scholarly journals Self-induced redox cycling coupled luminescence on nanopore recessed disk-multiscale bipolar electrodes

2015 ◽  
Vol 6 (5) ◽  
pp. 3173-3179 ◽  
Author(s):  
Chaoxiong Ma ◽  
Lawrence P. Zaino III ◽  
Paul W. Bohn
Keyword(s):  
Redox Cycling ◽  
Bipolar Electrode ◽  
Bipolar Electrodes ◽  
Disk Electrodes

Self-induced redox cycling at nanopore ring-disk electrodes is coupled, through a bipolar electrode, to a remote fluorigenic reporter reaction.

scholarly journals Redox Cycling at an Array of Interdigitated Bipolar Electrodes for Enhanced Sensitivity in Biosensing

2021 ◽  
Author(s):  
Janis S Borchers ◽  
Claire R Campbell ◽  
Savanah B Van Scoy ◽  
Morgan J Clark ◽  
Robbyn K. Anand
Keyword(s):  
Redox Cycling ◽  
Bipolar Electrodes ◽  
Enhanced Sensitivity

scholarly journals Redox Cycling at an Array of Interdigitated Bipolar Electrodes for Enhanced Sensitivity in Biosensing

2021 ◽  
Author(s):  
Janis S. Borchers ◽  
Claire Campbell ◽  
Savanah B. Van Scoy ◽  
Morgan J. Clark ◽  
Robbyn Anand
Keyword(s):  
Electrochemical Sensors ◽  
Single Cells ◽  
Redox Cycling ◽  
Single Pair ◽  
Bipolar Electrodes ◽  
Spatially Resolved ◽  
Enhanced Sensitivity ◽  
Sensing Applications ◽  
Wide Range ◽  
Amplification Strategy

An array of many bipolar electrodes (BPEs) can be controlled by a single pair of driving electrodes yet allows for multiplexedanalysis of many individual biomarkers or single cells at once. A wide range of bipolar electrochemical sensors have been devised, many of which operate under battery power and produce visible signals (e.g., luminescent, electrochromic) appropriate for smartphone or naked eye readout. These features of BPEs are advantageous in the context of clinical and environmental sensing applications at the point of need. However, the sensitivity of BPEs is poor in comparison to direct measurement of current at an individual electrode, and therefore, the enhancement of signals obtained at BPEs is an active area of research. Here, we describe signal amplification by redox cycling accomplished by interdigitation of each BPE in an array with a shared driving electrode. We evaluate amplification obtained for interelectrode spacing in the range of 35 𝜇m to 15 𝜇m. Each interdigitated BPE (IDBPE) in the array has an independent, reproducible, and linear response to a reversible electroactive analyte. Therefore, this universal amplification strategy allows for multiplexed or spatially resolved sensing in point-of-need applications.

Abstract 19778: Novel Strategy for Improved Substrate Mapping of the Atria: Omnipolar Catheter and Signal Processing Technology Assesses Electrogram Signals Along Physiologic and Anatomic Directions

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
D Curtis Deno ◽  
Ram Balachandran ◽  
Dennis Morgan ◽  
Stéphane Massé ◽  
Kumaraswamy Nanthakumar
Keyword(s):  
Signal Amplitude ◽  
Orientation Dependence ◽  
Electrode Pair ◽  
Bipolar Electrode ◽  
Bipolar Electrodes ◽  
Surface Normal ◽  
3D Mapping System ◽  
Potential Strategy ◽  
Novel Strategy ◽  
Definition Of

Introduction: Substrate mapping is evolving as a potential strategy for atrial fibrillation ablation. Defining scar borders and functional boundaries is typically under taken with bipolar electrodes. Catheter orientation affects electrogram (EGM) signal amplitude due to an orientation dependence of bipoles. We developed orientation independent Omnipolar Technology (OT) and compared OT EGM amplitude with traditional bipolar (Bi) methods. Methods: Four anesthetized swine were studied in 6 sessions with a 3D mapping system and a multielectrode OT ablation catheter placed in RA and LA locations in 4 rhythms. With the OT catheter in a stable location, 30 successive atrial beats were acquired. OT electrodes provided bipole (Bi) as well as OT signals along both activation (OTa) and surface normal (OTn) directions. Peak to peak amplitudes (Vpp) of OT and Bi signals were compared for magnitude and consistency. Results: As shown in the table, OT signal amplitudes over all atrial locations and rhythms were greater than traditional bipole amplitudes. The coefficients of variation for signal amplitude over successive cardiac beats were substantially less for OTa and OTn (*p < 0.01 with respect to Bi) than for Bi, reflecting electrode pair orientation effects. Conclusions: Distinct electrogram signals were resolved by OT along physiologic (activation) and anatomic (surface normal) directions. Catheter orientation independent OT signal amplitudes were more self-consistent and reliable than those from orientation dependent bipolar electrode pairs. Omnipolar technology approaches may permit more accurate and specific definition of substrate and thus catheter ablation of arrhythmias.

scholarly journals Front Cover: Redox Cycling at an Array of Interdigitated Bipolar Electrodes for Enhanced Sensitivity in Biosensing (ChemElectroChem 18/2021)

2021 ◽  
Vol 8 (18) ◽  
pp. 3427-3427
Author(s):  
Janis S. Borchers ◽  
Claire R. Campbell ◽  
Savanah B. Van Scoy ◽  
Morgan J. Clark ◽  
Robbyn K. Anand
Keyword(s):  
Redox Cycling ◽  
Front Cover ◽  
Bipolar Electrodes ◽  
Enhanced Sensitivity

scholarly journals Modeling subcortical white matter stimulation

2019 ◽  
Author(s):  
Melissa Dali ◽  
Jennifer S. Goldman ◽  
Olivier Pantz ◽  
Alain Destexhe ◽  
Emmanuel Mandonnet
Keyword(s):  
Electrical Stimulation ◽  
Action Potentials ◽  
Subcortical White Matter ◽  
Bipolar Electrode ◽  
Individual Subject ◽  
Tissue Conductivity ◽  
Bipolar Electrodes ◽  
Stimulation Parameters ◽  
Monopolar Stimulation ◽  
Activation Depth

AbstractObjectiveIntracranial electrical stimulation of subcortical axonal tracts is particularly useful during brain surgery, where mapping helps identify and excise dysfunctional tissue while avoiding damage to functional structures. Stimulation parameters are generally set empirically and consequences for the spatial recruitment of axons within subcortical tracts are not well identified.ApproachComputational modeling is employed to study the effects of stimulation parameters on the recruitment of axons: monophasic versus biphasic stimuli induced with monopolar versus bipolar electrodes, oriented orthogonal or parallel to the tract, for isotropic and anisotropic tracts.Main resultsThe area and depth of axonal activation strongly depend on tissue conductivity and electrode parameters. The largest activation area results from biphasic stimulation with bipolar electrodes oriented orthogonal to axonal fasciculi, for anisotropic and especially isotropic tracts. For anisotropic tracts, the maximal activation depth is similar regardless of whether a monopolar or bipolar electrode is employed. For isotropic tracts, bipolar parallel and monopolar stimulation activate axons deeper than orthogonal bipolar stimulation. Attention is warranted during monophasic stimulation: a blockade of action potentials immediately under cathodes and a propagation of action potentials under anodes are found.SignificanceConsidering the spatial patterns of blockade and activation present during monophasic stimulation with both monopolar and bipolar electrodes, biphasic stimulation is recommended to explore subcortical axon responses during intraoperative mapping. Finally, the precise effect of electrical stimulation depends on conductivity profiles of tracts, and as such, should be explicitly considered for each individual subject and tract undergoing intracranial mapping.

Removal of Remazol Turquoise Blue (G-133) and Polyvinyl Alcohol (PVA) by Electrocoagulation using Monopolar and Bipolar Electrodes

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Sureyya Altin
Keyword(s):  
Polyvinyl Alcohol ◽  
Ph Value ◽  
Cod Removal ◽  
Electrode Configuration ◽  
Bipolar Electrode ◽  
Bipolar Electrodes ◽  
Initial Ph ◽  
Monopolar Electrodes ◽  
Removal Efficiencies ◽  
Color And Cod Removal

This study aims to investigate color and COD removal efficiencies of electrocoagulation (EC) process for dye solutions simulated by using polyvinyl alcohol (PVA) and reactive dyestuff of Remazol Turquoise Blue (G-133). The two different electrode configurations, namely monopolar and bipolar, were examined to find out the better alternative intensifying the performance of the process. The results obtained from these tests show that an EC cell with bipolar electrodes has produced slightly higher color and COD removal efficiencies than that of an EC cell with monopolar electrodes. The best removal efficiencies have been found for the both electrode configurations under the conditions that the time of electrolysis is 30 min, the constant direct current (DC) value 0.75 A and the initial pH value 3. Consequently, the bipolar electrode configuration (BPEC) has yielded 72.7 percent COD and 99.8 percent color removals while the monopolar electrode configuration (MPEC) producing 65.2 percent COD and 99.6 percent color removals.

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.

Sign in / Sign up

Export Citation Format

Share Document