Malleable Needle and Shape Memory Cannula for Nerve Implantation

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Solution Overview

Problem

Current electrical stimulation systems for treating conditions like chronic pain and Parkinson's disease face challenges in accurately implanting medical leads near sensitive nerves like the occipital and trigeminal nerves, due to anatomical variations and the need for precise placement to minimize tissue trauma and ensure effective therapy delivery.

Innovation Solution

A system utilizing a malleable needle and shape memory cannula that adapts to individual anatomical structures, allowing for precise definition of an insertion path and maintaining the cannula's shape after the needle is removed, enabling accurate placement of medical devices such as leads or fluid conduits near target tissue sites.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a rigid needle is used for implantation, then the structural stability is improved, but the adaptability to anatomical variations deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidadaptability to anatomical variations
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The needle is designed with a malleable portion that allows it to change shape dynamically during implantation. The proximal portion remains rigid for stable insertion, while the distal portion can be bent to accommodate anatomical variations, resolving the contradiction between structural stability and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The needle is divided into distinct segments: a rigid proximal portion for structural stability and insertion, and a malleable distal portion for adaptation to anatomical variations. This segmentation allows each part to fulfill its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the needle is made flexible to adapt to anatomy, then the adaptability is improved, but the manufacturing precision deteriorates

Engineering Contradiction:
Improveadaptability to anatomical structuresVSAvoidprecision of insertion path
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The needle transitions from a rigid state during manufacturing to a malleable state during use. The malleable portion can be precisely formed during manufacturing to guide the needle along a predetermined path, then softened to allow anatomical adaptation, maintaining both manufacturing precision and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The physical parameters of the needle (rigidity, flexibility) are changed through material selection and thermal processing. The needle material is chosen to have specific transition characteristics that allow it to maintain precision during insertion then adapt to anatomy when heated or manipulated.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If a straight insertion path is used, then the manufacturing precision is improved, but the adaptability to curved anatomical paths deteriorates

Engineering Contradiction:
Improveprecision of insertion pathVSAvoidability to reach target sites
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The needle is designed to transition from a straight configuration during manufacturing and initial insertion to a curved configuration when the malleable portion is bent. This allows the needle to maintain manufacturing precision for the initial path while adapting to curved anatomical paths to reach target sites.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The needle incorporates a malleable portion that can be bent into curved shapes to follow anatomical pathways. The ability to create controlled curvature in the needle allows it to navigate around anatomical structures while maintaining precise placement capability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Stability of the object's composition

If the cannula maintains a fixed shape, then the structural stability is improved, but the ability to conform to tissue paths deteriorates

Engineering Contradiction:
Improveshape stabilityVSAvoidconformity to tissue paths
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The cannula is made from shape memory material whose physical parameters change in response to temperature or other stimuli. The cannula maintains a stable first shape during insertion, then transitions to a second conforming shape when exposed to body temperature or specific conditions, resolving the contradiction between shape stability and tissue conformity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The shape memory material in the cannula undergoes a phase transition that allows it to change from a rigid, stable shape during insertion to a flexible, conforming shape when deployed. This phase transition enables the cannula to maintain structural integrity during delivery then adapt to the tissue path afterward.

Inventive Principle:
Principle #36Phase transitions

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

This approach enhances the precision and accuracy of implantation, reduces tissue trauma, and ensures effective delivery of electrical stimulation or fluid therapy by accommodating varying anatomical features, thereby improving treatment outcomes.

Implementation Method 1

The cannula comprises a shape memory material, which permits it to change from a first shape to a second shape upon withdrawal of the needle

Methodology Applied
Scientific EffectShape memory: Shape Memory Alloy

Data Source

PatentEP2142104B1Medical device implantation system
Publication Date: 2015.08.12 MEDTRONIC INC
  • EP2142104B1 patent drawingFigure 1A~1B
  • EP2142104B1 patent drawingFigure 2A~2B
  • EP2142104B1 patent drawingFigure 3

AI summary

The disclosure is directed to a method for implanting a medical device proximate to a target tissue site within an occipital region of a patient, such as proximate to an occipital nerve or a trigeminal nerve. The method comprises introducing an implant tool into a patient to define an insertion path to the target tissue site. The implant tool includes a shape memory cannula and a malleable needle at least partially disposed within an inner lumen of the cannula. The shape of the needle may be changed to accommodate different anatomical structures/features of the patient. Upon withdrawal of the needle from the cannula, the cannula may change shape, thereby changing the shape of the insertion path.