Conductive Thermoplastic Suture Welding for Knotless Loop Closure
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Solution Overview
Problem
Existing suture welding technologies face issues such as undesirable tissue heating, suture weakening, and the requirement of bulky, expensive ultrasonic equipment, which are not compatible with certain surgical procedures and curved or flexible instruments.
Innovation Solution
The use of electrically weldable polymer sutures and a novel apparatus that delivers and joins sutures using low-voltage electrical energy, allowing for precise control over weld parameters and enabling suture welding through curved paths without damaging adjacent tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If direct heat application is used to weld suture segments, then welding can be achieved, but undesirable heating of surrounding tissue occurs and the entire cross-section of the suture may melt causing weakness
Solution Approach 1:
The suture material incorporates a conductive core that concentrates electrical current and heat generation specifically at the interface between suture segments to be welded. This localized heating approach melts only the contact surfaces while leaving the bulk suture material intact, resolving the contradiction between achieving reliable welds and avoiding harmful heating of surrounding tissue and excessive melting of the suture cross-section.
Solution Approach 2:
The invention replaces direct thermal heating mechanisms with electrical resistance heating through a conductive core. This substitution allows precise control of heat generation at the weld interface through electrical current, enabling localized melting without the uncontrolled thermal diffusion that occurs with direct heat application methods.
2Reliability
If ultrasonic welding is used to fuse suture sections, then localized heating and suture strength preservation is achieved, but bulky expensive equipment is required and straight line access is needed
Solution Approach 1:
The invention replaces ultrasonic vibration-based heating with electrical resistance heating through a conductive core embedded in the suture. This substitution eliminates the need for bulky ultrasonic transducers and waveguides, allowing the welding apparatus to be compact and flexible enough for use with curved or flexible instruments in minimally invasive and robotic surgeries.
Solution Approach 2:
The conductive core is embedded within the suture structure itself, creating a nested configuration where the heating element is integrated into the object to be welded. This integration eliminates the need for separate external heating equipment, reducing device complexity and enabling use with flexible delivery systems.
3Reliability
If individual separate stitches are used to secure tissue edges, then each stitch can be independently secured, but each stitch requires an individual knot or loop-closing device increasing complexity and surgical time
Solution Approach 1:
The invention merges the suture ends by welding them together to form a continuous loop, eliminating the need for separate knots or loop-closing devices for each stitch. The conductive core enables reliable welding of suture segments, allowing multiple stitches to be formed as continuous loops that maintain tissue edges securely without requiring individual knot-tying operations.
Solution Approach 2:
The invention extracts and eliminates the knot-tying step from the suturing process by using welded loops instead. By removing the need for knots or separate loop-closing devices, the invention simplifies the overall suturing procedure while maintaining the security and reliability of individual stitch placement.
4Reliability
If conventional suture material is used, then biocompatibility is achieved, but the material cannot be welded using electrical energy
Solution Approach 1:
The suture material is constructed as a composite with a biocompatible outer layer and an inner conductive core. This composite structure combines the biocompatibility of medical-grade polymers with the electrical conductivity of metal or conductive polymer cores, enabling both biological safety and electrical weldability in a single integrated material system.
Solution Approach 2:
The conductive property is localized to the core of the suture material, while the outer surface maintains biocompatibility. This spatial differentiation of material properties allows the suture to exhibit both biocompatibility for tissue contact and electrical conductivity for welding operations at the interface between suture segments.
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 approach provides strong, reliable suture welds that replace knots or loop-closure devices, reducing surgical time and cost, and is compatible with minimally invasive and robotic surgeries.
Implementation Method 1
heat is generated by electrical resistance at the point of contact between said first portion and said second portion
Implementation Method 2
the melted regions of said first portion and said second portion re-solidify so that a weld is formed
Data Source
AI summary
An apparatus for forming a weld between a first portion of a biocompatible conductive thermoplastic material and a second portion of a biocompatible conductive thermoplastic material comprises a first electrode, a second electrode, and a structure for holding said first and second electrodes in opposition to one other with a space therebetween for receiving said first portion and said second portion in contact with one another. The structure is electrically non-conductive and an electrical circuit comprising a power source and a switch arranged such that closure of said switch applies a voltage potential across said first electrode and said second electrode so as to generate heat via electrical resistance, the heat being sufficient to melt regions of said first and second portions.