Locking Mechanism for Cannulated Surgical Instruments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surgical devices lack a locking mechanism for the inner stylet, which can lead to accidental penetration of surrounding tissue by the outer cannula during surgical procedures.
Innovation Solution
A locking mechanism is introduced that includes a locking member and biasing member, allowing the inner cannula to be locked relative to the outer cannula, preventing movement between specific positions and thus preventing inadvertent tissue penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If no locking mechanism is provided for the inner stylet, then the device structure remains simple, but accidental penetration of surrounding tissue by the outer cannula can occur
Solution Approach 1:
The surgical device is divided into distinct functional segments: an outer cannula with a sharp beveled cutting edge for tissue penetration, and an inner stylet with a blunt tip for protection. The locking mechanism further segments the control function, with a separate locking member that can independently engage or disengage to control the relative movement between the inner stylet and outer cannula. This segmentation allows the device to provide safety functionality without requiring complete redesign of the entire system.
Solution Approach 2:
A locking member is introduced as an intermediary component between the inner stylet and outer cannula. This locking member includes a formed end that engages with a recess in the inner stylet, acting as a mediator to control the relative longitudinal movement between the two main components. The locking member can be engaged or disengaged to selectively allow or prevent the inner stylet from moving relative to the outer cannula, providing controlled safety without permanent complexity.
2Reliability
If the inner stylet is locked in place, then accidental penetration is prevented, but the ability to adjust the inner cannula position is restricted
Solution Approach 1:
The locking mechanism is designed to be dynamic rather than static. The locking member can be selectively engaged or disengaged based on the procedural needs. When engaged, it provides reliable locking to prevent accidental penetration. When disengaged, it allows the inner stylet to move freely relative to the outer cannula, enabling position adjustment. This dynamic capability resolves the contradiction between reliability and adaptability.
Solution Approach 2:
The system allows change in the operational parameter of the inner stylet's longitudinal position. By changing the state of the locking member (engaged or disengaged), the system transitions between two distinct operational modes: a locked mode where the inner stylet position is fixed relative to the outer cannula, and an unlocked mode where the inner stylet can be freely adjusted. This parameter change approach enables both safety and adjustability at different times in the procedure.
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 locking mechanism effectively prevents accidental penetration of surrounding tissues by ensuring the inner cannula remains locked in a position where the blunt tip extends beyond the beveled cutting edge of the outer cannula, enhancing safety during surgical procedures.
Implementation Method 1
a biasing member operatively connecting between a first end of the locking member and the proximal handle to bias the locking member towards the first position
Data Source
AI summary
In accordance with at least one aspect of this disclosure, a locking mechanism for a surgical device includes one or more relatively movable telescoping tubular portions configured for movement along a longitudinal axis between a first position and a second position, the locking mechanism being associated with at least one of the relatively moveable tubular portions and being configured to selectively control the relative longitudinal movement of the one or more tubular portions between the first position and the second position.