Distributed Hearing Implant RF Link for MRI Compatibility
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Solution Overview
Problem
Conventional cochlear implants face issues with MRI compatibility due to external coils and magnets, which can cause discomfort, damage, and artifacts during scans, and have inefficiencies in power transfer due to large coil sizes and skin flap thickness variations.
Innovation Solution
A distributed implantable hearing system with a trans-tympanic membrane RF link, where an implantable coil is positioned in the middle ear cavity and a sound processing unit is in the ear canal, eliminating the need for external coils and magnets, and utilizing a robust housing design within the mastoid to protect components from external stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external coils and magnets are used in conventional cochlear implants, then power transfer is achieved, but MRI compatibility deteriorates causing discomfort, damage, and artifacts during scans
Solution Approach 1:
The patent removes external coils and magnets from the cochlear implant system, extracting the problematic components that cause MRI incompatibility. The implantable coil is positioned entirely within the skull, eliminating the need for external magnetic components that interfere with MRI scanning.
Solution Approach 2:
The implantable coil is nested within the skull structure, specifically positioned in the middle ear cavity through a trans-tympanic approach. This nesting eliminates exposure to external magnetic fields during MRI, as the coil is completely enclosed within the bone structure.
2Power
If large coil sizes are used for power transfer, then sufficient power delivery is achieved, but device size increases and skin flap thickness variations cause inefficiencies
Solution Approach 1:
The patent places the coil locally within the middle ear cavity, utilizing the thin bone structure of the tympanic membrane area. This localized positioning allows for a small coil size while maintaining effective power transfer, as the coil is positioned close to the optimal coupling point without requiring large dimensions.
Solution Approach 2:
The patent changes the positioning parameter of the coil from external or mastoid location to trans-tympanic position within the middle ear cavity. This parameter change optimizes the distance and coupling efficiency for power transfer, achieving high efficiency with a smaller coil size independent of skin flap thickness variations.
3Reliability
If implantable components are positioned deep within the skull, then MRI compatibility improves, but access for implantation and maintenance becomes more difficult
Solution Approach 1:
The patent uses the tympanic membrane and middle ear cavity as an intermediary access route to reach the implantable coil position. This natural anatomical pathway serves as a mediator that allows minimally invasive access to the deep skull location, avoiding the need for large mastoid openings or complex surgical procedures.
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
Improves MRI compatibility, reduces device size, increases efficiency in power transfer, and ensures consistent performance across different skin flap thicknesses, leading to enhanced reliability and comfort for users.
Implementation Method 1
an implantable coil configured to form a radio-frequency link with an external coil
Data Source
AI summary
Presented herein are distributed implantable hearing systems that have at least a main implant module that is physically separated from a distally positioned inner radio-frequency (RF) coil. Embodiments presented herein may include a main implant module positioned within a recipient's mastoid and an implantable coil positioned within a recipient's middle ear cavity