Estimation of current density distribution under electrodes for external defibrillation

Krasteva, Vessela; Papazov, Sava P

doi:10.1186/1475-925x-1-7

Cited by 55 publications

(22 citation statements)

References 18 publications

(18 reference statements)

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“…The non-uniformity decreased monotonically as the buffer layer thickness and resistivity increased. A reduction from 200 to 160% was also obtained by adding a ring of higher resistivity of 100 Wm around the perimeter [45]. For a planar copper electrode, 9 mm in diameter, a radially varying conical recession appeared to be the best design.…”

Section: Current Safety Limits For Applied Low Frequency Currents To mentioning

confidence: 97%

“…As might be expected from charge separation, alteration of the boundary shape alone led to no significant improvement. There was still substantial non-uniformity of current injection at the boundary of clover, daisy, and spiralshaped electrodes [57] or with inclusion of openings in defibrillation electrodes [45]. A recessed electrode design was also used in a Magnetic Resonance EIT application to avoid artefacts in MR images near the electrodes due to the RF shielding effect of copper electrode [48].…”

Section: Current Safety Limits For Applied Low Frequency Currents To mentioning

confidence: 99%

“…We believe that this use of a FEM to estimate current densities in the head for EIT is the first application of its kind, although similar approaches have been employed for other applications such as calculating current density in the eye [49], beneath external defibrillation electrodes [45] and beneath transcranial magnetic stimulator [44,46,53].…”

Section: Fem Simulationsmentioning

confidence: 99%

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Design of electrodes and current limits for low frequency electrical impedance tomography of the brain

2007

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For the novel application of recording of resistivity changes related to neuronal depolarization in the brain with electrical impedance tomography, optimal recording is with applied currents below 100 Hz, which might cause neural stimulation of skin or underlying brain. The purpose of this work was to develop a method for application of low frequency currents to the scalp, which delivered the maximum current without significant stimulation of skin or underlying brain. We propose a recessed electrode design which enabled current injection with an acceptable skin sensation to be increased from 100 muA using EEG electrodes, to 1 mA in 16 normal volunteers. The effect of current delivered to the brain was assessed with an anatomically realistic finite element model of the adult head. The modelled peak cerebral current density was 0.3 A/m(2), which was 5 to 25-fold less than the threshold for stimulation of the brain estimated from literature review.

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Section: Current Safety Limits For Applied Low Frequency Currents To mentioning

confidence: 97%

Section: Current Safety Limits For Applied Low Frequency Currents To mentioning

confidence: 99%

Section: Fem Simulationsmentioning

confidence: 99%

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Design of electrodes and current limits for low frequency electrical impedance tomography of the brain

2007

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“…Here, we demonstrate that the hydrogel ionic stimulators reduced these adverse effects ( Figure ). We injected a constant current of 65 mA at a density of 0.72 A cm −2 into an excised chicken breast and exposed rat TA muscle for 30 s, which is significantly higher than the pain threshold for the commercial textile electrodes (0.13 mA cm −2 ) and hydrogel‐coated electrodes (1.38 mA cm −2 ), but is relevant to the current density applied during electroporation and external defibrillation . Hydrogel ionic electrodes, carbon, and metal electrodes were tested (Figure S13, Supporting Information).…”

mentioning

confidence: 89%

Programmable Hydrogel Ionic Circuits for Biologically Matched Electronic Interfaces

et al. 2018

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The increased need for wearable and implantable medical devices has driven the demand for electronics that interface with living systems. Current bioelectronic systems have not fully resolved mismatches between engineered circuits and biological systems, including the resulting pain and damage to biological tissues. Here, salt/poly(ethylene glycol) (PEG) aqueous two-phase systems are utilized to generate programmable hydrogel ionic circuits. High-conductivity salt-solution patterns are stably encapsulated within PEG hydrogel matrices using salt/PEG phase separation, which route ionic current with high resolution and enable localized delivery of electrical stimulation. This strategy allows designer electronics that match biological systems, including transparency, stretchability, complete aqueous-based connective interface, distribution of ionic electrical signals between engineered and biological systems, and avoidance of tissue damage from electrical stimulation. The potential of such systems is demonstrated by generating light-emitting diode (LED)-based displays, skin-mounted electronics, and stimulators that deliver localized current to in vitro neuron cultures and muscles in vivo with reduced adverse effects. Such electronic platforms may form the basis of future biointegrated electronic systems.

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“…Action potentials can be argued to have useful frequency content between 100 Hz to about 8 kHz and signal amplitude that can go into single digit microvolt range [1]. It is evident from stimulation studies that several factors are significant; signal characteristics owe some dependency on physiological factors but are also modulated by electrode geometry [5], target neural tissue composition [2] and electrode impedance [6][7][8]. The presence of external noise as well as internal noise sources, common mode and power supply noise must also be kept in check.…”

Section: Neural Amplifiers Specificationsmentioning

confidence: 99%

A Survey of Neural Front End Amplifiers and Their Requirements toward Practical Neural Interfaces

Bharucha

Sepehrian

Gosselin

2014

JLPEA

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When designing an analog front-end for neural interfacing, it is hard to evaluate the interplay of priority features that one must upkeep. Given the competing nature of design requirements for such systems a good understanding of these trade-offs is necessary. Low power, chip size, noise control, gain, temporal resolution and safety are the salient ones. There is a need to expose theses critical features for high performance neural amplifiers as the density and performance needs of these systems increases. This review revisits the basic science behind the engineering problem of extracting neural signal from living tissue. A summary of architectures and topologies is then presented and illustrated through a rich set of examples based on the literature. A survey of existing systems is presented for comparison based on prevailing performance metrics.

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Estimation of current density distribution under electrodes for external defibrillation

Cited by 55 publications

References 18 publications

Design of electrodes and current limits for low frequency electrical impedance tomography of the brain

Design of electrodes and current limits for low frequency electrical impedance tomography of the brain

Programmable Hydrogel Ionic Circuits for Biologically Matched Electronic Interfaces

A Survey of Neural Front End Amplifiers and Their Requirements toward Practical Neural Interfaces

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