Abstract:
OBJECTIVE:Retinal prosthetic implants restore partial vision to patients blinded due to outer retinal degeneration, using a camera-guided multielectrode array (MEA) that electrically stimulates surviving retinal neurons. Commercial epi-retinal prostheses use millisecond-scale charge-balanced, symmetric, cathodic-first biphasic pulses to depolarize retinal ganglion cells (RGCs) and bipolar cells (BCs), frequently creating oblong perceptions of light related to axonal activation of RGCs. Stimulation strategies that avoid axonal stimulation and decrease the threshold of targeted neurons may significantly improve prosthetic vision in terms of spatial resolution and power efficiency. APPROACH:We developed a virus-transduced genetically encoded calcium indicator (GECI) GCaMP6f and microscopy platform for calcium imaging to record the neural activity from RGCs at single-cell resolution in wholemount retinas. Multiple stimulation paradigms were applied through a microelectrode array (MEA) with transparent indium tin oxide electrodes. The evoked neuronal activities were converted to corresponding 2D calcium imaging transient pattern and spatial threshold map to identify the ideal focal response which corresponds to optimal percept in patient. MAIN RESULTS:The proposed optical system with GCaMP6f is capable of recording from population of mouse RGCs in real time during electrical stimulation with precise location information relative to the stimulation sites. Optimal duration and phase order of pulse were identified to avoid axonal stimulation and selectively activate targeted RGC somas, without requiring a significant increase in stimulation charge. Additionally, we show that reduced stimulus threshold can be achieved with the special design of asymmetric anodic-first pulse. SIGNIFICANCE:Our findings support the possibility of manipulating the responses of RGCs through varying the stimulation waveform. Focal response can be achieved with relative short duration (⩽120 μs) pulses, and can be improved by reversing the standard phase order. The RGCs threshold can be significantly reduced by 33.3%-50% in terms of charge through applying hyperpolarizing pre-pulses with a 20:1 ratio (pre-pulse:stimulus pulse). The results support the future retinal prosthesis design that potentially forms more ideal shape perception with higher spatial resolution and power efficiency.
journal_name
J Neural Engjournal_title
Journal of neural engineeringauthors
Chang YC,Haji Ghaffari D,Chow RH,Weiland JDdoi
10.1088/1741-2552/aaf92bsubject
Has Abstractpub_date
2019-04-01 00:00:00pages
026017issue
2eissn
1741-2560issn
1741-2552journal_volume
16pub_type
杂志文章abstract::In this work we address the use of realtime cortical recordings for the generation of coherent, reliable and robust motor activity in spinal-lesioned animals through selective intraspinal microstimulation (ISMS). The spinal cord of adult rats was hemisectioned and groups of multielectrodes were implanted in both the c...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/8/4/046008
更新日期:2011-08-01 00:00:00
abstract:OBJECTIVE:Two-dimensional (2D) movement control is an important issue in brain-computer interfaces (BCIs) research because being able to move, for example, a cursor with the brain will enable patients with motor disabilities to control their environment. However, it is still a challenge to continuously control 2D movem...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/12/4/046021
更新日期:2015-08-01 00:00:00
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journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/11/2/026005
更新日期:2014-04-01 00:00:00
abstract::Corrosion is a prime concern for active implantable devices. In this paper we review the principles underlying the concepts of hermetic packages and encapsulation, used to protect implanted electronics, some of which remain widely overlooked. We discuss how technological advances have created a need to update the way ...
journal_title:Journal of neural engineering
pub_type: 杂志文章,评审
doi:10.1088/1741-2560/10/3/031002
更新日期:2013-06-01 00:00:00
abstract:OBJECTIVE:Powered robotic prostheses create a need for natural-feeling user interfaces and robust control schemes. Here, we examined the ability of a nonlinear autoregressive model to continuously map the kinematics of a transtibial prosthesis and electromyographic (EMG) activity recorded within socket to the future es...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/11/5/056027
更新日期:2014-10-01 00:00:00
abstract:OBJECTIVE:To evaluate the benefit of integrating thermal imaging into an artificial vision therapy system, the Argus II retinal prosthesis, in simplifying a complex scene and improving mobility performance in the presence of other persons. APPROACH:Four Argus II retinal implant users were evaluated on two tasks: to lo...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/aba4fb
更新日期:2020-08-04 00:00:00
abstract::The extraction of distinctly separable features from electroencephalogram (EEG) is one of the main challenges in designing a brain-computer interface (BCI). Existing feature extraction techniques for a BCI are mostly developed based on traditional signal processing techniques assuming that the signal is Gaussian and h...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/8/2/025014
更新日期:2011-04-01 00:00:00
abstract:OBJECTIVE:Fractional calculus plays a key role in the analysis of neural dynamics. In particular, fractional calculus has been recently exploited for analyzing complex biological systems and capturing intrinsic phenomena. Also, artificial neural networks have been shown to have complex neuronal dynamics and characteris...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/ab8dd6
更新日期:2020-06-12 00:00:00
abstract:OBJECTIVE:Analysis of intra- and perioperatively recorded cortical and basal ganglia local field potentials in human movement disorders has provided great insight into the pathophysiology of diseases such as Parkinson's, dystonia, and essential tremor. However, in order to better understand the network abnormalities an...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/11/1/016009
更新日期:2014-02-01 00:00:00
abstract::All of the human prosthetic visual systems implanted so far have been achromatic. Schmidt et al. (1996) reported that at low stimulation intensities their subject reported that phosphenes usually had a specific hue, but when the stimulus intensity was increased, they desaturated to white. We speculate here that previo...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/abd520
更新日期:2020-12-18 00:00:00
abstract:OBJECTIVE:Intracortical brain-machine interfaces (iBMIs) aim to restore efficient communication and movement ability for paralyzed patients. However, frequent recalibration is required for consistency and reliability, and every recalibration will require relatively large most current sample set. The aim in this study i...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/aaa8a4
更新日期:2018-04-01 00:00:00
abstract::Adaptive model theory (AMT) is a computational theory that addresses the difficult control problem posed by the musculoskeletal system in interaction with the environment. It proposes that the nervous system creates motor maps and task-dependent synergies to solve the problems of redundancy and limited central resourc...
journal_title:Journal of neural engineering
pub_type: 杂志文章,评审
doi:10.1088/1741-2560/2/3/S10
更新日期:2005-09-01 00:00:00
abstract::Functional mapping of eloquent cortex is a common and necessary component of neurosurgical operative planning. Current electrical stimulation-based techniques are inefficient, can evoke seizures and are prone to false-negative results. Here, we present a novel cortical mapping system that extracts event-related neural...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/9/4/046018
更新日期:2012-08-01 00:00:00
abstract:OBJECTIVE:Although electrode size should be miniaturized to provide higher selectivity for neural signal recording and to avoid tissue damage, small sized electrodes induce high impedance, which decreases recording quality. In this work, the electrode surface was modified to increase the effective surface area to lower...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/12/5/056018
更新日期:2015-10-01 00:00:00
abstract:OBJECTIVE:Due to low spatial resolution and poor signal-to-noise ratio of electroencephalogram (EEG), high accuracy classifications still suffer from lots of obstacles in the context of motor imagery (MI)-based brain-machine interface (BMI) systems. Particularly, it is extremely challenging to decode multiclass MI EEG ...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/aba7cd
更新日期:2020-08-11 00:00:00
abstract::Hybrid electro-optical neural stimulation is a novel paradigm combining the advantages of optical and electrical stimulation techniques while reducing their respective limitations. However, in order to fulfill its promise, this technique requires reduced variability and improved reproducibility. Here we used a compara...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/9/3/036003
更新日期:2012-06-01 00:00:00
abstract:OBJECTIVE:Visual prostheses are designed to restore partial functional vision in patients with total vision loss. Retinal visual prostheses provide limited capabilities as a result of low resolution, limited field of view and poor dynamic range. Understanding the influence of these parameters in the perception results ...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/abb9be
更新日期:2020-10-08 00:00:00
abstract:OBJECTIVE:In biomagnetic signal processing, the theory of the signal subspace has been applied to removing interfering magnetic fields, and a representative algorithm is the signal space projection algorithm, in which the signal/interference subspace is defined in the spatial domain as the span of signal/interference-s...
journal_title:Journal of neural engineering
pub_type: 杂志文章,评审
doi:10.1088/1741-2552/aa7693
更新日期:2017-10-01 00:00:00
abstract:OBJECTIVE:Brain-computer interfaces (BCI) are becoming important tools for assistive technology, particularly through the use of motor imagery (MI) for aiding task completion. However, most existing methods of MI classification have been applied in a trial-wise fashion, with window sizes of approximately 2 s or more. A...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/ab57c0
更新日期:2020-01-31 00:00:00
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journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/10/5/056018
更新日期:2013-10-01 00:00:00
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journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/8/6/065008
更新日期:2011-12-01 00:00:00
abstract:OBJECTIVE:We propose a new hybrid brain-computer interface (BCI) system that integrates two different EEG tasks: tactile selective attention (TSA) using a vibro-tactile stimulator on the left/right finger and motor imagery (MI) of left/right hand movement. Event-related desynchronization (ERD) from the MI task and stea...
journal_title:Journal of neural engineering
pub_type: 杂志文章,随机对照试验
doi:10.1088/1741-2560/11/6/066004
更新日期:2014-12-01 00:00:00
abstract:OBJECTIVE:The past two decades have seen dramatic progress in our ability to model brain signals recorded by electroencephalography, functional near-infrared spectroscopy, etc., and to derive real-time estimates of user cognitive state, response, or intent for a variety of purposes: to restore communication by the seve...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/10/5/056014
更新日期:2013-10-01 00:00:00
abstract:OBJECTIVE:Damage to the brain, as a result of various medical conditions, impacts the everyday life of patients and there is still no complete cure to neurological disorders. Neuroprostheses that can functionally replace the damaged neural circuit have recently emerged as a possible solution to these problems. Here we ...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/aa98e9
更新日期:2018-02-01 00:00:00
abstract:OBJECTIVE:Analyzing and interpreting the activity of a heterogeneous population of neurons can be challenging, especially as the number of neurons, experimental trials, and experimental conditions increases. One approach is to extract a set of latent variables that succinctly captures the prominent co-fluctuation patte...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2560/10/6/066012
更新日期:2013-12-01 00:00:00
abstract:OBJECTIVE:Activity-dependent stimulation (ADS) is designed to strengthen the connections between neuronal circuits and therefore may be a promising tool for promoting neurophysiological reorganization following a brain injury. To successfully perform this technique, two criteria must be met: (1) spikes in the extracell...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/ab3319
更新日期:2019-10-29 00:00:00
abstract:OBJECTIVE:When developing approaches for automatic preprocessing of electroencephalogram (EEG) signals in non-isolated demanding environment such as intensive care unit (ICU) or even outdoor environment, one of the major concerns is varying nature of characteristics of different artifacts in time, frequency and spatial...
journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/abb5bd
更新日期:2020-10-15 00:00:00
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journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/aae0c9
更新日期:2018-12-01 00:00:00
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journal_title:Journal of neural engineering
pub_type: 杂志文章
doi:10.1088/1741-2552/ab2b7d
更新日期:2019-10-10 00:00:00
abstract:OBJECTIVE:Recent advances in neural engineering have restored mobility to people with paralysis, relieved symptoms of movement disorders, reduced chronic pain, restored the sense of hearing, and provided sensory perception to individuals with sensory deficits. APPROACH:This progress was enabled by the team-based, inte...
journal_title:Journal of neural engineering
pub_type: 杂志文章,评审
doi:10.1088/1741-2552/ab4869
更新日期:2019-11-12 00:00:00