A novel cochlear implant coding strategy based on the neural excitability has been developed and implemented using Matlab/Simulink. Unlike present day coding strategies, the Excitability Controlled Coding (ECC) strate...A novel cochlear implant coding strategy based on the neural excitability has been developed and implemented using Matlab/Simulink. Unlike present day coding strategies, the Excitability Controlled Coding (ECC) strategy uses a model of the excitability state of the target neural population to determine its stimulus selection, with the aim of more efficient stimulation as well as reduced channel interaction. Central to the ECC algorithm is an excitability state model, which takes into account the supposed refractory behaviour of the stimulated neural populations. The excitability state, used to weight the input signal for selecting the stimuli, is estimated and updated after the presentation of each stimulus, and used iteratively in selecting the next stimulus. Additionally, ECC regulates the frequency of stimulation on a given channel as a function of the corresponding input stimulus intensity. Details of the model, implementation and results of benchtop plus subjective tests are presented and discussed. Compared to the Advanced Combination Encoder (ACE) strategy, ECC produces a better spectral representation of an input signal, and can potentially reduce channel interactions. Pilot test results from 4 CI recipients suggest that ECC may have some advantage over ACE for complex situations such as speech in noise, possibly due to ECC’s ability to present more of the input spectral contents compared to ACE, which is restricted to a fixed number of maxima. The ECC strategy represents a neuro-physiological approach that could potentially improve the perception of more complex sound patterns with cochlear implants.展开更多
Magnetic resonance imaging(MRI)has become the gold standard for the diagnosis of many pathologies.Using MRI in patients with auditory implants can however raise concerns due to mutual interactions between the implant ...Magnetic resonance imaging(MRI)has become the gold standard for the diagnosis of many pathologies.Using MRI in patients with auditory implants can however raise concerns due to mutual interactions between the implant and imaging device,resulting in potential patient risks.Several implant manufacturers have been working towards more MRI safe devices.Older devices are however often labelled for more stringent conditions,possibly creating confusion with patients and professionals.With this myriad of different devices that are implanted in patients for lifetimes of at least 20 years,it is crucial that both patients and professionals have a clear understanding of the safety of their devices.This work aims at providing an exhaustive overview on the MRI safety of active auditory implants.The available industry standards that are followed by manufacturers are outlined and an overview of the latest scientific developments focusing on the last five years is provided.In addition,based on the analysis of the adverse events reported to the Food and Drug Administration(FDA)and in literature within the past ten years,a systematic review of the most commonly occurring issues for patients with auditory implants in the MRI environment is provided.Results indicate that despite the release of more MRI conditional active hearing implants on the market,adverse events still occur.An extensive overview is provided on the MRI safety of active auditory implants,aiming to increase the understanding of the topic for healthcare professionals and contribute to safer scanning conditions for patients.展开更多
文摘A novel cochlear implant coding strategy based on the neural excitability has been developed and implemented using Matlab/Simulink. Unlike present day coding strategies, the Excitability Controlled Coding (ECC) strategy uses a model of the excitability state of the target neural population to determine its stimulus selection, with the aim of more efficient stimulation as well as reduced channel interaction. Central to the ECC algorithm is an excitability state model, which takes into account the supposed refractory behaviour of the stimulated neural populations. The excitability state, used to weight the input signal for selecting the stimuli, is estimated and updated after the presentation of each stimulus, and used iteratively in selecting the next stimulus. Additionally, ECC regulates the frequency of stimulation on a given channel as a function of the corresponding input stimulus intensity. Details of the model, implementation and results of benchtop plus subjective tests are presented and discussed. Compared to the Advanced Combination Encoder (ACE) strategy, ECC produces a better spectral representation of an input signal, and can potentially reduce channel interactions. Pilot test results from 4 CI recipients suggest that ECC may have some advantage over ACE for complex situations such as speech in noise, possibly due to ECC’s ability to present more of the input spectral contents compared to ACE, which is restricted to a fixed number of maxima. The ECC strategy represents a neuro-physiological approach that could potentially improve the perception of more complex sound patterns with cochlear implants.
基金GF received funding from Flanders Innovation and Entrepreneurship(HBC.2018.0184)Cochlear Ltd.NV receives funding from Research Foundation Flanders(FWO 1804816N)as a senior clinical investigator.
文摘Magnetic resonance imaging(MRI)has become the gold standard for the diagnosis of many pathologies.Using MRI in patients with auditory implants can however raise concerns due to mutual interactions between the implant and imaging device,resulting in potential patient risks.Several implant manufacturers have been working towards more MRI safe devices.Older devices are however often labelled for more stringent conditions,possibly creating confusion with patients and professionals.With this myriad of different devices that are implanted in patients for lifetimes of at least 20 years,it is crucial that both patients and professionals have a clear understanding of the safety of their devices.This work aims at providing an exhaustive overview on the MRI safety of active auditory implants.The available industry standards that are followed by manufacturers are outlined and an overview of the latest scientific developments focusing on the last five years is provided.In addition,based on the analysis of the adverse events reported to the Food and Drug Administration(FDA)and in literature within the past ten years,a systematic review of the most commonly occurring issues for patients with auditory implants in the MRI environment is provided.Results indicate that despite the release of more MRI conditional active hearing implants on the market,adverse events still occur.An extensive overview is provided on the MRI safety of active auditory implants,aiming to increase the understanding of the topic for healthcare professionals and contribute to safer scanning conditions for patients.
