Stimulation Needle Stylet Twist Engagement Mechanism
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Solution Overview
Problem
Previous sacral nerve stimulation needles face challenges in maintaining optimal stimulation position during stylet removal and have a reduced working length due to the need for external attachment of a stimulator device, which can cause cannula movement and expose uninsulated portions.
Innovation Solution
A stimulation needle apparatus with a stylet assembly that engages with a cannula assembly using a twist engagement mechanism, allowing for rotational disengagement to prevent cannula movement and integrating a stylet connection for efficient stimulation delivery without exposing additional uninsulated portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the stylet is removed by gripping the cannula and pulling the stylet hub in opposing directions, then the stylet can be removed from the cannula, but the cannula may move with respect to the patient, potentially losing the optimal stimulation position
Solution Approach 1:
The stylet and cannula are divided into separate components with distinct engagement features. The stylet hub includes a hub lumen that receives the cannula hub, creating a segmented but connected system that allows controlled separation without compromising overall stability during the removal process
Solution Approach 2:
The cannula hub acts as an intermediary element between the stylet hub and the cannula body. This intermediate connection point allows the stylet to be removed while the cannula remains stabilized, as the hub interface controls the separation mechanics and prevents unintended cannula movement
2Adaptability or versatility
If the stimulator device is clipped to the proximal end of the cannula for trial stimulations, then trial stimulations can be performed, but the overall working length of the needle is decreased because the first uninsulated portion must be exposed
Solution Approach 1:
The stimulator device attachment functionality is merged with the stylet hub structure. The hub lumen and engagement features are integrated into the same component that houses the electrical connection, combining the mechanical attachment and electrical stimulation functions in a single integrated assembly that does not require additional uninsulated portions
Data Source
Figure 1~3
Figure 4A~5B
Figure 6~7B
AI summary
In various examples, a stimulation needle apparatus is used for selectively administering a trial stimulation to body tissue of a patient. The stimulation needle apparatus includes a cannula assembly including a cannula and a cannula hub disposed at a proximal cannula end. A stylet assembly includes a stylet sized and shaped to fit within a cannula lumen. A stylet hub is disposed at the proximal stylet end and is configured to engage with the cannula hub. With the stylet hub engaged with the cannula hub, the distal stylet end extends distally from the distal cannula end. A stylet connection is electrically coupled with the stylet and is configured to electrically couple with a stimulator device, such that, a stimulation pulse delivered by the stimulator device is conducted from the stylet connection through the stylet to the distal stylet end to administer the trial stimulation.