4Measurement precision
If the suture is pulled during testing to assess attachment strength, then pull-out force measurement is achieved, but operator fatigue increases due to manual handling
Solution Approach 1:
The testing apparatus automatically performs the pull-out force measurement without requiring manual operator intervention. The system self-actuates the suture pulling mechanism, automatically records the force data from load cells, and displays the results. This automation eliminates the physical effort and repetitive manual handling that cause operator fatigue while maintaining precise measurement capabilities.
Solution Approach 2:
The patent replaces manual mechanical pulling and measurement operations with an automated electromechanical testing system. Load cells and force sensors automatically measure the pull-out force, while motors and actuators replace manual suture pulling. This substitution of manual mechanical operations with automated sensing and actuation systems eliminates operator fatigue while preserving accurate measurement capabilities.
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
This system enhances the efficiency and reliability of swaging and testing, minimizing material failure and ensuring consistent attachment strength by providing precise control over the swaging and testing processes, reducing operator fatigue, and optimizing output.
Implementation Method 1
A load cell is disposed between the top and bottom plates for measuring a force applied during pull testing of the attached needle and suture
Implementation Method 2
The bottom swaging die includes a hinge mechanism with a bottom plate secured to the frame and a top plate overlying the bottom plate
Implementation Method 3
a swage die impinges upon the outer surface of the needle barrel, thereby compressing a portion of the bore onto the suture
Implementation Method 4
The compressed portion of the axial bore grasps the suture by mechanical interference and by surface friction
Implementation Method 5
The compressed portion of the axial bore grasps the suture by mechanical interference and by surface friction
Data Source
Figure 1~2
Figure 3~4
Figure 5A
AI summary
A swaging system for attaching surgical needles to sutures and testing the attachment strength includes a frame, a bottom swaging die mounted on the frame, and a top swaging die mounted on the frame and being moveable up and down along a swaging axis that is aligned with the bottom swaging die. The bottom swaging die includes a hinge mechanism with a bottom plate mounted to the frame and a top plate overlying the bottom plate. The top and bottom plates are pivotally connected for enabling the top plate to pivot relative to the bottom plate. The bottom swaging die includes a swaging tool that extends toward the top swaging die along the swaging axis, and a load cell disposed between the top and bottom plates for monitoring load. The system includes a control system having one or more pull test programs stored therein for evaluating pull tests on armed surgical needles to determine if the armed surgical needles are acceptable or unacceptable.