Flexible Shaft Stabilization for Multi-Planar Bending in Surgical Staplers
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Solution Overview
Problem
Endoscopic surgical stapling devices face challenges in maneuverability, particularly when accessing confined surgical sites, as the flexible beam can only bend in a single plane, limiting access to tissue during procedures.
Innovation Solution
A surgical stapling device with a flexible elongate body comprising an outer tube, a middle tube, and an inner cable, where the middle tube is movable within the outer tube along the inner cable to advance the clamp member between retracted and advanced positions, enhancing maneuverability and preventing buckling through stabilization by the inner and outer tubes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible beam is used in the drive assembly, then the device can bend in a single plane, but maneuverability to access confined surgical sites is limited
Solution Approach 1:
The flexible beam is divided into multiple segments (outer tube, middle tube, inner cable) that can move independently relative to each other. This segmentation allows each component to contribute to the overall flexibility while maintaining structural integrity, enabling access to confined surgical sites without excessive complexity in any single component.
Solution Approach 2:
The patent implements a nested structure where the inner cable is positioned within the middle tube, which is in turn positioned within the outer tube. This nested arrangement allows multiple elements to occupy the same spatial envelope, enabling complex maneuvers through coordinated movement of nested components while maintaining a relatively compact overall device structure.
2Adaptability or versatility
If the middle tube is made flexible to enable multi-planar bending, then access to tissue is improved, but the tube may buckle during actuation
Solution Approach 1:
Different portions of the drive assembly have different structural properties. The outer tube provides external structural support and maintains shape, while the inner cable provides internal tension support. The middle tube, positioned between these two elements, can flex without buckling because it is locally supported by both the outer tube (preventing external collapse) and the inner cable (preventing internal buckling).
Solution Approach 2:
The inner cable acts as a counterbalancing element that prevents the middle tube from buckling during actuation. As the middle tube flexes to enable multi-planar bending, the tensioned inner cable provides an opposing force that counteracts the buckling tendency, allowing the flexible tube to maintain structural stability during operation.
3Ease of operation
If a single-plane bending beam is used, then structural simplicity is maintained, but access to confined surgical sites is restricted
Solution Approach 1:
The drive assembly transitions from a static, rigid structure to a dynamic system where the middle tube can flex in multiple planes relative to the outer tube and inner cable. This dynamic capability allows the device to adapt its shape during insertion and positioning, enabling access to confined surgical sites while the control mechanisms remain relatively simple through the use of cables and tubes.
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 device improves access to tissue at surgical sites by allowing multi-planar bending, enhancing the ability to engage and staple tissue effectively, thereby improving the efficacy of endoscopic surgical procedures.
Implementation Method 1
The inner cable and the outer tube stabilize and prevent buckling of the middle tube during actuation of the stapling device
Data Source
AI summary
A surgical stapling device includes a housing assembly that is coupled to a tool assembly by a flexible elongate body that having an outer tube, a middle tube, and an inner cable. Each of the outer tube and the inner cable has a proximal end portion fixedly connected to the housing assembly and a distal end portion that is fixedly connected to the tool assembly. The middle tube is positioned within the outer tube about the inner cable and is movable from a retracted position to an advanced position to operate the tool assembly.