Adjustable Stylet Handle for Spinal Cord Stimulation Leads

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Solution Overview

Problem

Current stylet handle manufacturing techniques make it difficult to adjust the length of stylet wires due to manufacturing variability, leading to custom cutting requirements and potential damage during spinal cord stimulation procedures.

Innovation Solution

A stylet handle with a locking insert that includes a channel system allowing the stylet wire to be adjusted by bending excess wire and locking it in place, ensuring the correct length for the therapy delivery element, thereby facilitating easier insertion and reducing the risk of kinking or bending.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional overmolding or snap-fit techniques are used to attach the stylet handle, then the manufacturing process is simple, but the stylet wire length cannot be adjusted for manufacturing tolerances

Engineering Contradiction:
Improvestylet wire length adjustmentVSAvoidhandle structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The handle is divided into two separate halves that can be assembled around the stylet wire. This segmentation allows the stylet wire to be inserted first, then the handle halves are snapped together to secure it, enabling length adjustment while maintaining a relatively simple manufacturing process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The handle transitions from a fixed-structure design to a dynamic assembly where the two halves can be separated and reassembled. This allows the stylet wire length to be adjusted by removing the handle, cutting or extending the wire, and reattaching the handle halves.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the stylet wire length is fixed during manufacturing, then the manufacturing process is efficient, but custom cutting is required to accommodate tolerance variations

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidstylet wire length precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The stylet wire is inserted into the handle assembly before the handle halves are permanently joined. This preliminary positioning allows for length adjustments to be made before final assembly, accommodating tolerance variations without requiring post-assembly custom cutting.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The stylet wire length parameter can be varied to accommodate different lead lengths and tolerance requirements. The adjustable handle design enables the wire length to be modified within a range, providing flexibility to meet different manufacturing specifications without compromising productivity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the stylet wire distal end is rounded to prevent lead damage, then the lead is protected during insertion, but the stylet wire must be cut at the proximal end for length adjustment

Engineering Contradiction:
Improvelead protection during insertionVSAvoidstylet wire length adjustment
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The handle acts as an intermediary structure that secures the stylet wire at the proximal end. This allows the distal end to maintain its rounded protective shape while the proximal end is secured in the handle, enabling length adjustment without compromising lead protection during insertion.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2564893B1Adjustable wire length stylet handle
Publication Date: 2018.08.08 NUVECTRA CORP
  • EP2564893B1 patent drawingFigure 1
  • EP2564893B1 patent drawingFigure 2
  • EP2564893B1 patent drawingFigure 3

AI summary

A stylet-lead assembly including a therapy delivery element and a stylet. The therapy delivery element includes a proximal end with a plurality of electrical contacts adapted to electrically couple with an implantable pulse generator, a distal end with a plurality of electrodes electrically coupled to the electrical contacts, and a lumen having a lumen length extending from the proximal end to almost the distal end. The stylet handle includes a locking insert has a first channel adapted to receive the proximal end of the stylet wire. The portion of the stylet wire extending beyond a proximal end of the locking insert includes at least one bend. A stylet handle has an opening at a distal end adapted to compressively engage the proximal end of the stylet wire to the locking insert, such that an exposed portion of the stylet wire measured from the distal end of the stylet wire to a distal end of the locking insert generally comprises the lumen length.