151
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Falcón González JC, Borkoski Barreiro S, Ramos De Miguel A, Ramos Macías A. Improvement of speech perception in noise and quiet using a customised Frequency-Allocation Programming (FAP) method. ACTA ACUST UNITED AC 2019; 39:178-185. [PMID: 31131837 PMCID: PMC6536028 DOI: 10.14639/0392-100x-2013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 09/14/2018] [Indexed: 11/23/2022]
Affiliation(s)
| | | | - A Ramos De Miguel
- Psychoacoustic and Balance Research Laboratory, Las Palmas University Hospital, Spain
| | - A Ramos Macías
- Otorhinolaryngology Department, Las Palmas University Hospital, Spain
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152
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Yang J, Liang Q, Chen H, Liu Y, Xu L. Singing Proficiency of Members of a Choir Formed by Prelingually Deafened Children With Cochlear Implants. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2019; 62:1561-1573. [PMID: 31021668 PMCID: PMC6808322 DOI: 10.1044/2019_jslhr-h-18-0385] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/21/2018] [Accepted: 01/20/2019] [Indexed: 06/09/2023]
Abstract
Purpose A group of 10 prelingually deafened children with cochlear implants (CIs) formed a choir and received 21 months of formal music training. The purpose of this study was to evaluate the singing proficiency of these children. Method The participants included all choir members (7 girls and 3 boys, mean age of 9.5 years old) who were unilateral CI users. Meanwhile, 8 age-matched children with normal hearing were recruited as controls and were trained on 1 song for 2 weeks. Individual singing samples without instrument accompaniment were recorded from all participants. The singing samples were subject to acoustic analysis in which the fundamental frequency (F0) of each note was extracted and the duration was measured. Five metrics were developed and computed to quantify the accuracy of their pitch and rhythm performance. The 5 metrics included (a) percent correct of F0 contour direction of adjacent notes, (b) mean deviation of the normalized F0 across the notes, (c) mean deviation of the pitch intervals, (d) mean deviation of adjacent note duration ratio, and (e) mean absolute deviation of note duration. Results The choir members with CIs demonstrated high accuracy in both pitch and tempo measures and performed on par with the children with normal hearing. Early start of music training after implantation and use of bimodal hearing contributed to the development of better music ability in these children with CIs. Conclusion These findings indicated that rigorous music training could facilitate high singing proficiency in prelingually deafened children with CIs.
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Affiliation(s)
- Jing Yang
- Department of Communication Sciences and Disorders, University of Wisconsin–Milwaukee
| | | | - Haotong Chen
- Department of Communication Sciences and Disorders, Ohio University, Athens
| | | | - Li Xu
- Department of Communication Sciences and Disorders, Ohio University, Athens
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153
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Ma Y, Wise AK, Shepherd RK, Richardson RT. New molecular therapies for the treatment of hearing loss. Pharmacol Ther 2019; 200:190-209. [PMID: 31075354 DOI: 10.1016/j.pharmthera.2019.05.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/02/2019] [Indexed: 12/11/2022]
Abstract
An estimated 466 million people suffer from hearing loss worldwide. Sensorineural hearing loss is characterized by degeneration of key structures of the sensory pathway in the cochlea such as the sensory hair cells, the primary auditory neurons and their synaptic connection to the hair cells - the ribbon synapse. Various strategies to protect or regenerate these sensory cells and structures are the subject of intensive research. Yet despite recent advances in our understandings of the capacity of the cochlea for repair and regeneration there are currently no pharmacological or biological interventions for hearing loss. Current research focusses on localized cochlear drug, gene and cell-based therapies. One of the more promising drug-based therapies is based on neurotrophic factors for the repair of the ribbon synapse after noise exposure, as well as preventing loss of primary auditory neurons and regrowth of the auditory neuron fibers after severe hearing loss. Drug therapy delivery technologies are being employed to address the specific needs of neurotrophin and other therapies for hearing loss that include the need for high doses, long-term delivery, localised or cell-specific targeting and techniques for their safe and efficacious delivery to the cochlea. Novel biomaterials are enabling high payloads of drugs to be administered to the cochlea with subsequent slow-release properties that are proving to be beneficial for treating hearing loss. In parallel, new gene therapy technologies are addressing the need for cell specificity and high efficacy for the treatment of both genetic and acquired hearing loss with promising reports of hearing recovery. Some biomaterials and cell therapies are being used in conjunction with the cochlear implant ensuring therapeutic benefit to the primary neurons during electrical stimulation. This review will introduce the auditory system, hearing loss and the potential for repair and regeneration in the cochlea. Drug delivery to the cochlea will then be reviewed, with a focus on new biomaterials, gene therapy technologies, cell therapy and the use of the cochlear implant as a vehicle for drug delivery. With the current pre-clinical research effort into therapies for hearing loss, including clinical trials for gene therapy, the future for the treatment for hearing loss is looking bright.
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Affiliation(s)
- Yutian Ma
- Bionics Institute, East Melbourne, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia; University of Melbourne, Department of Chemical Engineering, Parkville, Victoria, Australia
| | - Andrew K Wise
- Bionics Institute, East Melbourne, Australia; University of Melbourne, Medical Bionics Department, East Melbourne, Australia; University of Melbourne, Department of Surgery - Otolaryngology, East Melbourne, Australia
| | - Robert K Shepherd
- Bionics Institute, East Melbourne, Australia; University of Melbourne, Medical Bionics Department, East Melbourne, Australia; University of Melbourne, Department of Surgery - Otolaryngology, East Melbourne, Australia
| | - Rachael T Richardson
- Bionics Institute, East Melbourne, Australia; University of Melbourne, Medical Bionics Department, East Melbourne, Australia; University of Melbourne, Department of Surgery - Otolaryngology, East Melbourne, Australia.
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154
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Bas E, Anwar MR, Goncalves S, Dinh CT, Bracho OR, Chiossone JA, Van De Water TR. Laminin-coated electrodes improve cochlear implant function and post-insertion neuronal survival. Neuroscience 2019; 410:97-107. [PMID: 31059743 DOI: 10.1016/j.neuroscience.2019.04.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 12/20/2022]
Abstract
The benefits of Cochlear implant (CI) technology depend among other factors on the proximity of the electrode array to the spiral ganglion neurons. Laminin, a component of the extracellular matrix, regulates Schwann cell proliferation and survival as well as reorganization of actin fibers within their cytoskeleton, which is necessary for myelination of peripheral axons. In this study we explore the effectiveness of laminin-coated electrodes in promoting neuritic outgrowth from auditory neurons towards the electrode array and the ability to reduce acoustic and electric auditory brainstem response (i.e. aABR and eABR) thresholds. In vitro: Schwann cells and neurites are attracted towards laminin-coated surfaces with longer neuritic processes in laminin-coated dishes compared to uncoated dishes. In vivo: Animals implanted with laminin-coated electrodes experience significant decreases in eABR and aABR thresholds at selected frequencies compared to the results from the uncoated electrodes group. At 1 month post implantation there were a greater number of spiral ganglion neurons and neuritic processes projecting into the scala tympani of animals implanted with laminin-coated electrodes compared to animals with uncoated electrodes. These data suggest that Schwann cells are attracted towards laminin-coated electrodes and promote neuritic outgrowth/ guidance and promote the survival of spiral ganglion neurons following electrode insertion trauma.
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Affiliation(s)
- Esperanza Bas
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America.
| | - Mir R Anwar
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Stefania Goncalves
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Christine T Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Olena R Bracho
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Juan A Chiossone
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Thomas R Van De Water
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States of America
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155
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Aplin FP, Fridman GY. Implantable Direct Current Neural Modulation: Theory, Feasibility, and Efficacy. Front Neurosci 2019; 13:379. [PMID: 31057361 PMCID: PMC6482222 DOI: 10.3389/fnins.2019.00379] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/02/2019] [Indexed: 12/25/2022] Open
Abstract
Implantable neuroprostheses such as cochlear implants, deep brain stimulators, spinal cord stimulators, and retinal implants use charge-balanced alternating current (AC) pulses to recover delivered charge and thus mitigate toxicity from electrochemical reactions occurring at the metal-tissue interface. At low pulse rates, these short duration pulses have the effect of evoking spikes in neural tissue in a phase-locked fashion. When the therapeutic goal is to suppress neural activity, implants typically work indirectly by delivering excitation to populations of neurons that then inhibit the target neurons, or by delivering very high pulse rates that suffer from a number of undesirable side effects. Direct current (DC) neural modulation is an alternative methodology that can directly modulate extracellular membrane potential. This neuromodulation paradigm can excite or inhibit neurons in a graded fashion while maintaining their stochastic firing patterns. DC can also sensitize or desensitize neurons to input. When applied to a population of neurons, DC can modulate synaptic connectivity. Because DC delivered to metal electrodes inherently violates safe charge injection criteria, its use has not been explored for practical applicability of DC-based neural implants. Recently, several new technologies and strategies have been proposed that address this safety criteria and deliver ionic-based direct current (iDC). This, along with the increased understanding of the mechanisms behind the transcutaneous DC-based modulation of neural targets, has caused a resurgence of interest in the interaction between iDC and neural tissue both in the central and the peripheral nervous system. In this review we assess the feasibility of in-vivo iDC delivery as a form of neural modulation. We present the current understanding of DC/neural interaction. We explore the different design methodologies and technologies that attempt to safely deliver iDC to neural tissue and assess the scope of application for direct current modulation as a form of neuroprosthetic treatment in disease. Finally, we examine the safety implications of long duration iDC delivery. We conclude that DC-based neural implants are a promising new modulation technology that could benefit from further chronic safety assessments and a better understanding of the basic biological and biophysical mechanisms that underpin DC-mediated neural modulation.
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Affiliation(s)
- Felix P Aplin
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States
| | - Gene Y Fridman
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States.,Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States
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156
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Nogueira W, Cosatti G, Schierholz I, Egger M, Mirkovic B, Buchner A. Toward Decoding Selective Attention From Single-Trial EEG Data in Cochlear Implant Users. IEEE Trans Biomed Eng 2019; 67:38-49. [PMID: 30932825 DOI: 10.1109/tbme.2019.2907638] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Previous results showed that it is possible to decode an attended speech source from EEG data via the reconstruction of the speech envelope in normal hearing (NH) listeners. However, so far it is unknown that how the performance of such a decoder is affected by the decrease in spectral resolution and the electrical artifacts introduced by a cochlear implant (CI) in users of these prostheses. NH listeners and bilateral CI users participated in the present study. Speeches from two audio books, one uttered by a male voice and one by a female voice, were presented to NH listeners and CI users. Participants were instructed to attend to one of the two speech streams presented dichotically while a 96-channel EEG was recorded. Speech envelope reconstruction from the EEG data was obtained by training decoders using a regularized least square estimation method. Decoding accuracy was defined as the percentage of accurately reconstructed trials for each subject. For NH listeners, the experiment was repeated using a vocoder to reduce spectral resolution and simulate speech perception with a CI in NH listeners. The results showed a decoding accuracy of 80.9 % using the original sound files in NH listeners. The performance dropped to 73.2 % in the vocoder condition and to 71.5 % in the group of CI users. In sum, although the accuracy drops when the spectral resolution becomes worse, the results show the feasibility to decode the attended sound source in NH listeners with a vocoder simulation, and even in CI users, albeit more training data are needed.
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157
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Holder JT, Reynolds SM, Sunderhaus LW, Gifford RH. Current Profile of Adults Presenting for Preoperative Cochlear Implant Evaluation. Trends Hear 2019; 22:2331216518755288. [PMID: 29441835 PMCID: PMC6027468 DOI: 10.1177/2331216518755288] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Considerable advancements in cochlear implant technology (e.g., electric acoustic stimulation) and assessment materials have yielded expanded criteria. Despite this, it is unclear whether individuals with better audiometric thresholds and speech understanding are being referred for cochlear implant workup and pursuing cochlear implantation. The purpose of this study was to characterize the mean auditory and demographic profile of adults presenting for preoperative cochlear implant workup. Data were collected prospectively for all adult preoperative workups at Vanderbilt from 2013 to 2015. Subjects included 287 adults (253 postlingually deafened) with a mean age of 62.3 years. Each individual was assessed using the minimum speech test battery, spectral modulation detection, subjective questionnaires, and cognitive screening. Mean consonant-nucleus-consonant word scores, AzBio sentence scores, and pure-tone averages for postlingually deafened adults were 10%, 13%, and 89 dB HL, respectively, for the ear to be implanted. Seventy-three individuals (25.4%) met labeled indications for Hybrid-L and 207 individuals (72.1%) had aidable hearing in the better hearing ear to be used in a bimodal hearing configuration. These results suggest that mean speech understanding evaluated at cochlear implant workup remains very low despite recent advancements. Greater awareness and insurance accessibility may be needed to make cochlear implant technology available to those who qualify for electric acoustic stimulation devices as well as individuals meeting conventional cochlear implant criteria.
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Affiliation(s)
- Jourdan T Holder
- 1 Department of Hearing and Speech Science, Vanderbilt Bill Wilkerson Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Susan M Reynolds
- 1 Department of Hearing and Speech Science, Vanderbilt Bill Wilkerson Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Linsey W Sunderhaus
- 1 Department of Hearing and Speech Science, Vanderbilt Bill Wilkerson Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - René H Gifford
- 1 Department of Hearing and Speech Science, Vanderbilt Bill Wilkerson Center, Vanderbilt University Medical Center, Nashville, TN, USA.,2 Advanced Bionics, Valencia, CA, USA.,3 Cochlear Americas, Englewood, CO, USA.,4 Frequency Therapeutics, Woburn, MA, USA
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158
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Hess CL, Misurelli SM, Litovsky RY. Spatial Release From Masking in 2-Year-Olds With Normal Hearing and With Bilateral Cochlear Implants. Trends Hear 2019; 22:2331216518775567. [PMID: 29761735 PMCID: PMC5956632 DOI: 10.1177/2331216518775567] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
This study evaluated spatial release from masking (SRM) in 2- to 3-year-old children who are deaf and were implanted with bilateral cochlear implants (BiCIs), and in age-matched normal-hearing (NH) toddlers. Here, we examined whether early activation of bilateral hearing has the potential to promote SRM that is similar to age-matched NH children. Listeners were 13 NH toddlers and 13 toddlers with BiCIs, ages 27 to 36 months. Speech reception thresholds (SRTs) were measured for target speech in front (0°) and for competitors that were either Colocated in front (0°) or Separated toward the right (+90°). SRM was computed as the difference between SRTs in the front versus in the asymmetrical condition. Results show that SRTs were higher in the BiCI than NH group in all conditions. Both groups had higher SRTs in the Colocated and Separated conditions compared with Quiet, indicating masking. SRM was significant only in the NH group. In the BiCI group, the group effect of SRM was not significant, likely limited by the small sample size; however, all but two children had SRM values within the NH range. This work shows that to some extent, the ability to use spatial cues for source segregation develops by age 2 to 3 in NH children and is attainable in most of the children in the BiCI group. There is potential for the paradigm used here to be used in clinical settings to evaluate outcomes of bilateral hearing in very young children.
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159
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Ernst A, Baumgaertel RM, Diez A, Battmer RD. Evaluation of a wireless contralateral routing of signal (CROS) device with the Advanced Bionics Naída CI Q90 sound processor. Cochlear Implants Int 2019; 20:182-189. [DOI: 10.1080/14670100.2019.1586151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Arneborg Ernst
- Department of Otolaryngology, Unfallkrankenhaus Berlin, Warener Str. 7, 12683 Berlin, Germany
| | - Regina M. Baumgaertel
- Clinical Research International, Advanced Bionics GmbH, Feodor-Lynen-Str. 35, 30625 Hannover, Germany
| | - Angie Diez
- HörPunkt im Oberlinhaus GmbH, Tuchmacherstr. 49, 14482 Potsdam, Germany
| | - Rolf-Dieter Battmer
- Department of Otolaryngology, Unfallkrankenhaus Berlin, Warener Str. 7, 12683 Berlin, Germany
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160
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Amichetti NM, Atagi E, Kong YY, Wingfield A. Linguistic Context Versus Semantic Competition in Word Recognition by Younger and Older Adults With Cochlear Implants. Ear Hear 2019; 39:101-109. [PMID: 28700448 PMCID: PMC5741484 DOI: 10.1097/aud.0000000000000469] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The increasing numbers of older adults now receiving cochlear implants raises the question of how the novel signal produced by cochlear implants may interact with cognitive aging in the recognition of words heard spoken within a linguistic context. The objective of this study was to pit the facilitative effects of a constraining linguistic context against a potential age-sensitive negative effect of response competition on effectiveness of word recognition. DESIGN Younger (n = 8; mean age = 22.5 years) and older (n = 8; mean age = 67.5 years) adult implant recipients heard 20 target words as the final words in sentences that manipulated the target word's probability of occurrence within the sentence context. Data from published norms were also used to measure response entropy, calculated as the total number of different responses and the probability distribution of the responses suggested by the sentence context. Sentence-final words were presented to participants using a word-onset gating paradigm, in which a target word was presented with increasing amounts of its onset duration in 50 msec increments until the word was correctly identified. RESULTS Results showed that for both younger and older adult implant users, the amount of word-onset information needed for correct recognition of sentence-final words was inversely proportional to their likelihood of occurrence within the sentence context, with older adults gaining differential advantage from the contextual constraints offered by a sentence context. On the negative side, older adults' word recognition was differentially hampered by high response entropy, with this effect being driven primarily by the number of competing responses that might also fit the sentence context. CONCLUSIONS Consistent with previous research with normal-hearing younger and older adults, the present results showed older adult implant users' recognition of spoken words to be highly sensitive to linguistic context. This sensitivity, however, also resulted in a greater degree of interference from other words that might also be activated by the context, with negative effects on ease of word recognition. These results are consistent with an age-related inhibition deficit extending to the domain of semantic constraints on word recognition.
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Affiliation(s)
- Nicole M. Amichetti
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA
| | - Eriko Atagi
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA
- Department of Communication Sciences and Disorders, Northeastern University, Boston, MA, USA
| | - Ying-Yee Kong
- Department of Communication Sciences and Disorders, Northeastern University, Boston, MA, USA
| | - Arthur Wingfield
- Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA
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161
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Abstract
Hearing loss is present in millions of people worldwide. Current treatment for patients with severe to profound hearing loss consists of cochlear implantation. Providing the cochlear nerve is intact, patients generally benefit greatly from this intervention, frequently achieving significant improvements in speech comprehension. There are, however, some cases where current technology does not provide patients with adequate benefit. Ongoing research in cell transplantation and gene therapy promises to lead to new developments that will improve the function of cochlear implants. Translation of these experimental approaches is presently at an early stage. This review focuses on the application of biological therapies in severe hearing loss and discusses some of the barriers to translating basic scientific research into clinical reality. We emphasize the application of these novel therapies to cochlear implantation.
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Affiliation(s)
- A Roemer
- Klinik für Hals-Nasen-Ohren-Heilkunde OE 6500, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - H Staecker
- Department of Otolaryngology - Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS, USA
| | - S Sasse
- Klinik für Hals-Nasen-Ohren-Heilkunde OE 6500, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - T Lenarz
- Klinik für Hals-Nasen-Ohren-Heilkunde OE 6500, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - A Warnecke
- Klinik für Hals-Nasen-Ohren-Heilkunde OE 6500, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
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162
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Trevlakis SE, Boulogeorgos AAA, Sofotasios PC, Muhaidat S, Karagiannidis GK. Optical wireless cochlear implants. BIOMEDICAL OPTICS EXPRESS 2019; 10:707-730. [PMID: 30800510 PMCID: PMC6377899 DOI: 10.1364/boe.10.000707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/10/2018] [Accepted: 10/10/2018] [Indexed: 06/09/2023]
Abstract
In the present contribution, we introduce a wireless optical communication-based system architecture which is shown to significantly improve the reliability and the spectral and power efficiency of the transcutaneous link in cochlear implants (CIs). We refer to the proposed system as optical wireless cochlear implant (OWCI). In order to provide a quantified understanding of its design parameters, we establish a theoretical framework that takes into account the channel particularities, the integration area of the internal unit, the transceivers misalignment, and the characteristics of the optical units. To this end, we derive explicit expressions for the corresponding average signal-to-noise-ratio, outage probability, ergodic spectral efficiency and capacity of the transcutaneous optical link (TOL). These expressions are subsequently used to assess the dependence of the TOL's communication quality on the transceivers design parameters and the corresponding channels characteristics. The offered analytic results are corroborated with respective results from Monte Carlo simulations. Our findings reveal that the OWCI is a particularly promising architecture that drastically increases the reliability and effectiveness of the CI TOL, whilst it requires considerably lower transmit power when compared to the corresponding widely-used radio frequency (RF) solution.
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Affiliation(s)
- Stylianos E. Trevlakis
- Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki,
Greece
- Department of Electrical and Computer Engineering, Khalifa University of Science and Technology, UAE-127788 Abu Dhabi,
United Arab Emirates
| | - Alexandros-Apostolos A. Boulogeorgos
- Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki,
Greece
- Department of Digital Systems, University of Piraeus, GR-18534 Piraeus,
Greece
| | - Paschalis C. Sofotasios
- Department of Electrical and Computer Engineering, Khalifa University of Science and Technology, UAE-127788 Abu Dhabi,
United Arab Emirates
- Department of Electronics and Communications Engineering, Tampere University of Technology, FI-33720 Tampere,
Finland
| | - Sami Muhaidat
- Department of Electrical and Computer Engineering, Khalifa University of Science and Technology, UAE-127788 Abu Dhabi,
United Arab Emirates
| | - George K. Karagiannidis
- Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki,
Greece
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163
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Sanderson AP, Rogers ETF, Verschuur CA, Newman TA. Exploiting Routine Clinical Measures to Inform Strategies for Better Hearing Performance in Cochlear Implant Users. Front Neurosci 2019; 12:1048. [PMID: 30697145 PMCID: PMC6340939 DOI: 10.3389/fnins.2018.01048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/24/2018] [Indexed: 11/21/2022] Open
Abstract
Neuroprostheses designed to interface with the nervous system to replace injured or missing senses can significantly improve a patient's quality of life. The challenge remains to provide implants that operate optimally over several decades. Changes in the implant-tissue interface may precede performance problems. Tools to identify and characterize such changes using existing clinical measures would be highly valuable. Modern cochlear implant (CI) systems allow easy and regular measurements of electrode impedance (EI). This measure is routinely performed as a hardware integrity test, but it also allows a level of insight into the immune-mediated response to the implant, which is associated with performance outcomes. This study is a 5-year retrospective investigation of MED-EL CI users at the University of Southampton Auditory Implant Service including 176 adult ears (18-91) and 74 pediatric ears (1-17). The trend in EI in adults showed a decrease at apical electrodes. An increase was seen at the basal electrodes which are closest to the surgery site. The trend in the pediatric cohort was increasing EI over time for nearly all electrode positions, although this group showed greater variability and had a smaller sample size. We applied an outlier-labeling rule to statistically identify individuals that exhibit raised impedance. This highlighted 14 adult ears (8%) and 3 pediatric ears (5%) with impedance levels that deviated from the group distribution. The slow development of EI suggests intra-cochlear fibrosis and/or osteogenesis as the underlying mechanism. The usual clinical intervention for extreme impedance readings is to deactivate the relevant electrode. Our findings highlight some interesting clinical contradictions: some cases with raised (but not extreme) impedance had not prompted an electrode deactivation; and many cases of electrode deactivation had been informed by subjective patient reports. This emphasizes the need for improved objective evidence to inform electrode deactivations in borderline cases, for which our outlier-labeling approach is a promising candidate. A data extraction and analysis protocol that allows ongoing and automated statistical analysis of routinely collected data could benefit both the CI and wider neuroprosthetics communities. Our approach provides new tools to inform practice and to improve the function and longevity of neuroprosthetic devices.
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Affiliation(s)
- Alan P. Sanderson
- Institute of Sound and Vibration Research, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Edward T. F. Rogers
- Institute for Life Sciences and Optoelectronics Research Centre, University of Southampton, Southampton, United Kingdom
| | - Carl A. Verschuur
- Auditory Implant Service, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom
| | - Tracey A. Newman
- Clinical Neurosciences, Institute for Life Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
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164
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Chung Y, Buechel BD, Sunwoo W, Wagner JD, Delgutte B. Neural ITD Sensitivity and Temporal Coding with Cochlear Implants in an Animal Model of Early-Onset Deafness. J Assoc Res Otolaryngol 2019; 20:37-56. [PMID: 30623319 DOI: 10.1007/s10162-018-00708-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/17/2018] [Indexed: 01/04/2023] Open
Abstract
Users of cochlear implant (CI) face challenges in everyday situations such as understanding conversations in noise, even with CIs in both ears. These challenges are related to difficulties with tasks that require fine temporal processing such as discrimination of pulse rates or interaural time differences (ITD), a major cue for sound localization. The degradation in temporal processing and ITD sensitivity are especially acute in those who lost hearing in early childhood. Here, we characterized temporal coding and ITD sensitivity of single neurons in a novel animal model of early-onset deafness. Rabbits were deafened as neonates and deprived of auditory stimulation until they reached adult age when single-unit recordings from the auditory midbrain were made chronically using an unanesthetized preparation. The results are compared to measurements from adult-deafened rabbits with normal auditory development to understand the effect of early-onset deafness on neural temporal coding and ITD sensitivity. Neurons in the inferior colliculus (IC) of early-deafened rabbits were less likely to show sustained, excitatory responses to pulse train stimulation and more likely to show suppressive responses compared to neurons in adult-deaf animals. Fewer neurons showed synchronized responses to pulse trains at any rate in the early-deaf group. In addition, fewer neurons showed significant ITD sensitivity in their overall firing rate in the early-deaf group compared to adult-deaf animals. Neural ITD discrimination thresholds in the early-deaf group were poorer than thresholds in adult-deaf group, especially at high pulse rates. The overall degradation in neural ITD sensitivity is consistent with the difficulties encountered by human CI users with early-onset hearing loss. These results lay the groundwork for investigating whether the degradations in temporal coding and ITD sensitivity observed in early-deaf animals can be reversed by appropriate CI stimulation during development.
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Affiliation(s)
- Yoojin Chung
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear, Boston, MA, 02114, USA.
- Department of Otolaryngology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Brian D Buechel
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear, Boston, MA, 02114, USA
- Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, 02115, USA
| | - Woongsang Sunwoo
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear, Boston, MA, 02114, USA
- Department of Otolaryngology, Harvard Medical School, Boston, MA, 02115, USA
- Department of Otolaryngology, Gachon University Gil Medical Center, Incheon, 405-760, South Korea
| | - Joseph D Wagner
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear, Boston, MA, 02114, USA
| | - Bertrand Delgutte
- Eaton-Peabody Laboratories, Massachusetts Eye & Ear, Boston, MA, 02114, USA
- Department of Otolaryngology, Harvard Medical School, Boston, MA, 02115, USA
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165
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Luntz M, Khuri M, Khayr R, Gedaon Khuri W, Yehudai N, Shpak T. Cochlear implantation outcome in straightforward cases: can we do more for adults who cannot understand speech using hearing aids alone? Acta Otolaryngol 2018; 138:1070-1079. [PMID: 30686138 DOI: 10.1080/00016489.2018.1516298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Many adults with moderate-profound hearing loss whose speech recognition has deteriorated and are no longer benefitting from hearing aids (HAs) could benefit from cochlear implantation (CI). Of these, only <5% are implanted. In order to inform eligible patients about expected results and ease the route to implantation, better guidelines for candidate selection are needed. OBJECTIVES To provide reliable guidelines by determining, in a well-characterized group of implantees, the minimal expected post-CI scores for monosyllabic (MS) word recognition. PATIENTS AND METHODS In total, 20 adults unilateral implantees considered (prior to implantation) straightforward CI candidates were assessed ≥20 months post-CI. Their post-CI CI-aided thresholds and MS word recognition were compared to their pre-CI scores. In addition, SSQ12 scores were evaluated post-CI. RESULTS Post-CI, thresholds were 40 dB or better in all participants, and 35 dB or better in 95% of them. 90% scored 60% or better on MS words in quiet. In speech noise all scored 15-60% and 50% scored 45-60%. Poorer unaided pre-CI thresholds yielded greater patient satisfaction. CONCLUSIONS Adults with moderate-profound hearing loss, whose speech recognition has deteriorated, are no longer benefitting from HAs and fulfil defined criteria for straightforward CI, should be referred for formal CI candidacy evaluation.
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Affiliation(s)
- Michal Luntz
- The Ear and Hearing program, Department of Otolaryngology, Bnai-Zion Medical Center, Haifa, Israel
- The Bruce Rappaport Faculty of Medicine, Technion. Israel Institute of Technology, Haifa, Israel
- Department of Communication Disorders, Haifa University, Haifa, Israel
| | - Mahir Khuri
- The Ear and Hearing program, Department of Otolaryngology, Bnai-Zion Medical Center, Haifa, Israel
| | - Ranin Khayr
- The Ear and Hearing program, Department of Otolaryngology, Bnai-Zion Medical Center, Haifa, Israel
- Department of Communication Disorders, Haifa University, Haifa, Israel
| | - Wadeah Gedaon Khuri
- The Ear and Hearing program, Department of Otolaryngology, Bnai-Zion Medical Center, Haifa, Israel
| | - Noam Yehudai
- The Ear and Hearing program, Department of Otolaryngology, Bnai-Zion Medical Center, Haifa, Israel
- The Bruce Rappaport Faculty of Medicine, Technion. Israel Institute of Technology, Haifa, Israel
| | - Talma Shpak
- The Ear and Hearing program, Department of Otolaryngology, Bnai-Zion Medical Center, Haifa, Israel
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166
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Luo X, Kern A, Pulling KR. Vocal emotion recognition performance predicts the quality of life in adult cochlear implant users. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 144:EL429. [PMID: 30522282 DOI: 10.1121/1.5079575] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 10/29/2018] [Indexed: 06/09/2023]
Abstract
Clinical tests of cochlear implant (CI) outcomes in sentence recognition cannot fully reflect CI users' self-reported quality of life (QoL). Here, vocal emotion recognition scores, speech reception thresholds (SRTs), and demographic factors were tested as predictors of QoL scores assessed with the Nijmegen Cochlear Implant Questionnaire in postlingually deafened adult CI users. After correction for multiple comparisons, vocal emotion recognition scores were significantly correlated with QoL scores in all subdomains (social interaction, self-esteem, etc.), while SRTs and duration of CI use were not. Vocal emotion recognition may thus be used in clinic to accurately and broadly predict QoL with CIs.
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Affiliation(s)
- Xin Luo
- College of Health Solutions, Arizona State University, 975 South Myrtle Avenue, P.O. Box 870102, Tempe, Arizona 85287, USA ; ;
| | - Ashley Kern
- College of Health Solutions, Arizona State University, 975 South Myrtle Avenue, P.O. Box 870102, Tempe, Arizona 85287, USA ; ;
| | - Kathryn R Pulling
- College of Health Solutions, Arizona State University, 975 South Myrtle Avenue, P.O. Box 870102, Tempe, Arizona 85287, USA ; ;
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167
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Mamach M, Kessler M, Bankstahl JP, Wilke F, Geworski L, Bengel FM, Kurt S, Berding G. Visualization of the auditory pathway in rats with 18F-FDG PET activation studies based on different auditory stimuli and reference conditions including cochlea ablation. PLoS One 2018; 13:e0205044. [PMID: 30278068 PMCID: PMC6168174 DOI: 10.1371/journal.pone.0205044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/18/2018] [Indexed: 11/18/2022] Open
Abstract
Activation studies with positron emission tomography (PET) in auditory implant users explained some of the mechanisms underlying the variability of achieved speech comprehension. Since future developments of auditory implants will include studies in rodents, we aimed to inversely translate functional PET imaging to rats. In normal hearing rats, activity in auditory and non-auditory regions was studied using 18F-fluorodeoxyglucose (18F-FDG) PET with 3 different acoustic conditions: sound attenuated laboratory background, continuous white noise and rippled noise. Additionally, bilateral cochlea ablated animals were scanned. 3D image data were transferred into a stereotaxic standard space and evaluated using volume of interest (VOI) analyses and statistical parametric mapping (SPM). In normal hearing rats alongside the auditory pathway consistent activations of the nucleus cochlearis (NC), olivary complex (OC) and inferior colliculus (IC) were seen comparing stimuli with background. In this respect, no increased activation could be detected in the auditory cortex (AC), which even showed deactivation with white noise stimulation. Nevertheless, higher activity in the AC in normal hearing rats was observed for all 3 auditory conditions against the cochlea ablated status. Vice versa, in ablated status activity in the olfactory nucleus (ON) was higher compared to all auditory conditions in normal hearing rats. Our results indicate that activations can be demonstrated in normal hearing animals based on 18F-FDG PET in nuclei along the central auditory pathway with different types of noise stimuli. However, in the AC missing activation with respect to the background advises the need for more rigorous background noise attenuation for non-invasive reference conditions. Finally, our data suggest cross-modal activation of the olfactory system following cochlea ablation–underlining, that 18F-FDG PET appears to be well suited to study plasticity in rat models for cochlear implantation.
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Affiliation(s)
- Martin Mamach
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany
- * E-mail:
| | - Mariella Kessler
- Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Jens P. Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Florian Wilke
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Lilli Geworski
- Department of Medical Physics and Radiation Protection, Hannover Medical School, Hannover, Germany
| | - Frank M. Bengel
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Simone Kurt
- Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany
- Department of Otolaryngology, Hannover Medical School, Hannover, Germany
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine CIPMM, Saarland University, Homburg, Germany
| | - Georg Berding
- Cluster of Excellence Hearing4all, Hannover Medical School, Hannover, Germany
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
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168
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Ren C, Yang J, Zha D, Lin Y, Liu H, Kong Y, Liu S, Xu L. Spoken word recognition in noise in Mandarin-speaking pediatric cochlear implant users. Int J Pediatr Otorhinolaryngol 2018; 113:124-130. [PMID: 30173970 PMCID: PMC6175707 DOI: 10.1016/j.ijporl.2018.07.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/22/2018] [Accepted: 07/22/2018] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The purpose of the present study was to compare spoken word recognition performance in the presence of speech spectrum-shaped noise and four-talker babbles in Mandarin-speaking children with cochlear implants (CIs). METHODS Participants included 33 children with unilateral CIs (with a mean age of 10.4 ± 2.9 years old and a mean length of CI use of 7.5 ± 3.0 years). The Standard Chinese version of Lexical Neighborhood Test was implemented in quiet, speech-spectrum-shaped noise (SSN), and four-talker babble (FTB). The signal-to-noise ratios (SNRs) were set at +5 and + 10 dB for both types of maskers. Participants responded by verbally repeating each word they heard and the response was scored as the percentage accuracy of recognition performance. A Generalized Linear Model (GLM) fitting, correlational tests, and a two-way repeated-measures ANOVA were conducted on the percent-correct data. RESULTS Word recognition in quiet was on average 74.5% correct but dropped to 57.3% and 48.8% correct for SSN and FTB at 10 dB SNR, respectively, and 44.4% and 32.6% correct for SSN and FTB at 5 dB SNR, respectively. In both quiet and noise conditions, the participants showed lower recognition accuracy for the hard words than for the easy words. Disyllabic words were recognized with higher accuracy rates than were the monosyllabic words. The GLM analysis revealed that all four tested factors (masker type, SNR, lexical neighborhood feature, and lexical type) showed significant impacts on word recognition in children with CIs. Word recognition scores in the two types of maskers were significantly correlated for the disyllabic words at both SNRs and monosyllabic words at 10 dB SNR. CONCLUSIONS The present study demonstrated that the lexical features such as the lexical neighborhood characteristics and lexical type had significant effects on speech recognition performance in both quiet and noise conditions in pediatric CI users. Children with years of experience of CI use still encountered remarkable difficulties in everyday listening environment although their speech recognition in quiet reached relatively desired level. Fluctuating noise, such as speech babbles, caused greater challenge than steady-state noise for speech recognition in children with CIs.
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Affiliation(s)
- Cuncun Ren
- Department of Otolaryngology, Xijing Hospital, Xi'an, China; Beijing Tongren Hospital, Beijing Institute of Otolaryngology, Capital Medical University, Beijing, China
| | - Jing Yang
- Communication Sciences and Disorders, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Dingjun Zha
- Department of Otolaryngology, Xijing Hospital, Xi'an, China
| | - Ying Lin
- Department of Otolaryngology, Xijing Hospital, Xi'an, China
| | - Haihong Liu
- Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Ying Kong
- Beijing Tongren Hospital, Beijing Institute of Otolaryngology, Capital Medical University, Beijing, China
| | - Sha Liu
- Beijing Tongren Hospital, Beijing Institute of Otolaryngology, Capital Medical University, Beijing, China.
| | - Li Xu
- Communication Sciences and Disorders, Ohio University, Athens, OH, USA.
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169
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Wasmann JWA, van Eijl RHM, Versnel H, van Zanten GA. Assessing auditory nerve condition by tone decay in deaf subjects with a cochlear implant. Int J Audiol 2018; 57:864-871. [PMID: 30261773 DOI: 10.1080/14992027.2018.1498598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The condition of the auditory nerve is a factor determining hearing performance of cochlear implant (CI) recipients. Abnormal loudness adaptation is associated with poor auditory nerve survival. We examined which stimulus conditions are suitable for tone decay measurements to differentiate between CI recipients with respect to their speech perception. Tone decay was defined here as occurring when the percept disappears before the stimulus stops. We measured the duration of the percept of a 60-s pulse train. Current levels ranged from below threshold up to maximum acceptable loudness, pulse rates from 250 to 5000 pulses/s, and duty cycles (percentages of time the burst of pulses is on) from 10% to 100%. Ten adult CI recipients were included: seven with good and three with poor speech perception. Largest differences among the subjects were found at 5000 pulses/s and 100% duty cycle. The well performing subjects had a continuous percept of the 60-s stimulus within 3 dB above threshold. Two poorly performing subjects showed abnormal loudness adaptation, that is, no continuous percept even at levels greater than 6 dB above threshold. We conclude that abnormal loudness adaptation can be detected via an electric tone decay test using a high pulse rate and 100% duty cycle.
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Affiliation(s)
- Jan-Willem A Wasmann
- a Department of Otorhinolaryngology and Head & Neck Surgery , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands.,b Department of Otorhinolaryngology , Radboud University Medical Center , Nijmegen , The Netherlands
| | - Ruben H M van Eijl
- a Department of Otorhinolaryngology and Head & Neck Surgery , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands.,c Brain Center Rudolf Magnus , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands
| | - Huib Versnel
- a Department of Otorhinolaryngology and Head & Neck Surgery , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands.,c Brain Center Rudolf Magnus , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands
| | - Gijsbert A van Zanten
- a Department of Otorhinolaryngology and Head & Neck Surgery , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands.,c Brain Center Rudolf Magnus , University Medical Center Utrecht, Utrecht University , Utrecht , The Netherlands
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170
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Mitrasinovic S, Brown AP, Schaefer AT, Chang SD, Appelboom G. Silicon Valley new focus on brain computer interface: hype or hope for new applications? F1000Res 2018; 7:1327. [PMID: 30705750 PMCID: PMC6343225 DOI: 10.12688/f1000research.15726.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/14/2018] [Indexed: 11/28/2022] Open
Abstract
In the last year there has been increasing interest and investment into developing devices to interact with the central nervous system, in particular developing a robust brain-computer interface (BCI). In this article, we review the most recent research advances and the current host of engineering and neurological challenges that must be overcome for clinical application. In particular, space limitations, isolation of targeted structures, replacement of probes following failure, delivery of nanomaterials and processing and understanding recorded data. Neural engineering has developed greatly over the past half-century, which has allowed for the development of better neural recording techniques and clinical translation of neural interfaces. Implementation of general purpose BCIs face a number of constraints arising from engineering, computational, ethical and neuroscientific factors that still have to be addressed. Electronics have become orders of magnitude smaller and computationally faster than neurons, however there is much work to be done in decoding the neural circuits. New interest and funding from the non-medical community may be a welcome catalyst for focused research and development; playing an important role in future advancements in the neuroscience community.
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Affiliation(s)
| | | | - Andreas T. Schaefer
- The Francis Crick Institute, London, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Steven D. Chang
- Department of Neurosurgery, Stanford University Medical Center, Brighton, USA
| | - Geoff Appelboom
- Department of Neurosurgery, Stanford University Medical Center, Brighton, USA
- Byers Center for Biodesign, Stanford University School of Medicine, Brighton, USA
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171
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Feron K, Lim R, Sherwood C, Keynes A, Brichta A, Dastoor PC. Organic Bioelectronics: Materials and Biocompatibility. Int J Mol Sci 2018; 19:E2382. [PMID: 30104515 PMCID: PMC6121695 DOI: 10.3390/ijms19082382] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/08/2018] [Accepted: 08/10/2018] [Indexed: 01/06/2023] Open
Abstract
Organic electronic materials have been considered for a wide-range of technological applications. More recently these organic (semi)conductors (encompassing both conducting and semi-conducting organic electronic materials) have received increasing attention as materials for bioelectronic applications. Biological tissues typically comprise soft, elastic, carbon-based macromolecules and polymers, and communication in these biological systems is usually mediated via mixed electronic and ionic conduction. In contrast to hard inorganic semiconductors, whose primary charge carriers are electrons and holes, organic (semi)conductors uniquely match the mechanical and conduction properties of biotic tissue. Here, we review the biocompatibility of organic electronic materials and their implementation in bioelectronic applications.
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Affiliation(s)
- Krishna Feron
- Centre for Organic Electronics, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
| | - Rebecca Lim
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
| | - Connor Sherwood
- Centre for Organic Electronics, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
| | - Angela Keynes
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
| | - Alan Brichta
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
| | - Paul C Dastoor
- Centre for Organic Electronics, University of Newcastle, Callaghan, Newcastle, NSW 2308, Australia.
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172
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Souza P, Wright R, Gallun F, Reinhart P. Reliability and Repeatability of the Speech Cue Profile. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2018; 61:2126-2137. [PMID: 30073277 PMCID: PMC6198918 DOI: 10.1044/2018_jslhr-h-17-0341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 01/13/2018] [Accepted: 04/08/2018] [Indexed: 05/26/2023]
Abstract
PURPOSE Researchers have long noted speech recognition variability that is not explained by the pure-tone audiogram. Previous work (Souza, Wright, Blackburn, Tatman, & Gallun, 2015) demonstrated that a small number of listeners with sensorineural hearing loss utilized different types of acoustic cues to identify speechlike stimuli, specifically the extent to which the participant relied upon spectral (or temporal) information for identification. Consistent with recent calls for data rigor and reproducibility, the primary aims of this study were to replicate the pattern of cue use in a larger cohort and to verify stability of the cue profiles over time. METHOD Cue-use profiles were measured for adults with sensorineural hearing loss using a syllable identification task consisting of synthetic speechlike stimuli in which spectral and temporal dimensions were manipulated along continua. For the first set, a static spectral shape varied from alveolar to palatal, and a temporal envelope rise time varied from affricate to fricative. For the second set, formant transitions varied from labial to alveolar and a temporal envelope rise time varied from approximant to stop. A discriminant feature analysis was used to determine to what degree spectral and temporal information contributed to stimulus identification. A subset of participants completed a 2nd visit using the same stimuli and procedures. RESULTS When spectral information was static, most participants were more influenced by spectral than by temporal information. When spectral information was dynamic, participants demonstrated a balanced distribution of cue-use patterns, with nearly equal numbers of individuals influenced by spectral or temporal cues. Individual cue profile was repeatable over a period of several months. CONCLUSION In combination with previously published data, these results indicate that listeners with sensorineural hearing loss are influenced by different cues to identify speechlike sounds and that those patterns are stable over time.
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Affiliation(s)
- Pamela Souza
- Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL
- Knowles Hearing Center, Northwestern University, Evanston, IL
| | - Richard Wright
- Department of Linguistics, University of Washington, Seattle
| | - Frederick Gallun
- National Center for Rehabilitative Auditory Research, Portland VA Medical Center, Oregon
- Otolaryngology–Head and Neck Surgery, Oregon Health and Science University, Portland
| | - Paul Reinhart
- Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL
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173
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Steinmetzger K, Rosen S. The role of envelope periodicity in the perception of masked speech with simulated and real cochlear implants. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 144:885. [PMID: 30180719 DOI: 10.1121/1.5049584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 07/22/2018] [Indexed: 06/08/2023]
Abstract
In normal hearing, complex tones with pitch-related periodic envelope modulations are far less effective maskers of speech than aperiodic noise. Here, it is shown that this masker-periodicity benefit is diminished in noise-vocoder simulations of cochlear implants (CIs) and further reduced with real CIs. Nevertheless, both listener groups still benefitted significantly from masker periodicity, despite the lack of salient spectral pitch cues. The main reason for the smaller effect observed in CI users is thought to be an even stronger channel interaction than in the CI simulations, which smears out the random envelope modulations that are characteristic for aperiodic sounds. In contrast, neither interferers that were amplitude-modulated at a rate of 10 Hz nor maskers with envelopes specifically designed to reveal the target speech enabled a masking release in CI users. Hence, even at the high signal-to-noise ratios at which they were tested, CI users can still exploit pitch cues transmitted by the temporal envelope of a non-speech masker, whereas slow amplitude modulations of the masker envelope are no longer helpful.
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Affiliation(s)
- Kurt Steinmetzger
- Speech, Hearing and Phonetic Sciences, University College London, Chandler House, 2 Wakefield Street, London, WC1N 1PF, United Kingdom
| | - Stuart Rosen
- Speech, Hearing and Phonetic Sciences, University College London, Chandler House, 2 Wakefield Street, London, WC1N 1PF, United Kingdom
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174
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Carney LH. Supra-Threshold Hearing and Fluctuation Profiles: Implications for Sensorineural and Hidden Hearing Loss. J Assoc Res Otolaryngol 2018; 19:331-352. [PMID: 29744729 PMCID: PMC6081887 DOI: 10.1007/s10162-018-0669-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 04/19/2018] [Indexed: 12/22/2022] Open
Abstract
An important topic in contemporary auditory science is supra-threshold hearing. Difficulty hearing at conversational speech levels in background noise has long been recognized as a problem of sensorineural hearing loss, including that associated with aging (presbyacusis). Such difficulty in listeners with normal thresholds has received more attention recently, especially associated with descriptions of synaptopathy, the loss of auditory nerve (AN) fibers as a result of noise exposure or aging. Synaptopathy has been reported to cause a disproportionate loss of low- and medium-spontaneous rate (L/MSR) AN fibers. Several studies of synaptopathy have assumed that the wide dynamic ranges of L/MSR AN fiber rates are critical for coding supra-threshold sounds. First, this review will present data from the literature that argues against a direct role for average discharge rates of L/MSR AN fibers in coding sounds at moderate to high sound levels. Second, the encoding of sounds at supra-threshold levels is examined. A key assumption in many studies is that saturation of AN fiber discharge rates limits neural encoding, even though the majority of AN fibers, high-spontaneous rate (HSR) fibers, have saturated average rates at conversational sound levels. It is argued here that the cross-frequency profile of low-frequency neural fluctuation amplitudes, not average rates, encodes complex sounds. As described below, this fluctuation-profile coding mechanism benefits from both saturation of inner hair cell (IHC) transduction and average rate saturation associated with the IHC-AN synapse. Third, the role of the auditory efferent system, which receives inputs from L/MSR fibers, is revisited in the context of fluctuation-profile coding. The auditory efferent system is hypothesized to maintain and enhance neural fluctuation profiles. Lastly, central mechanisms sensitive to neural fluctuations are reviewed. Low-frequency fluctuations in AN responses are accentuated by cochlear nucleus neurons which, either directly or via other brainstem nuclei, relay fluctuation profiles to the inferior colliculus (IC). IC neurons are sensitive to the frequency and amplitude of low-frequency fluctuations and convert fluctuation profiles from the periphery into a phase-locked rate profile that is robust across a wide range of sound levels and in background noise. The descending projection from the midbrain (IC) to the efferent system completes a functional loop that, combined with inputs from the L/MSR pathway, is hypothesized to maintain "sharp" supra-threshold hearing, reminiscent of visual mechanisms that regulate optical accommodation. Examples from speech coding and detection in noise are reviewed. Implications for the effects of synaptopathy on control mechanisms hypothesized to influence supra-threshold hearing are discussed. This framework for understanding neural coding and control mechanisms for supra-threshold hearing suggests strategies for the design of novel hearing aid signal-processing and electrical stimulation patterns for cochlear implants.
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Affiliation(s)
- Laurel H Carney
- Departments of Biomedical Engineering, Neuroscience, and Electrical & Computer Engineering, Del Monte Institute for Neuroscience, University of Rochester, 601 Elmwood Ave., Box 603, Rochester, NY, 14642, USA.
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175
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Cassar IR, Titus ND, Grill WM. An improved genetic algorithm for designing optimal temporal patterns of neural stimulation. J Neural Eng 2018; 14:066013. [PMID: 28747582 DOI: 10.1088/1741-2552/aa8270] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Electrical neuromodulation therapies typically apply constant frequency stimulation, but non-regular temporal patterns of stimulation may be more effective and more efficient. However, the design space for temporal patterns is exceedingly large, and model-based optimization is required for pattern design. We designed and implemented a modified genetic algorithm (GA) intended for design optimal temporal patterns of electrical neuromodulation. APPROACH We tested and modified standard GA methods for application to designing temporal patterns of neural stimulation. We evaluated each modification individually and all modifications collectively by comparing performance to the standard GA across three test functions and two biophysically-based models of neural stimulation. MAIN RESULTS The proposed modifications of the GA significantly improved performance across the test functions and performed best when all were used collectively. The standard GA found patterns that outperformed fixed-frequency, clinically-standard patterns in biophysically-based models of neural stimulation, but the modified GA, in many fewer iterations, consistently converged to higher-scoring, non-regular patterns of stimulation. SIGNIFICANCE The proposed improvements to standard GA methodology reduced the number of iterations required for convergence and identified superior solutions.
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176
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Kronenberger WG, Henning SC, Ditmars AM, Pisoni DB. Language processing fluency and verbal working memory in prelingually deaf long-term cochlear implant users: A pilot study. Cochlear Implants Int 2018; 19:312-323. [PMID: 29976119 DOI: 10.1080/14670100.2018.1493970] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVE Verbal working memory (WM) is more strongly correlated with spoken language skills in prelingually deaf, early-implanted cochlear implant (CI) users than in normal-hearing (NH) peers, suggesting that CI users access WM in order to support and compensate for their slower, more effortful spoken language processing. This pilot study tested the feasibility and validity of a dual-task method for establishing the causal role of WM in basic language processing (lexical access speed) in samples of 9 CI users (ages 8-26 years) and 9 NH peers. METHODS Participants completed tests of lexical access speed (rapid automatized picture naming test and lexical decision test) under two administration conditions: a standard condition and a dual-task WM condition requiring participants to hold numerals in WM during completion of the lexical access speed tests. RESULTS CI users showed more dual-task interference (decline in speed during the WM condition compared to the standard condition) than NH peers, indicating that their lexical access speed was more dependent on engagement of WM resources. Furthermore, dual-task interference scores were significantly correlated with several measures of speed-based executive functioning (EF), consistent with the hypothesis that the dual-task method reflects the involvement of EF in language processing. CONCLUSION These pilot study results support the feasibility and validity of the dual-task WM method for investigating the influence of WM in the basic language processing of CI users. Preliminary findings indicate that CI users are more dependent on the use of WM as a compensatory strategy during slow-effortful basic language processing than NH peers.
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Affiliation(s)
- William G Kronenberger
- a Department of Psychiatry , Indiana University School of Medicine , Indianapolis , IN , USA.,b DeVault Otologic Research Laboratory, Department of Otolaryngology-Head and Neck Surgery , Indiana University School of Medicine , Indianapolis , IN , USA
| | - Shirley C Henning
- b DeVault Otologic Research Laboratory, Department of Otolaryngology-Head and Neck Surgery , Indiana University School of Medicine , Indianapolis , IN , USA
| | - Allison M Ditmars
- b DeVault Otologic Research Laboratory, Department of Otolaryngology-Head and Neck Surgery , Indiana University School of Medicine , Indianapolis , IN , USA
| | - David B Pisoni
- b DeVault Otologic Research Laboratory, Department of Otolaryngology-Head and Neck Surgery , Indiana University School of Medicine , Indianapolis , IN , USA.,c Speech Research Laboratory, Department of Psychological and Brain Sciences , Indiana University , Bloomington , IN , USA
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Liu Y, Zhu Y, Liu J, Zhang Y, Liu J, Zhai J. Design of Bionic Cochlear Basilar Membrane Acoustic Sensor for Frequency Selectivity Based on Film Triboelectric Nanogenerator. NANOSCALE RESEARCH LETTERS 2018; 13:191. [PMID: 29971697 PMCID: PMC6029990 DOI: 10.1186/s11671-018-2593-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/06/2018] [Indexed: 05/07/2023]
Abstract
Sensorineural hearing loss tops the list of most suffering disease for the sake of its chronic, spirit pressing, and handicapped features, which can happen to all age groups, from newborns to old folks. Laggard technical design as well as external power dependence of conventional cochlear implant cumbers agonized patients and restrict its wider practical application, driving researchers to seek for fundamental improvement. In this paper, we successfully proposed a novel bionic cochlear basilar membrane acoustic sensor in conjugation with triboelectric nanogenerator. By trapezoidally distributing nine silver electrodes on both two polytetrafluoroethylene membranes, a highly frequency-selective function was fulfilled in this gadget, ranging from 20 to 3000 Hz. It is believed to be more discernable with the increment of electrode numbers, referring to the actual basilar membrane in the cochlear. Besides, the as-made device can be somewhat self-powered via absorption of vibration energy carried by sound, which tremendously facilitates its potential users. As a consequence, the elaborate bionic system provides an innovative perspective tackling the problem of sensorineural hearing loss.
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Affiliation(s)
- Yudong Liu
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083 China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yaxing Zhu
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083 China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jingyu Liu
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083 China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yang Zhang
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083 China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Juan Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing, China
| | - Junyi Zhai
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083 China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049 China
- Center on Nanoenergy Research, School of Physical Science and Technology, Guangxi University, Nanning, 530004 China
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Goncalves SB, Ribeiro JF, Silva AF, Costa RM, Correia JH. Design and manufacturing challenges of optogenetic neural interfaces: a review. J Neural Eng 2018; 14:041001. [PMID: 28452331 DOI: 10.1088/1741-2552/aa7004] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Optogenetics is a relatively new technology to achieve cell-type specific neuromodulation with millisecond-scale temporal precision. Optogenetic tools are being developed to address neuroscience challenges, and to improve the knowledge about brain networks, with the ultimate aim of catalyzing new treatments for brain disorders and diseases. To reach this ambitious goal the implementation of mature and reliable engineered tools is required. The success of optogenetics relies on optical tools that can deliver light into the neural tissue. Objective/Approach: Here, the design and manufacturing approaches available to the scientific community are reviewed, and current challenges to accomplish appropriate scalable, multimodal and wireless optical devices are discussed. SIGNIFICANCE Overall, this review aims at presenting a helpful guidance to the engineering and design of optical microsystems for optogenetic applications.
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Affiliation(s)
- S B Goncalves
- CMEMS-UMinho, Department of Industrial Electronics, University of Minho, Guimaraes, Portugal
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Nagathil A, Schlattmann JW, Neumann K, Martin R. Music complexity prediction for cochlear implant listeners based on a feature-based linear regression model. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 144:1. [PMID: 30075690 DOI: 10.1121/1.5044514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper presents a model for predicting music complexity as perceived by cochlear implant (CI) users. To this end, 10 CI users and 19 normal-hearing (NH) listeners rated 12 selected music pieces on a bipolar music complexity scale and 5 other perception-related scales. The results indicate statistically significant differences in the ratings between CI and NH listeners. In particular, the ratings among different scales were significantly correlated for CI users, which hints at a common, hidden scale. The median complexity ratings by CI listeners and features accounting for high-frequency energy, spectral center of gravity, spectral bandwidth, and roughness were used to train a linear principal component regression model for an average CI user. The model was evaluated by means of cross-validation and using an independent database of processed chamber music signals for which music preferences scores by CI users were available. The predictions indicate a clear linear relationship with the preference scores, confirming the negative correlation between music complexity and music preference for CI users found in previous studies. The proposed model is a first step toward an instrumental evaluation procedure in the emerging field of music processing for CIs.
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Affiliation(s)
- Anil Nagathil
- Institute of Communication Acoustics, Ruhr-Universität Bochum, Bochum, 44780, Germany
| | | | - Katrin Neumann
- Department of Phoniatrics and Pediatric Audiology, Clinic of Otorhinolaryngology, Head and Neck Surgery, St. Elisabeth-Hospital, Ruhr-Universität Bochum, Bochum, 44787, Germany
| | - Rainer Martin
- Institute of Communication Acoustics, Ruhr-Universität Bochum, Bochum, 44780, Germany
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180
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Fridman G. Safe Direct Current Stimulator design for reduced power consumption and increased reliability. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:1082-1085. [PMID: 29060062 DOI: 10.1109/embc.2017.8037015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Current state of the art neural prosthetics, such as cochlear implants, spinal cord stimulators, and deep brain stimulators use implantable pulse generators (IPGs) to excite neural activity. Inhibition of neural firing is typically indirect and requires excitation of neurons that then have inhibitory projections downstream. Safe Direct Current Stimulator (SDCS) technology is designed to convert electronic pulses delivered to electrodes embedded within an implantable device to ionic direct current (iDC) at the output of the device. iDC from the device can then control neural extracellular potential with the intent of being able to not only excite, but also inhibit and sensitize neurons, thereby greatly expanding the possible applications of neuromodulation therapies and neural interface mechanisms. While the potential applications and proof of concept of this device have been the focus of previous work, the published descriptions of this technology leave significant room for power and reliability optimization. We describe and model a novel device construction designed to reduce power consumption by a factor of 12 and to improve its reliability by a factor of 8.
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181
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Zhang W, Kim SM, Wang W, Cai C, Feng Y, Kong W, Lin X. Cochlear Gene Therapy for Sensorineural Hearing Loss: Current Status and Major Remaining Hurdles for Translational Success. Front Mol Neurosci 2018; 11:221. [PMID: 29997477 PMCID: PMC6028713 DOI: 10.3389/fnmol.2018.00221] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/06/2018] [Indexed: 12/19/2022] Open
Abstract
Sensorineural hearing loss (SNHL) affects millions of people. Genetic mutations play a large and direct role in both congenital and late-onset cases of SNHL (e.g., age-dependent hearing loss, ADHL). Although hearing aids can help moderate to severe hearing loss the only effective treatment for deaf patients is the cochlear implant (CI). Gene- and cell-based therapies potentially may preserve or restore hearing with more natural sound perception, since their theoretical frequency resolution power is much higher than that of cochlear implants. These biologically-based interventions also carry the potential to re-establish hearing without the need for implanting any prosthetic device; the convenience and lower financial burden afforded by such biologically-based interventions could potentially benefit far more SNHL patients. Recently major progress has been achieved in preclinical studies of cochlear gene therapy. This review critically evaluates recent advances in the preclinical trials of gene therapies for SNHL and the major remaining challenges for the development and eventual clinical translation of this novel therapy. The cochlea bears many similarities to the eye for translational studies of gene therapies. Experience gained in ocular gene therapy trials, many of which have advanced to clinical phase III, may provide valuable guidance in improving the chance of success for cochlear gene therapy in human trials. A discussion on potential implications of translational knowledge gleaned from large numbers of advanced clinical trials of ocular gene therapy is therefore included.
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Affiliation(s)
- Wenjuan Zhang
- Department of Otolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sun Myoung Kim
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA, United States
| | - Wenwen Wang
- Department of Otolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | | | - Yong Feng
- Xiangya School of Medicine, Changsha, China
| | - Weijia Kong
- Department of Otolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xi Lin
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA, United States
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Abstract
BACKGROUND During the past few decades various questionnaires have been developed to evaluate quality of life using audiological measures. The Hearing Implant Sound Quality Index (HISQUI) was developed especially for patients with a cochlear implant (CI). The aim of this study was to evaluate subjective hearing improvement after CI surgery and to correlate the results with objective measuring methods such as pure-tone and speech audiometry. MATERIALS AND METHODS Pre- and postoperative data of 57 patients who received a cochlear implant (CIs) were retrospectively analyzed. For evaluation of subjective hearing ability the HISQUI questionnaire consisting of 19 questions was used as reference. Pure-tone audiometry and Freiburger monosyllable word tests were used as objective measurements for hearing. RESULTS The mean HISQUI score increased on average from 53.0 prior to surgery to 69.0 after surgery. In addition, there were significant improvements in all seven subgroups of the questionnaire divisions. A correlation of rSp = 0.53 before surgery and rSp = 0.36 after surgery between the HISQUI scores and Freiburg monosyllable word test was recorded. In addition the 4FPTA (four frequency pure tone average) value correlated negatively with rSp = -0.48 with the HISQUI total score before surgery. CONCLUSION The moderate correlation of both subjective and objective measurement methods underlines the importance of enquiring the patients' subjective perception and satisfaction. Through the combination of subjective statements and measurements of speech comprehension it is possible to obtain a comprehensive picture of the hearing performance of CI recipients.
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Affiliation(s)
- N Volleth
- Audiologische Abteilung, Hals-Nasen-Ohrenklinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Waldstr. 1, 91054, Erlangen, Deutschland
| | - A Hast
- Audiologische Abteilung, Hals-Nasen-Ohrenklinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Waldstr. 1, 91054, Erlangen, Deutschland
| | - E K Lehmann
- Audiologische Abteilung, Hals-Nasen-Ohrenklinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Waldstr. 1, 91054, Erlangen, Deutschland
| | - U Hoppe
- Audiologische Abteilung, Hals-Nasen-Ohrenklinik, Kopf- und Halschirurgie, Universitätsklinikum Erlangen, Waldstr. 1, 91054, Erlangen, Deutschland.
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183
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Photopolymerized Microfeatures Guide Adult Spiral Ganglion and Dorsal Root Ganglion Neurite Growth. Otol Neurotol 2018; 39:119-126. [PMID: 29227456 DOI: 10.1097/mao.0000000000001622] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
HYPOTHESIS Microtopographical patterns generated by photopolymerization of methacrylate polymer systems will direct growth of neurites from adult neurons, including spiral ganglion neurons (SGNs). BACKGROUND Cochlear implants (CIs) provide hearing perception to patients with severe to profound hearing loss. However, their ability to encode complex auditory stimuli is limited due, in part, to poor spatial resolution caused by spread of the electrical currents in the inner ear. Directing the regrowth of SGN peripheral processes towards stimulating electrodes could help reduce current spread and improve spatial resolution provided by the CI. Previous work has demonstrated that micro- and nano-scale patterned surfaces precisely guide the growth of neurites from a variety of neonatal neurons including SGNs. Here, we sought to determine the extent to which adult neurons likewise respond to these topographical surface features. METHODS Photopolymerization was used to fabricate methacrylate polymer substrates with micropatterned surfaces of varying amplitudes and periodicities. Dissociated adult dorsal root ganglion neurons (DRGNs) and SGNs were cultured on these surfaces and the alignment of the neurite processes to the micropatterns was determined. RESULTS Neurites from both adult DRGNs and SGNs significantly aligned to the patterned surfaces similar to their neonatal counterparts. Further DRGN and SGN neurite alignment increased as the amplitude of the microfeatures increased. Decreased pattern periodicity also improved neurite alignment. CONCLUSION Microscale surface topographic features direct the growth of adult SGN neurites. Topographical features could prove useful for guiding growth of SGN peripheral axons towards a CI electrode array.
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184
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Wong YT, Ahnood A, Maturana MI, Kentler W, Ganesan K, Grayden DB, Meffin H, Prawer S, Ibbotson MR, Burkitt AN. Feasibility of Nitrogen Doped Ultrananocrystalline Diamond Microelectrodes for Electrophysiological Recording From Neural Tissue. Front Bioeng Biotechnol 2018; 6:85. [PMID: 29988378 PMCID: PMC6024013 DOI: 10.3389/fbioe.2018.00085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 06/05/2018] [Indexed: 01/19/2023] Open
Abstract
Neural prostheses that can monitor the physiological state of a subject are becoming clinically viable through improvements in the capacity to record from neural tissue. However, a significant limitation of current devices is that it is difficult to fabricate electrode arrays that have both high channel counts and the appropriate electrical properties required for neural recordings. In earlier work, we demonstrated nitrogen doped ultrananocrystalline diamond (N-UNCD) can provide efficacious electrical stimulation of neural tissue, with high charge injection capacity, surface stability and biocompatibility. In this work, we expand on this functionality to show that N-UNCD electrodes can also record from neural tissue owing to its low electrochemical impedance. We show that N-UNCD electrodes are highly flexible in their application, with successful recordings of action potentials from single neurons in an in vitro retina preparation, as well as local field potential responses from in vivo visual cortex tissue. Key properties of N-UNCD films, combined with scalability of electrode array fabrication with custom sizes for recording or stimulation along with integration through vertical interconnects to silicon based integrated circuits, may in future form the basis for the fabrication of versatile closed-loop neural prostheses that can both record and stimulate.
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Affiliation(s)
- Yan T. Wong
- Department of Physiology and Department of Electrical and Computer Systems Engineering, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Arman Ahnood
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
| | - Matias I. Maturana
- Department of Biomedical Engineering, University of Melbourne, Melbourne, VIC, Australia
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC, Australia
| | - William Kentler
- Department of Biomedical Engineering, University of Melbourne, Melbourne, VIC, Australia
| | | | - David B. Grayden
- Department of Biomedical Engineering, University of Melbourne, Melbourne, VIC, Australia
| | - Hamish Meffin
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Science University of Melbourne, Melbourne, VIC, Australia
| | - Steven Prawer
- School of Physics, University of Melbourne, Melbourne, VIC, Australia
| | - Michael R. Ibbotson
- National Vision Research Institute, Australian College of Optometry, Carlton, VIC, Australia
- Department of Optometry and Vision Science University of Melbourne, Melbourne, VIC, Australia
| | - Anthony N. Burkitt
- Department of Biomedical Engineering, University of Melbourne, Melbourne, VIC, Australia
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Mishchenko MA, Gerasimova SA, Lebedeva AV, Lepekhina LS, Pisarchik AN, Kazantsev VB. Optoelectronic system for brain neuronal network stimulation. PLoS One 2018; 13:e0198396. [PMID: 29856855 PMCID: PMC5983492 DOI: 10.1371/journal.pone.0198396] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 05/20/2018] [Indexed: 11/23/2022] Open
Abstract
We propose an optoelectronic system for stimulation of living neurons. The system consists of an electronic circuit based on the FitzHugh–Nagumo model, an optical fiber, and a photoelectrical converter. We used this system for electrical stimulation of hippocampal living neurons in acute hippocampal brain slices (350-μm thick) obtained from a 20–28 days old C57BL/6 mouse or a Wistar rat. The main advantage of our system over other similar stimulators is that it contains an optical fiber for signal transmission instead of metallic wires. The fiber is placed between the electronic circuit and stimulated neurons and provides galvanic isolation from external electrical and magnetic fields. The use of the optical fiber allows avoiding electromagnetic noise and current flows which could affect metallic wires. Furthermore, it gives us the possibility to simulate “synaptic plasticity” by adaptive signal transfer through optical fiber. The proposed optoelectronic system (hybrid neural circuit) provides a very high efficiency in stimulating hippocampus neurons and can be used for restoring brain activity in particular regions or replacing brain parts (neuroprosthetics) damaged due to a trauma or neurodegenerative diseases.
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Affiliation(s)
- Mikhail A. Mishchenko
- National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
- * E-mail:
| | - Svetlana A. Gerasimova
- National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Albina V. Lebedeva
- National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Lyubov S. Lepekhina
- National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Alexander N. Pisarchik
- Center for Biomedical Technology, Technical University of Madrid, Campus Montegancedo, Pozuelo de Alarcón, Madrid, Spain
| | - Victor B. Kazantsev
- National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
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187
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Improved Speech Perception in Cochlear Implant Users With Interleaved High-Rate Pulse Trains. Otol Neurotol 2018; 39:e319-e324. [DOI: 10.1097/mao.0000000000001790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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188
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A Follow-Up Study on Music and Lexical Tone Perception in Adult Mandarin-Speaking Cochlear Implant Users. Otol Neurotol 2018; 38:e421-e428. [PMID: 28984805 DOI: 10.1097/mao.0000000000001580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The aim was to evaluate the development of music and lexical tone perception in Mandarin-speaking adult cochlear implant (CI) users over a period of 1 year. STUDY DESIGN Prospective patient series. SETTING Tertiary hospital and research institute. PATIENTS Twenty five adult CI users, with ages ranging from 19 to 75 years old, participated in a year-long follow-up evaluation. There were also 40 normal hearing adult subjects who participated as a control group to provide the normal value range. INTERVENTIONS Musical sounds in cochlear implants (Mu.S.I.C.) test battery was undertaken to evaluate music perception ability. Mandarin Tone Identification in Noise Test (M-TINT) was used to assess lexical tone recognition. The tests for CI users were completed at 1, 3, 6, and 12 months after the CI switch-on. MAIN OUTCOMES MEASURES Quantitative and statistical analysis of their results from music and tone perception tests. RESULTS The performance of music perception and tone recognition both demonstrated an overall improvement in outcomes during the entire 1-year follow-up process. The increasing trends were obvious in the early period especially in the first 6 months after switch-on. There was a significant improvement in the melody discrimination (p < 0.01), timbre identification (p < 0.001), tone recognition in quiet (p < 0.0001), and in noise (p < 0.0001). CONCLUSIONS Adult Mandarin-speaking CI users show an increasingly improved performance on music and tone perception during the 1-year follow-up. The improvement was the most prominent in the first 6 months of CI use. It is essential to strengthen the rehabilitation training within the first 6 months.
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189
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Erhardt JB, Fuhrer E, Gruschke OG, Leupold J, Wapler MC, Hennig J, Stieglitz T, Korvink JG. Should patients with brain implants undergo MRI? J Neural Eng 2018. [DOI: 10.1088/1741-2552/aab4e4] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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190
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Wissel K, Brandes G, Pütz N, Angrisani GL, Thieleke J, Lenarz T, Durisin M. Platinum corrosion products from electrode contacts of human cochlear implants induce cell death in cell culture models. PLoS One 2018; 13:e0196649. [PMID: 29763442 PMCID: PMC5953457 DOI: 10.1371/journal.pone.0196649] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 04/17/2018] [Indexed: 12/18/2022] Open
Abstract
Despite the technological progress made with cochlear implants (CI), impedances and their diagnosis remain a focus of interest. Increases in impedance have been related to technical defects of the electrode as well as inflammatory and/or fibrosis along the electrode. Recent studies have demonstrated highly increased impedances as the result of corroded platinum (Pt) electrode contacts. This in vitro study examined the effects of Pt ions and compounds generated by corrosion of the electrode contacts of a human CI on cell metabolism. Since traces of solid Pt in surrounding cochlear tissues have been reported, the impact of commercially available Pt nanoparticles (Pt-NP, size 3 nm) on the cell culture model was also determined. For this purpose, the electrode contacts were electrically stimulated in a 0.5% aqueous NaCl solution for four weeks and the mass fraction of the platinum dissolute (Pt-Diss) was determined by mass spectrometry (ICP-MS). Metabolic activity of the murine fibroblasts (NIH 3T3) and the human neuroblastoma (SH-SY5Y) cells was determined using the WST-1 assay following exposure to Pt-Diss and Pt-NP. It was found that 5–50 μg/ml of the Pt-NP did not affect the viability of both cell types. In contrast, 100 μg/ml of the nanoparticles caused significant loss in metabolic activity. Furthermore, transmission electron microscopy (TEM) revealed mitochondrial swelling in both cell types indicating cytotoxicity. Additionally, TEM demonstrated internalized Pt-NP in NIH 3T3 cells in a concentration dependent manner, whereas endocytosis in SH-SY5Y cells was virtually absent. In comparison with the Pt-NP, the corrosion products (Pt-Diss) with concentrations between 1.64 μg/ml and 8.2 μg/ml induced cell death in both cell lines in a concentration dependent manner. TEM imaging revealed both mitochondrial disintegration and swelling of the endoplasmic reticulum, suggesting that Pt ions trigger cytotoxicity in both NIH 3T3 and SH-SY5Y cell lines by interacting with the respiratory chain.
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Affiliation(s)
- Kirsten Wissel
- Department of Otorhinolaryngology, Hannover Medical School, Hannover, Germany
- Cluster of Excellence ‘Hearing 4 all’, NIFE, Hannover, Germany
- * E-mail:
| | - Gudrun Brandes
- Institute of Neuroanatomy and Cell Biology, Center of Anatomy and Cell Biology, Hannover Medical School, Hannover, Germany
| | - Nils Pütz
- Department of Otorhinolaryngology, Hannover Medical School, Hannover, Germany
- Biotechnology Center, TU Dresden, Dresden, Germany
| | | | - Jan Thieleke
- Institute of Inorganic Chemistry, Leibniz University Hannover, Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Hannover Medical School, Hannover, Germany
- Cluster of Excellence ‘Hearing 4 all’, NIFE, Hannover, Germany
| | - Martin Durisin
- Department of Otorhinolaryngology, Hannover Medical School, Hannover, Germany
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191
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Radotić V, Braeken D, Drviš P, Mattotti M, Kovačić D. Advantageous environment of micro-patterned, high-density complementary metal-oxide-semiconductor electrode array for spiral ganglion neurons cultured in vitro. Sci Rep 2018; 8:7446. [PMID: 29748613 PMCID: PMC5945660 DOI: 10.1038/s41598-018-25814-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 04/20/2018] [Indexed: 12/24/2022] Open
Abstract
This study investigated micro-patterned, high-density complementary metal–oxide–semiconductor (CMOS) electrode array to be used as biologically permissive environment for organization, guidance and electrical stimulation of spiral ganglion neurons (SGN). SGNs extracted and isolated from cochleae of P5-P7 rat pups and adult guinea pigs were cultured 1, 4 and 7 days in vitro on glass coverslips (control) and CMOS electrode array. The cultures were analyzed visually and immunohistochemically for SGN presence, outgrowth, neurite alignment, neurite length, neurite asymmetry as well as the contact of a neuronal soma and neurites with the micro-electrodes. Our findings indicate that topographical environment of CMOS chip with micro-patterned pillars enhanced growth, survival, morphology, neural orientation and alignment of SGNs in vitro compared to control. Smaller spacing (0.8–1.6 µm) between protruding pillars on CMOS led SGNs to develop structured and guided neurites oriented along three topographical axes separated by 60°. We found morphological basis for positioning of the micro-electrodes on the chip that was appropriate for direct contact of SGNs with them. This configuration allowed CMOS electrode array to electrically stimulate the SGN whose responses were observed with live Fluo 4 calcium imaging.
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Affiliation(s)
- Viktorija Radotić
- Laboratory for Biophysics and Medical Neuroelectronics, Department of Physics, University of Split, Faculty of Science, R.Boškovića 33, HR-21000, Split, Croatia.,The Center of Research Excellence for Science and Technology Integrating Mediterranean region (STIM), University of Split, Poljička 35, HR-21000, Split, Croatia.,Speech and Hearing Research Laboratory, University of Split, School of Medicine, Šoltanska 2, HR-21000, Split, Croatia
| | - Dries Braeken
- Cell and Tissue Technologies group, Life Science Technologies department, Imec, Kapeldreef 75, B-3001, Leuven, Belgium
| | - Petar Drviš
- University Hospital Centre Split, Department of Otorhinolaryngology & Head and Neck Surgery, Spinčićeva 1, HR-21000, Split, Croatia
| | - Marta Mattotti
- Speech and Hearing Research Laboratory, University of Split, School of Medicine, Šoltanska 2, HR-21000, Split, Croatia
| | - Damir Kovačić
- Laboratory for Biophysics and Medical Neuroelectronics, Department of Physics, University of Split, Faculty of Science, R.Boškovića 33, HR-21000, Split, Croatia. .,The Center of Research Excellence for Science and Technology Integrating Mediterranean region (STIM), University of Split, Poljička 35, HR-21000, Split, Croatia. .,Speech and Hearing Research Laboratory, University of Split, School of Medicine, Šoltanska 2, HR-21000, Split, Croatia.
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192
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Land R, Radecke JO, Kral A. Congenital Deafness Reduces, But Does Not Eliminate Auditory Responsiveness in Cat Extrastriate Visual Cortex. Neuroscience 2018; 375:149-157. [DOI: 10.1016/j.neuroscience.2018.01.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/25/2018] [Accepted: 01/30/2018] [Indexed: 01/12/2023]
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193
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Cheng C, Thakur R, Nair AR, Sterrett S, Fridman G. Miniature Elastomeric Valve Design for Safe Direct Current Stimulator. IEEE BIOMEDICAL CIRCUITS AND SYSTEMS CONFERENCE : HEALTHCARE TECHNOLOGY : [PROCEEDINGS]. IEEE BIOMEDICAL CIRCUITS AND SYSTEMS CONFERENCE 2018; 2017:1-4. [PMID: 30406220 DOI: 10.1109/biocas.2017.8325194] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
For safety reasons, commercial neural implants use charge-balanced biphasic pulses to interact with target neurons using metal electrodes. Short biphasic pulses are used to avoid irreversible electrochemical reactions at the electrode-tissue interfaces. Biphasic pulses are effective at exciting neurons, but quite limited in inhibiting their activity. In contrast, direct current can both excite and inhibit neurons, however delivered to metal electrodes, it causes toxic electrochemical reactions. We recently introduced Safe Direct Current Stimulator (SDCS) technology, which can excite or inhibit neurons without violating the safety criteria. Instead of direct current, SDCS generates an ionic direct current (iDC) from a biphasic input signal using a network of fluidic channels and mechanical valves. A key enabler towards transforming SDCS concept from a benchtop design to an implantable neural prosthesis is the design of a miniature valve. In this work, we present poly-dimethylsiloxane (PDMS) based elastomeric valves, squeeze valve (SV) and plunger valve (PV) capable of being actuated using a shape memory alloy wire.
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Affiliation(s)
- Chaojun Cheng
- Mechanical Engineering, Johns Hopkins University, Baltimore, USA
| | - Raviraj Thakur
- Otolaryngology HNS, Johns Hopkins University, Baltimore, USA
| | | | - Scott Sterrett
- Biomedical Engineering, Johns Hopkins University, Baltimore, USA
| | - Gene Fridman
- Otolarynology HNS, Johns Hopkins University, Baltimore, USA
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194
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Advances in Materials for Recent Low-Profile Implantable Bioelectronics. MATERIALS 2018; 11:ma11040522. [PMID: 29596359 PMCID: PMC5951368 DOI: 10.3390/ma11040522] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/20/2018] [Accepted: 03/26/2018] [Indexed: 12/28/2022]
Abstract
The rapid development of micro/nanofabrication technologies to engineer a variety of materials has enabled new types of bioelectronics for health monitoring and disease diagnostics. In this review, we summarize widely used electronic materials in recent low-profile implantable systems, including traditional metals and semiconductors, soft polymers, biodegradable metals, and organic materials. Silicon-based compounds have represented the traditional materials in medical devices, due to the fully established fabrication processes. Examples include miniaturized sensors for monitoring intraocular pressure and blood pressure, which are designed in an ultra-thin diaphragm to react with the applied pressure. These sensors are integrated into rigid circuits and multiple modules; this brings challenges regarding the fundamental material’s property mismatch with the targeted human tissues, which are intrinsically soft. Therefore, many polymeric materials have been investigated for hybrid integration with well-characterized functional materials such as silicon membranes and metal interconnects, which enable soft implantable bioelectronics. The most recent trend in implantable systems uses transient materials that naturally dissolve in body fluid after a programmed lifetime. Such biodegradable metallic materials are advantageous in the design of electronics due to their proven electrical properties. Collectively, this review delivers the development history of materials in implantable devices, while introducing new bioelectronics based on bioresorbable materials with multiple functionalities.
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195
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Stauss S, Honma I. Biocompatible Batteries—Materials and Chemistry, Fabrication, Applications, and Future Prospects. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20170325] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Sven Stauss
- Chemistry of Energy Conversion Devices Laboratory, Research Center for Sustainable Science & Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Itaru Honma
- Chemistry of Energy Conversion Devices Laboratory, Research Center for Sustainable Science & Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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196
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Zhong LL, Zhang Y, Liang XJ, Hou K, Han JW, Wang FY, Hao QQ, Jiang QQ, Yu N, Guo WW, Yang SM. Inner ear structure of miniature pigs measured by multi-planar reconstruction techniques. Am J Transl Res 2018; 10:709-717. [PMID: 29636861 PMCID: PMC5883112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/21/2017] [Indexed: 06/08/2023]
Abstract
To study the structures of the scala vestibuli and tympani of miniature pigs in order to evaluate the feasibility of using miniature pigs as the animal model for cochlear implant. The temporal bones of three miniature pigs with normal hearing were scanned by micro-CT. With the aid of the Mimics software, we reconstructed the 3D structure of inner ear basing on the serial images of the miniature pig, and obtained dimensions of the scala vestibuli and tympani with multi-planar reconstruction (MPR) technique. The constructed slicing images displayed the fine structures of the cochlea. The results of our study showed that the cross-sectional areas of the scala tympani were greatest at 2.67 ± 0.90 mm2 when the circumferential length from the starting point of basal turn of the cochlea reached to 1.16 mm. The scala vestibuli has a largest width and height at the starting point of basal turn. The width and the height were 2.65 ± 0.45 mm and 2.43 ± 0.2 mm respectively. The largest width and height of the scala tympani were 2.17 ± 0.30 mm and 1.83 ± 0.42 mm. The result of our study suggests that the cochlea of miniature pigs is highly consistent with human's. Miniature pigs may be used as a new model for cochlear implant. MPR technique may be used as a new approach to obtain further information of patient's cochlea in surgeons which is helpful to select suitable cochlear implant devices and surgery approach.
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Affiliation(s)
- Ling-Ling Zhong
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
- Department of Otolayngology, Head & Neck Surgery, The Tianjin Children’s HospitalTianjin 300074, P. R. China
| | - Yan Zhang
- Department of Otorhinolaryngology Head and Neck Surgery, The First Hospital of Jilin UniversityChangchun 130021, Jilin, P. R. China
| | - Xiao-Jie Liang
- Department of Otolaryngeal-Head Neck Surgery, The Army General Hospita of PLABeijing 100700, P. R. China
| | - Kun Hou
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Jia-Wei Han
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Fang-Yuan Wang
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Qing-Qing Hao
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Qing-Qing Jiang
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Ning Yu
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Wei-Wei Guo
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
| | - Shi-Ming Yang
- Department of Otolayngology, Head & Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General HospitalBeijing 100853, P. R. China
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197
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McCreery D, Yadev K, Han M. Responses of neurons in the feline inferior colliculus to modulated electrical stimuli applied on and within the ventral cochlear nucleus; Implications for an advanced auditory brainstem implant. Hear Res 2018; 363:85-97. [PMID: 29573880 DOI: 10.1016/j.heares.2018.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 03/01/2018] [Accepted: 03/06/2018] [Indexed: 11/25/2022]
Abstract
Auditory brainstem implants (ABIs) can restore useful hearing to persons with deafness who cannot benefit from cochlear implants. However, the quality of hearing restored by ABIs rarely is comparable to that provided by cochlear implants in persons for whom those are appropriate. In an animal model, we evaluated elements of a prototype of an ABI in which the functions of macroelectrodes on the surface of the dorsal cochlear nucleus would be integrated with the function of multiple penetrating microelectrodes implanted into the ventral cochlear nucleus. The surface electrodes would convey most of the range of loudness percepts while the intranuclear microelectrodes would sharpen and focus pitch percepts. In the present study, stimulating electrodes were implanted chronically on the surface of the animal's dorsal cochlear nucleus (DCN) and also within their ventral cochlear nucleus (VCN). Recording microelectrodes were implanted into the central nucleus of the inferior colliculus (ICC). The electrical stimuli were sinusoidally modulated stimulus pulse trains applied on the DCN and within the VCN. Temporal encoding of neuronal responses was quantified as vector strength (VS) and as full-cycle rate of neuronal activity in the ICC. VS and full-cycle AP rate were measured for 4 stimulation modes; continuous and transient amplitude modulation of the stimulus pulse trains, each delivered via the macroelectrode on the surface of the DCN and then by the intranuclear penetrating microelectrodes. In the proposed clinical device the functions of the surface and intranuclear microelectrodes could best be integrated if there is minimal variation in the neuronal responses across the range of modulation depth, modulation frequencies, and across the four stimulation modes. In this study VS did vary as much as 34% across modulation frequency and modulation depth within a stimulation mode, and up to 40% between modulation modes. However, these intra- and inter-mode variances differed for different stimulation rates, and at 500 Hz the inter-mode differences in VS and across the range of modulation frequencies and modulation depths was<Roman> = </Roman>24% and the intra-modal differences were<Roman> = </Roman>15%. The findings were generally similar for rate encoding of modulation depth, although the depth of transient amplitude modulation delivered by the surface electrode was weakly encoded as full-cycle rate. Overall, our findings support the concept of a clinical ABI that employs surface stimulation and intranuclear microstimulation in an integrated manner.
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Affiliation(s)
- Douglas McCreery
- Neural Engineering Program at Huntington Medical Research Institutes, 734 Fairmount Ave, Pasadena, CA 91105, USA.
| | - Kamal Yadev
- Rigetti Computing, 775Heinz Avenue, Berkeley, CA 94710, USA.
| | - Martin Han
- Biomedical Engineering Department, School of Engineering & Institute of Material Sciences, The University of Connecticut at Storrs, 260Glenbrook Rd, Unit 3247, Storrs, Connecticut 06269-3247, USA.
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198
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Hay-McCutcheon MJ, Peterson NR, Pisoni DB, Kirk KI, Yang X, Parton J. Performance variability on perceptual discrimination tasks in profoundly deaf adults with cochlear implants. JOURNAL OF COMMUNICATION DISORDERS 2018; 72:122-135. [PMID: 29395103 PMCID: PMC5860985 DOI: 10.1016/j.jcomdis.2018.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 01/09/2018] [Accepted: 01/22/2018] [Indexed: 06/07/2023]
Abstract
OBJECTIVES The purpose of this study was to evaluate performance on two challenging listening tasks, talker and regional accent discrimination, and to assess variables that could have affected the outcomes. STUDY DESIGN A prospective study using 35 adults with one cochlear implant (CI) or a CI and a contralateral hearing aid (bimodal hearing) was conducted. Adults completed talker and regional accent discrimination tasks. METHODS Two-alternative forced-choice tasks were used to assess talker and accent discrimination in a group of adults who ranged in age from 30 years old to 81 years old. RESULTS A large amount of performance variability was observed across listeners for both discrimination tasks. Three listeners successfully discriminated between talkers for both listening tasks, 14 participants successfully completed one discrimination task and 18 participants were not able to discriminate between talkers for either listening task. Some adults who used bimodal hearing benefitted from the addition of acoustic cues provided through a HA but for others the HA did not help with discrimination abilities. Acoustic speech feature analysis of the test signals indicated that both the talker speaking rate and the fundamental frequency (F0) helped with talker discrimination. For accent discrimination, findings suggested that access to more salient spectral cues was important for better discrimination performance. CONCLUSIONS The ability to perform challenging discrimination tasks successfully likely involves a number of complex interactions between auditory and non-auditory pre- and post-implant factors. To understand why some adults with CIs perform similarly to adults with normal hearing and others experience difficulty discriminating between talkers, further research will be required with larger populations of adults who use unilateral CIs, bilateral CIs and bimodal hearing.
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Affiliation(s)
- Marcia J Hay-McCutcheon
- The University of Alabama, Department of Communicative Disorders, Speech and Hearing Center, Box 870242, United States.
| | | | - David B Pisoni
- Indiana University, Department of Psychological and Brain Sciences, United States
| | - Karen Iler Kirk
- The University of Illinois at Urbana-Champaign, Department of Communication Sciences and Disorders, United States
| | - Xin Yang
- The University of Alabama, Information Systems, Statistics, Management Sciences, United States
| | - Jason Parton
- The University of Alabama, Information Systems, Statistics, Management Sciences, United States
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199
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Távora-Vieira D, Wedekind A, Marino R, Purdy SC, Rajan GP. Using aided cortical assessment as an objective tool to evaluate cochlear implant fitting in users with single-sided deafness. PLoS One 2018; 13:e0193081. [PMID: 29470548 PMCID: PMC5823436 DOI: 10.1371/journal.pone.0193081] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 01/22/2018] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVES To assess the use of cortical auditory evoked potentials (CAEPs) to verify, and if necessary, optimize the cochlear implant (CI) fitting of adult CI users with postlingual single-sided deafness (SSD). METHODS Sound field cortical responses to the speech tokens /m/, /g/, /t/, and /s/ were recorded from input to the CI while the normal hearing ear was masked. Responses were evaluated by visual inspection and classified as presence or absence of the CAEPs components P1, N1, P2. In case of an absence fitting was adjusted accordingly. After fitting, subjects were asked to use their new setting for 2-3 weeks for acclimatization purposes and then return for retesting. At retesting, new CAEP recordings were performed to objectively ensure that the new fitting maps effectively activated the auditory cortex. RESULTS In 14/19 subjects, as per visual inspection, clear CAEPs were recorded by each speech token and were, therefore, not refit. In the other 5 subjects, CAEPs could not be evoked for at least one speech token. The fitting maps in these subjects were adjusted until clear CAEPs were evoked for all 4 speech tokens. CONCLUSIONS CAEP can be used to quickly and objectively verify the suitability of CI fitting in experienced adult CI users with SSD. If used in the early post-implantation stage, this method could help CI users derive greater benefit for CI use and, therefore, be more committed to auditory training.
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Affiliation(s)
- Dayse Távora-Vieira
- Otolaryngology, Head & Neck Surgery, School of Surgery, University of Western Australia, Perth, Australia
- Fiona Stanley Hospital, Perth, Australia
| | - Andre Wedekind
- Otolaryngology, Head & Neck Surgery, School of Surgery, University of Western Australia, Perth, Australia
| | - Roberta Marino
- Otolaryngology, Head & Neck Surgery, School of Surgery, University of Western Australia, Perth, Australia
- Fiona Stanley Hospital, Perth, Australia
| | - Suzanne C. Purdy
- School of Physhology, Faculty of Science, University of Auckland, Auckland, New Zealand
- Eisdell Moore Centre, Hearing and Balance Research, Auckland, New Zealand
| | - Gunesh P. Rajan
- Otolaryngology, Head & Neck Surgery, School of Surgery, University of Western Australia, Perth, Australia
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200
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Patro C, Mendel LL. Gated Word Recognition by Postlingually Deafened Adults With Cochlear Implants: Influence of Semantic Context. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2018; 61:145-158. [PMID: 29242894 DOI: 10.1044/2017_jslhr-h-17-0141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/28/2017] [Indexed: 06/07/2023]
Abstract
PURPOSE The main goal of this study was to investigate the minimum amount of sensory information required to recognize spoken words (isolation points [IPs]) in listeners with cochlear implants (CIs) and investigate facilitative effects of semantic contexts on the IPs. METHOD Listeners with CIs as well as those with normal hearing (NH) participated in the study. In Experiment 1, the CI users listened to unprocessed (full-spectrum) stimuli and individuals with NH listened to full-spectrum or vocoder processed speech. IPs were determined for both groups who listened to gated consonant-nucleus-consonant words that were selected based on lexical properties. In Experiment 2, the role of semantic context on IPs was evaluated. Target stimuli were chosen from the Revised Speech Perception in Noise corpus based on the lexical properties of the final words. RESULTS The results indicated that spectrotemporal degradations impacted IPs for gated words adversely, and CI users as well as participants with NH listening to vocoded speech had longer IPs than participants with NH who listened to full-spectrum speech. In addition, there was a clear disadvantage due to lack of semantic context in all groups regardless of the spectral composition of the target speech (full spectrum or vocoded). Finally, we showed that CI users (and users with NH with vocoded speech) can overcome such word processing difficulties with the help of semantic context and perform as well as listeners with NH. CONCLUSION Word recognition occurs even before the entire word is heard because listeners with NH associate an acoustic input with its mental representation to understand speech. The results of this study provide insight into the role of spectral degradation on the processing of spoken words in isolation and the potential benefits of semantic context. These results may also explain why CI users rely substantially on semantic context.
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Affiliation(s)
| | - Lisa Lucks Mendel
- School of Communication Sciences & Disorders, University of Memphis, TN
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