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Natural gas is transported from production areas using high-pressure pipelines to pass through pressure reducing stations and then to the consumer. When temperatures drop, the problem of freezing of natural gas and ice appears. To protect against this phenomenon, we use a water bath to improve the temperature of the gas before reducing its pressure. One of the essential elements in the design of a low thermal efficiency water bath heater is the gas coil that runs inside the heater. In this study, the analysis of heat transfers and gas flow velocity inside the corrugated coil was performed with varying wave amplitude (10 mm, 15 mm, and 20 mm). The three-dimensional unsteady Reynolds-Navier-Stokes equations are solved using both the realizable k-ε turbulent model and the finite volume method to obtain the flow field. The results of this study showed that using corrugated coils with a larger capacity leads to an increase in the Nusselt number and friction factor, respectively, by about 6.57% and 114%. In general, the heat exchange inside the corrugated twisted gas coil can be enhanced by increasing the wave amplitude. [ABSTRACT FROM AUTHOR]

Output power is an important performance metric related to static or quasi-static wireless power transfer (WPT). As an important component of WPT, the electrical parameters of a magnetic coupling mechanism (MCM) are directly related to its output characteristics. Notably, an optimal WPT design is largely based on MCMs using the same primary and secondary coils. However, in some scenarios involving limited space, the physical structure and electrical parameters of the coils cannot be kept completely consistent. Based on the influence of physical parameters on coupling performance and system characteristics, an optimal design method for MCMs using different primary and secondary coils to ensure maximum output power is proposed. The best receiving coil within a limited space that achieves maximum power at a specific location was selected. Experiments were conducted, with the corresponding results verifying the correctness of theoretical and simulation analyses, as well as the effectiveness of the proposed method.

Abstract Simple and practical methods have been provided for the mutual inductance between rectangular and circular coils with parallel axes. The 2D Integral solution is given for the coils without the axial overlap. To improve the efficacy of the proposed approach for the partial or full axial overlap, the series solution derived by the truncated region eigenfunction expansion (TREE) is provided. Both integral and TREE expressions show very high accuracy through comparison with the finite element method simulation and experiment results. Numerical comparisons reveal that the TREE solution is the most efficient while keeping sufficient accuracy, and it is also applicable to all sorts of coil positions.

Objectives: Endoscopic ultrasound (EUS)‐guided injection of cyanoacrylate (CYA) for primary prophylaxis (PP) of gastric varices (GV) is controversial. This study evaluates the safety and efficacy of this intervention. Methods: Patients treated for PP of GV bleeding by EUS injection of CYA with or without coils were identified. Endoscopic techniques, outcomes, and adverse events (AEs) were reviewed and compared with a group treated for secondary prophylaxis (SP). Patients were followed until: (i) loss to follow‐up; (ii) GV bleeding; (iii) interventional radiology or surgery decompression; (iv) liver transplant; or (v) death or comfort care. Results: One hundred and nineteen patients (61 men; mean 59 ± 12 years) underwent EUS for PP (n = 24) or SP (n = 95). The PP group was treated with CYA alone (n = 18) or with coils (n = 4). Eight (33%) mild (n = 6) or moderate (n = 2) AEs and no index GV bleeding occurred during a mean of 6.1 ± 5.9 months follow‐up. Repeat EUS in 22 (92%) PP patients showed 7 (32%) residual GVs, which were retreated with CYA alone (n = 6) or with coils (n = 1). Two (29%) mild (n = 1) or moderate (n = 1) AEs occurred after repeat EUS and 1/22 (5%) index GV bleed occurred during a mean 23 ± 25 months follow‐up. Compared to the SP group, the PP group had lower Model for End‐stage Liver Disease (MELD) score (P = 0.03), fewer GV stigmata (P < 0.001), required less CYA (P = 0.019) during index EUS, and had a longer time between index and surveillance EUS (P = 0.014). The incidence of AEs and GV bleeding between the two groups were similar. Conclusion: Posttreatment GV bleeding and AEs are similar following EUS‐guided primary and secondary GV prophylaxis. [ABSTRACT FROM AUTHOR]

A mathematical model is presented for the optimisation of an Electromagnetic Halbach Array (EHA) for wireless power transfer. The mathematical model is based on Biot‐Savart's law of magnetic field in a current‐carrying square loop. The model is validated through static electromagnetic simulations in ANSYS Maxwell and found to be accurate and effective when predicting the magnetic field within the EHA box. To verify the analytical and simulation results, an EHA was fabricated, and experimental verification was carried out. The results show that the mathematical model can be widely used in the analysis and design optimisation of EHAs of any size and with diverse parameters in the case of single‐layer square spiral planar coils. [ABSTRACT FROM AUTHOR]

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In industry, to improve the power factor in low-voltage power substations, a power factor controller (the most used method) can be installed which connects capacitors banks (connected, or not, with coils) in the electrical installation. The most important parameters of power engineering are the power factors that indicate the efficiency of energy use. Currently, many non-linear consumers (more single-phase than three-phase) are used on low voltages. Harmonics (currents and/or voltages) are the most important dynamic component of power quality, affecting electrical equipment performance and also reducing power factors. The purpose of this analysis is to increase the displacement power factor and to decrease the total harmonic distortion (for the current) in the conditions where there are linear and non-linear consumers, where the power factor must be improved with capacitors banks. Relevant different consumers have been selected for both the industry and the home sector, as follows: inductive motors that are linear, inductive consumers, compact fluorescent lamps that are non-linear, and capacitive consumers. This analysis was carried out depending on the number of steps used for the power factor controller, the values of the capacitors banks, the AC reactor (connected in series with all consumers), and the LC shunt filters. For a slight deformation regime, a large number of capacitors banks with different values ensure a finer adjustment of the displacement factor. The maximum number of steps that regulators can command should not necessarily be used (the reliability of the installation decreases with the increase in the number of capacitors banks), but a reduced number of steps can be used, which can lead to higher values of displacement power factors. To improve the deforming regime and to increase the displacement power factor, the use of LC shunt filters, connected to a small number of steps, will also increase the displacement power factor (over 0.9) and decrease the total harmonic distortion (up to 7–10%) for the current. Weaker results were obtained with AC reactors connected to the power supply phases of consumers and, if a larger number of stages were used, to which LC shunt filters were connected, these filters become difficult to calibrate (resonances occur). [ABSTRACT FROM AUTHOR]

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair. [ABSTRACT FROM AUTHOR]

Simple and practical methods have been provided for the mutual inductance between rectangular and circular coils with parallel axes. The 2D Integral solution is given for the coils without the axial overlap. To improve the efficacy of the proposed approach for the partial or full axial overlap, the series solution derived by the truncated region eigenfunction expansion (TREE) is provided. Both integral and TREE expressions show very high accuracy through comparison with the finite element method simulation and experiment results. Numerical comparisons reveal that the TREE solution is the most efficient while keeping sufficient accuracy, and it is also applicable to all sorts of coil positions. [ABSTRACT FROM AUTHOR]

Purpose To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment. Materials and Methods A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI. Results When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils. Conclusion The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization.

The demand for biomedical devices that can collect high-fidelity data from patients in various environments, inside and outside medical clinics, and can provide high-precision diagnosis and long-term monitoring, is high in the healthcare industry. Among different sensing technologies, this study specifically focuses on providing a review of inductive sensing-based devices used in healthcare. Although the concept of inductive sensing has been used in other fields aside from healthcare, we believe that there is a high potential for a wide range of use of this sensing method across various biomedical devices due to the low cost, flexibility in the sensor design, mature fabrication technologies, and high sensitivity. This review first summarizes the mechanisms of inductive sensing-based devices and design considerations. Then, three main groups of applications that are used in healthcare and rely mainly on inductive sensing for their diagnosis and treatments are presented, including motion tracking and continuous monitoring systems, bio-signal detection systems, and imaging biological tissues. We conclude with a summary of the current status of inductive sensing devices used in healthcare, highlighting the promising capabilities and barriers to overcome.

In this paper, we present a 6.78 MHz Pulsed Wireless Power Transfer (PWPT) system specifically designed for powering the electronics placed on a suction roll of a paper mill machinery, thus enabling rotating equipment monitoring. The system utilizes a pair of different resonant coils to maintain a stable coupling coefficient for a fraction of the roll rotation period while guaranteeing compactness and ease of installation. Designed using both Commercial-off-the-Shelf (COTS) and custom components, the developed WPT system achieves a DC-DC efficiency of 62% in the specific working conditions. The transferred power is used to supply an Internet-of-Things (IoT) node that continuously measures and transmits data about the operation status. A fully operational system for battery and angular position monitoring has been developed and tested in a laboratory environment. This research presents a comprehensive analysis of the system and explores the interaction of different coils to maintain a stable coupling coefficient in dynamic applications. The same approach can be employed for rotating machinery with similar geometrical constraints or more general dynamic applications characterized by periodic movements and limited space for the coupling system.

Using dynamic wireless charging systems in conjunction with electric vehicles (EV) could revolutionize transportation in the future by enabling faster driving and non-stop battery charging. Dynamic wireless power transfer can fix the autonomy problems with electric vehicles. The fact that this charging device gets its power from the electrical grid has some serious drawbacks, too. Utilizing alternate sources, like PV generators, is therefore seen to be a potential answer. This study aims to illustrate the advantages that can arise from the interplay of renewable energy sources with wireless recharge systems for electric vehicles in this environment. Therefore, this paper is built and has regrouped the needed sections that can define the wireless recharge concept based on an alternative energy source. Simulation results were adapted by the Matlab Simulink platform, where more than one situation is tested and examined. This is by testing the influence of the vehicleꞌs speed on the wireless charging performances and by testing what effect can be done if the climatic conditions are varied, especially on the global performances of the wireless recharge tool.

Endovascular aortic aneurysm repair is widely used for the treatment of abdominal aortic aneurysm (AAA), but has a 10% to 40% incidence of type II endoleak during follow-up. There are various techniques to treat these endoleaks in the case of enlarging of the AAA, but the clinical effectiveness is low. In recent years, preemptive AAA sac embolization has shown some encouraging results with significant AAA shrinkage. However, the presence of embolic material can complicate continued endoleak detection making assessment of treatment outcome difficult. We investigate the ability of contrast-enhanced-ultrasound examination to detect endoleaks in patients undergoing preemptive coil embolization of the AAA sac.

Purpose: To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment. Materials and Methods: A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI. Results: When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils. Conclusion: The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization. [ABSTRACT FROM AUTHOR]

The design of a wireless power transfer system with double rectangular coils for 11 kW power transfer is considered. System modeling and numerical calculation of the system parameters are described. Coils are made from available Litz wire, which has a smaller than necessary diameter for the required power. Thus, a setup with double layer coils was developed, which resulted in a modified design. Starting from a system consisting of coupled coils, as suggested by the standard for wireless power transfer Level 3 in class Z1, different coil and ferrite shield layouts were tested in numerical simulations, and their parameters were calculated. The prototype was constructed based on the simulated model with the best results and properties. Numerical results were verified by laboratory measurements, and a successful power transfer at 11 kW was achieved. [ABSTRACT FROM AUTHOR]

The human population has a constant growth which creates a great demand for volumes of quality food free of chemical fertilizers, then it is of vital importance to optimize the production processes. Magnetism was chosen as a source of radiation to stimulate the growth of beet seeds. This vegetable was chosen because in studies carried out it was detected that beets are an important source of vitamins and minerals, especially for sports of high physical effort such as cycling. To carry out this study we have coils capable of generating 10mT, 20mT and 30mT. The seeds were exposed for 1min, 10min, 30min, following an experimental design. The seeds were sown and monitored recording the data of both irradiated and control seeds. The data obtained were organized for the respective statistical analysis and to obtain a proposal of a mathematical model that represents the experiment. A benefit in plant growth of up to 2.5 cm was obtained using 30 mT radiation with respect to the control group seeds. [ABSTRACT FROM AUTHOR]

Background: Endovascular treatment of visceral and renal artery aneurysms and pseudoaneurysms is an effective, minimally invasive treatment that has been successfully used since the early 1990s, with refined and expanded techniques and tools currently offering excellent outcomes. Due to increased detection of such lesions in recent years, many of which are asymptomatic, revision of the indications for intervention and the correct endovascular treatment approaches has become essential. Purpose: This document will presume that the indication for treatment is clear and approved by the multidisciplinary team and will define the standards required for the performance of each intervention, as well as their relative advantages and limitations. CIRSE Standards of Practice documents are not intended to impose a standard of clinical patient care, but recommend a reasonable approach to, and best practices for, the performance of the endovascular treatment of visceral and renal artery aneurysms and pseudoaneurysms. Methods: The writing group was established by the CIRSE Standards of Practice Committee and consisted of five clinicians with internationally recognised expertise in endovascular treatments. The writing group reviewed the existing literature on visceral and renal artery aneurysms and pseudoaneurysms, performing an evidence search using PubMed to identify publications in English and relating to human subjects from 1990 to 2022. The final recommendations were formulated through consensus. Results: Endovascular treatment has an established role in the successful management of visceral and renal artery aneurysms and pseudoaneurysms, and this Standards of Practice document provides up-to-date recommendations for its safe performance. [ABSTRACT FROM AUTHOR]

Parallel transmission (pTX) techniques are required to tackle a number of challenges, e.g., the inhomogeneous distribution of the transmit field and elevated specific absorption rate (SAR), in ultra-high field (UHF) MR imaging. Additionally, they offer multiple degrees of freedom to create temporally- and spatially-tailored transverse magnetization. Given the increasing availability of MRI systems at 7 T and above, it is anticipated that interest in pTX applications will grow accordingly. One of the key components in MR systems capable of pTX is the design of the transmit array, as this has a major impact on performance in terms of power requirements, SAR and RF pulse design. While several reviews on pTX pulse design and the clinical applicability of UHF exist, there is currently no systematic review of pTX transmit/transceiver coils and their associated performance. In this article, we analyze transmit array concepts to determine the strengths and weaknesses of different types of design. We systematically review the different types of individual antennas employed for UHF, their combination into pTX arrays, and methods to decouple the individual elements. We also reiterate figures-of-merit (FoMs) frequently employed to describe the performance of pTX arrays and summarize published array designs in terms of these FoMs. [ABSTRACT FROM AUTHOR]

Simultaneously operating MR-PET systems have the potential to provide synergetic multi-parametric information, and, as such, interest surrounding their use and development is increasing. However, despite the potential advantages offered by fully combined MR-PET systems, implementing this hybrid integration is technically laborious, and any factors degrading the quality of either modality must be circumvented to ensure optimal performance. In order to attain the best possible quality from both systems, most full MR-PET integrations tend to place the shielded PET system inside the MRI system, close to the target volume of the subject. The radiofrequency (RF) coil used in MRI systems is a key factor in determining the quality of the MR images, and, in simultaneous acquisition, it is generally positioned inside the PET system and PET imaging region, potentially resulting in attenuation and artefacts in the PET images. Therefore, when designing hybrid MR-PET systems, it is imperative that consideration be given to the RF coils inside the PET system. In this review, we present current state-of-the-art RF coil designs used for hybrid MR-PET experiments and discuss various design strategies for constructing PET transparent RF coils. [ABSTRACT FROM AUTHOR]

Background: Although bleeding from gastric varices is less observed than esophageal variceal bleeding (VB) (25% vs. 64%), it is associated with an exceedingly high mortality rate of up to 45%. Current guidelines suggest that endoscopic cyanoacrylate injection therapy (ECI) is the first-line treatment for gastric variceal bleeding (GVB). A major concern, however, is the possibility of embolic incidents, which are clinically evident in approximately 1% of cases. There are no guidelines for secondary prophylaxis of GVB. Radiological treatments using a transjugular intrahepatic portosystemic shunt (TIPS) or balloon occlusive transvenous obliteration (BRTO) are considered viable. However, they are not universally inapplicable; for instance, in the setting of pulmonary hypertension (TIPS). EUS-guided combined injection therapy (EUS-CIT) (embolization coils + cyanoacrylate) is an emerging procedure with a perceived reduced risk of systemic embolization. Case presentation: A patient with alcoholic liver cirrhosis was subjected to EUS-CIT as a secondary prophylaxis for GVB. He had three VB episodes of prior presentation treated by endoscopic band ligation (EBL) and ECI. Due to recurrent episodes of bleeding, he was referred to TIPS, but was considered contraindicated due to severe pulmonary hypertension. EUS-CIT was conducted with two embolization coils inserted into the varix, followed by an injection of 1.5 mL of cyanoacrylate glue. A 19 Ga needle, 0.035″ 14/70 mm coils, non-diluted n-butyl-caynoacrylate, and a transgastric approach were utilized. There were no immediate complications. Complete obliteration of the GV was observed in a follow-up endoscopy on day 30. Subsequent endoscopies in months three and six showed no progression of gastric varices. Conclusions: Our initial experience with EUS-CIT suggests that it can be successfully used as secondary prophylaxis for recurrent GVB. [ABSTRACT FROM AUTHOR]

The speed of implementation of electric vehicles depends on the level of development of the charging infrastructure, which is subject to ever new requirements, including increasing ease of use and reducing charging time. A solution to the problem could be an introduction of wireless charging of electric vehicles (inductive charging device – WPT). However, in order to produce an effective WPT (without preliminary calculation and modeling the efficiency of the device may not reach 10 %), it is necessary to select the parameters of the coils and simulate the frequency characteristics of the voltage. For this purpose, as part of the implementation of the project to create a mobile charging installation for electric vehicles, the problem of modeling the operation of the WPT has been solved. In accordance with the technical specifications, a coil has been built in Excel, which was used as geometry in Comsol to evaluate the distribution of magnetic fields. To study the frequency characteristics, the CST Studio program has been used. Using these programs, we simulated various methods for implementing the WPT with obtaining frequency characteristics. It has been confirmed that the coupling coefficient increases with decreasing distance between parts of the WPT. Calculations of resonant circuits and the expected efficiency for both types of resonant circuits have been carried out, and it has been concluded that decreasing the distance leads to a decrease in the resonant frequency of the system of connected circuits. The developed model allows us to obtain the values of the circuit capacitances for the formation of resonance, move on to practical implementation and verify the resulting models.

Abstract This paper proposes a mutually decoupled transmission and receiver coil (MDC) system to improve the sensitivity of inductively coupled communication. The proposed communication system is intended to be mounted on the frame of a spectacle and used to transfer a detectable voltage signal through weak inductive coupling with an implant measuring intraocular pressure (IOP). The implant consists of a coil that resonates with a capacitor. The capacitance of this capacitor is designed to change with the IOP, thus leading to a change in the self‐resonant frequency of the implant. The transmission coils excite the implant, while the decoupled receiver coils continuously monitor the self‐resonant frequency of the implant. The induced voltage across the receiver coil is used to determine the IOP. Simulation results show that a 1.43% change in the sensor capacitance leads to a 1 mV change in the voltage induced across the receiver coils. The experimental results reveal that raising the self‐inductance of the MDC on the transmission side results in a 0.5%/mV increase in sensitivity.

Modeling blood flow in aneurysms treated with coils could be used to understand the complete embolization of the aneurysm, through thrombus formation that fills the entire sac. Modeling of the endovascular coil mass as a porous medium is a technique that allows for study of aneurysm hemodynamics, efficiently for patient-specific treatment outcome predictions. Models in the literature use mean porosity of coils in the aneurysmal volume, proving inadequate for outcome prediction. However, models that consider heterogeneous porosity distribution have shown more accurate hemodynamics. We recently published the porous crown model, considering the heterogeneous coil mass distribution, validated on two patients. This study aims (i) to validate the porous crown model for a larger cohort (eight patients), and (ii) to propose a porous medium model translatable to clinical practice in treatment planning. We analyzed the porosity distribution of the endovascular coils deployed inside the cerebral aneurysm phantoms of eight patients using 3D x-ray synchrotron images. The permeability and inertial factor of the porous crown model are calculated using previously published methodology. We propose a new "bilinear" porous model, that uses the same hypothesis, but the permeability and inertial factor can be defined from just basic information available in the neuro-suite, i.e., the aneurysmal sac volume and the coil volume fraction targeted by the neurosurgeon. These two models are compared to the coil-resolved simulations, considered as the gold standard. The results show that both the porous crown model and the bilinear model produce similarly accurate hemodynamics in the aneurysm. The error in the standard (mean porosity) porous model is 66%, whereas the error of the bilinear model is 26%, compared to the coil-resolved. The bilinear model is promising as a means of treatment outcome prediction at time of intervention. [ABSTRACT FROM AUTHOR]

This paper proposes a mutually decoupled transmission and receiver coil (MDC) system to improve the sensitivity of inductively coupled communication. The proposed communication system is intended to be mounted on the frame of a spectacle and used to transfer a detectable voltage signal through weak inductive coupling with an implant measuring intraocular pressure (IOP). The implant consists of a coil that resonates with a capacitor. The capacitance of this capacitor is designed to change with the IOP, thus leading to a change in the self‐resonant frequency of the implant. The transmission coils excite the implant, while the decoupled receiver coils continuously monitor the self‐resonant frequency of the implant. The induced voltage across the receiver coil is used to determine the IOP. Simulation results show that a 1.43% change in the sensor capacitance leads to a 1 mV change in the voltage induced across the receiver coils. The experimental results reveal that raising the self‐inductance of the MDC on the transmission side results in a 0.5%/mV increase in sensitivity. [ABSTRACT FROM AUTHOR]

A wide variety of coils are available for vascular embolization. This study aimed to evaluate the safety and efficacy of a new Prestige coil. We carried out retrospective analysis of a multicenter's registry data collected between February 2022 and November 2022. The choice of embolization agent used to treat peripheral vascular anomalies was left to the investigator's discretion. Patients for whom at least one Prestige coil was used were included in Series 1. All other patients were included in Series 2. Efficacy and safety were evaluated. Patients were followed up for one month. In total, 220 patients were included, 110 in each series. Patients included 149 men (67.7%) and 71 women (32.3%), with a median age of 62.5 years (IQR: 35.8–73). Patient ages were similar in the two series. Complete occlusion of the targeted vessel was reported in 96.4% (n = 106/110) of patients in Series 1 and in 99.7% (n = 109/110) in Series 2. Four patients experienced non-serious adverse events (1.8%, n = 4/220): one experienced back pain and one vomiting in Series 1; one patient had off-target embolization and one a puncture site hematoma in Series 2. Sixteen patients (7.2%, n = 16/220) were lost to follow up. Improvement in the patient's general state at one month was reported in 79.0% (n = 83/105) of patients in Series 1 and in 74.7% (n = 74/99) in Series 2. Ten deaths occurred, five in Series 1 (4.8%, n = 5/105) and five in Series 2 (5.1%, n = 5/99). These deaths all concerned critically ill patients embolized for emergent arterial bleeding. In conclusion, the 1-month follow-up showed that Prestige coils, alone or in combination, are efficient and safe. [ABSTRACT FROM AUTHOR]

In recent years, significant advancements have been made in endovascular therapy for aortic dissection, resulting in the development of various treatment methods. Nevertheless, there is a contentious discussion regarding the suitability of different treatment methods for addressing the unique features of individual lesions. Specifically, the matter of whether the presence of small intimal tears or multiple distal tears requires extensive aortic coverage with graft stents, which may block the blood supply to important organs, intercostal arteries, or lumbar arteries, remains unresolved. Further research is necessary to determine the need for complex fenestrated or branched endovascular aortic repair (F/B-EVAR) in the management of chronic post-dissection aneurysms involving visceral arteries. Our report highlights the successful endovascular repair of three patients with aortic dissection, encompassing one Stanford A type and two Stanford B types. Utilizing the Amplatzer Vascular Plug (AVP) alone or in combination with the coil embolization technique, we achieved favorable clinical outcomes. This article aims to provide valuable insights and new perspectives on the tailored management of aortic dissection by conducting a comprehensive examination of the subtle differences in the treatment processes and techniques applied to these three patients.

The mechanical and thermal analysis of the superconducting magnets, forming an innovative fixed-field bending section for use in a proton therapy gantry, is presented here. The design concept has a large momentum acceptance, covering the full proton energy range of 70 to 220 MeV with fixed field in the superconducting magnets, and uses a simple magnet geometry based on double-pancake high temperature superconductor coils. The main planned steps for the assembly and fabrication of the magnets are discussed. The mechanical analyses of the magnet, with emphasis on the stress state of the conductor during the powering of the magnet, is here described. The thermal analysis investigating the adequacy of the copper structure surrounding the conductor to extract the heat deposited in the conductor during powering is also discussed in detail.

Superconducting electron cyclotron resonance ion sources (ECRISs) using NbTi coils and optimized for 28 GHz resonant heating have been successfully operated for almost two decades. Moving to higher heating frequencies requires increased magnetic fields, but traditional racetrack-and-solenoid ECRIS structures are at their limit using NbTi. Rather than moving to a superconductor untested in this field, the Mixed Axial and Radial field System (MARS) being developed at Lawrence Berkeley National Laboratory employs a novel closed-loop-coil design that more efficiently utilizes conductor fields and will allow the use of NbTi in a next-generation, 45 GHz ECRIS. This article presents the design of the shell-based support structure central to the MARS-D magnet design, as well as structural analysis of its components and optimization of pre-load parameters that will guarantee its successful operation.

Abstract Toroidal inductors are widely used in power electronic systems. With the increasing switching frequency of power devices, the AC losses of high‐frequency inductor windings have become an issue that cannot be ignored in design. A method with low computational time cost and high accuracy is urgently needed by designers. This paper proposes a modified analytical method for winding loss calculation of toroidal inductors based on the one‐dimensional Dowell method and the two‐dimensional Ferreira method, and proposes a compensated analytical model considering the proximity effect of inter‐turn conductors of toroidal windings. The analytical method calculates the non‐linear porosity of toroidal windings, and can accurately solve the AC losses of toroidal inductors with arbitrary porosity winding encapsulation. The analytical results are in good agreement with the finite element method (FEM) and experimental data. The experimental measurement data verifies the validity of the proposed model within 1‐MHz frequency, the calculation error of the modified analytical method is less than 25%, and the calculation error of the compensated analytical model is reduced to 10%.

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair.

Abstract Endovascular embolization techniques are showing an extraordinary potential to treat patients suffering from complex neurovascular malformations. The embolization with liquid embolic agents via Onyx is a prominent approach to treat arteriovenous malformation (AVM). However, intraoperative reflux of the liquid agents can be very challenging and, thus, is impairing full success of endovascular treatment. A possible technique to prevent intraoperative endovascular reflux is the pressure-cooker technique (PCT) utilizing coils to build a wedge proximal to the AVM. Few modifications of the PCT have been developed in the recent years to improve effectiveness of embolization procedure. Hereby, we present a novel PCT modification utilizing extra-soft Kaneka coils and glue to build well-fitting wedges. After the application of extremely soft bare coils with high trackability, flexibility and crossability, liquid agents can be injected with reduced reflux. We think the pressure-cooker technique with extra-soft Kaneka coils enables more efficient embolization in even farther, tinier and more tortuous target vessels. This technical note presents two illustrative patient cases with treatment-refractory, high-grade cerebral arteriovenous malformations which were successfully treated via embolization with PCT in which the plug was formed with Kaneka coils.

Additive manufacturing using Powder Bed Fusion by Laser Beam (PBF-LB) enables products with high design freedom. In addition, the ability to process more than one material in all three spatial directions makes it possible to produce highly functional components in one single process. This article investigates whether multi-material manufacturing using PBF-LB is suitable for producing coils for electric motors, which are designed with integrated cooling channels to increase the power density. For this purpose, the copper alloy CuCr1Zr for the coils and the stainless steel 1.4404 (316L) for the core are processed simultaneously. The component designs were verified using 2D and 3D finite element analysis and then manufactured in a multi-material PBF-LB process. While good electrical conductivity of the copper alloy was achieved by heat treatment, it was found that thermal distortion caused deviations from the nominal geometry. The measurement of the electrical properties showed that this distortion leads to short-circuit currents within the coils and the teeth. On this basis, ideas for solutions were developed, with the help of which the functionality of the coils can be ensured or the power density can also be increased. In addition to adapting the design of the component, this includes processing additional or other materials, such as soft magnetic composites.

Purpose: To design and implement a multi‐coil (MC) array for B0 field generation for image encoding and simultaneous advanced shimming in a novel 1.5T head‐only MRI scanner. Methods: A 31‐channel MC array was designed following the unique constraints of this scanner design: The vertically oriented magnet is very short, stopping shortly above the shoulders of a sitting subject, and includes a window for the subject to see through. Key characteristics of the MC hardware, the B0 field generation capabilities, and thermal behavior, were optimized in simulations prior to its construction. The unit was characterized via bench testing. B0 field generation capabilities were validated on a human 4T MR scanner by analysis of experimental B0 fields and by comparing images for several MRI sequences acquired with the MC array to those acquired with the system's linear gradients. Results: The MC system was designed to produce a multitude of linear and nonlinear magnetic fields including linear gradients of up to 10 kHz/cm (23.5 mT/m) with MC currents of 5 A per channel. With water cooling it can be driven with a duty cycle of up to 74% and ramp times of 500 μs. MR imaging experiments encoded with the developed multi‐coil hardware were largely artifact‐free; residual imperfections were predictable, and correctable. Conclusion: The presented compact multi‐coil array is capable of generating image encoding fields with amplitudes and quality comparable to clinical systems at very high duty cycles, while additionally enabling high‐order B0 shimming capabilities and the potential for nonlinear encoding fields. [ABSTRACT FROM AUTHOR]

Toroidal inductors are widely used in power electronic systems. With the increasing switching frequency of power devices, the AC losses of high‐frequency inductor windings have become an issue that cannot be ignored in design. A method with low computational time cost and high accuracy is urgently needed by designers. This paper proposes a modified analytical method for winding loss calculation of toroidal inductors based on the one‐dimensional Dowell method and the two‐dimensional Ferreira method, and proposes a compensated analytical model considering the proximity effect of inter‐turn conductors of toroidal windings. The analytical method calculates the non‐linear porosity of toroidal windings, and can accurately solve the AC losses of toroidal inductors with arbitrary porosity winding encapsulation. The analytical results are in good agreement with the finite element method (FEM) and experimental data. The experimental measurement data verifies the validity of the proposed model within 1‐MHz frequency, the calculation error of the modified analytical method is less than 25%, and the calculation error of the compensated analytical model is reduced to 10%. [ABSTRACT FROM AUTHOR]

Uterine rupture (UR) is an unexpected, rare, and serious obstetrical condition, occurring in less than 0.1% of pregnancies. Complete UR is defined as a direct communication between the uterine cavity and the peritoneum due to a complete rupture of the myometrium. Here, we present 2 cases of non-surgical management of UR following vaginal delivery, which were both treated by uterine transarterial embolization (UAE). A 26-year-old woman (G0P0) was referred to the emergency ward at 35 weeks of amenorrhea to treat the rupture of membranes, in the context of twin pregnancy. A vaginal delivery was performed and blood loss exceeded 2 liters. Gelatin sponge was injected in an attempt to occlude the right uterine artery. The injection was unsuccessful. After the medical team's discussion, it was decided to definitively occlude the right uterine artery. A 37-year-old woman (G3P3) was referred for a vaginal delivery for a medical termination at 38 weeks of amenorrhea. The ultrasound revealed a left latero-uterine pelvic hematoma, suggestive of UR. Four fibered coils were used to definitively occlude the left uterine artery. Computed tomography scan showed a progressive resorption of hematoma and satisfactory enhancement of the uterine wall in the 2 cases. Transarterial embolization may allow for bleeding to stop without resorting to exploratory laparotomy, with ad-integrum restitution of the uterine wall, and thus prevent a potential hysterectomy. The findings in these 2 cases suggest that UAE should be considered if pregnant women develop UR after delivery.

In industry, to improve the power factor in low-voltage power substations, a power factor controller (the most used method) can be installed which connects capacitors banks (connected, or not, with coils) in the electrical installation. The most important parameters of power engineering are the power factors that indicate the efficiency of energy use. Currently, many non-linear consumers (more single-phase than three-phase) are used on low voltages. Harmonics (currents and/or voltages) are the most important dynamic component of power quality, affecting electrical equipment performance and also reducing power factors. The purpose of this analysis is to increase the displacement power factor and to decrease the total harmonic distortion (for the current) in the conditions where there are linear and non-linear consumers, where the power factor must be improved with capacitors banks. Relevant different consumers have been selected for both the industry and the home sector, as follows: inductive motors that are linear, inductive consumers, compact fluorescent lamps that are non-linear, and capacitive consumers. This analysis was carried out depending on the number of steps used for the power factor controller, the values of the capacitors banks, the AC reactor (connected in series with all consumers), and the LC shunt filters. For a slight deformation regime, a large number of capacitors banks with different values ensure a finer adjustment of the displacement factor. The maximum number of steps that regulators can command should not necessarily be used (the reliability of the installation decreases with the increase in the number of capacitors banks), but a reduced number of steps can be used, which can lead to higher values of displacement power factors. To improve the deforming regime and to increase the displacement power factor, the use of LC shunt filters, connected to a small number of steps, will also increase the displacement power factor (over 0.9) and decrease the total harmonic distortion (up to 7–10%) for the current. Weaker results were obtained with AC reactors connected to the power supply phases of consumers and, if a larger number of stages were used, to which LC shunt filters were connected, these filters become difficult to calibrate (resonances occur).

Background: Although bleeding from gastric varices is less observed than esophageal variceal bleeding (VB) (25% vs. 64%), it is associated with an exceedingly high mortality rate of up to 45%. Current guidelines suggest that endoscopic cyanoacrylate injection therapy (ECI) is the first-line treatment for gastric variceal bleeding (GVB). A major concern, however, is the possibility of embolic incidents, which are clinically evident in approximately 1% of cases. There are no guidelines for secondary prophylaxis of GVB. Radiological treatments using a transjugular intrahepatic portosystemic shunt (TIPS) or balloon occlusive transvenous obliteration (BRTO) are considered viable. However, they are not universally inapplicable; for instance, in the setting of pulmonary hypertension (TIPS). EUS-guided combined injection therapy (EUS-CIT) (embolization coils + cyanoacrylate) is an emerging procedure with a perceived reduced risk of systemic embolization. Case presentation: A patient with alcoholic liver cirrhosis was subjected to EUS-CIT as a secondary prophylaxis for GVB. He had three VB episodes of prior presentation treated by endoscopic band ligation (EBL) and ECI. Due to recurrent episodes of bleeding, he was referred to TIPS, but was considered contraindicated due to severe pulmonary hypertension. EUS-CIT was conducted with two embolization coils inserted into the varix, followed by an injection of 1.5 mL of cyanoacrylate glue. A 19 Ga needle, 0.035″ 14/70 mm coils, non-diluted n-butyl-caynoacrylate, and a transgastric approach were utilized. There were no immediate complications. Complete obliteration of the GV was observed in a follow-up endoscopy on day 30. Subsequent endoscopies in months three and six showed no progression of gastric varices. Conclusions: Our initial experience with EUS-CIT suggests that it can be successfully used as secondary prophylaxis for recurrent GVB.

Endovascular embolization techniques are showing an extraordinary potential to treat patients suffering from complex neurovascular malformations. The embolization with liquid embolic agents via Onyx is a prominent approach to treat arteriovenous malformation (AVM). However, intraoperative reflux of the liquid agents can be very challenging and, thus, is impairing full success of endovascular treatment. A possible technique to prevent intraoperative endovascular reflux is the pressure-cooker technique (PCT) utilizing coils to build a wedge proximal to the AVM. Few modifications of the PCT have been developed in the recent years to improve effectiveness of embolization procedure. Hereby, we present a novel PCT modification utilizing extra-soft Kaneka coils and glue to build well-fitting wedges. After the application of extremely soft bare coils with high trackability, flexibility and crossability, liquid agents can be injected with reduced reflux. We think the pressure-cooker technique with extra-soft Kaneka coils enables more efficient embolization in even farther, tinier and more tortuous target vessels. This technical note presents two illustrative patient cases with treatment-refractory, high-grade cerebral arteriovenous malformations which were successfully treated via embolization with PCT in which the plug was formed with Kaneka coils. [ABSTRACT FROM AUTHOR]

Abstract Background Embolisation of the parenchymal tract is a key step after any other transhepatic or transplenic percutaneous portal vein catheterization since eventual venous bleeding is difficult to control and may require surgical management. Different techniques have been proposed to perform tract embolisation. The aim of this study is to compare the safety and efficacy of different techniques of haemostasis of the parenchymal tract. Materials and methods All the interventional procedures with percutaneous transhepatic or transplenic access to the portal vein (excluding ipsilateral portal vein embolisation) from January 2010 to July 2020, in two tertiary hospitals, were retrospectively analyzed. The following data were evaluated: access site, the technique of embolisation, technical success in terms of immediate thrombosis of the tract, safety and clinical efficacy in terms of the absence of hemorrhagic and thrombotic complications. Results One-hundred-sixty-one patients underwent 220 percutaneous transhepatic or transplenic portal vein catheterization procedures. The main indications were pancreatic islet transplantation, portal anastomotic stenosis after liver transplantation, and portal vein thrombosis recanalization. As embolic materials gelfoam was used in 105 cases, metallic micro-coils in 54 cases, and cyanoacrylic glue in 44 cases; in 17 cases the parenchymal tract was not embolized. Technical success was 98% without significant difference among groups (p-value = 0.22). Eighteen post-procedural abdominal bleedings occurred, all grade 3 and were managed conservatively; difference among groups was not significant (p-value = 0.25). We detected 12 intrahepatic portal branch thromboses not related to the embolisation technique; only one case of non-target embolisation was documented after liver tract embolisation with glue, without clinical consequences. Conclusion Embolisation of the parenchymal tract after percutaneous portal vein catheterization is technically safe and effective. No significant differences were found between coils, glue, and gelfoam in effectiveness and complications rate. Level of evidence Level 3, Cohort study.

Abstract Background Superior rectal artery (SRA) aneurysms are rare. Although melena is the most common symptom, it has not been observed in cases of aneurysms located in the SRA trunk. Here, we report a case of a ruptured SRA trunk aneurysm successfully treated with coil embolization. Including our case, three of the four reported cases of SRA trunk aneurysms were related to neurofibromatosis type 1 (NF1). Case presentation A 52-year-old woman with NF1 was referred to our hospital for the investigation of an abdominal mass with back pain. She had previously undergone a blood transfusion at another hospital for anemia without melena. Computed tomography angiography revealed a ruptured SRA trunk aneurysm measuring 3 cm in diameter and surrounded by a retroperitoneal hematoma. The aneurysm was isolated by embolizing the SRA trunk distally and proximally. Distal embolization was performed retrogradely from the internal iliac artery (IIA) via the middle rectal artery (MRA)-SRA anastomosis because the antegrade approach from the inferior mesenteric artery (IMA) failed. To our knowledge, this is the first case of successful coil embolization of an IMA branch through the IIA. Conclusion SRA trunk aneurysms are rare; however, they are frequently associated with NF1. Antegrade distal embolization beyond the aneurysm is sometimes difficult to achieve. In such cases, a retrograde approach via MRA-SRA anastomosis can be the choice for isolating SRA trunk aneurysms.

Single-wire power transmission (SWPT) is a power transmission method that uses only one wire to realize long-distance transmission of power. For deep insight, the theory of electromagnetic surface waves in this article is applied to reveal the principle of a long-distance large-scale SWPT system. Maxwell's equations under two different media in this system are established, based on them and the boundary conditions on the interface of the media, the propagation law of electromagnetic field energy in the SWPT system is analyzed. A simulation model is built by high frequency simulator structure (HFSS). The distribution law of the Poynting vector in different situations is studied to verify the correctness of the theoretical analysis. Moreover, long-distance transmission experiments are carried in the campus. It is shown that the transmission power can reach 300 W or 135 W when the transmission distance is 100 m or 200 m, respectively. [ABSTRACT FROM AUTHOR]