keyword
MENU ▼
Read by QxMD icon Read
search

Electric current spread

keyword
https://www.readbyqxmd.com/read/28093818/intraoperative-microstimulation-predicts-outcome-of-postoperative-macrostimulation-in-subthalamic-nucleus-deep-brain-stimulation-for-parkinson-s-disease
#1
Raja Mehanna, Andre G Machado, John E Connett, Faisal Alsaloum, Scott E Cooper
BACKGROUND: In deep brain stimulation (DBS) of the subthalamic nucleus for treatment of Parkinson's Disease, a commonly encountered stimulation side effect is involuntary muscle contractions from spread of electrical current to cortico-spinal and cortico-bulbar fibers in the internal capsule. During surgery, a variety of techniques, including microelectrode recording (MER), are used to avoid positioning the DBS electrode too close to the internal capsule. At some centers, MER includes stimulating through the microelectrode (microstimulation)...
January 17, 2017: Neuromodulation: Journal of the International Neuromodulation Society
https://www.readbyqxmd.com/read/28058649/electrically-pumped-iii-n-microcavity-light-emitters-incorporating-an-oxide-confinement-aperture
#2
Ying-Yu Lai, Tsu-Chi Chang, Ya-Chen Li, Tien-Chang Lu, Shing-Chung Wang
In this work, we report on electrically pumped III-N microcavity (MC) light emitters incorporating oxide confinement apertures. The utilized SiO2 aperture can provide a planar ITO design with a higher index contrast (~1) over other previously reported approaches. The fabricated MC light emitter with a 15-μm-aperture shows a turn-on voltage of 3.3 V, which is comparable to conventional light emitting diodes (LEDs), showing a good electrical property of the proposed structure. A uniform light output profile within the emission aperture suggesting the good capability of current spreading and current confinement of ITO and SiO2 aperture, respectively...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28028801/transcranial-magnetic-stimulation-basic-principles-and-clinical-applications-in-migraine
#3
Anthony T Barker, Kevin Shields
PURPOSE: Transcranial magnetic stimulation (TMS) is a neurophysiological technique with a long established pedigree of safety, tolerability, and efficacy. Initially TMS was used to study the function of the cerebral cortex, but it has now become a treatment for migraine, one of the most common and debilitating neurological conditions. In this review we discuss the scientific background and development of the technique. We explore its application for the treatment of migraine and ponder the possible mechanisms of action in this most common neurological condition...
December 28, 2016: Headache
https://www.readbyqxmd.com/read/27990816/glass-based-transparent-conductive-electrode-its-application-to-visible-to-ultraviolet-light-emitting-diodes
#4
Tae Ho Lee, Kyeong Heon Kim, Byeong Ryong Lee, Ju Hyun Park, E Fred Schubert, Tae Geun Kim
Nitride-based ultraviolet light-emitting diodes (UV LEDs) are promising replacements for conventional UV lamps. However, the external quantum efficiency of UV LEDs is much lower than for visible LEDs due to light absorption in the p-GaN contact and electrode layers, along with p-AlGaN growth and doping issues. To minimize such absorption, we should obtain direct ohmic contact to p-AlGaN using UV-transparent ohmic electrodes and not use p-GaN as a contact layer. Here, we propose a glass-based transparent conductive electrode (TCE) produced using electrical breakdown (EBD) of an AlN thin film, and we apply the thin film to four (Al)GaN-based visible and UV LEDs with thin buffer layers for current spreading and damage protection...
December 28, 2016: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/27990231/fast-simulation-and-optimization-tool-to-explore-selective-neural-stimulation
#5
Mélissa Dali, Olivier Rossel, David Guiraud
In functional electrical stimulation, selective stimulation of axons is desirable to activate a specific target, in particular muscular function. This implies to simulate a fascicule without activating neighboring ones i.e. to be spatially selective. Spatial selectivity is achieved by the use of multicontact cuff electrodes over which the stimulation current is distributed. Because of the large number of parameters involved, numerical simulations provide a way to find and optimize electrode configuration. The present work offers a computation effective scheme and associated tool chain capable of simulating electrode-nerve interface and find the best spread of current to achieve spatial selectivity...
June 13, 2016: European Journal of Translational Myology
https://www.readbyqxmd.com/read/27960585/challenges-for-the-application-of-optical-stimulation-in-the-cochlea-for-the-study-and-treatment-of-hearing-loss
#6
Rachael T Richardson, Alexander C Thompson, Andrew K Wise, Karina Needham
Electrical stimulation has long been the most effective strategy for evoking neural activity from bionic devices and has been used with great success in the cochlear implant to allow deaf people to hear speech and sound. Despite its success, the spread of electrical current stimulates a broad region of neural tissue meaning that contemporary devices have limited precision. Optical stimulation as an alternative has attracted much recent interest for its capacity to provide highly focused stimuli, and therefore, potentially improved sensory perception...
February 2017: Expert Opinion on Biological Therapy
https://www.readbyqxmd.com/read/27914377/evaluating-multipulse-integration-as-a-neural-health-correlate-in-human-cochlear-implant-users-relationship-to-spatial-selectivity
#7
Ning Zhou, Bryan E Pfingst
The decrease of psychophysical detection thresholds as a function of pulse rate for a fixed-duration electrical pulse train is referred to as multipulse integration (MPI). The MPI slopes correlate with anatomical and physiological indices of cochlear health in guinea pigs with cochlear implants. The aim of the current study was to assess whether the MPI slopes were related to the spatial spread of activation by electrical stimulation. The hypothesis was that MPI is dependent on the total number of excitable neurons at the stimulation site, with broader neural excitation producing a steeper threshold decrease as a function of stimulation rate...
September 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27893099/electrically-evoked-responses-in-the-rabbit-cortex-induced-by-current-steering-with-penetrating-optic-nerve-electrodes
#8
Yan Yan, Yiliang Lu, Menghui Li, Zengguang Ma, Pengjia Cao, Yao Chen, Xiaodong Sun, Xinyu Chai, Qiushi Ren, Liming Li
Purpose: Current steering is a neural stimulation strategy that uses simultaneous stimulation of adjacent electrodes to produce additional intermediate stimulation sites and thus improves spatial resolution. We investigated the feasibility of current steering using electrophysiological and computational methods after implanting paired penetrating electrodes into the rabbit's optic nerve (ON). Methods: Penetrating electrodes at different interelectrode distances were implanted into the ON and electrically evoked cortical potentials (EEPs) in V1 recorded with a 6 × 8 array...
November 1, 2016: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/27826248/slow-conduction-in-the-border-zones-of-patchy-fibrosis-stabilizes-the-drivers-for-atrial-fibrillation-insights-from-multi-scale-human-atrial-modeling
#9
Ross Morgan, Michael A Colman, Henry Chubb, Gunnar Seemann, Oleg V Aslanidi
Introduction: The genesis of atrial fibrillation (AF) and success of AF ablation therapy have been strongly linked with atrial fibrosis. Increasing evidence suggests that patient-specific distributions of fibrosis may determine the locations of electrical drivers (rotors) sustaining AF, but the underlying mechanisms are incompletely understood. This study aims to elucidate a missing mechanistic link between patient-specific fibrosis distributions and AF drivers. Methods: 3D atrial models integrated human atrial geometry, rule-based fiber orientation, region-specific electrophysiology, and AF-induced ionic remodeling...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27799905/cerebellar-and-spinal-direct-current-stimulation-in-children-computational-modeling-of-the-induced-electric-field
#10
Serena Fiocchi, Paolo Ravazzani, Alberto Priori, Marta Parazzini
Recent studies have shown that the specific application of transcranial direct current stimulation (tDCS) over the cerebellum can modulate cerebellar activity. In parallel, transcutaneous spinal DC stimulation (tsDCS) was found to be able to modulate conduction along the spinal cord and spinal cord functions. Of particular interest is the possible use of these techniques in pediatric age, since many pathologies and injuries, which affect the cerebellar cortex as well as spinal cord circuits, are diffuse in adults as well as in children...
2016: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/27715440/the-impact-of-several-craniotomies-on-transcranial-motor-evoked-potential-monitoring-during-neurosurgery
#11
Ryosuke Tomio, Takenori Akiyama, Masahiro Toda, Takayuki Ohira, Kazunari Yoshida
OBJECTIVE Transcranial motor evoked potential (tMEP) monitoring is popular in neurosurgery; however, the accuracy of tMEP can be impaired by craniotomy. Each craniotomy procedure and changes in the CSF levels affects the current spread. The aim of this study was to investigate the influence of several craniotomies on tMEP monitoring by using C3-4 transcranial electrical stimulation (TES). METHODS The authors used the finite element method to visualize the electric field in the brain, which was generated by TES, using realistic 3D head models developed from T1-weighted MR images...
October 7, 2016: Journal of Neurosurgery
https://www.readbyqxmd.com/read/27708378/electrochemical-noise-and-impedance-of-au-electrode-electrolyte-interfaces-enabling-extracellular-detection-of-glioma-cell-populations
#12
Paulo R F Rocha, Paul Schlett, Ulrike Kintzel, Volker Mailänder, Lode K J Vandamme, Gunther Zeck, Henrique L Gomes, Fabio Biscarini, Dago M de Leeuw
Microelectrode arrays (MEA) record extracellular local field potentials of cells adhered to the electrodes. A disadvantage is the limited signal-to-noise ratio. The state-of-the-art background noise level is about 10 μVpp. Furthermore, in MEAs low frequency events are filtered out. Here, we quantitatively analyze Au electrode/electrolyte interfaces with impedance spectroscopy and noise measurements. The equivalent circuit is the charge transfer resistance in parallel with a constant phase element that describes the double layer capacitance, in series with a spreading resistance...
October 6, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27692514/from-municipal-industrial-wastewater-sludge-and-fog-to-fertilizer-a-proposal-for-economic-sustainable-sludge-management
#13
Božidar Bratina, Andrej Šorgo, Janez Kramberger, Urban Ajdnik, Lidija Fras Zemljič, Janez Ekart, Riko Šafarič
After a ban on the depositing of untreated sludge in landfills, the sludge from municipal and industrial water-treatment plants can be regarded as a problem. Waste products of the water treatment process can be a problem or an opportunity - a source for obtaining raw materials. In the European Union, raw sludge and fats, oil and grease (FOG) from municipal and industrial wastewater treatment plants (WWTP) cannot be deposited in any natural or controlled environment. For this reason, it must be processed (stabilized, dried) to be used later as a fertilizer, building material, or alternative fuel source suitable for co-incineration in high temperature furnaces (power plants or concrete plants)...
December 1, 2016: Journal of Environmental Management
https://www.readbyqxmd.com/read/27660329/transcutaneous-periorbital-electrical-stimulation-in-the-treatment-of-dry-eye
#14
Emilio Pedrotti, Francesca Bosello, Adriano Fasolo, Anna C Frigo, Ivan Marchesoni, Alfredo Ruggeri, Giorgio Marchini
PURPOSE: To evaluate efficacy and safety of transcutaneous application of electrical current on symptoms and clinical signs of dry eye (DE). METHODS: 27 patients with DE underwent transcutaneous electrostimulation with electrodes placed onto the periorbital region of both eyes and manual stimulation with a hand-piece conductor moved by the operator. Each patient underwent 12 sessions of 22 min spread over 2 months, two sessions per week in the first month and one session per week in the second month...
September 22, 2016: British Journal of Ophthalmology
https://www.readbyqxmd.com/read/27636387/the-underlying-mechanism-of-preventing-facial-nerve-stimulation-by-triphasic-pulse-stimulation-in-cochlear-implant-users-assessed-with-objective-measure
#15
Andreas Bahmer, Uwe Baumann
HYPOTHESIS: Triphasic pulse stimulation prevents from facial nerve stimulation (FNS) because of a different electromyographic input-output function compared with biphasic pulse stimulation. BACKGROUND: FNS is sometimes observed in cochlear implant users as an unwanted side effect of electrical stimulation of the auditory nerve. The common stimulation applied in current cochlear implant consists of biphasic pulse patterns. Two common clinical remedies to prevent unpleasant FNS caused by activation of certain electrodes are to expand their pulse phase duration or simply deactivate them...
October 2016: Otology & Neurotology
https://www.readbyqxmd.com/read/27636181/modification-of-electrophysiological-activity-pattern-after-anterior-thalamic-deep-brain-stimulation-for-intractable-epilepsy-report-of-3-cases
#16
Hae Yu Kim, Yun Jung Hur, Heung-Dong Kim, Kang Min Park, Sung Eun Kim, Tae Gyu Hwang
OBJECTIVE Thalamic stimulation can provoke electroencephalography (EEG) synchronization or desynchronization, which can help to reduce the occurrence of seizures in intractable epilepsy, though the underlying mechanism is not fully understood. Therefore, the authors investigated changes in EEG electrical activity to better understand the seizure-reducing effects of deep brain stimulation (DBS) in patients with intractable epilepsy. METHODS Electrical activation patterns in the epileptogenic brains of 3 patients were analyzed using classical low-resolution electromagnetic tomography analysis recursively applied (CLARA)...
September 16, 2016: Journal of Neurosurgery
https://www.readbyqxmd.com/read/27626943/hydropower-s-biogenic-carbon-footprint
#17
Laura Scherer, Stephan Pfister
Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2...
2016: PloS One
https://www.readbyqxmd.com/read/27604784/perceptual-spaces-induced-by-cochlear-implant-all-polar-stimulation-mode
#18
Jeremy Marozeau, Colette M McKay
It has been argued that a main limitation of the cochlear implant is the spread of current induced by each electrode, which activates an inappropriately large range of sensory neurons. To reduce this spread, an alternative stimulation mode, the all-polar mode, was tested with five participants. It was designed to activate all the electrodes simultaneously with appropriate current levels and polarities to recruit narrower regions of auditory nerves at specific intracochlear electrode positions (denoted all-polar electrodes)...
2016: Trends in Hearing
https://www.readbyqxmd.com/read/27587998/on-the-basis-of-synaptic-integration-constancy-during-growth-of-a-neuronal-circuit
#19
Adriana De-La-Rosa Tovar, Prashant K Mishra, Francisco F De-Miguel
We studied how a neuronal circuit composed of two neuron types connected by chemical and electrical synapses maintains constant its integrative capacities as neurons grow. For this we combined electrophysiological experiments with mathematical modeling in pairs of electrically-coupled Retzius neurons from postnatal to adult leeches. The electrically-coupled dendrites of both Retzius neurons receive a common chemical input, which produces excitatory postsynaptic potentials (EPSPs) with varying amplitudes. Each EPSP spreads to the soma, but also crosses the electrical synapse to arrive at the soma of the coupled neuron...
2016: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/27569402/stimulus-characteristics-in-electroconvulsive-therapy-a-pragmatic-review
#20
Francisco Javier Sanz-Fuentenebro
The process of normalization electroconvulsive therapy (ECT) requires, among other actions, disseminating the latest information on this technique. One of the most complex aspects is the electrical stimulus, whose knowledge should be spread and put into practice. In this paper we review the available information about frequency and number of ECT sessions, and efficacy of each electrode placement. We also present two approaches to determine the ECT charge: stimulus titration versus age-based method; and the limitations of the summary metrics of charge, being necessary to expand our knowledge of the parameters that configure the stimulus: duration, current amplitude frequency and pulse width...
August 25, 2016: Revista de Psiquiatrí́a y Salud Mental
keyword
keyword
20008
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"