Collapsible Barbed Sutures with Flexible Flaps
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Solution Overview
Problem
Conventional barbed sutures face issues with reliability, durability, and tissue damage due to rigid barbs, which can lead to catastrophic failure and increased risk of injury or death, especially under pulsatile loads, and they often require complex manufacturing processes.
Innovation Solution
A barbed suture with a flexible thread featuring an S-shaped cross-sectional profile, channels for barb collapse, and angled slots to minimize outer diameter and prevent 'sawing' effects, allowing for axial projection without radial projection, enhancing flexibility and reducing tissue damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If barbed sutures use rigid barbs to improve anchoring strength, then reliability is improved, but tissue damage increases due to sawing effects and drag
Solution Approach 1:
The barbs are designed to be flexible rather than rigid, allowing them to dynamically adjust their configuration. When the suture is pulled through tissue, the barbs flex and collapse inward to minimize drag and prevent sawing effects. When load is applied in the anchoring direction, the barbs engage with tissue to provide secure anchoring. This dynamic behavior resolves the contradiction between needing strength and avoiding tissue damage.
Solution Approach 2:
The patent changes the physical state and mechanical properties of the barbs from rigid to flexible by controlling the extrusion process and material properties. The barbs are extruded with specific geometric parameters including angled slots that allow controlled flexibility. This parameter change enables the barbs to transition between a low-profile state during insertion and an engaged state during anchoring, simultaneously reducing tissue damage and maintaining anchoring strength.
2Reliability
If barbed sutures use complex manufacturing processes to improve barb durability, then reliability is improved, but device complexity increases
Solution Approach 1:
The manufacturing process merges the formation of multiple features into a single extrusion step. The barbs, channels, and angled slots are all formed simultaneously during the extrusion process rather than requiring separate machining or processing steps. This integration maintains barb durability through precise geometric control while significantly reducing manufacturing process complexity.
Solution Approach 2:
The patent uses extrusion parameter control to achieve complex barb geometries with high durability. By carefully controlling extrusion parameters such as die geometry, material flow, and cooling rates, the process produces barbs with precise angles, smooth surfaces, and integrated channels. This parameter-based approach creates durable barbs through a relatively simple one-step extrusion process rather than complex multi-step manufacturing.
3Reliability
If barbed sutures have barbs that project radially to improve anchoring, then anchoring strength is improved, but outer diameter increases causing increased drag
Solution Approach 1:
The barbs are designed with flexibility to dynamically change their projection state. During suture passage through tissue, the barbs collapse inward toward the core, minimizing the outer diameter and reducing drag. When anchoring load is applied, the barbs flex outward to engage with tissue structures. This dynamic transformation allows the suture to have small diameter during insertion while providing strong anchoring when needed.
Solution Approach 2:
The patent incorporates channels within the suture structure that provide three-dimensional space for barb movement. The barbs can collapse into these internal channels, effectively using the third dimension (radial collapse into channels) to reduce the outer diameter. This dimensional approach allows barbs to occupy space during anchoring while retracting into the suture core during passage, resolving the diameter-strength contradiction.
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~4C
AI summary
A barbed suture (120) includes a flexible thread (122) having a core with a leading end (136), a trailing end (138), and a central axis (124). -The barbed suture (120) includes a first flexible flap (130) connected to the core, the first flap extending between the leading and trailing ends of the core, and a second flexible flap (134) connected to the core, the second flap (134) extending between the leading and trailing ends (136,138) of the core. The flexible flaps (130,134) and the core have an S-shaped profile when viewed in cross- section. The barbed suture (120) includes first and second slots (140,150) formed in the respective first and second flaps (130,134) for dividing the flaps (130,134) into first and second barbs (146,156) projecting from the core, whereby each slot (140,150) extends outwardly from the core and rearwardly toward the trailing end (138) of the core.