Surgical Needle Selective Flexural Rigidity
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Solution Overview
Problem
Existing surgical instruments face challenges in reliably passing and retrieving sutures through soft tissues due to non-linear pathways, requiring needles that are both flexible and rigid, and often necessitate complex mechanisms that add complexity to the design and procedural steps.
Innovation Solution
The development of a surgical apparatus with a needle featuring a selectively bendable portion that can change its cross-sectional shape to control flexural rigidity, allowing it to bend and maintain rigidity along non-linear pathways, and a suture passer with user-controlled activation to facilitate suture manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the needle is made rigid to pass through tissue, then tissue penetration reliability is improved, but the needle cannot navigate non-linear pathways
Solution Approach 1:
The needle incorporates a selectively bendable portion that can transition between rigid and flexible states. When straight, the needle is rigid for reliable tissue penetration. When the intermediate portion is bent, the needle can navigate non-linear pathways through the cannula. This dynamic flexibility allows the needle to adapt its shape based on operational requirements.
Solution Approach 2:
The needle has different structural properties at different locations. The proximal and distal portions maintain rigidity for effective tissue engagement, while the intermediate portion is designed to be selectively bendable. This local differentiation allows the needle to simultaneously achieve rigid tissue penetration at the tips while allowing flexible navigation through the intermediate section.
2Adaptability or versatility
If the needle is made flexible to navigate non-linear pathways, then pathway adaptability is improved, but tissue penetration reliability deteriorates
Solution Approach 1:
The needle maintains its rigidity when straight for reliable tissue penetration, and only becomes flexible when the intermediate portion is intentionally bent to navigate non-linear pathways. This dynamic state change ensures that flexibility is introduced only when needed for pathway navigation, not during tissue penetration.
Solution Approach 2:
The intermediate portion of the needle is specifically designed to be selectively bendable, while the proximal and distal portions remain rigid. This localized flexibility allows the needle to bend only in the intermediate section to navigate pathways, while the tip sections maintain sufficient rigidity for reliable tissue engagement.
3Reliability
If complex mechanisms are added to the instrument for suture retrieval, then suture retrieval capability is improved, but device complexity increases
Solution Approach 1:
The needle itself performs the suture retrieval function by actively grasping the suture through its implant interface. The needle does not require separate retrieval mechanisms or secondary features on the instrument - it serves both the function of passing suture through tissue and retrieving it by pulling back on the suture with its implant interface.
Solution Approach 2:
The functions of suture passing and suture retrieval are merged into a single needle component. The implant interface on the needle serves dual purposes: it captures the suture during the passing operation and then actively grasps and retrieves the suture during the retrieval operation, eliminating the need for separate mechanisms.
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 solution enables consistent and efficient passage and retrieval of sutures through tissues with reduced procedural complexity, improving the reliability and ease of use in surgical procedures.
Implementation Method 1
the cross-sectional shape is non-rectangular and non-circular, wherein the intermediate portion comprises a selectively bendable portion at which the intermediate portion is designed to bend, wherein the flexural rigidity of the selectively bendable portion can be controlled through variation of the cross-sectional shape
Data Source
Figure 1~2A
Figure 2B~2D
Figure 3A~3C
AI summary
An implant manipulator 400 may have a distal end 312 that retains an implant 710, a proximal end 310, and an intermediate portion 414 between the ends 310, 312. The intermediate portion 414 may have a cross-sectional shape that extends along a nonlinear pathway 532. The intermediate portion 414 may have a selectively bendable portion 430 in which the cross-sectional shape varies to facilitate bending when desired. The implant manipulator 400 may be a needle for a suture passer 1200, with a suture capture feature 360 at the distal end 312. The suture capture feature 360 may have first and second members 350, 352 that flex apart to permit entry of the suture 710 into a suture capture hole 730 wherein the suture 710 is retained until released. A suture passer 1200 may receive the needle in a bore 1250 shaped to change the cross-sectional shape to facilitate or restrict bending of the needle, as needed.