Stylet Locking Mechanism for Endoluminal Introducer
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Solution Overview
Problem
Existing endoluminal introducer devices face issues with the stylet moving longitudinally during transportation and manipulation, causing filters or other implants to be prematurely released from the introducer, rendering the device unusable.
Innovation Solution
Incorporating a locking device that requires the unlocking of a lock actuator to allow the stylet to move, preventing movement even against the biasing spring, ensuring the stylet remains locked in position until intentionally released, which includes a lock actuator co-operable with a receiver element on the stylet or catheter, allowing for multiple locking positions to accommodate different devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring element is used to bias the stylet to a retracted position, then the filter is retained within the introducer during transportation and manipulation, but knocks or jolts can cause the stylet to move longitudinally and push the filter out, unhooking it from the stylet
Solution Approach 1:
A locking device is engaged before transportation or manipulation to preliminarily secure the stylet in a fixed position, preventing unintended movement from knocks or jolts. The locking device must be deliberately unlocked before the stylet can move, ensuring the filter remains securely retained during handling.
Solution Approach 2:
The locking device applies a counteracting force or constraint that opposes the spring element's biasing force, preventing the stylet from moving longitudinally despite the spring's pressure. This preliminary anti-action stabilizes the stylet position against the destabilizing effect of the spring during transportation.
2Ease of operation
If the stylet is freely moveable within the catheter under spring bias, then deployment and retrieval operations can be facilitated, but the introducer assembly becomes unusable when the filter comes loose during transportation
Solution Approach 1:
The system transitions from a static locked state during transportation to a dynamic unlocked state during operation. The locking device allows the stylet to be fixed when needed (transportation) and freely moveable when required (deployment/retrieval), providing conditional stability and mobility based on operational phase.
Solution Approach 2:
The locking device acts as an intermediary mechanism between the spring element and the stylet, controlling whether the spring's biasing force can move the stylet. When locked, it blocks the spring's action; when unlocked, it allows the spring to facilitate deployment and retrieval operations.
3Reliability
If a locking device is added to prevent stylet movement, then the filter remains securely attached during transportation, but the device complexity increases
Solution Approach 1:
The locking device is nested within the existing catheter and stylet structure, integrating the locking functionality into the existing components rather than adding entirely separate external mechanisms. This minimizes the increase in overall device complexity while achieving the reliability improvement.
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 prevents unintended movement of the stylet during transportation and manipulation, ensuring the filter or implant remains securely attached to the introducer, enhancing the reliability and usability of the device.
Implementation Method 1
a biasing element for biasing the stylet to a retracted position within the catheter
Implementation Method 2
a locking device for locking the stylet relative to the catheter, wherein operation of the actuator requires unlocking of the locking device
Data Source
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AI summary
An introducer for use in the implantation and retrieval of a device in a patient includes a catheter (43) within which a stylet (14) is slidably carried, the stylet (14) being biased to a retracted position by a spring (35) and deployable by depression of an actuator (50). A locking device (40) locks the stylet (14) relative to the catheter (43) such that the locking device (40) must be disengaged prior to operation of the actuator (50). In the preferred embodiment, both the locking device (40) and the actuator (50) must be actuated by movement thereof in a direction substantially perpendicular to the direction of motion of the stylet (14). In an alternative embodiment, it is the catheter (43) which moves relative to the stylet (14).