Cochlear Implant Perimodiolar Flexure Positioning
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Solution Overview
Problem
Current cochlear implant designs fail to position stimulating contacts in the basal section of the cochlea adjacent to the modiolar wall, limiting their effectiveness in stimulating spiral ganglion cells due to a straight basal section that prevents close proximity to the modiolar wall.
Innovation Solution
A stimulating assembly with a pre-formed perimodiolar flexure in the basal section, which has elastic properties and a shape that positions all stimulating contacts adjacent to the modiolar wall after insertion, utilizing a superelastic shaping member and molding process to create a curled distal section and continuous arcuate bend in the proximal section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a straight basal section is used in the stimulating assembly, then the assembly is easier to insert through the cochlea opening, but the stimulating contacts cannot be positioned adjacent to the modiolar wall
Solution Approach 1:
The perimodiolar flexure is pre-formed in the basal section before insertion, storing elastic energy that automatically positions the stimulating contacts adjacent to the modiolar wall after insertion. This preliminary configuration enables the assembly to self-adjust to the correct position without requiring complex insertion maneuvers or post-insertion adjustment procedures.
Solution Approach 2:
The basal section is designed with specific elastic properties and a predetermined shape that allows it to transition from a compressed insertion state to an expanded operational state. The flexure's elastic modulus and geometric parameters are optimized to provide sufficient force for positioning while maintaining biocompatibility and avoiding damage to surrounding cochlear structures.
2Reliability
If stimulating contacts are positioned closer to the modiolar wall, then auditory signal transmission is improved, but the power requirements increase
Solution Approach 1:
The stimulating contacts are positioned in different locations along the cochlear implant array, with basal section contacts placed adjacent to the modiolar wall for optimal high-frequency stimulation. This localized positioning strategy ensures that each contact stimulates the appropriate region of the cochlea with minimal energy expenditure, matching the spatial distribution of spiral ganglion cells across different frequency regions.
3Manufacturing precision
If a perimodiolar flexure is formed in the basal section, then stimulating contacts are positioned adjacent to the modiolar wall, but the assembly complexity increases
Solution Approach 1:
The perimodiolar flexure is constructed from a flexible material with controlled elastic properties that allows the basal section to bend and conform to the modiolar wall geometry. This flexible structure achieves precise positioning without requiring complex mechanical actuation systems, motors, or electronic control mechanisms, thereby maintaining device simplicity while improving positioning accuracy.
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 design allows for closer positioning of stimulating contacts to the modiolar wall, potentially reducing power requirements and improving auditory signal transmission by targeting spiral ganglion cells more effectively.
Implementation Method 1
a perimodiolar flexure formed in the basal section having elastic properties and a shape so as to, after insertion into the cochlea, position all of the stimulating contacts disposed in the basal section adjacent to a modiolar wall of the cochlea
Implementation Method 2
forming a pre-curved superelastic shaping member so as to include a curled distal section and a continuous arcuate bend in a proximal section
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Embodiments presented herein are generally directed to a stimulating assembly of a cochlear implant that includes a perimodiolar flexure. The perimodiolar flexure is formed in a basal section of the stimulating assembly and has elastic properties and a shape so as to, after insertion into the cochlea, position the stimulating contacts disposed in the basal section of the stimulating assembly adjacent to a modiolar wall of the cochlea.