Suture Passing Hook With Flexible Cable Actuation for Curved Tissue Access
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Solution Overview
Problem
Existing endoscopic and arthroscopic suturing instruments face challenges in passing and retrieving suture through tissue due to complex needle bends, which cause frustration in actuation and potential buckling of wires, especially when angular offsets are required.
Innovation Solution
A surgical instrument with a flexible construct, such as a flexible cable or rope, is used to deploy and retract a capturing member along a complex needle curve, allowing for adjustable bends and improved maneuverability through a malleable shaft, coupled with a handle mechanism to apply tension for deployment and retraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a complex needle bend with angular offset is used to target tissue locations in endoscopic procedures, then access to target tissue is improved, but hook actuation becomes frustrated and wire buckling occurs
Solution Approach 1:
The needle is divided into multiple segments that can independently articulate, allowing the distal tip to reach angular offsets while keeping the proximal shaft relatively straight for easy actuation. The proximal third of the needle can be articulated to position the distal tip at desired angular offsets while maintaining a relatively straight configuration that facilitates hook actuation.
Solution Approach 2:
The needle transitions from a fixed configuration to a dynamic, adjustable structure where the proximal third can be articulated by the user to create the needed angular offset. This dynamic adjustment allows the needle to adapt to different tissue locations while maintaining ease of operation through simple articulation movements.
2Ease of operation
If a rigid push mechanism is used to actuate the hook along the needle, then hook deployment is achieved, but the mechanism cannot easily translate along complex needle curves and higher loads cause buckling
Solution Approach 1:
A flexible cable is used instead of a rigid push mechanism to transmit actuation forces along the complex needle curve. The flexible cable can easily navigate the curved geometry of the needle without causing buckling, while still effectively deploying and retracting the hook through tension application.
Solution Approach 2:
The flexible cable serves as an intermediary between the user's actuation input and the hook mechanism. It translates the user's proximal movements into effective hook deployment while accommodating the complex geometry of the needle without direct mechanical contact that would cause buckling.
3Adaptability or versatility
If the needle shaft is made malleable to allow adjustable bends, then maneuverability through tissue is improved, but structural stability is reduced
Solution Approach 1:
The needle shaft is segmented into a proximal third that is malleable and adjustable, while the distal portion maintains structural stability for reliable tissue penetration and hook actuation. This segmentation allows the proximal portion to be manipulated for positioning while the distal portion provides stable functionality.
Solution Approach 2:
Different portions of the needle shaft have different mechanical properties: the proximal third is designed to be malleable and adjustable for maneuverability, while the distal portion maintains higher structural stability for reliable operation. This local differentiation of mechanical properties resolves the contradiction between overall flexibility and structural stability.
Data Source
AI summary
A suture passing instrument for manipulating and passing suture through a tissue is disclosed. 5 The instrument includes a handle, an elongate shaft extending from the handle, a hook movably disposed within the elongate shaft. The elongate shaft includes a distal portion having an open end. The hook is movable from a retracted configuration in which at least a portion the hook is situated within the elongate shaft, and a deployed configuration in which the hook extends distally from the open end. The hook is operatively coupled to an actuator of the handle via a 10 coupling member and the hook is moved from the retracted configuration to the deployed configuration be applying tension to the coupling member.