Reproducible ABI Electrode Placement via Cochlear Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current auditory brainstem implant systems face challenges in determining an optimal electrode array placement due to non-frequency-specific electrically evoked auditory brainstem responses, leading to suboptimal hearing perception compared to cochlear implants.
Innovation Solution
A surgical placement system using a cochlear implant electrode array to iteratively deliver stimulation signals and sense afferent and efferent nerve responses to determine the optimal placement location for the auditory brainstem implant electrode array, leveraging frequency-resolved measurements to improve tonotopic alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional electrical evoked auditory brainstem responses are used for electrode placement, then the placement process is simple, but the hearing perception is suboptimal due to non-frequency-specific responses
Solution Approach 1:
The cochlear implant electrode array is used for dual purposes: its traditional function of delivering stimulation signals to the cochlea, and an additional function of sensing efferent nerve signals from the brainstem. This multi-functionality allows frequency-resolved measurements without requiring separate sensing equipment, thereby improving measurement precision while limiting the increase in device complexity.
Solution Approach 2:
The cochlear implant electrode array serves as an intermediary tool that enables indirect measurement of efferent signals. By stimulating the cochlea and detecting the resulting brainstem responses through the same electrode array, the system obtains frequency-specific placement information without direct access to brainstem neural tissue.
2Manufacturing precision
If iterative stimulation and sensing process is used to determine optimal placement, then tonotopic alignment is improved, but the placement time increases
Solution Approach 1:
The iterative process uses feedback from detected efferent nerve signals to guide electrode placement optimization. Each stimulation-sensing cycle provides frequency-specific information about the current placement quality, allowing progressive refinement of electrode position to achieve optimal tonotopic alignment with the brainstem.
Solution Approach 2:
The system performs preliminary iterative optimizations using only afferent signals first, which provide initial placement guidance. This preliminary action reduces the search space for subsequent efferent signal-based optimization, thereby reducing total placement time while maintaining precision.
3Measurement precision
If multiple electrode contacts are tested for optimal placement, then placement accuracy is improved, but the number of stimulation signals required increases
Solution Approach 1:
The system tests multiple electrode contacts but uses partial action by limiting the number of stimulation signals applied to each contact. Rather than exhaustive testing with multiple signal types and intensities, the method uses a reduced set of stimulation signals that provide sufficient information for accurate placement determination, thereby reducing energy consumption while maintaining precision.
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 allows for reproducible and optimal placement of the ABI electrode array, enhancing hearing perception by aligning with natural tonotopicity and reducing adverse stimulation effects, resulting in improved hearing outcomes for patients.
Implementation Method 1
a cochlear implant with an implanted stimulation electrode can electrically stimulate auditory nerve tissue with small currents delivered by multiple electrode contacts
Implementation Method 2
The afferent nerve fibers are configured to sense action potentials in the cochlea in response to the stimulation signal
Implementation Method 3
The efferent nerve fibers are configured to sense action potentials in the auditory brainstem in response to the stimulation signal
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A surgical placement system is configured for determining an optimal placement location for an auditory brainstem implant (ABI) electrode array. A cochlear implant (CI) electrode array is inserted into a patient cochlea, and the ABI electrode array is initially placed at an initial placement location on a patient brainstem. The optimal placement location for the ABI electrode array is then determined by, for multiple electrode contacts on the ABI electrode array: i. selecting a specific electrode contact, ii. delivering a stimulation signal to the selected electrode contact, iii. sensing an efferent nerve signal from the stimulation signal using the electrode contacts of the CI electrode array, and iv. determining a maximum response location in the patient cochlea where a largest efferent nerve signal is sensed. The ABI electrode array is then repositioned to the optimal placement location.