Programmable Swaging Press Control for Needle-Suture Attachment
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Solution Overview
Problem
Existing swaging presses face limitations in setup adjustments, force and displacement control, real-time feedback, and precision in attaching surgical needles to sutures, leading to issues like needle cracking and loss of attachment, especially with advanced alloys, and are not suitable for delicate surgical procedures.
Innovation Solution
A programmable swaging press equipped with a load cell, servomotor, and microprocessor for precise control of displacement and load, along with real-time feedback, to ensure accurate and reliable attachment of surgical needles to sutures, using a control system that adjusts parameters based on pre-programmed algorithms and provides visual and audible signals for quality assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If manual or semi-automated swaging procedures are used, then device complexity is reduced, but manufacturing precision and reliability deteriorate due to inconsistent force and displacement control
Solution Approach 1:
The patent replaces traditional mechanical linkage-based press mechanisms with a programmable motor-driven system featuring servo or stepper motors. This substitution enables precise digital control of force and displacement parameters while maintaining mechanical swaging functionality, directly resolving the contradiction between precision and complexity.
Solution Approach 2:
The patent incorporates load cells and position sensors that provide real-time feedback to a microprocessor control system. This closed-loop feedback mechanism allows the system to automatically adjust and maintain precise force and displacement control during swaging operations, achieving high manufacturing precision without requiring overly complex mechanical mechanisms.
2Measurement precision
If simple mechanical linkages or pneumatic actuators are used, then device complexity is reduced, but control precision over force and displacement deteriorates
Solution Approach 1:
The patent replaces simple mechanical linkages and pneumatic actuators with motor-driven systems equipped with digital encoders and load cells. This substitution enables precise digital measurement and control of force and displacement parameters, achieving high measurement precision while the added electronic control components are manageable in complexity.
Solution Approach 2:
The patent employs load cells for force measurement and servo/stepper motors with encoders for displacement measurement, all connected to a microprocessor that processes this data in real-time. This feedback system continuously monitors and adjusts parameters to maintain precision, with the control complexity being justified by the significant improvement in measurement accuracy.
3Strength
If advanced needle alloys are used to improve needle strength, then needle strength increases, but susceptibility to cracking during swaging increases due to reduced malleability
Solution Approach 1:
The patent employs a programmable motor-driven press that can dynamically adjust the swaging force profile during operation. The system can apply force in multiple stages with varying rates, allowing the needle material to deform progressively without exceeding its elastic limit, thereby preventing cracking in strong but less malleable advanced alloys.
Solution Approach 2:
The patent implements a multi-hit swaging process where the needle is subjected to repeated, controlled impacts rather than a single large force. The programmable system can pause between hits and adjust force levels, allowing stress redistribution and preventing crack formation in high-strength needle materials.
4Strength
If multiple percussive strikes are applied during swaging to improve attachment strength, then attachment strength increases, but risk of needle cracking increases due to cumulative stress
Solution Approach 1:
The patent implements a controlled multi-hit swaging process where the programmable press applies a series of periodic impacts to the needle. The microprocessor controls the timing, force, and number of strikes, allowing cumulative attachment strength while monitoring total displacement to prevent excessive stress that would cause cracking.
Solution Approach 2:
The patent uses load cells and position sensors to provide real-time feedback during each percussive strike. The microprocessor monitors the cumulative displacement and force applied, automatically adjusting subsequent strikes to ensure the total stress remains within safe limits while achieving the desired attachment strength through multiple controlled impacts.
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 programmable swaging press enhances the reliability and efficiency of attaching surgical needles by ensuring precise control over displacement and load, reducing the risk of needle cracking and improving attachment quality, making it suitable for fine sutures used in cardiovascular surgery and other delicate procedures.
Implementation Method 1
A load cell is provided on the bottom swaging die for recording load data
Implementation Method 2
a servomotor is coupled with the top swaging die for recording location data that corresponds to the location of the top swaging die on the swaging axis
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. The compressed portion of the axial bore grasps the suture by mechanical interference and by surface friction
Implementation Method 4
the microprocessor uses the recorded location data to calculate the total displacement during the swage event
Data Source
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 conducting pull tests on armed surgical needles to determine if the armed surgical needles are acceptable or unacceptable.