1
|
Marx M, Laborde ML, Algans C, Tartayre M, James CJ. Barriers to Early Progress in Adult Cochlear Implant Outcomes. Ear Hear 2024:00003446-990000000-00329. [PMID: 39129126 DOI: 10.1097/aud.0000000000001559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
OBJECTIVES Adult cochlear implant (CI) recipients obtain varying levels of speech perception from their device. Adult CI users adapt quickly to their CI if they have no peripheral "bottom-up" or neurocognitive "top-down" limiting factors. Our objective here was to understand the influence of limiting factors on the progression of sentence understanding in quiet and in noise, initially and over time. We hypothesized that the presence of limiting factors, detected using a short test battery, would predictably influence sentence recognition with practical consequences. We aimed to validate the test battery by comparing the presence of limiting factors and the success criteria of >90% sentence understanding in quiet 1 month after activation. DESIGN The study was a single-clinic, cross-sectional, retrospective design incorporating 32 adult unilateral Nucleus CI users aged 27 to 90 years (mean = 70, SD = 13.5). Postoperative outcome was assessed through sentence recognition scores in quiet and in varying signal to noise ratios at 1 day, 1 to 2 months, and up to 2 years. Our clinic's standard test battery comprises physiological and neurocognitive measures. Physiological measures included electrically evoked compound action potentials for recovery function, spread of excitation, and polarity effect. To evaluate general cognitive function, inhibition, and phonological awareness, the Montreal Cognitive Assessment screening test, the Stroop Color-Word Test, and tests 3 and 4 of the French Assessment of Reading Skills in Adults over 16 years of age, respectively were performed. Physiological scores were considered abnormal, and therefore limiting, when total neural recovery periods and polarity effects, for both apical and basal electrode positions, were >1.65 SDs from the population mean. A spread of excitation of >6 electrode units was also considered limiting. For the neurocognitive tests, scores poorer than 1.65 SDs from published normal population means were considered limiting. RESULTS At 1 month, 13 out of 32 CI users scored ≥90% sentence recognition in quiet with no significant dependence on age. Subjects with no limiting peripheral or neurocognitive factors were 8.5 times more likely to achieve ≥90% score in quiet at 1 month after CI switch-on (p = 0.010). In our sample, we detected 4 out of 32 cases with peripheral limiting factors that related to neural health or poor electrode-neural interface at both apical and basal positions. In contrast, neurocognitive limiting factors were identified in 14 out of 32 subjects. Early sentence recognition scores were predictive of long-term sentence recognition thresholds in noise such that limiting factors appeared to be of continuous influence. CONCLUSIONS Both peripheral and neurocognitive processing factors affect early sentence recognition after CI activation. Peripheral limiting factors may have been detected less often than neurocognitive limiting factors because they were defined using sample-based criteria versus normal population-based criteria. Early performance was generally predictive of long-term performance. Understanding the measurable covariables that limit CI performance may inform follow-up and improve counseling. A score of ≥90% for sentence recognition in quiet at 1 month may be used to define successful progress; whereas, lower scores indicate the need for diagnostic testing and ongoing rehabilitation. Our findings suggest that sentence test scores as early as 1 day after activation can provide vital information for the new CI user and indicate the need for rehabilitation follow-up.
Collapse
Affiliation(s)
- Mathieu Marx
- Service Oto Rhino Laryngologie Hôpital Riquet, Toulouse, France
| | | | - Carol Algans
- Service Oto Rhino Laryngologie Hôpital Riquet, Toulouse, France
| | | | | |
Collapse
|
2
|
Callejón-Leblic MA, Lazo-Maestre M, Fratter A, Ropero-Romero F, Sánchez-Gómez S, Reina-Tosina J. A full-head model to investigate intra and extracochlear electric fields in cochlear implant stimulation. Phys Med Biol 2024; 69:155010. [PMID: 38925131 DOI: 10.1088/1361-6560/ad5c38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 06/26/2024] [Indexed: 06/28/2024]
Abstract
Objective.Despite the widespread use and technical improvement of cochlear implant (CI) devices over past decades, further research into the bioelectric bases of CI stimulation is still needed. Various stimulation modes implemented by different CI manufacturers coexist, but their true clinical benefit remains unclear, probably due to the high inter-subject variability reported, which makes the prediction of CI outcomes and the optimal fitting of stimulation parameters challenging. A highly detailed full-head model that includes a cochlea and an electrode array is developed in this study to emulate intracochlear voltages and extracochlear current pathways through the head in CI stimulation.Approach.Simulations based on the finite element method were conducted under monopolar, bipolar, tripolar (TP), and partial TP modes, as well as for apical, medial, and basal electrodes. Variables simulated included: intracochlear voltages, electric field (EF) decay, electric potentials at the scalp and extracochlear currents through the head. To better understand CI side effects such as facial nerve stimulation, caused by spurious current leakage out from the cochlea, special emphasis is given to the analysis of the EF over the facial nerve.Main results.The model reasonably predicts EF magnitudes and trends previously reported in CI users. New relevant extracochlear current pathways through the head and brain tissues have been identified. Simulated results also show differences in the magnitude and distribution of the EF through different segments of the facial nerve upon different stimulation modes and electrodes, dependent on nerve and bone tissue conductivities.Significance.Full-head models prove useful tools to model intra and extracochlear EFs in CI stimulation. Our findings could prove useful in the design of future experimental studies to contrast FNS mechanisms upon stimulation of different electrodes and CI modes. The full-head model developed is freely available for the CI community for further research and use.
Collapse
Affiliation(s)
- M A Callejón-Leblic
- Otorhinolaryngology Department, Virgen Macarena University Hospital, Seville 41009, Spain
- Oticon Medical, 28108 Madrid, Spain
- Dept. Signal Theory and Communications, Biomedical Engineering Group, University of Seville, Seville 41092, Spain
| | - M Lazo-Maestre
- Otorhinolaryngology Department, Virgen Macarena University Hospital, Seville 41009, Spain
| | - A Fratter
- Oticon Medical, 06220 Vallauris, France
| | - F Ropero-Romero
- Otorhinolaryngology Department, Virgen Macarena University Hospital, Seville 41009, Spain
| | - S Sánchez-Gómez
- Otorhinolaryngology Department, Virgen Macarena University Hospital, Seville 41009, Spain
| | - J Reina-Tosina
- Dept. Signal Theory and Communications, Biomedical Engineering Group, University of Seville, Seville 41092, Spain
| |
Collapse
|
3
|
Yin M, Wang X, Zhang L, Shu G, Wang Z, Huang S, Yin M. A Scalable, Programmable Neural Stimulator for Enhancing Generalizability in Neural Interface Applications. BIOSENSORS 2024; 14:323. [PMID: 39056599 PMCID: PMC11275035 DOI: 10.3390/bios14070323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/20/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024]
Abstract
Each application of neurostimulators requires unique stimulation parameter specifications to achieve effective stimulation. Balancing the current magnitude with stimulation resolution, waveform, size, and channel count is challenging, leading to a loss of generalizability across broad neural interfaces. To address this, this paper proposes a highly scalable, programmable neurostimulator with a System-on-Chip (SOC) capable of 32 channels of independent stimulation. The compliance voltage reaches up to ±22.5 V. A pair of 8-bit current-mode DACs support independent waveforms for source and sink operations and feature a user-selectable dual range for low-current intraparenchymal microstimulation with a resolution of 4.31 μA/bit, as well as high current stimulation for spinal cord and DBS applications with a resolution of 48.00 μA/bit, achieving a wide stimulation range of 12.24 mA while maintaining high-resolution biological stimulation. A dedicated communication protocol enables full programmable control of stimulation waveforms, effectively improving the range of stimulation parameters. In vivo electrophysiological experiments successfully validate the functionality of the proposed stimulator. This flexible stimulator architecture aims to enhance its generality across a wide range of neural interfaces and will provide more diverse and refined stimulation strategies.
Collapse
Affiliation(s)
- Meng Yin
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| | - Xiao Wang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| | - Liuxindai Zhang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| | - Guijun Shu
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| | - Zhen Wang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| | - Shoushuang Huang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| | - Ming Yin
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou 570228, China; (M.Y.)
- Key Laboratory of Biomedical Engineering of Hainan Province, One Health Institute, Hainan University, Haikou 570228, China
| |
Collapse
|
4
|
Gaultier C, Goehring T. Recovering speech intelligibility with deep learning and multiple microphones in noisy-reverberant situations for people using cochlear implants. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2024; 155:3833-3847. [PMID: 38884525 DOI: 10.1121/10.0026218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 05/10/2024] [Indexed: 06/18/2024]
Abstract
For cochlear implant (CI) listeners, holding a conversation in noisy and reverberant environments is often challenging. Deep-learning algorithms can potentially mitigate these difficulties by enhancing speech in everyday listening environments. This study compared several deep-learning algorithms with access to one, two unilateral, or six bilateral microphones that were trained to recover speech signals by jointly removing noise and reverberation. The noisy-reverberant speech and an ideal noise reduction algorithm served as lower and upper references, respectively. Objective signal metrics were compared with results from two listening tests, including 15 typical hearing listeners with CI simulations and 12 CI listeners. Large and statistically significant improvements in speech reception thresholds of 7.4 and 10.3 dB were found for the multi-microphone algorithms. For the single-microphone algorithm, there was an improvement of 2.3 dB but only for the CI listener group. The objective signal metrics correctly predicted the rank order of results for CI listeners, and there was an overall agreement for most effects and variances between results for CI simulations and CI listeners. These algorithms hold promise to improve speech intelligibility for CI listeners in environments with noise and reverberation and benefit from a boost in performance when using features extracted from multiple microphones.
Collapse
Affiliation(s)
- Clément Gaultier
- Cambridge Hearing Group, Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, United Kingdom
| | - Tobias Goehring
- Cambridge Hearing Group, Medical Research Council Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, United Kingdom
| |
Collapse
|
5
|
Eitutis ST, Tam YC, Roberts I, Swords C, Tysome JR, Donnelly NP, Axon PR, Bance ML. Detecting and managing partial shorts in Cochlear implants: A validation of scalp surface potential testing. Clin Otolaryngol 2022; 47:641-649. [PMID: 35833359 DOI: 10.1111/coa.13963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 05/18/2022] [Accepted: 06/21/2022] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To investigate the value of scalp surface potentials to identify and manage partial short circuits to ground in cochlear implant electrodes. DESIGN A retrospective review of patients with suspected partial short circuits. MAIN OUTCOME MEASURE Electrical output of individual electrodes was measured using scalp surface potentials for patients reporting a change in hearing function. Electrical output was compared to functional performance and impedance measurements to determine if devices with suspected partial short circuits were experiencing a decrease in performance as a result of reduced electrical output. Electrical output was checked in an artificial cochlea for two implants following explant surgery to confirm scalp surface potential results. RESULTS All patients with suspected partial short circuits (n = 49) had reduced electrical output, a drop in impedances to approximately ½ of previously stable measurements or to below 2 kΩ, an atypical electrical field measurement (EFI) and a decline in hearing function. Only devices with an atypical EFI showed reduced electrical output. Results of scalp based surface potentials could be replicated in an artificial cochlea following explantation of the device. All explant reports received to date (n = 42) have confirmed partial short circuits, with an additional four devices failing integrity tests. CONCLUSION Surface potential measurements can detect partial shorts and had 100% correlation with atypical EFI measurements, which are characteristic of a partial short to ground in this device. Surface potentials can help determine the degree to which the electrode array is affected, particularly when behavioural testing is limited or not possible.
Collapse
Affiliation(s)
- Susan T Eitutis
- Cambridge Hearing Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Yu Chuen Tam
- Cambridge Hearing Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Iwan Roberts
- Cambridge Hearing Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Chloe Swords
- Cambridge Hearing Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Department of ENT, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - James R Tysome
- Cambridge Hearing Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Department of ENT, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Neil P Donnelly
- Department of ENT, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Patrick R Axon
- Department of ENT, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Manohar L Bance
- Cambridge Hearing Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Department of ENT, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| |
Collapse
|
6
|
Eitutis ST, Carlyon RP, Tam YC, Salorio-Corbetto M, Vanat Z, Tebbutt K, Bardsley R, Powell HRF, Chowdhury S, Tysome JR, Bance ML. Management of Severe Facial Nerve Cross Stimulation by Cochlear Implant Replacement to Change Pulse Shape and Grounding Configuration: A Case-series. Otol Neurotol 2022; 43:452-459. [PMID: 35085112 PMCID: PMC8915992 DOI: 10.1097/mao.0000000000003493] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To investigate the combined effect of changing pulse shape and grounding configuration to manage facial nerve stimulation (FNS) in cochlear implant (CI) recipients. PATIENTS Three adult CI recipients with severe FNS were offered a replacement implant when standard stimulation strategies and programming adjustments did not resolve symptoms. Our hypothesis was that the facial nerve was less likely to be activated when using anodic pulses with "mixed-mode" intra-cochlear and extra-cochlear current return. INTERVENTION All patients were reimplanted with an implant that uses a pseudo-monophasic anodic pulse shape, with mixed-mode grounding (stimulus mixed-mode anodic)-the Neuro Zti CI (Oticon Medical). This device also allows measurements of neural function and loudness with monopolar, symmetric biphasic pulses (stimulus MB), the clinical standard used by most CIs as a comparison. MAIN OUTCOME MEASURES The combined effect of pulse shape and grounding configuration on FNS was monitored during surgery. Following CI activation, FNS symptoms and performance with the Neuro Zti implant were compared with outcomes before reimplantation. RESULTS FNS could only be recorded using stimulus MB for all patients. In clinical use, all patients reported reduced FNS and showed an improvement in Bamford-Kowal-Bench sentences recognition compared with immediately before reimplantation. Bamford-Kowal-Bench scores with a male speaker were lower compared with measurements taken before the onset of severe FNS for patients 1 and 2. CONCLUSIONS In patients where CI auditory performance was severely limited by FNS, charge-balanced pseudo-monophasic stimulation mode with a mixed-mode grounding configuration limited FNS and improved loudness percept compared with standard biphasic stimulation with monopolar grounding.
Collapse
Affiliation(s)
- Susan T Eitutis
- Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust
- Cambridge Hearing Group, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge
| | - Robert P Carlyon
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, Cambridge
| | - Yu Chuen Tam
- Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust
- Cambridge Hearing Group, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge
| | - Marina Salorio-Corbetto
- Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust
- Cambridge Hearing Group, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge
| | - Zebunnisa Vanat
- Emmeline Centre, Cambridge University Hospitals NHS Foundation Trust
| | | | | | | | | | - James R Tysome
- Cambridge Hearing Group, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge
| | - Manohar L Bance
- Cambridge Hearing Group, Department of Clinical Neurosciences, Cambridge Biomedical Campus, University of Cambridge
| |
Collapse
|
7
|
Joly CA, Reynard P, Hermann R, Seldran F, Gallego S, Idriss S, Thai-Van H. Intra-Cochlear Current Spread Correlates with Speech Perception in Experienced Adult Cochlear Implant Users. J Clin Med 2021; 10:jcm10245819. [PMID: 34945115 PMCID: PMC8709369 DOI: 10.3390/jcm10245819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/03/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022] Open
Abstract
Broader intra-cochlear current spread (ICCS) implies higher cochlear implant (CI) channel interactions. This study aimed to investigate the relationship between ICCS and speech intelligibility in experienced CI users. Using voltage matrices collected for impedance measurements, an individual exponential spread coefficient (ESC) was computed. Speech audiometry was performed to determine the intelligibility at 40 dB Sound Pressure Level (SPL) and the 50% speech reception threshold: I40 and SRT50 respectively. Correlations between ESC and either I40 or SRT50 were assessed. A total of 36 adults (mean age: 50 years) with more than 11 months (mean: 34 months) of CI experience were included. In the 21 subjects for whom all electrodes were active, ESC was moderately correlated with both I40 (r = −0.557, p = 0.009) and SRT50 (r = 0.569, p = 0.007). The results indicate that speech perception performance is negatively affected by the ICCS. Estimates of current spread at the closest vicinity of CI electrodes and prior to any activation of auditory neurons are indispensable to better characterize the relationship between CI stimulation and auditory perception in cochlear implantees.
Collapse
Affiliation(s)
- Charles-Alexandre Joly
- Institut de l’Audition, Institut Pasteur, Université de Paris, INSERM, 75012 Paris, France; (C.-A.J.); (P.R.)
- Université Claude Bernard Lyon 1, 69100 Villeurbanne, France; (R.H.); (S.G.)
- Service d’Audiologie et d’Explorations Otoneurologiques, Hôpital Edouard Herriot, Hospices Civils de Lyon, 69003 Lyon, France;
| | - Pierre Reynard
- Institut de l’Audition, Institut Pasteur, Université de Paris, INSERM, 75012 Paris, France; (C.-A.J.); (P.R.)
- Université Claude Bernard Lyon 1, 69100 Villeurbanne, France; (R.H.); (S.G.)
- Service d’Audiologie et d’Explorations Otoneurologiques, Hôpital Edouard Herriot, Hospices Civils de Lyon, 69003 Lyon, France;
| | - Ruben Hermann
- Université Claude Bernard Lyon 1, 69100 Villeurbanne, France; (R.H.); (S.G.)
- Integrative, Multisensory, Perception, Action and Cognition Team (IMPACT), Inserm U1028, CNRS UMR5292, Lyon Neuroscience Research Center, 69675 Bron, France
- Service d’ORL, Chirurgie Cervico-Faciale et d’Audiophonologie, Hospices Civils de Lyon, Hôpital Edouard Herriot, 69003 Lyon, France
| | | | - Stéphane Gallego
- Université Claude Bernard Lyon 1, 69100 Villeurbanne, France; (R.H.); (S.G.)
- Neuronal Dynamics and Audition Team (DNA), Laboratory of Cognitive Neuroscience, CNRS UMR7291, Aix-Marseille University, CEDEX 3, 13331 Marseille, France
| | - Samar Idriss
- Service d’Audiologie et d’Explorations Otoneurologiques, Hôpital Edouard Herriot, Hospices Civils de Lyon, 69003 Lyon, France;
| | - Hung Thai-Van
- Institut de l’Audition, Institut Pasteur, Université de Paris, INSERM, 75012 Paris, France; (C.-A.J.); (P.R.)
- Université Claude Bernard Lyon 1, 69100 Villeurbanne, France; (R.H.); (S.G.)
- Service d’Audiologie et d’Explorations Otoneurologiques, Hôpital Edouard Herriot, Hospices Civils de Lyon, 69003 Lyon, France;
- Correspondence:
| |
Collapse
|
8
|
Lei IM, Jiang C, Lei CL, de Rijk SR, Tam YC, Swords C, Sutcliffe MPF, Malliaras GG, Bance M, Huang YYS. 3D printed biomimetic cochleae and machine learning co-modelling provides clinical informatics for cochlear implant patients. Nat Commun 2021; 12:6260. [PMID: 34716306 PMCID: PMC8556326 DOI: 10.1038/s41467-021-26491-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 10/06/2021] [Indexed: 02/07/2023] Open
Abstract
Cochlear implants restore hearing in patients with severe to profound deafness by delivering electrical stimuli inside the cochlea. Understanding stimulus current spread, and how it correlates to patient-dependent factors, is hampered by the poor accessibility of the inner ear and by the lack of clinically-relevant in vitro, in vivo or in silico models. Here, we present 3D printing-neural network co-modelling for interpreting electric field imaging profiles of cochlear implant patients. With tuneable electro-anatomy, the 3D printed cochleae can replicate clinical scenarios of electric field imaging profiles at the off-stimuli positions. The co-modelling framework demonstrated autonomous and robust predictions of patient profiles or cochlear geometry, unfolded the electro-anatomical factors causing current spread, assisted on-demand printing for implant testing, and inferred patients' in vivo cochlear tissue resistivity (estimated mean = 6.6 kΩcm). We anticipate our framework will facilitate physical modelling and digital twin innovations for neuromodulation implants.
Collapse
Affiliation(s)
- Iek Man Lei
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom.,The Nanoscience Centre, University of Cambridge, Cambridge, United Kingdom
| | - Chen Jiang
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Department of Electronic Engineering, Tsinghua University, Beijing, 100084, China
| | - Chon Lok Lei
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau.,Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Simone Rosalie de Rijk
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Yu Chuen Tam
- Emmeline Centre for Hearing Implants, Addenbrookes Hospital, Cambridge, United Kingdom
| | - Chloe Swords
- Department of Physiology, Development and Neurosciences, Cambridge, United Kingdom
| | | | - George G Malliaras
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Manohar Bance
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.
| | - Yan Yan Shery Huang
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom. .,The Nanoscience Centre, University of Cambridge, Cambridge, United Kingdom.
| |
Collapse
|