Detection of Chloride Using Microelectrodes in Closed Bipolar Electrode Scheme

2021 ◽  
Vol MA2021-02 (55) ◽  
pp. 1609-1609
Author(s):  
David Probst ◽  
Inyoung Lee ◽  
Jeffrey E Dick ◽  
Koji Sode
Keyword(s):  
Bipolar Electrode

Accuracy of diffusion tensor magnetic resonance imaging tractography assessed using intraoperative subcortical stimulation mapping and magnetic source imaging

2007 ◽  
Vol 107 (3) ◽  
pp. 488-494 ◽  
Author(s):  
Jeffrey I. Berman ◽  
Mitchel S. Berger ◽  
Sungwon Chung ◽  
Srikantan S. Nagarajan ◽  
Roland G. Henry
Keyword(s):  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Fiber Tracking ◽  
Bipolar Electrode ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Motor Pathway ◽  
Magnetic Source ◽  
Subcortical Stimulation

Object Resecting brain tumors involves the risk of damaging the descending motor pathway. Diffusion tensor (DT)–imaged fiber tracking is a noninvasive magnetic resonance (MR) technique that can delineate the subcortical course of the motor pathway. The goal of this study was to use intraoperative subcortical stimulation mapping of the motor tract and magnetic source imaging to validate the utility of DT-imaged fiber tracking as a tool for presurgical planning. Methods Diffusion tensor-imaged fiber tracks of the motor tract were generated preoperatively in nine patients with gliomas. A mask of the resultant fiber tracks was overlaid on high-resolution T1- and T2-weighted anatomical MR images and used for stereotactic surgical navigation. Magnetic source imaging was performed in seven of the patients to identify functional somatosensory cortices. During resection, subcortical stimulation mapping of the motor pathway was performed within the white matter using a bipolar electrode. Results A total of 16 subcortical motor stimulations were stereotactically identified in nine patients. The mean distance between the stimulation sites and the DT-imaged fiber tracks was 8.7 ±3.1 mm (±standard deviation). The measured distance between subcortical stimulation sites and DT-imaged fiber tracks combines tracking technique errors and all errors encountered with stereotactic navigation. Conclusions Fiber tracks delineated using DT imaging can be used to identify the motor tract in deep white matter and define a safety margin around the tract.

Amplitude cancellation reduces the size of motor unit potentials averaged from the surface EMG

2006 ◽  
Vol 100 (6) ◽  
pp. 1928-1937 ◽  
Author(s):  
Kevin G. Keenan ◽  
Dario Farina ◽  
Roberto Merletti ◽  
Roger M. Enoka
Keyword(s):  
Motor Unit ◽  
Conduction Velocity ◽  
Motor Units ◽  
Surface Emg ◽  
Excitation Level ◽  
Bipolar Electrode ◽  
Emg Signal ◽  
Motor Unit Synchronization ◽  
Rate Coding ◽  
Simulated Surface

The purpose of the study was to evaluate the influence of selected physiological parameters on amplitude cancellation in the simulated surface electromyogram (EMG) and the consequences for spike-triggered averages of motor unit potentials derived from the interference and rectified EMG signals. The surface EMG was simulated from prescribed recruitment and rate coding characteristics of a motor unit population. The potentials of the motor units were detected on the skin over a hand muscle with a bipolar electrode configuration. Averages derived from the EMG signal were generated using the discharge times for each of the 24 motor units with lowest recruitment thresholds from a population of 120 across three conditions: 1) excitation level; 2) motor unit conduction velocity; and 3) motor unit synchronization. The area of the surface-detected potential was compared with potentials averaged from the interference, rectified, and no-cancellation EMGs. The no-cancellation EMG comprised motor unit potentials that were rectified before they were summed, thereby preventing cancellation between the opposite phases of the potentials. The percent decrease in area of potentials extracted from the rectified EMG was linearly related to the amount of amplitude cancellation in the interference EMG signal, with the amount of cancellation influenced by variation in excitation level and motor unit conduction velocity. Motor unit synchronization increased potentials derived from both the rectified and interference EMG signals, although cancellation limited the increase in area for both potentials. These findings document the influence of amplitude cancellation on motor unit potentials averaged from the surface EMG and the consequences for using the procedure to characterize motor unit properties.

Enhanced Electrochemiluminescence in the Microwell Bipolar Electrode Array Prepared with an Optical Fiber Bundle

2021 ◽  
Author(s):  
Haidong Li ◽  
Tian Zhang ◽  
Han Zhou ◽  
Zhicheng Zhang ◽  
Miaoxia Liu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Fiber Bundle ◽  
Electrode Array ◽  
Bipolar Electrode ◽  
Optical Fiber Bundle

Left coronary cusp ablation to eliminate epicardial substrates – a novel strategy for left ventricular summit ventricular tachycardia ablation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
W Phanthawimol ◽  
Y Komatsu ◽  
M Hattori ◽  
Q.J Naeemah ◽  
S Shimoo ◽  
...  
Keyword(s):  
Coronary Vessels ◽  
Left Ventricular ◽  
Bipolar Electrode ◽  
Coronary Vein ◽  
Ventricular Tachycardia Ablation ◽  
First Case ◽  
Rf Energy ◽  
Coronary Cusp ◽  
Novel Strategy ◽  
Communicating Vein

Abstract Background Catheter ablation of LV summit VT can be challenging due to possible subepicardial or intramural site of origin and its close proximity to the major coronary vessels. Objective Local electrograms monitoring inside LV summit communicating vein potentially defines arrhythmogenic substrates and facilitates ablation from the adjacent anatomical structures. Results We experienced two cases of LV summit VT with epicardial local abnormal ventricular activities (Epi-LAVA) recorded from distal bipolar electrode of the 2F microcatheter in communicating vein close to the superior portion of LV summit. During sinus rhythm, Epi-LAVA displayed isolated late fractionated potentials in the first case but had initial fractionated potentials fused with terminal portion of far-field ventricular signals and late isolated potentials exhibiting 2:1 conduction in the second case. Epi-LAVA represented earliest ventricular signals during VT in both cases. Pace mapping at Epi-LAVA sites yielded single QRS morphology with excellent pacemap score and induced VT. Our strategy was to perform ablation at the facing site of Epi-LAVA aiming to eliminate the potentials transmurally. Radiofrequency (RF) energy was applied above and under the left coronary cusp opposite to Epi-LAVA sites using 3.5-mm tip open-irrigation catheter with a power of 30–35 W for 60 seconds under real-time intracardiac echocardiograhic guidance. VT was slowed and terminated in 1 second. Repeat ablation delayed and completely abolished Epi-LAVA followed by noninducibility of VT. Anatomical proximity of the left coronary cusp semilunar insertion and subepicardial or intramural site of origin possibly dictates successful ablation. Epi-LAVA from coronary vein mapping serve as a new landmark of the ablation target with a measurable procedural endpoint. Conclusion Elimination of epicardial substrates with RF energy application at the left coronary cusp can be a novel strategy for LV summit VT ablation. Funding Acknowledgement Type of funding source: None

scholarly journals On the Effect of Anion Exchange Ionomer Binders in Bipolar Electrode Membrane Interface Water Electrolysis

2021 ◽  
Author(s):  
Britta Mayerhöfer ◽  
Konrad Ehelebe ◽  
Florian Dominik Speck ◽  
Markus Bierling ◽  
Johannes Bender ◽  
...  
Keyword(s):  
Proton Exchange Membrane ◽  
Water Electrolysis ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Bipolar Electrode ◽  
Electrode Interface ◽  
Exchange Membrane ◽  
Electrode Membrane ◽  
Pem Water Electrolyzer

Bipolar membrane|electrode interface water electrolyzers (BPEMWE) were found to outperform a proton exchange membrane (PEM) water electrolyzer reference in a similar membrane electrode assembly (MEA) design based on individual porous...

scholarly journals The Electrode Modality Development in Pulsed Electric Field Treatment Facilitates Biocellular Mechanism Study and Improves Cancer Ablation Efficacy

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Chao Cen ◽  
Xinhua Chen
Keyword(s):  
Electric Field ◽  
Laser Scanning ◽  
Specific Treatment ◽  
Pulsed Electric Field ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Invasive Technique ◽  
Bipolar Electrode ◽  
Pulsed Electric Field Treatment ◽  
Electric Field Treatment

Pulsed electric field treatment is now widely used in diverse biological and medical applications: gene delivery, electrochemotherapy, and cancer therapy. This minimally invasive technique has several advantages over traditional ablation techniques, such as nonthermal elimination and blood vessel spare effect. Different electrodes are subsequently developed for a specific treatment purpose. Here, we provide a systematic review of electrode modality development in pulsed electric field treatment. For electrodes invented for experiment in vitro, sheet electrode and electrode cuvette, electrodes with high-speed fluorescence imaging system, electrodes with patch-clamp, and electrodes with confocal laser scanning microscopy are introduced. For electrodes invented for experiment in vivo, monopolar electrodes, five-needle array electrodes, single-needle bipolar electrode, parallel plate electrodes, and suction electrode are introduced. The pulsed electric field provides a promising treatment for cancer.

Treatment of As(V) and As(III) by electrocoagulation using Al and Fe electrode

2009 ◽  
Vol 60 (5) ◽  
pp. 1341-1346 ◽  
Author(s):  
W. H. Kuan ◽  
C. Y. Hu ◽  
M. C. Chiang
Keyword(s):  
Passive Film ◽  
Potentiodynamic Polarization ◽  
Electrode Materials ◽  
Initial Period ◽  
Electrode System ◽  
Initial Solution ◽  
Alkaline Condition ◽  
Bipolar Electrode ◽  
Pitting Potential ◽  
Fe Hydroxide

A batch electrocoagulation (EC) process with bipolar electrode and potentiodynamic polarization tests with monopolar systems were investigated as methods to explore the effects of electrode materials and initial solution pH on the As(V) and As(III) removal. The results displayed that the system with Al electrode has higher reaction rate during the initial period from 0 to 25 minutes than that of Fe electrode for alkaline condition. The pH increased with the EC time because the As(V) and As(III) removal by either co-precipitation or adsorption resulted in that the OH positions in Al-hydroxide or Fe-hydroxide were substituted by As(V) and As(III). The pH in Fe electrode system elevate higher than that in Al electrode because the As(V) removal substitutes more OH position in Fe-hydroxide than that in Al-hydroxide. EC system with Fe electrode can successfully remove the As(III) but system with Al electrode cannot because As(III) can strongly bind to the surface of Fe-hydroxide with forming inner-sphere species but weakly adsorb to the Al-hydroxide surface with forming outer-sphere species. The acidic solution can destroy the deposited hydroxide passive film then allow the metallic ions liberate into the solution, therefore, the acidic initial solution can enhance the As(V) and As(III) removal. The over potential calculation and potentiodynamic polarization tests reveal that the Fe electrode systems possess higher over potential and pitting potential than that of Al electrode system due to the fast hydrolysis of and the occurrence of Fe-hydroxide passive film.

Treatment of Septate Uterus with Bipolar Electrode

2013 ◽  
Vol 20 (6) ◽  
pp. S110
Author(s):  
A.G. Rincon ◽  
B.I. Chacin
Keyword(s):  
Bipolar Electrode ◽  
Septate Uterus

Neurotransmission in the medulla mediating insular cortical and lateral hypothalamic sympathetic responses

1998 ◽  
Vol 76 (7-8) ◽  
pp. 737-746 ◽  
Author(s):  
Kenneth S Butcher ◽  
David F Cechetto
Keyword(s):  
Receptor Antagonist ◽  
Sympathetic Nerve ◽  
Pressor Response ◽  
Ventrolateral Medulla ◽  
Bipolar Electrode ◽  
Hypothalamic Area ◽  
Renal Nerve ◽  
Lateral Hypothalamic ◽  
Baseline Activity ◽  
Sympathetic Responses

Previous evidence has shown sympathetic nerve responses to insular cortical (IC) stimulation are mediated by synapses within the lateral hypothalamic area (LHA) and ventrolateral medulla (VLM). The present study was aimed at determining the neurotransmitter(s) and receptor(s) involved at the synapse in the VLM. Twenty male Wistar rats were instrumented for renal nerve, arterial pressure, and heart rate recording. The IC or the LHA was stimulated with a bipolar electrode (200-1000 µA; 2 ms; 0.8 Hz) to elicit sympathetic nerve responses. Antagonists were then pressure-injected into the VLM (300 nL). Bilateral and unilateral kynurenate (25 mM) resulted in 100% block of IC- and LHA-stimulated sympathetic nerve responses. Bilateral injection of the non-NMDA (N-methyl-D-aspartate) receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 200 µM) also resulted in up to 100% block of IC and LHA sympathetic responses. In addition, unilateral injections of CNQX were made in two animals, resulting in 100 and 83% block of LHA sympathetic responses. Bilateral injection of the NMDA receptor antagonist DL-2-amino-5-phosphonopentanoic acid (AP5; 200µM) did not affect the response to IC or LHA stimulation. Kynurenate, CNQX, and AP5 all resulted in an elevation of baseline sympathetic nerve activity and a pressor response. Kynurenate resulted in a 263 ± 79% increase in baseline activity, while CNQX and AP5 resulted in 83 ± 19% and 91 ± 21% increases, respectively. Bilateral injections of antagonists for GABAA (bicuculline; 0.1 µM), acetylcholine (atropine; 0.1 µM) and catecholaminergic alpha and beta receptors (phentolamine and propranolol: 0.1 µM) had no effect on LHA sympathetic responses. Thus, sympathetic responses originating in the IC and LHA are mediated by a non-NMDA receptors in the VLM, which are likely AMPA receptors.Key words: insular cortex, ventrolateral medulla, glutamate, sympathetic activity.

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