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Abstract In this study, a 3 × 3 blue micro-LED array with a pixel size of 10 × 10 μm2 and a pitch of 15 μm was fabricated on an epilayer grown on a sapphire substrate using metalorganic chemical vapor deposition technology. The fabrication process involved photolithography, wet and dry etching, E-beam evaporation, and ion implantation technology. Arsenic multi-energy implantation was utilized to replace the mesa etching for electrical isolation, where the implantation depth increased with the average energy. Different ion depth profiles had varying effects on electrical properties, such as forward current and leakage currents, potentially causing damage to the n-GaN layer and increasing the series resistance of the LEDs. As the implantation depth increased, the light output power and peak external quantum efficiency of the LEDs also increased, improving from 5.33 to 9.82%. However, the efficiency droop also increased from 46.3 to 48.6%.

In this study, a 3 × 3 blue micro-LED array with a pixel size of 10 × 10 μm2 and a pitch of 15 μm was fabricated on an epilayer grown on a sapphire substrate using metalorganic chemical vapor deposition technology. The fabrication process involved photolithography, wet and dry etching, E-beam evaporation, and ion implantation technology. Arsenic multi-energy implantation was utilized to replace the mesa etching for electrical isolation, where the implantation depth increased with the average energy. Different ion depth profiles had varying effects on electrical properties, such as forward current and leakage currents, potentially causing damage to the n-GaN layer and increasing the series resistance of the LEDs. As the implantation depth increased, the light output power and peak external quantum efficiency of the LEDs also increased, improving from 5.33 to 9.82%. However, the efficiency droop also increased from 46.3 to 48.6%. [ABSTRACT FROM AUTHOR]

A 62‐year‐old man with a history of catheter ablation for atrial fibrillation and atrial tachycardia (AT) received a line of block of the mitral isthmus (MI) and electrical isolation of the left atrial appendage (LAA). Upon entrainment pacing, AT recurred and was diagnosed as peri‐mitral AT (PMAT) with electrical irrelevance of MI, LAA, and left pulmonary vein, having a critical isthmus identified as Marshall bundle (MB). MB was then infused with ethanol, leading to the successful treatment of the PMAT. [ABSTRACT FROM AUTHOR]

Introduction: To investigate the optimal range of quantitative ablation index (AI) value during superior vena cava (SVC) electrical isolation by radiofrequency catheter ablation (RFCA). Methods: First, in a development cohort of patients with atrial fibrillation (AF), the RFCA with 40 W was performed to complete SVC isolation guided by the conduction breakthrough point from the right atrium to SVC. Then, the range of AI value was calculated by offline analysis on different segments of SVC. Lastly, for the validation of AF patients, the safety and effectiveness of SVC isolation with the optimized target range of AI value were evaluated with an additional adenosine test. Results: A total of 101 patients with AF were included in the study (44 patients in the development cohort/57 in the validation cohort). The segmental ablation strategy was applied in 70% of the patients. According to the offline analysis of the AI values in the development cohort, the target AI value range was set as 350–400. The success rate of SVC isolation in the validation cohort was significantly higher than that in the exploration cohort (100% vs. 90.9%, p =.02), and no complications occurred in the exploration cohort. During the adenosine test, the recovery rate of electrical conduction in SVC was significantly lower than that in the pulmonary vein (3.5% vs. 17.5%). Conclusion: The target AI value with a range from 350 to 400 is safe and effective for high‐power RFCA to complete SVC isolation. [ABSTRACT FROM AUTHOR]

This paper presents a novel topology of a modified isolated single-ended-primary-inductance converter (SEPIC) with a model predictive control (MPC) approach applied to direct current (DC) electronic loads. The proposed converter uses an actual transformer rather than a coupled inductor for isolation between the source and the load. The transformer allows the proposed converter to operate at a higher switching frequency, ultimately reducing the passive components' size. A low-power hardware prototype is developed and tested with a model predictive control algorithm under variable input voltages and load conditions. The performance of the proposed converter is demonstrated to be satisfactory under steady state, as well as sudden input voltage transients. The proposed converter utilizes a switched capacitor technique to generate alternating current in both windings of the transformer. As the coupled inductor is eliminated from the circuit, the problem of high voltage spikes occurring due to leakage inductances is also eliminated for the proposed converter. Therefore, the proposed converter can be used for isolated medium power applications. The experimental results show that the efficiency of the proposed converter reached 96%. The MPC allows this converter's DC voltage level to remain stable even as the input voltage and output terminal load change. Lastly, this converter with an MPC approach can be applied to different DC electronic loads, improving DC power quality and DC electronic load life. [ABSTRACT FROM AUTHOR]

Due to the different grounding methods of the neutral line, the performance of the alternating current uninterruptible power supply (UPS) system will be greatly affected when the multiple power supply systems are switched to each other. Firstly, based on tripolar and quadrupole automatic transfer switch, the circuit equivalent model of multiple power supply system was established through different grounding modes. The advantages and disadvantages of different circuit structures were discussed, and the performance index of multi-power system circuit was simulated and verified by building MATLAB/ Simulink simulation model. Based on the circuit of the multi-power system, the MATLAB/ Simulink simulation model of the UPS circuit of the multi-power system was built, and the key performance indexes of the UPS circuit of the multi-power system were simulated. Secondly, three kinds of UPS circuit structure optimization schemes of multi-power system were proposed to optimize the performance indexes of UPS circuit of multi-power system, such as no stray current, no neutral line shunting, continuous neutral line grounding reference, electrical isolation between multiple input power sources, input power and output power sources, and input power and bypass power sources. Finally, three optimized and enhanced circuit MATLAB/ Simulink simulation models were constructed, and the performance indexes of the three UPS circuits were simulated. The experimental results demonstrate that the improved scheme three of “multi-power system UPS power circuit with bypass isolation transformer” has the optimal performance indexes of the multi-power system UPS power circuit. [ABSTRACT FROM AUTHOR]

This paper presents a novel topology of a modified isolated single-ended-primary-inductance converter (SEPIC) with a model predictive control (MPC) approach applied to direct current (DC) electronic loads. The proposed converter uses an actual transformer rather than a coupled inductor for isolation between the source and the load. The transformer allows the proposed converter to operate at a higher switching frequency, ultimately reducing the passive components’ size. A low-power hardware prototype is developed and tested with a model predictive control algorithm under variable input voltages and load conditions. The performance of the proposed converter is demonstrated to be satisfactory under steady state, as well as sudden input voltage transients. The proposed converter utilizes a switched capacitor technique to generate alternating current in both windings of the transformer. As the coupled inductor is eliminated from the circuit, the problem of high voltage spikes occurring due to leakage inductances is also eliminated for the proposed converter. Therefore, the proposed converter can be used for isolated medium power applications. The experimental results show that the efficiency of the proposed converter reached 96%. The MPC allows this converter’s DC voltage level to remain stable even as the input voltage and output terminal load change. Lastly, this converter with an MPC approach can be applied to different DC electronic loads, improving DC power quality and DC electronic load life.

The Smart Discrete concept which monolithically integrates a vertical high-voltage power device with low-voltage smart circuits has been widely adopted in silicon world for many years and may bring similar benefits to SiC world. For example, it is highly desirable to integrate a gate driver circuit onto a high-voltage SiC thyristor for ultra-fast turn-on. However, the electrical isolation between the vertical high-voltage power device and the low-voltage circuit elements remains a major technical challenge for silicon, and even more so for SiC due to the very limited processing options. In this article, we propose a combination of shallow junction isolation (JI) and partial dielectric isolation (DI) for high-voltage 4H-SiC smart thyristor, which is monolithically integrated with low-voltage nMESFET circuits. The characterization of fabricated devices and analysis of leakage currents across the isolation structure have been done to experimentally verify the feasibility of the isolation method. 8 V parasitic lateral NPNP thyristor between a 6.3 kV 4H-SiC thyristor and isolation moats, 175 V lateral PNP transistor between the passive resistor and isolation moats, and 10 V lateral reverse-biased p-n diode between nMESFET and isolation moats are experimentally demonstrated. [ABSTRACT FROM AUTHOR]

The etch damage caused by the conventional bench-top etching process makes it difficult to produce Nano-LED devices. Recently, some scholars have studied the use of ion injection to achieve electrical isolation between pixels for the purpose of pixelation. In this paper, we focus on the distribution characteristics of ions in GaN targets to improve the effective light-emitting area ratio of devices by reducing the lateral diffusion effect of ions. [ABSTRACT FROM AUTHOR]

ObjectiveThe objective of this study was to observe the safety and efficacy of electrophysiological mapping following the Cox-Maze IV procedure and to investigate whether a correlation exists between recurrence of atrial fibrillation (AF) with the completeness of bidirectional electrical isolation and the inducibility of AF immediately after the Cox-Maze IV procedure.MethodsTotally, 80 consecutive patients who suffered from aortic valve or mitral valve disease and persistent AF were randomly enrolled into the control group and electrophysiological mapping following the Cox-Maze IV group (Electrophysio-Maze group). In the Electrophysio-Maze group, patients underwent concomitant Cox-Maze procedure and following electrophysiological mapping of ablation lines in mitral isthmus, left atrial “box,” and tricuspid annulus. If the bidirectional electrical isolation of tricuspid annulus ablation line is incomplete, whether to implement supplementary ablation will be independently decided by the operator. Before and after the Cox-Maze IV procedure, AF induction was performed. All patients in both groups were continuously followed-up and underwent electrocardiogram Holter monitoring after 6 months.ResultsIn total, 42 Electrophysio-Maze patients and 38 controls were enrolled. Compared with patients in the control group, there were shorter hospital stay, better cardiac remodeling changes, and higher relief from AF during the follow-up period of 6 months in the Electrophysio-Maze group. Within the Electrophysio-Maze group, the rate of incomplete the bidirectional electrical isolation of “box” ablation lines was zero, and the rate of incomplete bidirectional electrical isolation of mitral isthmus ablation line or tricuspid annulus ablation line was 23.8%. After two cases of successful complementary ablation on the tricuspid annulus ablation line, the final incomplete bidirectional electrical isolation of annulus ablation lines was 19.0%. There were correlations between late AF recurrence after 6 months with incomplete bidirectional electrical isolation of annulus ablation lines and AF induction immediately after the Cox-Maze IV procedure.ConclusionElectrophysiological mapping following the Cox-Maze procedure is safe and effective. Electrophysiological mapping in the Cox-Maze procedure can find out the non-transmural annulus ablation lines by assessing the completeness of bidirectional electrical isolation of ablation lines, guide supplementary ablation, and predict AF recurrence after 6 months.

To make full use of the power of the microgrid and improve the reliability of the power supply system, a flexible interconnection control strategy for the DC microgrid cluster based on isolated bidirectional DC–DC converters is proposed in this paper. First, an isolated bidirectional DC–DC converter is used to flexibly interconnect the two DC microgrids based on electrical isolation to ensure that both DC microgrids can operate independently, and then the extended phase shift control is adopted for the isolated bidirectional DC–DC converter, which increases the control dimension and controls flexibility. At the same time, the extended phase shift control circuit is improved, which solves the traditional constant power transmission problem and ensures the real-time bidirectional transfer of energy between microgrids. The microgrid cluster simulation platform is built in MATLAB/Simulink, and the electrical isolation effect of the isolated bidirectional DC–DC converter is verified through simulation. At the same time, it is verified that the shift ratio of the regulating converter can realize the energy between the microgrids in the microgrid cluster, which improves the stability of the system.

To make full use of the power of the microgrid and improve the reliability of the power supply system, a flexible interconnection control strategy for the DC microgrid cluster based on isolated bidirectional DC–DC converters is proposed in this paper. First, an isolated bidirectional DC–DC converter is used to flexibly interconnect the two DC microgrids based on electrical isolation to ensure that both DC microgrids can operate independently, and then the extended phase shift control is adopted for the isolated bidirectional DC–DC converter, which increases the control dimension and controls flexibility. At the same time, the extended phase shift control circuit is improved, which solves the traditional constant power transmission problem and ensures the real-time bidirectional transfer of energy between microgrids. The microgrid cluster simulation platform is built in MATLAB/Simulink, and the electrical isolation effect of the isolated bidirectional DC–DC converter is verified through simulation. At the same time, it is verified that the shift ratio of the regulating converter can realize the energy between the microgrids in the microgrid cluster, which improves the stability of the system. [ABSTRACT FROM AUTHOR]

GaN based Photonic Integrated Circuits (PICs) have now become a global contender for their wide range of applications owing their physical characteristics. The GaN material system acts as a promising platform; compatible with silicon and sapphire substrates. Both the carrier transport and carrier removal techniques are vital to develop the efficient platform for the integration of photonic circuits. We demonstrate the carrier removal mechanism in silicon (Si) doped GaN (0001) epitaxially grown on c-plane sapphire wafer using ion engineering of the devices. Ion-engineered regions within the active layers of the device are modelled, fabricated and characterized to assess the isolation created. Helium and Carbon ions with pre-designed doses and energies are used to irradiate the device structures. We have modelled and fabricated ion-engineered regions within the active layers and studied the carrier transport properties on said regions to isolate that particular part with either of active photonic components placed at the common platform. After ion irradiation, detailed analysis in terms of electric field dependent current characteristics, sheet resistance, carrier mobilities, activation energies, dark and photo currents under zero (ground) and multiple biases are examined to see the extent of charge leakage and to map the charge behavior under nominal operation. Device characteristics under wide regime of annealing temperatures ranging from 300°C to 1000°C are mapped to evaluate the thermal stability of implant driven isolated regions. Activation energies of implanted and parent regions has also been studied. The dark and photon driven electric currents at ground and under biased have been measured to investigate the photo-induced transport phenomenon.

Background: Electrical isolation of the left atrial appendage (LAA) improves outcomes of patients with persistent atrial fibrillation (AF) but may increase the risk of thromboembolism.Objective: The purpose of this study was to describe a method to map and ablate appendage drivers without complete electrical isolation.Methods: One hundred thirteen patients underwent an ablation procedure for persistent AF. The procedure was performed during AF and consisted of pulmonary vein and posterior LA isolation as well as ablation of the LAA. The right atrium (RA) was targeted in patients with a right-to-left gradient in cycle length (CL). The end point of appendage ablation was CL slowing or AF termination but not complete isolation.Results: Among the 113 patients (mean age 64.6 ± 8.6 years; ejection fraction 54% ± 13%; LA diameter 46 ± 6.5 mm), radiofrequency ablation terminated AF in 51 patients (45%). RA ablation was performed in 41 patients (36%) at the index or repeat procedure. The mean AF CL in the RA appendage (RAA) was shorter than that in the LAA (160 ± 32 ms vs 186 ± 29 ms; P < .01) in these patients. The most frequent target in the RA was the RAA (CLs approaching 50-60 ms). Discontinuing radiofrequency ablation upon AF termination or conduction slowing prevented LAA isolation. After a mean follow-up of 24 ± 15 months, 89 patients (78%) remained arrhythmia-free without antiarrhythmic medications.Conclusion: An ablation strategy guided by the AF CL addresses LAA drivers without complete electrical isolation and also helps identify the RAA as a source of persistent AF. [ABSTRACT FROM AUTHOR]

In power circuits, the gate drivers are required to provide an optimal and safe switching of power semiconductor devices. Nowadays, the gate driver boards include more and more features, such as short-circuit detection, soft-shutdown, temperature sensing, on-state voltage monitoring. Research works are in progress on the integration of on-line monitoring features for a predictive maintenance. The instrumentation of the gate drive system supposes the integration of a communication system to transmit the monitoring data. In high-power designs, a galvanic isolation is mandatory on the gate driver board. The parasitic capacitance seen on the isolation barrier is critical in these designs as it can lead to the circulation of common mode currents during the switching. Adding extra optocouplers or transformers on the isolation barrier is, therefore, risky due to electromagnetic interference constraints. In this article, a new bidirectional data transmission method is proposed for gate drivers used for driving 1.2 kV silicon carbide (SiC) power metal oxide semiconductor field effect transistors (mosfets). The proposed method enables the energy transmission and a bidirectional data exchange on a single power supply transformer. The experimental results are provided demonstrating 1 Mb/s for TxD and 16 kb/s for RxD. The targeted application is the health monitoring of SiC power mosfets using the gate driver board. [ABSTRACT FROM AUTHOR]

Compared with AC distribution networks, DC distribution networks reduce the utilisation of power converters, power loss, and construction cost. In DC distribution network, the high-frequency modular multilevel DC converter (MDCC), which connects the low-voltage DC link with medium- or high-voltage DC links, becomes a practical equipment to realise the bus connection, voltage conversion, and electrical isolation. Especially, high-frequency link (HFL) modulation plays an important role in converter performance. The square-wave (SW) modulation obtains better power transfer capability and higher DC voltage utilisation. However, the SW modulation leads to a large dv/dt stress upon HFL transformer. The sinusoidal, triangle and quasi-square-wave (QSW) modulations reduce dv/dt and harmonics significantly. However, the power transfer capability and DC voltage utilisation are also reduced. To address dv/dt stress problem, ensure high DC-voltage utilisation and maintain a strong power transfer capability simultaneously, a hybrid-wave modulation strategy, which composed of QSW and SW modulation, is proposed for MDCC. The experimental results verify the analysis and proposed scheme.

Compared with AC distribution networks, DC distribution networks reduce the utilisation of power converters, power loss, and construction cost. In DC distribution network, the high-frequency modular multilevel DC converter (MDCC), which connects the low-voltage DC link with medium- or high-voltage DC links, becomes a practical equipment to realise the bus connection, voltage conversion, and electrical isolation. Especially, high-frequency link (HFL) modulation plays an important role in converter performance. The square-wave (SW) modulation obtains better power transfer capability and higher DC voltage utilisation. However, the SW modulation leads to a large dv/dt stress upon HFL transformer. The sinusoidal, triangle and quasi-square-wave (QSW) modulations reduce dv/dt and harmonics significantly. However, the power transfer capability and DC voltage utilisation are also reduced. To address dv/dt stress problem, ensure high DC-voltage utilisation and maintain a strong power transfer capability simultaneously, a hybrid-wave modulation strategy, which composed of QSW and SW modulation, is proposed for MDCC. The experimental results verify the analysis and proposed scheme. [ABSTRACT FROM AUTHOR]

The pixelation of Micro-LED still faces intractable technological problems with the shrinkage of pixel by using conventional mesa etching processes, such as reduced luminous efficiency and tough metal interconnection. In this work, a novel pixelation strategy using fluorine (F) ion implantation with tailored injection energy and dose has been proposed and investigated through simulation and experiment. It is found that both the injection depth and spatial distribution range are determined by injection energy. The lateral spreading of the F ions could be effectively suppressed by decreasing injection energy and increasing dose while achieving equal electrical isolation. Furthermore, the uniformity of lateral spreading could be improved by introducing multi-energy injections. For verification and demonstration, Micro-LED arrays with fixed pitch and various pixel sizes were fabricated by F ion implantation, both photoluminescence and electroluminescence characteristics show that the pixel contrast and uniformity are well maintained even for the Micro-LED array with pixel size of 10 μm. For Micro-LED array with pitch and pixel sizes of 40 μm and 10 μm, the reverse leakage currents at a reverse bias voltage of −5 V is 1.45 × 10−7 A, which is lower than that formed by conventional bench top etching. The pixelation method by fluorine ion implantation with tailored injection energy and dose is expected to be able to pave the way toward high-performance Micro-LED and Nano-LED displays. • A novel pixelation strategy using fluorine ion implantation with tailored injection energy and dose was proposed. • The spatial distribution and electrical isolation effects of F ions in P-GaN were studied by finite element simulation. • The uniformity of lateral spreading was improved by introducing multi-energy injections. • Micro-LED arrays with pixel size of 10 μm and low leakage current were fabricated. [ABSTRACT FROM AUTHOR]

The control of mosfet or IGBT transistors is carried out by a dedicated circuit called « driver », which is located as close as possible to the power module. It transmits switch-on and switch-off orders coming from the control unit and ensures the integrity of the component through safety functions. It also provides a galvanic isolation essential to guarantee the effective functioning of the system and the users’ safety. Switching times of SiC mosfet are faster than Si IGBT, and SiC mosfet can also work under a greater dc voltage than Si mosfet. This involves the presence of higher dv/dt in the converter. In this paper, a communication function is studied to be integrated into the new generations of drivers for SiC mosfet . The interest of the implementation of a communication system in a driver is presented. Currently available solutions on the market to provide isolation to communication channels are debated. The theoretical development of a solution called « CAN-ISO » is detailed and experimental results under a high peak voltage of 2 kV and a high dv/dt equal to \text125\;\textkV/\mu\texts are presented. [ABSTRACT FROM AUTHOR]

Ion implantation can be applied to form the electrical isolation in AlGaAs/GaAs Quantum Cascade Laser (QCL) instead of mesa etching. In this paper, we present in detail the designing of hydrogen implant isolation scheme, alongside with its verification and study of thermal stability by structural and electrical characterization techniques. Our scheme employed 4 µm thick metallic mask made mainly of gold which also served as contact layer, and 640 keV hydrogen implantation to a fluency of 1 × 10 15 cm −2 . We obtained the sheet resistivity R SH of (1.5 ± 0.9) × 10 9 Ω/□. The critical temperature for the hydrogen implant isolation fabrication of the AlGaAs/GaAs QCL was determined to be 310 ℃. Defect density dropped to residual levels after 1 min annealing at 300 ℃ and 400 ℃, while the material was still resistive with R SH above 10 8 Ω/□. Based on our simulated vacancy maps we concluded that the minimum width of the masking structure should be at least 5 µm to avoid the effects of lateral isolation for the given implantation conditions. The QCL device fabricated with this isolation scheme operated with threshold current densities of 6 kA/cm 2 at the temperature of 77 K. Ultimately, we confirmed the applicability of hydrogen implant isolation for the manufacturing of optical devices. [ABSTRACT FROM AUTHOR]

Electronics systems for space application always demand higher performance, weight saving and volume diminution etc. without sacrificing their reliability. As part of this stringent requirement, a few circuit blocks which are repeatedly used in various inertial systems are being realized in Hybrid Micro Circuits (HMCs). Recently, a few batches of HMCs fabricated by a specific vendor showed low electrical isolation between the HMC package body and other functional pins at ambient temperature. However, the electrical isolation values were found to be normal at elevated temperatures. The low electrical isolation was causing leakage current between pins or package body to other pins. This makes the performance of the HMCs unpredictable during its operational period. In this paper, study and analysis conducted with respect to the low electrical isolation observed in HMCs are discussed. Root cause of the problem was analyzed by conducting methodical and systematic tests based on a formulated Ishikawa model. The major tests conducted in this analysis include external visual inspection, isolation measurements, Scanning Electron Microscopy (SEM), leak tests, Residual Gas Analysis (RGA), internal visual inspection etc. Based on the test results, root cause of the isolation problem was narrowed down to process related, which was one of the primary causes as stipulated in Ishikawa model. The real cause of the problem was the formation of ammonium hydroxide inside the HMC due to the presence of ammonia and moisture. The defective HMCs showed very large quantity of these conducting residues inside the HMCs during the RGA test. These residues emanated from the epoxy material used to attach the alumina substrate in the HMC. These faulty HMCs have not undergone vacuum baking properly before being sealed due to faulty functioning of the chamber. Hence residual gases and moisture could not be outgassed completely before sealing. Internal visual inspection of the HMCs revealed spill over of substrate attach epoxy to the Glass To Metal Seal (GTMS) thereby bridging the package pin and HMC body. Ammonium hydroxide present in this bridged epoxy was causing the low electrical isolation at ambient condition. The electrical isolation that resulted from the ammonium hydroxide is quantified and the results were found comparable with the measured values. At elevated temperatures, the ammonium hydroxide again decomposes to ammonia and water vapor and loses its conductivity and the isolation values become normal. [ABSTRACT FROM AUTHOR]

This paper proposes an isolated single-ended primary-inductor converter (SEPIC) dc–dc converter with ripple-free input current and lossless snubber. The proposed converter is based on a conventional isolated SEPIC converter to enable electrical isolation and high voltage gain using a coupled inductor. The input current ripple is significantly reduced by utilizing an auxiliary circuit that also functions as a lossless snubber circuit with an additional diode. Moreover, the maximum switch voltage stress is clamped to a low voltage by the snubber circuit. Therefore, a low voltage rating mosfet that has low $R_{{\rm{DS(on)}}}$ can be utilized as a main switch device. Hence, the total power efficiency is improved. Experimental results from a 100 W prototype, which are presented to verify the theoretic analysis and performance of the proposed converter. [ABSTRACT FROM PUBLISHER]

Left atrial appendage (LAA) exclusion with the use of the AtriClip (AtriCure, Inc., OH, USA) device has been shown to be a safe, effective, and durable strategy predominantly to reduce the lifelong risk of thromboembolism and stroke in patients with atrial fibrillation (AF). We present a case showing electrical isolation of the LAA after its exclusion with the AtriClip device during hybrid ablation for the treatment of longstanding persistent AF. Our case demonstrates the effectiveness of the AtriClip device in not only mechanically occluding the LAA but also electrically isolating it, thereby addressing an electrical driver of AF in addition to reducing its thromboembolic sequelae. [ABSTRACT FROM AUTHOR]

Background: In arrhythmogenic right ventricular cardiomyopathy (ARVC) patients with extensive right ventricular free wall (RVFW) abnormal substrate, large-area homogenization with combined epicardial and endocardial approach is time consuming and often inadequate for modification., Objectives: This study aimed to explore the feasibility and efficacy of RVFW abnormal substrate isolation in such patients to control ventricular tachycardia (VT)., Methods: Eight consecutive ARVC patients with VT who had extensive abnormal RVFW substrate were included. VT induction was performed before substrate mapping and modification. Detailed voltage mapping was done during sinus rhythm. A circumferential linear lesion was deployed along the border zone of low-voltage area on the RVFW to achieve electrical isolation. Other small areas with fractionated or late potentials were further homogenized., Results: All 8 patients had RVFW endocardial low-voltage area. The entire RV low-voltage area was 113.8 ± 84.1 cm 2 (49.6% ± 29.8%) and the dense scar was 59.6 ± 39.8 cm 2 (25.0% ± 14.1%). Electrical isolation of abnormal substrate was achieved in 5 of 8 (62.5%) patients via endocardial approach alone and 3 of 8 (37.5%) patients via a combination of endocardial and epicardial approach. Electrical isolation was verified by slow automaticity (5 of 8, 62.5%) or RV noncapture (3 of 8, 37.5%) during high-output pacing inside the encircled area. VTs were induced in 6 patients before ablation, and all patients were rendered noninducible after ablation. During a median follow-up of 43 months (range: 24-53 months), 7 of 8 (87.5%) patients remained free of sustained VT., Conclusions: Electrical isolation of RVFW is feasible and can be the option in ARVC patients with extensive abnormal substrate., Competing Interests: Funding Support and Author Disclosures This trial was supported by National key research and development program of China (2017YFC1307800). Dr Chen has received lecture fees from Biosense Webster, St. Jude Medical, Medtronic, Bayer, and Boehringer Ingelheim. All other authors have reported that they have no relationships relevant to the contents of this paper., (Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

In view of problem that performance of RS485 bus will be decreased by underground complex electromagnetic environment, so as to influence data transmission of coal mine safety monitoring and control system, the paper indicated that it should make anti-interference design of RS485 bus through aspects of fault insurance circuit, electrical isolation, interface protection of anti-surge over-voltage and communication software programming, and gave implementation of the anti-interference design. The actual application showed that the anti-interference design can ensure stable running of data transmission of coal mine safety monitoring and control system.