Auditory Prostheses Research with Multiple Channel Intracochlear Stimulation in Man

1978 ◽  
Vol 87 (6_suppl) ◽  
pp. 5-39 ◽  
Author(s):  
D. K. Eddington ◽  
W. H. Dobelle ◽  
M. G. Mladejovsky ◽  
D. E. Brackmann ◽  
J. L. Parkin
Keyword(s):  
Single Channel ◽  
Speech Discrimination ◽  
Electrode Arrays ◽  
Multiple Channel ◽  
Intelligible Speech ◽  
Electrode Interaction ◽  
Stimulation System ◽  
Place Pitch ◽  
Channel Electrode

Although single-channel electrode arrays implanted in the scala tympani of deaf patients are useful as an aid to lip reading and for distinguishing some environmental sounds, they do not transmit intelligible speech. However, multichannel electrode arrays, which take advantage of the cochlea's tonotopic organization, may be capable of generating the complex patterns of neural activity necessary for speech discrimination. In this study, multichannel electrodes were implanted in the cochleas of four volunteers, with access to the connecting wires made through the skin via a percutaneous connector. The major portion of the data presented is from two of these subjects: one has been bilaterally deaf since birth and the other has been unilaterally deaf for 15 years. Preliminary results of experiments with two more recently implanted subjects are described as well as experiments with a fifth volunteer who was implanted with five electrodes by House in 1969. Data on pitch and loudness discrimination as well as the effects of stimulation parameters on threshold, impedance, and electrode interaction are presented. Place pitch and periodicity pitch were observed in all five volunteers. The results of pitch-matching experiments with the unilaterally deaf volunteer were consistent with tonotopic maps of the cochlea, and experiments indicated that a pitch continuum may be achieved by combining place and periodicity pitch modulation. Preliminary experiments in tune recognition with one subject demonstrate his ability to recognize simple melodies based on periodicity pitch cues. These results, coupled with the finding that subjective sensations remain stable over the long-term, support the feasibility of providing artificial hearing with a multichannel cochlear stimulation system.

Current Status of Multichannel Cochlear Protheses

1979 ◽  
Vol 88 (5) ◽  
pp. 729-733 ◽  
Author(s):  
F. Terry Hambrecht
Keyword(s):  
Nerve Stimulation ◽  
Nerve Fibers ◽  
Current Status ◽  
Electrode Arrays ◽  
Acoustic Environment ◽  
Research Questions ◽  
Place Pitch ◽  
Frequency Of Stimulation ◽  
Safety Range

Multichannel cochlear prostheses are being developed and evaluated with emphasis on providing sensory deaf individuals enough information about their acoustic environment to permit communication by ordinary speech. Studies of the safety of the electrode arrays and stimulus values indicate that the remaining nerve fibers will not be damaged at the levels that will be typically used in human prostheses, but that a narrow safety range exists for suprathreshold stimuli. Early multichannel human implants have demonstrated that place pitch can be utilized with scali tympani implants, but this has not been demonstrated with modiolar electrode arrays. With both approaches, information about pitch can be conveyed by the frequency of stimulation. Research questions remain on the long-term viability of the eighth nerve with stimulated implants, on the interactions of closely spaced electrodes, on optimal methods of encoding the acoustic signal for multichannel nerve stimulation and on the ability of deaf individuals to utilize this information.

Present Status and Future Development of the Cochlear Prosthesis

1975 ◽  
Vol 84 (4) ◽  
pp. 494-498 ◽  
Author(s):  
Robin P. Michelson ◽  
Michael M. Merzenich ◽  
Robert A. Schindler ◽  
David N. Schindler
Keyword(s):  
Electrical Stimulation ◽  
Communication Skills ◽  
Auditory Nerve ◽  
Single Channel ◽  
Speech Discrimination ◽  
Cochlear Prosthesis ◽  
Aural Rehabilitation ◽  
Complex Sounds ◽  
Place Pitch ◽  
Stimulation Of

Presently devised single channel devices generate relatively primitive sensation of hearing. They provide some enhancement of communication skills for the totally deaf. Definite psychological advantages for the totally deaf have been observed. Pitch discrimination is by the mechanism of “periodicity pitch.” No “place” pitch encoding is possible. The recognition of complex sounds is not possible. Multiple segments of auditory nerve must be stimulated in a manner which will simulate the complex patterns of neural activity necessary for speech discrimination. Electrodes can be optimized and the pathophysiological consequences of electrical stimulation can be determined in experimental animals. The perceptual consequences of electrical stimulation, however, can best be determined in man himself. How much we will have to rely on known and future methods of aural rehabilitation will depend upon how well perceptual speech patterns can be generated by electrical stimulation of the auditory nerve.

Component analysis reveals sharp tuning of the local field potential in the guinea pig auditory cortex

2013 ◽  
Vol 109 (1) ◽  
pp. 261-272 ◽  
Author(s):  
Alain de Cheveigné ◽  
Jean-Marc Edeline ◽  
Quentin Gaucher ◽  
Boris Gourévitch
Keyword(s):  
Auditory Cortex ◽  
Local Field ◽  
Receptive Fields ◽  
Field Potential ◽  
Component Analysis ◽  
Electrode Arrays ◽  
Linear Combinations ◽  
Spectrotemporal Receptive Fields ◽  
Analysis Technique ◽  
Channel Electrode

Local field potentials (LFPs) recorded in the auditory cortex of mammals are known to reveal weakly selective and often multimodal spectrotemporal receptive fields in contrast to spiking activity. This may in part reflect the wider “listening sphere” of LFPs relative to spikes due to the greater current spread at low than high frequencies. We recorded LFPs and spikes from auditory cortex of guinea pigs using 16-channel electrode arrays. LFPs were processed by a component analysis technique that produces optimally tuned linear combinations of electrode signals. Linear combinations of LFPs were found to have sharply tuned responses, closer to spike-related tuning. The existence of a sharply tuned component implies that a cortical neuron (or group of neurons) capable of forming a linear combination of its inputs has access to that information. Linear combinations of signals from electrode arrays reveal information latent in the subspace spanned by multichannel LFP recordings and are justified by the fact that the observations themselves are linear combinations of neural sources.

scholarly journals PKA drives an increase in AMPA receptor unitary conductance during LTP in the hippocampus

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pojeong Park ◽  
John Georgiou ◽  
Thomas M. Sanderson ◽  
Kwang-Hee Ko ◽  
Heather Kang ◽  
...  
Keyword(s):  
Ampa Receptors ◽  
Single Channel ◽  
Hippocampal Slices ◽  
Long Term Potentiation ◽  
Theta Burst Stimulation ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Necessary And Sufficient ◽  
Theta Burst

AbstractLong-term potentiation (LTP) at hippocampal CA1 synapses can be expressed by an increase either in the number (N) of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors or in their single channel conductance (γ). Here, we have established how these distinct synaptic processes contribute to the expression of LTP in hippocampal slices obtained from young adult rodents. LTP induced by compressed theta burst stimulation (TBS), with a 10 s inter-episode interval, involves purely an increase in N (LTPN). In contrast, either a spaced TBS, with a 10 min inter-episode interval, or a single TBS, delivered when PKA is activated, results in LTP that is associated with a transient increase in γ (LTPγ), caused by the insertion of calcium-permeable (CP)-AMPA receptors. Activation of CaMKII is necessary and sufficient for LTPN whilst PKA is additionally required for LTPγ. Thus, two mechanistically distinct forms of LTP co-exist at these synapses.

scholarly journals ANALISIS KINERJA SISTEM ANTRIAN DALAM MENGOPTIMALKAN PELAYANAN PASIEN RAWAT JALAN DI RSUD HAJI MAKASSAR

2018 ◽  
Vol 14 (3) ◽  
pp. 228-238
Author(s):  
Maat Pono
Keyword(s):  
Single Channel ◽  
Multiple Channel ◽  
Query System

Tujuan dari penelitian ini untuk mengetahui kinerja sistem antrian yang saat ini digunakan oleh RSUD Haji Makassar. Berdasarkan hasil penelitian, model antrian yang saat ini diterapkan pada bagian registrasi pasien rawat jalan di RSUD Haji Makassar menunjukkan kinerja yang belum begitu baik pada loket pendaftaran, adapun model yang saat ini digunakan adalah sistem antrian model jalur tunggal atau Single Channel Query System (M/M/1). Berdasarkan hasil observasi dan perhitungan menggunakan rumus dari model (M/M/1) diketahui pasien lama membutuhkan waktu berada dalam antrian adalah selama 57,27 menit serta orang dalam antrian sebanyak 21 orang dan ini terjadi pada periode waktu 09.00-10.00 sampai 10.00-11.00. Untuk pasien baru membutuhkan waktu berada dalam antrian selama 50 menit dan jumlah orang dalam antrian sebanyak 5 orang dan ini terjadi pada periode waktu 09.00-10.00 sampai 11.00-12.00. Alternatif yang dapat menangani masalah pada loket pendaftaran adalah dengan merubah komposisi server dengan menggunakan Multiple Channel Query System (M/M/s) melalui model ini waktu yang dibutuhkan pasien lama didalam antrian menurun menjadi 0,8 menit, serta pasien lama dalam antrian yang awalnya 21 orang menjadi 1,24 orang, dengan alternatif ini kinerja sistem antrian dapat lebih optimal.

IMPLEMENTATION OF MULTIPLE-CHANNEL CAPACITIVE ECG MEASUREMENT BASED ON CONDUCTIVE FABRIC

2013 ◽  
Vol 25 (06) ◽  
pp. 1350052 ◽  
Author(s):  
Yue-Der Lin ◽  
Ya-Hsuech Chien ◽  
Shih-Fan Wang ◽  
Cheng-Lun Tsai ◽  
Hen-Hong Chang ◽  
...  
Keyword(s):  
Circuit Diagram ◽  
Test Results ◽  
Theoretic Analysis ◽  
Multiple Channel ◽  
Conductive Fabric ◽  
The Subject ◽  
The Common ◽  
Power Line Interference ◽  
Electrocardiogram Ecg

Capacitive electrocardiogram (cECG) measurement is an attractive approach for long-term health monitoring. However, there is little literature available for the implementation of multiple-channel cECG system in standard limb leads. The circuit diagram for such a system is also rarely available in literature. This paper presents a multiple-channel limb-lead cECG system that utilized conductive fabrics as the capacitive sensors. The design criteria and the corresponding circuit diagram are described in detail. The proposed system also incorporates the capacitive driven-body (CDB) circuit to reduce the common-mode power-line interference (PLI). The presented system is verified to be stable by theoretic analysis and long-term experiments. The signals acquired by the presented system are competitive with those by commercially available electrocardiogram (ECG) machines. The feasible size and distance to the subject for the sensor made by conductive fabric have also been evaluated by a series of tests. From the test results, the sensor is suggested to be of greater than 60 cm2 in area and not more than 3 mm in distance for cECG measurement.

scholarly journals Evaluation of Seven Atmospheric Profiles from Reanalysis and Satellite-Derived Products: Implication for Single-Channel Land Surface Temperature Retrieval

2020 ◽  
Vol 12 (5) ◽  
pp. 791 ◽  
Author(s):  
Jingjing Yang ◽  
Si-Bo Duan ◽  
Xiaoyu Zhang ◽  
Penghai Wu ◽  
Cheng Huang ◽  
...  
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Single Channel ◽  
Landsat 8 ◽  
Atmospheric Profiles ◽  
Atmospheric Profile

Land surface temperature (LST) is vital for studies of hydrology, ecology, climatology, and environmental monitoring. The radiative-transfer-equation-based single-channel algorithm, in conjunction with the atmospheric profile, is regarded as the most suitable one with which to produce long-term time series LST products from Landsat thermal infrared (TIR) data. In this study, the performances of seven atmospheric profiles from different sources (the MODerate-resolution Imaging Spectroradiomete atmospheric profile product (MYD07), the Atmospheric Infrared Sounder atmospheric profile product (AIRS), the European Centre for Medium-range Weather Forecasts (ECMWF), the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA2), the National Centers for Environmental Prediction (NCEP)/Global Forecasting System (GFS), NCEP/Final Operational Global Analysis (FNL), and NCEP/Department of Energy (DOE)) were comprehensively evaluated in the single-channel algorithm for LST retrieval from Landsat 8 TIR data. Results showed that when compared with the radio sounding profile downloaded from the University of Wyoming (UWYO), the worst accuracies of atmospheric parameters were obtained for the MYD07 profile. Furthermore, the root-mean-square error (RMSE) values (approximately 0.5 K) of the retrieved LST when using the ECMWF, MERRA2, NCEP/GFS, and NCEP/FNL profiles were smaller than those but greater than 0.8 K when the MYD07, AIRS, and NCEP/DOE profiles were used. Compared with the in situ LST measurements that were collected at the Hailar, Urad Front Banner, and Wuhai sites, the RMSE values of the LST that were retrieved by using the ECMWF, MERRA2, NCEP/GFS, and NCEP/FNL profiles were approximately 1.0 K. The largest discrepancy between the retrieved and in situ LST was obtained for the NCEP/DOE profile, with an RMSE value of approximately 1.5 K. The results reveal that the ECMWF, MERRA2, NCEP/GFS, and NCEP/FNL profiles have great potential to perform accurate atmospheric correction and generate long-term time series LST products from Landsat TIR data by using a single-channel algorithm.

scholarly journals Effect of Closed-Loop Vibration Stimulation on Heart Rhythm during Naps

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4136 ◽  
Author(s):  
Sang Ho Choi ◽  
Heenam Yoon ◽  
Hyung Won Jin ◽  
Hyun Bin Kwon ◽  
Seong Min Oh ◽  
...  
Keyword(s):  
High Frequency ◽  
Closed Loop ◽  
Low Frequency ◽  
Heart Rhythm ◽  
Quality Of Sleep ◽  
Stimulation Condition ◽  
Term Basis ◽  
Stimulation System

Sleep plays a primary function for health and sustains physical and cognitive performance. Although various stimulation systems for enhancing sleep have been developed, they are difficult to use on a long-term basis. This paper proposes a novel stimulation system and confirms its feasibility for sleep. Specifically, in this study, a closed-loop vibration stimulation system that detects the heart rate (HR) and applies −n% stimulus beats per minute (BPM) computed on the basis of the previous 5 min of HR data was developed. Ten subjects participated in the evaluation experiment, in which they took a nap for approximately 90 min. The experiment comprised one baseline and three stimulation conditions. HR variability analysis showed that the normalized low frequency (LF) and LF/high frequency (HF) parameters significantly decreased compared to the baseline condition, while the normalized HF parameter significantly increased under the −3% stimulation condition. In addition, the HR density around the stimulus BPM significantly increased under the −3% stimulation condition. The results confirm that the proposed stimulation system could influence heart rhythm and stabilize the autonomic nervous system. This study thus provides a new stimulation approach to enhance the quality of sleep and has the potential for enhancing health levels through sleep manipulation.

Extracochlear Implantation: Technique and Results

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 111-113 ◽  
Author(s):  
B. Fraysse ◽  
M. J. Soulier ◽  
H. Urgell ◽  
P. Levy ◽  
F. Furia ◽  
...  
Keyword(s):  
Signal Processing ◽  
Single Channel ◽  
Round Window ◽  
Pectoral Muscle ◽  
Rehabilitation Program ◽  
Implantation Technique ◽  
Facial Recess ◽  
Deaf Adults ◽  
Channel Electrode

The authors present an overview of the technique and results in the rehabilitation of totally deaf adults by an extracochlear single-channel electrode. Eight patients were implanted with a follow-up of at least 6 months. Sound signal processing, the receiver, and the electrode are described. The access to the round window is through the facial recess. The internal coil is placed over the pectoral muscle. The rehabilitation program consists of training patients to recognize background sounds up to more discriminating exercises. The results are discussed.

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