scholarly journals Real-Time Impedance Monitoring During Electroporation Processes in Vegetal Tissue Using a High-Performance Generator

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3158 ◽  
Author(s):  
Borja López-Alonso ◽  
Héctor Sarnago ◽  
Óscar Lucía ◽  
Pablo Briz ◽  
José Miguel Burdío
Keyword(s):  
Real Time ◽  
High Voltage ◽  
High Performance ◽  
Low Voltage ◽  
Treatment Time ◽  
Irreversible Electroporation ◽  
The State ◽  
Reversible Electroporation ◽  
High Voltage Generator ◽  
Vegetal Tissue

Classical application of electroporation is carried out by using fixed protocols that do not clearly assure the complete ablation of the desired tissue. Nowadays, new methods that pursue the control of the treatment by studying the change in impedance during the applied pulses as a function of the electric field are being developed. These types of control seek to carry out the treatment in the fastest way, decreasing undesired effects and treatment time while ensuring the proper tumour ablation. The objective of this research is to determine the state of the treatment by continuously monitoring the impedance by using a novel versatile high-voltage generator and sensor system. To study the impedance dynamics in real time, the use of pulses of reduced voltage, below the threshold of reversible electroporation, is tested to characterise the state-of-the-treatment without interfering with it. With this purpose, a generator that provides both low voltage for sense tissue changes and high voltage for irreversible electroporation (IRE) was developed. In conclusion, the characterisation of the effects of electroporation in vegetal tissue, combined with the real-time monitoring of the state-of-the-treatment, will enable the provision of safer and more effective treatments.

Irreversible Electroporation (IRE) to Treat Brain Tumors

2008 ◽  
Author(s):  
Paulo A. Garcia ◽  
John Robertson ◽  
John Rossmeisl ◽  
Rafael V. Davalos
Keyword(s):  
Cell Death ◽  
Cell Membrane ◽  
Brain Tumors ◽  
High Voltage ◽  
Electric Pulse ◽  
Irreversible Electroporation ◽  
Transient Effect ◽  
Electric Pulses ◽  
Thermal Cell ◽  
Reversible Electroporation

Electroporation is the phenomenon in which permeability of the cell membrane to ions and macromolecules is increased by exposing the cell to short (microsecond to millisecond) high voltage electric pulses [1]. The application of the electric pulse can have no effect, can have a transient effect known as reversible electroporation, or can cause permanent permeation known as irreversible electroporation (IRE) which leads to non-thermal cell death by necrosis [1, 2].

A Novel Device Structure for High Voltage, High Performance Amorphous Silicon Thin-Film Transistors

1996 ◽  
Vol 424 ◽  
Author(s):  
A. M. Miri ◽  
P. S. Gudem ◽  
S. G. Chamberlain ◽  
A. Nathan
Keyword(s):  
Thin Film ◽  
High Voltage ◽  
Thin Film Transistors ◽  
High Performance ◽  
Low Voltage ◽  
Silicon Thin Film ◽  
Device Structure ◽  
Linear Region ◽  
Output Characteristics ◽  
Voltage Breakdown

AbstractConventional high voltage thin-film transistors (HVTFTs) suffer from performance limitations such as low on-current, Vx, shift and large curvature in the linear region of the output characteristics. These limitations are associated with the highly resistive dead region in conventional HVTFT structures. In this paper, we present a novel TFT structure which has a high on-current, improved output characteristics in the linear region, and no Vx shift. The higher on-current and significant improvement in output characteristics allows faster switching. Elimination of the Vx shift leads to more reliable circuit operation. The new structure is based on the conventional low voltage TFT (LVTFT) structure except that it does not suffer from low-voltage breakdown. The low-voltage breakdown of the gate nitride in conventional LVTFTs is perceived to be due to spiking of the drain metallization into the underlying layers which creates regions of very high electric field. In our novel structure, a higher breakdown is achieved by locating the metal contacts away from the gate edge while keeping the necessary drain to gate overlap through a heavily doped microcrystalline layer. Therefore, the new TFT extends the same performance as LVTFTs to high voltage operation. Furthermore, this structure also enhances the yield and reliability by minimizing the common faults in TFTs such as short circuits between gate, source and drain.

scholarly journals Modeling of Inactivation of Biofilm Composing Bacteria with Low Intensity Electric Field: Prediction of Lowest Intensity and Mechanism

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Mokhamad Tirono ◽  
Suhariningsih
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Staphylococcus Epidermidis ◽  
Treatment Time ◽  
Irreversible Electroporation ◽  
Pockels Effect ◽  
Low Intensity ◽  
Reversible Electroporation ◽  
Effect Of Treatment ◽  
Number Of Bacteria

Sterilization using high-intensity electric fields is detrimental to health if safety is inadequate, so it is necessary to study the possibility of sterilization using low-intensity electric fields. This study aims to determine the lowest electric field intensity and treatment time to deactivate the bacteria that make up the biofilms and explain the mechanism of inactivation. The study samples were biofilms from the bacteria Pseudomonas aeruginosa and Staphylococcus epidermidis grown on the catheter. The modeling formula was developed from the Pockels effect and the Weibull distribution with the treatment using a square pulse-shaped electric field with a pulse width of 50 μs and an intensity of 2.0-4.0 kV/ cm. The results showed that the threshold for irreversible electroporation of both samples occurred in the treatment using an electric field with an intensity of 3.5 kV/cm and 3.75 kV/ cm, respectively, where the size and type of Gram of bacteria influenced. Moreover, the time of the treatment had an effect when irreversible electroporation occurred. However, when there was reversible electroporation, the effect of treatment time on the reduction in the number of bacteria was not significant. Also, changes in conductivity affected the reduction in the number of bacteria when reversible electroporation occurred.

A Novel Device Structure for High Voltage, High Performance Amorphous Silicon Thin-Film Transistors

1996 ◽  
Vol 420 ◽  
Author(s):  
A. M. Miri ◽  
P. S. Gudem ◽  
S. G. Chamberlain ◽  
A. Nathan
Keyword(s):  
Thin Film ◽  
High Voltage ◽  
Thin Film Transistors ◽  
High Performance ◽  
Low Voltage ◽  
Silicon Thin Film ◽  
Device Structure ◽  
Linear Region ◽  
Output Characteristics ◽  
Voltage Breakdown

AbstractConventional high voltage thin-film transistors (HVTFTs) suffer from performance limitations such as low on-current, Vx. shift and large curvature in the linear region of the output characteristics. These limitations are associated with the highly resistive dead region in conventional HVTFT structures. In this paper, we present a novel TFT structure which has a high on-current, improved output characteristics in the linear region, and no Vx, shift. The higher on-current and significant improvement in output characteristics allows faster switching. Elimination of the Vx shift leads to more reliable circuit operation. The new structure is based on the conventional low voltage TFT (LVTFT) structure except that it does not suffer from low-voltage breakdown. The low-voltage breakdown of the gate nitride in conventional LVTFTs is perceived to be due to spiking of the drain metallization into the underlying layers which creates regions of very high electric field. In our novel structure, a higher breakdown is achieved by locating the metal contacts away from the gate edge while keeping the necessary drain to gate overlap through a heavily doped microcrystalline layer. Therefore, the new TFT extends the same performance as LVTFTs to high voltage operation. Furthermore, this structure also enhances the yield and reliability by minimizing the common faults in TFTs such as short circuits between gate, source and drain.

scholarly journals Toward a clinical real time tissue ablation technology: combining electroporation and electrolysis (E2)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e7985 ◽  
Author(s):  
Enric Guenther ◽  
Nina Klein ◽  
Paul Mikus ◽  
Florin Botea ◽  
Mihail Pautov ◽  
...  
Keyword(s):  
Real Time ◽  
Irreversible Electroporation ◽  
Ease Of Use ◽  
Tissue Ablation ◽  
Electrical Field ◽  
Field Pulse ◽  
Solid Malignancies ◽  
Reversible Electroporation ◽  
Series Of Experiments ◽  
Histological Results

Background Percutaneous image-guided tissue ablation (IGA) plays a growing role in the clinical management of solid malignancies. Electroporation is used for IGA in several modalities: irreversible electroporation (IRE), and reversible electroporation with chemotoxic drugs, called electrochemotherapy (ECT). It was shown that the combination of electrolysis and electroporation—E2—affords tissue ablation with greater efficiency, that is, lower voltages, lower energy and shorter procedure times than IRE and without the need for chemotoxic additives as in ECT. Methods A new E2 waveform was designed that delivers optimal doses of electroporation and electrolysis in a single waveform. A series of experiments were performed in the liver of pigs to evaluate E2 in the context of clinical applications. The goal was to find initial parameter boundaries in terms of electrical field, pulse duration and charge as well as tissue behavior to enable real time tissue ablation of clinically relevant volumes. Results Histological results show that a single several hundred millisecond long E2 waveform can ablate large volume of tissue at relatively low voltages while preserving the integrity of large blood vessels and lumen structures in the ablation zone without the use of chemotoxic drugs or paralyzing drugs during anesthesia. This could translate clinically into much shorter treatment times and ease of use compared to other techniques that are currently applied.

scholarly journals Wide Load Range ZVS Three-level DC-DC Converter: Modular Structure, Redundancy Ability, and Reduced Filters Size

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3537 ◽  
Author(s):  
Yong Shi ◽  
Zhuoyi Xu
Keyword(s):  
Power Systems ◽  
High Voltage ◽  
High Performance ◽  
Low Voltage ◽  
Modular Architecture ◽  
Load Range ◽  
Zero Voltage Switching ◽  
Conduction Loss ◽  
Zero Current Switching ◽  
Zero Current

In future dc distributed power systems, high performance high voltage dc-dc converters with redundancy ability are welcome. However, most existing high voltage dc-dc converters do not have redundancy ability. To solve this problem, a wide load range zero-voltage switching (ZVS) three-level (TL) dc-dc converter is proposed, which has some definitely good features. The primary switches have reduced voltage stress, which is only Vin/2. Moreover, no extra clamping component is needed, which results simple primary structure. Redundancy ability can be obtained by both primary and secondary sides, which means high system reliability. With proper designing of magnetizing inductance, all primary switches can obtain ZVS down to 0 output current, and in addition, the added conduction loss can be neglected. TL voltage waveform before the output inductor is obtained, which leads small volume of the output filter. Four secondary MOSFETs can be switched in zero-current switching (ZCS) condition over wide load range. Finally, both the primary and secondary power stages are modular architecture, which permits realizing any given system specifications by low voltage, standardized power modules. The operation principle, soft switching characteristics are presented in this paper, and the experimental results from a 1 kW prototype are also provided to validate the proposed converter.

Analysis of Step Up Transformer for Pulsed Electric Fields Generator

2016 ◽  
Vol 3 (1) ◽  
pp. 59
Author(s):  
Yoppy Yoppy ◽  
Mohamad Khoirul Anam ◽  
Yudhistira Yudhistira ◽  
Priyo Wibowo ◽  
Harry Arjadi ◽  
...  
Keyword(s):  
Electric Fields ◽  
High Voltage ◽  
Low Voltage ◽  
Voltage Drop ◽  
Pulsed Electric Fields ◽  
Maximum Energy ◽  
Leakage Inductance ◽  
Voltage Generator ◽  
High Voltage Generator ◽  
Rising Time

<em><span>Pulsed electric fields (PEF) is a novel non-thermal food processing whose purpose is</span><span lang="EN-US"> </span><span>inactivating microbes while at the same time preserving food’s nutrition, color, and taste. This paper presents an analysis of step up transormer for PEF high voltage generator. To achieve the optimum PEF effects, the pulse shape should resemble a square, which is characterized by low voltage drop and fast rising time. Through simulations, it has been shown that higher transformer inductance results in lower voltage drop. However at some points, further increasing the inductance would only produces negligible improvements. Meanwhile fast rising time can be achieved by minimizing leakage inductance and parasitic capacitance. Moreover, maximum energy transfer to the load can be obtained by reducing winding resistances. Finally, a case of high voltage generator using ignition coil has been evaluated. Due to its high winding resistances, ignition coil seems to be not suitable for PEF applications.</span></em>

scholarly journals DESIGN AND ANALYSIS OF A GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEM

2013 ◽  
pp. 76-79
Author(s):  
J. KISHORE KUMAR ◽  
V. LAKSHMI DEVI ◽  
CH. RAJESH KUMAR
Keyword(s):  
Power System ◽  
High Voltage ◽  
High Performance ◽  
Low Voltage ◽  
Harmonic Distortion ◽  
System Control ◽  
Voltage Gain ◽  
Pv System ◽  
Pv Array ◽  
High Voltage Gain

A grid-connected photovoltaic (PV) power system with high voltage gain is proposed, and the steady-state model analysis and the control strategy of the system are presented in this paper. For a typical PV array, the output voltage is relatively low, and a high voltage gain is obligatory to realize the grid-connected function. The proposed PV system employs a ZVT-interleaved boost converter with winding-coupled inductors and active-clamp circuits as the first power-processing stage, which can boost a low voltage of the PV array up to a high dc-bus voltage. Two compensation units are added to perform in the system control loops to achieve the low total harmonic distortion and fast dynamic response of the output current. Furthermore, a simple maximum-power-point-tracking method based on power balance is applied in the PV system to reduce the system complexity and cost with a high performance. At last, a 2-kW prototype has been built and tested to verify the theoretical analysis of the paper.

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