Cochlear Implant Pulse Selection Inhibition for Temporal Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cochlear implant stimulation coding strategies face limitations in achieving high temporal accuracy and fine structure information, particularly at high pulse durations, leading to a loss of temporal information and reduced frequency coding capabilities.
Innovation Solution
A multi-channel electrode array with an audio processing stage, timing and envelope detector, and pulse selection amplitude definition stage that uses a pulse selection inhibition function to selectively deliver stimulation pulses based on envelope signals and inhibition states, allowing for higher temporal accuracy and reduced pulse deselection, even at long pulse durations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high pulse durations are used in CSSS coding, then power consumption is reduced, but temporal accuracy deteriorates and maximum coded frequency decreases
Solution Approach 1:
The patent implements dynamic pulse duration adjustment where the pulse duration is varied based on the instantaneous signal envelope and temporal accuracy requirements. During periods requiring high temporal precision, shorter pulses are used, while during low-activity periods, longer pulses reduce power consumption. This dynamic adaptation resolves the contradiction between power efficiency and temporal accuracy.
Solution Approach 2:
The system changes the pulse duration parameter adaptively based on signal characteristics and coding requirements. By modulating the pulse width parameter in response to envelope levels and temporal precision needs, the system optimizes the trade-off between energy consumption and temporal coding accuracy, allowing long pulses only when temporal precision requirements are lower.
2Device complexity
If high pulse durations are used in CSSS coding, then device complexity is reduced, but temporal information loss increases
Solution Approach 1:
The patent applies preliminary envelope detection and temporal fine structure extraction before pulse generation. By pre-processing the signal to identify critical temporal events and envelope characteristics, the system can then use simpler, longer pulses that still preserve essential temporal information. This preliminary analysis reduces the need for complex high-precision timing while maintaining temporal fidelity.
Solution Approach 2:
The patent introduces an envelope signal as an intermediary that carries temporal information in a form compatible with longer pulse durations. Instead of directly encoding fine temporal structure in pulse timing, the envelope serves as a mediator that preserves temporal information while allowing more relaxed pulse timing, thus reducing device complexity and information loss simultaneously.
3Measurement precision
If frame rate is increased to improve temporal accuracy, then temporal precision improves, but power consumption increases
Solution Approach 1:
The patent employs periodic stimulation frames with variable rates adapted to signal characteristics. Instead of maintaining a constantly high frame rate, the system uses periodic updating of stimulation parameters based on envelope detection, achieving high temporal precision only when necessary. This periodic action reduces average power consumption while maintaining temporal accuracy during critical periods.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An implantable device includes a multi-channel electrode array in which each channel is associated with an electrode in the array. An audio processing stage processes an input audio signal to produce output channel signals representing associated bands of audio frequencies. A timing and envelope detector processes the output channel signals in a sequence of sampling intervals, including, for each sampling interval, determining for each output channel signal: i. a set of requested pulse timings containing a plurality of pulse timing requests, and ii. a set of corresponding envelope signals representing pulse magnitude for pulse timing requests. A pulse selection amplitude definition stage determines for each set of requested pulse timings: i. a set of output pulses at specified times selected from the set of requested pulse timings based on a pulse selection inhibition function, and ii. a stimulation amplitude associated with each output pulse. The multi-channel electrode array applies the output pulses at their associated stimulation amplitudes to surrounding tissue.