Metallic Coils Research Articles

Folding and Bending Planar Coils for Highly Precise Soft Angle Sensing

AbstractSensors detecting angles created by deformable structures play an increasing role in soft robotics and wearable systems. However, the typical sensing method based on strain measurement strongly depends on the viscoelastic behaviors of soft substrates and on the location of sensors that affect the sensing reliability. In this work, the changes in magnetic field coupling produced in space by planar coil deformation are investigated, for implementing a new direct transduction strategy, the soft inductive angle sensing (SIAS). A numerical analysis tool is developed for rigorously studying the inductance variations resulting from planar coils’ bending, folding, and folding with a small arc. Copper or liquid metal coils, having different shapes, pitches, and sizes are built and characterized. Results show that the SIAS is hysteresis‐free, velocity‐independent, highly sensitive, ultrastable, and with fast response, guaranteeing highly precise (0.1° incremental folding angle change) and reliable measurements. It is insensitive to coil materials and to behavior of embedding soft materials, and scalable (across 10 times scale). The SIAS is adopted in three case studies (a self‐sensing origami, a sensorized soft pneumatic actuator, and a wearable sensor) to highlight its low implementation complexity, high‐performance, and versatility, providing some insights on the enormous potential of this mechanism.

Discoveries in Aerosol Science: Characterization of Nanoparticles Emitted From Metallic Coils in Electronic Cigarettes

Electronic (e-) cigarettes, also known as electronic nicotine delivery systems, are battery-operated devices that are growing in popularity worldwide. Although e-cigarettes are known to be safer than traditional cigarettes, their potential health risks have not been extensively reviewed yet. In this study, aerosol nanoparticles generated from e-cigarette heaters were characterized. Kanthal A1 (iron + chromium + aluminum) coils, without nicotine solution or a wick, were installed in an e-cigarette atomizer. The operating conditions were varied coil resistances (0.1–1.0 Ω), a set applied power (10 W), and a stable duty cycle (50%: 5 s on, 5 s off ). The size distribution and morphology of particles were collected by a scanning mobility particle sizer and evaluated by transmission electron microscopy, respectively. From an applied power of 10 W and a 50% duty cycle, the size and total number concentration (TNC) of particles emitted increased with greater coil resistances. Within these operating conditions, the average TNC of particles generated exhibited a steep decrease during the first 15 minutes of each trial. The TNC of particles decreased over time because surface oxidation (iron oxide layer) prevented further nanoparticle emission. As a result, a used coil may reduce the risk of the metal exposure from e-cigarettes. The results indicate that our designed and tested e-cigarette generation system is useful for future research that aims to investigate the health impacts of metallic particle inhalation on e-cigarette users.

Design and performance analysis of a new evacuated tube solar air heaters equipped with fins and coils

ABSTRACT Evacuated tube solar air heaters (ETSH) are efficient, easy to maintain, and have low energy losses due to the vacuum between the absorber and the outer tubes. In this study, a new ETSH with various configurations was built and experimentally tested to determine the best configuration with the highest thermal performance. The ETSH equipped with two different high thermal conductivity metal fins and coils to enhance the heat transfer between the fluid and the copper tube heat exchanger. The efficiency and temperature difference were experimentally investigated at different flow rates. It was observed that the system with aluminum fins has the highest air temperature difference at the lowest flow rate and the highest efficiency at the highest flow rate. At the highest solar irradiation of 1000 W/m2, the maximum obtained temperature difference was 88°C at a flow rate of 0.6m3/min, while the highest obtained efficiency was 37% at a flow rate of 1.25 m3/min. For the three systems, the temperature difference decreased and the efficiency increased with the increase in the flow rate.

Superior rectal artery embolization for bleeding internal hemorrhoids.

The aim of the present study was to evaluate clinical efficacy and safety of superselective embolization of the superior rectal artery (SRA) for the treatment of internal hemorrhoidal bleeding. Patients with stage II and stage III internal hemorrhoids, treated by interventional embolization of the SRA in our department between January 2017 and June 2019 were retrospectively evaluated. All patients suffering from disabling chronic hematochezia and some with relative contraindications for operation (n = 17) orrejectionofconventional hemorrhoidectomy (n = 15). Superselective SRA branch embolization was performed using gelatin sponge particles (350-560μm) and metallic coils (2-3mm). This treatment process was planned by a multidisciplinary team consisting of proctologist,gastroenterologist and radiologist. The surgical efficacy, postoperative complications and follow-up outcomes were observed. There were 32 patients (18 males, mean age 52 ± 12years, range: 22-78years), 12 (37%) with stage II hemorrhoids and 20 (63%) with stage III hemorrhoids. Embolization was successful in all patients, and bleeding symptoms resolved in 27 (84.4%) patients. The remaining 5 (15.6%) patients underwent either stapled hemorrhoidopexy (n = 4) or sclerotherapy (n = 1). Some patients experienced different degrees of pain (n = 4;12.5%), low fever (n = 11;34.4%), and tenesmus (n = 17;53.1%), which all spontaneously regressed without further treatment. All patients were followed up for at least 1year. There were no serious complications, such as infection, intestinal ischemia or massive hemorrhage. Four patients (14.8%) had rebleeding during the first months of follow-up. All patients with re-bleeding were successfully treated with internal iliac arteriography and branch embolization and did not experience further bleeds after a minimum follow up 3months follow-up. The short-term efficacy of superselective SRA embolization for grade II-III internal hemorrhoids is good, and this method is safe and feasible.

Obliteration of a Portosystemic Shunt by Hybrid Interventional Radiology Using a Transmesenteric Approach Under Minilaparotomy After Liver Transplantation: A Case Report

Hepatic encephalopathy that occurs long after liver transplantation (LT) is an uncommon condition. Here, we describe the successful case of a 65-year-old patient who underwent interventional radiology (IVR) using a transmesenteric approach under minilaparotomy for hepatic encephalopathy because of a portosystemic shunt 11 years after ABO-incompatible living donor LT with splenectomy. Enhanced computed tomography confirmed a huge portosystemic shunt and left gastric vein (LGV)-esophageal-azygos vein, which was not treated during LT. Liver stiffness measurements based on transient elastography did not show severe fibrosis in the liver graft. Since the hyperammonemia could not be managed with conventional medical treatment, balloon-occluded retrograde transvenous obliteration (BRTO) was indicated. However, it was difficult to perform because the drainage vein could not be approached from the inferior vena cava (IVC). Surgical shunt ligation was also difficult because of the history of multiple laparotomies. Although intraperitoneal adhesion was severe, the portosystemic shunt was successfully embolized with metallic coils and a plug by IVR using a transmesenteric approach under minilaparotomy. No complications occurred during the operation. His symptoms improved after the operation. The ammonia level and portal flow by ultrasound also improved. He was discharged 14 days after surgery without any complications.

Analysis of the Thermal Performance of the Embedded Composite Phase Change Energy Storage Wall.

In this study, the phase change paraffin and metal powder were mixed to form the composite phase change energy-storing material. This composite material was then injected into metal coil tubings at different coil spacings to form a composite phase change energy storage tubing system, which was then embedded in a wall. The thermal performance of the embedded phase change energy storage wall was investigated at various temperatures. The results showed that among the four types of aforementioned walls, the energy storage tubes at a spacing of 20 mm exhibited the smallest heat transfer and the largest surface heat storage coefficients. Therefore, this wall can block heat flow and temperature propagation effectively, and it exhibits excellent thermal insulating and heat storage performances and increased resistance to temperature fluctuations.

Modelling and Simulation of Below-the-Hook Lifting Device Balanced C-hook for Load to Investigate the Static and Model Analysis for Various Grades of Steels by Numerical Method

Below-the-Hook Lifting Devices will enable easy loading, unloading and transportation of heavy metal coils. A balanced c-hook is one of the widely used Below-the-Hook Lifting Devices works by inserting its lower arm inside the hole of coil. Multiple variations of c hooks are being used based on different load requirements, and different applications like paper roll c hooks to transport heavy paper rolls, spring loaded c hooks to reduce weight by avoiding counter weights etc. Structural and mechanical lifters may be modified or re-assessed, provided that such alterations are analyzed and approved. Balanced c-Hook are to be designed by considering forces imposed by the lifted load, the weights of the device’s parts, since balanced c hooks are subjected repeated loading and unloading, there is probability of failure due stress concentration. To prevent chances of failure, Prior study is required on this; the materials which are generally used for the C hook are considered for a particular loading condition of 10 Tons, Design of the bellow the hooks is done by numerical method. Modeling and Simulations are carried to determine the various factors like deformation, stresses generated and mode shapes. The comparison among all the selected materials is done to check the suitability of the material to use as a balanced C hook. For the generation of CAD model of C -Hook various geometrical features and Dimensions are selected as per the specification from ASME B30.20 standard. To investigate statics stress results and model are obtained from Finite element Method. from the results of the analysis it is observed that results obtained are in close match with each other and maximum stress concentration occurs at inner most surface.

Surface coil based on a dielectric resonator tuned to the higher-order modes

Magnetic resonance (MR) images spatial resolution, which is a key factor in early diagnosis of many diseases, is fundamentally limited by the signal-to-noise ratio, which in turn depends upon the efficiency of the receive radiofrequency coils design. Many various multi-channel coils were designed to improve the quality of MR images. Another way to enhance the quality of magnetic resonance imaging (MRI) is the implementation of resonators based on novel materials, such as high-permittivity dielectrics. Here, we investigate the potential for the sensitivity enhancement with higher-order modes of dielectric resonators. We numerically show that because of the unique near field spatial distribution of a dielectric resonator third-order mode, the receive performance can be substantially improved in comparison with a conventional metallic loop coil of the same dimensions. Moreover, we study the performance of the dielectric resonator in comparison with a metallic loop coil, which size was optimized to match the sensitivity of the resonator at a particular distance. We demonstrate a 9-fold larger planar field-of-view with the dielectric resonator than with the loop coil. Our work provides the design guidelines for the improvement of near-field MRI sensitivity with the dielectric resonators.

Embolization of medium-sized vessels with the penumbra occlusion device: evaluation of anchoring function

BackgroundThe penumbra occlusion device (POD) is a recently developed metallic coil with a unique anchor segment. The purpose of this study was to investigate the anchoring function of the POD for embolization of medium-sized vessels in detail.Materials and methodsWe reviewed a series of cases of proximal embolization of medium-sized vessels in which the POD was used. Endovascular outcomes and complications were assessed. The distance between the distal end of the first-indwelled POD and the microcatheter tip was defined as the “landing distance,” and this was also evaluated via fluoroscopic analysis.ResultsPOD deployment was successful in 17 of 18 patients. The median landing distance was 9.6 mm, and no distal POD migration was observed after the formation of anchor loops.ConclusionsThe specific anchoring function of the POD enables effective proximal occlusion of medium-sized vessels.

Effect of reaction time and microwave power on coil temperature during microwave-metal interaction pyrolysis of plastics

Rapid rise in production of plastic waste has posed a threat to environment due to its nonbiodegradable nature. In recent years, microwave assisted pyrolysis of plastic waste has emerged as a promising solution toward reduction of waste and recovery of value-added products and fuels. Previous works on microwave-metal interaction pyrolysis estimated only the peak value of coil temperature at a constant microwave power without monitoring complete reaction. The current study was directed toward investigating the effect of reaction time and variable microwave power on the coil temperature during microwave-metal interaction pyrolysis of plastics. The experiment was performed on individual plastics PS (polystyrene), PP (polypropylene) and LDPE (low density polyethylene) for comparative analysis. Pyrolysis was carried out for a reaction time of 30 minutes at different values of microwave power in the range of 500-2500 W. Type K thermocouple was used to monitor temperature of metal coil. Fluctuation in temperature of coil was found to be a consequence of interaction of coil and thermocouple with the microwaves. Maximum heating rate was observed in the first 5 minutes of microwave exposure. The slopes of average temperature versus microwave power were found to be nearly equal estimated as: PS = 0.24 °C/W, PP = 0.20 °C/W, LDPE = 0.18 °C/W, which indicated consistency in heating process for each plastic, achieved by the current set-up. Further, it was inferred that nature of plastic pyrolyzed had insignificant influence on coil temperature due to absence of direct contact between plastic and the coil.

Mass-Manufacturing of Sub-Micron Coated Metal Coils for Scaling-up the Production of Electrochemical Devices

Sandvik Surface Technology is a production unit within AB Sandvik Materials Technology (SMT). The business area SMT belongs to the Sandvik group and is a world-leading manufacturer of advanced stainless steels and special alloys for the most demanding industries. Sandvik Surface Technology offers a portfolio of cost-effective coated metal strip for applications such as batteries, fuel cells and electrolyzers.Metal coils are coated with sub-micron metal coatings according to customer specifications regarding composition and thickness of both the substrate and the coating in a Physical Vapour Deposition process through the roll-to-roll coating lines developed by Sandvik (Figure 1). This pre-coated solution reduces some of the handling that comes with batch coating of individual components and provides an outstanding opportunity for the cost-effective industrial mass production of electrochemical devices.Figure 1. Image of one of the coating lines developed by Sandvik in Sandviken (Sweden). The final coated metal coils are also shown.The Surface Research group at SMT Strategic Research provides vital knowledge and understanding of such a complex coating process which facilitates the development of the above-mentioned products. Scientific questions such as the development of the adequate coating and substrate composition for every electrochemical device, the influence of nanometric defects on the performance of the electrochemical device or the formation of stable and protective layers against corrosion after more than 20,000 h of operation are addressed and will be shown in this work. Figure 1

Design of Heating Coils Based on Space-Filling Fractal Curves for Highly Uniform Temperature Distribution

Heating coils utilize the concept of resistive heating to convert electrical energy into thermal energy. Uniform heating of the target area is the key performance indicator for heating coil design. Highly uniform distribution of temperature can be achieved by using a dense metal distribution in the area under consideration, however, this increases the cost of production significantly. A low-cost and efficient heating coil should have excellent temperature uniformity while having minimum metal consumption. In this work, space-filling fractal curves, such as Peano curve, Hilbert curve and Moore curve of various orders, have been studied as geometries for heating coils. In order to compare them in an effective way, the area of the geometries has been held constant at 30 mm × 30 mm and a constant power of 2 W has been maintained across all the geometries. Further, the thickness of the metal coils and their widths have been kept constant for all geometries. Finite Element Analysis (FEA) results show Hilbert and Moore curves of order-4, and Peano curve of order-3 outperform the typical double-spiral heater in terms of temperature uniformity and metal coil length.

Endovascular interventions in the treatment of pelvic congestion syndrome caused by May-Thurner syndrome

ObjectiveThe objective of this study was to assess the effect of various endovascular interventions on the clinical manifestations of the pelvic congestion syndrome (PCS) caused by May-Thurner syndrome (MTS). MethodsThe study included 12 female patients with PCS caused by MTS. Patients were examined by duplex ultrasound, computed tomography of the pelvic veins, and ovarian and pelvic venography. All 12 patients underwent endovascular stenting of the left common iliac vein (CIV), and 10 of them underwent subsequent endovascular embolization of the left gonadal vein. The indication for stenting was the presence of stenosis (>50%) of the CIV with clinical symptoms and signs of PCS. Self-expanding stents (Wallstent, 14-16 mm × 60-90 mm; Boston Scientific, Marlborough, Mass) were used. Patients with persistent symptoms of PCS after stenting underwent gonadal vein embolization with MReye metal coils (diameter, 10-15 mm; length, 10-20 cm; Cook Medical, Bloomington, Ind). ResultsTechnical success of stenting, namely, the restoration of normal patency of the left CIV, was achieved in 12 patients. In two patients, a stent was displaced toward the inferior vena cava, which required implantation of a second stent. In another patient, the stent was displaced into the inferior vena cava at 6 months after the intervention, which was not associated with any complication during the follow-up period. The mean venous pelvic pain severity score decreased from 7.7 ± 0.8 at baseline to 4.8 ± 0.3 after 1 month and stayed at this level during the 6-month follow-up period. Complete elimination of PCS symptoms at 6 months after stenting was achieved in 2 patients, and 10 patients underwent embolization of the left gonadal vein 6 months after stenting because of persistent pelvic pain. ConclusionsEndovascular stenting of the left CIV is an effective technique for relieving symptoms of PCS due to MTS in only 16.6% of patients. Stenting of the left CIV in combination with embolization of gonadal veins results in elimination of the signs of PCS in 83.4% of patients. Probably only gonadal vein embolization can be used in the treatment of MTS-related PCS. To confirm this hypothesis, further comparative studies are warranted.

Estimating metal exposure from e-cigarettes

E-cigarette liquids and vapors contain metals and metalloids at levels likely to be harmful to people’s health, and people who vape have higher levels of these elements in their blood and other bodily fluids than cigarette and cigar smokers do, according to a review of data from 24 studies (Environ. Health Perspect. 2020, DOI: 10.1289/EHP5686). These smoking devices use a metal coil to heat a nicotine solution, generating a vapor. The coil itself is a metal source; so are solders inside the liquid reservoir. Several of the studies show that total metal levels rise after the liquid in these devices gets heated, lending support to the theory that the heating process is what releases the elements. Further, the metal levels in the aerosols that users inhale tend to be higher than those in the liquids. Studies of samples from users, including blood and urine, showed that e-cigarettes are a source

New approaches to embolization of aneurysms (liquid embolic agents)

Various materials are currently available for the endovascular treatment of aneurysms. The choice of material depends on the location and configuration of the aneurysm. To ensure optimal aneurysm treatment, the filling material must incorporate the aneurysm and isolate it from the parent vessel by forming an endothelial layer and neointima proliferation along the aneurysm neck. As aresult, the aneurysm can be permanently isolated from the blood flow and the weakened vessel wall can be stabilized in the long term in order to prevent subsequent rupture. Bare metal coils are currently most commonly used. In recent years, liquid embolic agents have increasingly been developed for the endovascular treatment of aneurysms. One of the reasons is that the injected fluid completely fills the aneurysm lumen, so there is no gap between the filling material and the aneurysm wall, regardless of the shape of the aneurysm. Most of the preclinical and clinical studies are available for Onyx. In particular for the treatment of mycotic aneurysms and distal aneurysms of the posterior circulation, liquid embolization with Onyx has already proven to be apossible, effective treatment method.

Electromagnetic Characteristics of Shape Memory Spring

Electric impedance is widely used in imaging and detection techniques. The applications range from non-destructive testing, structural health monitoring, and geophysical imaging to medical imaging. The frequency of the signal used for the measurement ranges from less than 1 Hz to about 1 GHz. This paper addresses the measurement and evaluation of the phase dependent electrical resistance, inductance, capacitance, and impedance of a shape memory alloy (SMA) spring (BMX 150, Toki Corporation). The material characteristics can be obtained by means of their electromechanical impedance. Experimental procedures are implemented and the electrical characteristics are obtained for a wide range of frequency. The electrical resistance, inductance, impedances of the austenite and martensite phase are determined, also the quality factor of the Bio Metal coil to be (9.465 – 9.95) Ω and (10.358 – 10.8) Ω, (0.458 – 0.38) μH and (0.458 – 0.36) μH and, (9.47 – 10.24) Ω and (10.36 – 11.11) Ω respectively for the frequency range of 100 kHz - 1MHz. The quality factor of the Bio Metal ranges between 0.03 and 0.2 during heating and, 0.028 and 0.022 during the cooling phase. The experimental results herein show that an equivalent circuit of the SMA spring is a series resistor-inductor circuit with a parasitic capacitance effect. The electromagnetic behaviour of SMA is determined using a finite element tool.

Micro-CT and histopathology methods to assess host response of aneurysms treated with shape memory polymer foam-coated coils versus bare metal coil occlusion devices.

Recent studies utilizing shape memory polymer foams to coat embolizing coils have shown potential benefits over current aneurysm treatments. In the current study utilizing a rabbit-elastase aneurysm model, the performance of test article (foam-coated coil [FCC]) and control (bare platinum coils [BPCs]) devices were compared at 30, 90, and 180 days using micro-CT and histological assessments. The host response was measured by identifying the cells regionally present within the aneurysm, and assessing the degree of residual debris and connective tissue. The 3D reconstructions of aneurysms provided context for histologic findings, and aided in the overall aneurysm assessment. At all time points, >75% of the cells categorized in each aneurysm were associated with a bioactive yet biocompatible host response (vs. the remainder of cells that were associated with acute inflammation). The extracellular matrix exhibited a transition from residual fibrin at 30 days to a greater degree of connective tissue at 90 and 180 days. Although the control BPC-treated aneurysms exhibited a greater degree of connective tissue at the earliest time point examined (30 days), by 180 days, the FCC-treated aneurysms had more connective tissue and less debris overall than the control aneurysms. When considering cell types and extracellular matrix composition, the overall host response scores were significantly better in FCC-treated aneurysms at the later time point. Based on the results of these metrics, the FCC device may lead to an advanced tissue remodeling response over BPC occlusion devices.

A Unique Presentation of Splenic Artery Aneurysm During Pregnancy

Visceral arterial (VAA) and, specifically, splenic arterial aneurysms (SAA) are rare entities often associated with pregnancy. When ruptured, they can be fatal and require emergent management. This case report includes a review of the relevant literature and describes a unique, multidisciplinary approach to managing such an aneurysm. We describe the difficult situation of an already rupturing aneurysm and the careful coordination of obstetric, surgical, vascular, and interventional radiology teams. The distinctiveness of this case continues with the intraoperative finding of metallic coils freely protruding into the peritoneum from a recently coil-embolized ruptured splenic artery aneurysm. Such iatrogenic foreign bodies are a product of the integration of multiple specialities that can provide life-saving care when managing critical surgical disease such as ruptured splenic artery aneurysms. Multidisciplinary approaches should be considered depending upon the resources available at one’s institution.

Derivation of analytical dependencies for determining stiffness parameters of vibration isolators of vibratory machine

Problem statement. While designing vibration isolators, the essential attention should be paid to the safety factors such as the levels of vibration and noise, as well as to the material and the structure of isolators. In major vibratory technological equipment, there are used full-metal vibration isolators, which can be designed in the form of coil (cylindrical, conical, helico-spiral) or flat (leaf-type, disc-type) springs. The problems of stress-strain analysis of metal springs used for vibration isolation of various vibratory equipment are of urgent interest among the designers and researcher. The engineering techniques of step-by-step calculation of full-metal vibration isolators of different types of vibratory technological machines are not thoroughly presented in the modern information resources. Purpose. The present paper is aimed at developing and implementing the detailed algorithm of determining the stiffness parameters of the metal coil springs used for vibration isolation of large-scale vibratory machines. Methodology. The investigations are carried out using the basic laws and principles of solid mechanics and theory of vibrations. The calculations were conducted using MathCAD software; the computer simulation of the spring’s stress-strain state was performed using SolidWorks software. Findings (results) and originality (novelty). The improved design of the vibratory conveyer-separator is considered. The engineering technique of calculating the passive vibration isolators of various vibratory equipment designed in the form of metal coil springs is developed. The proposed technique is implemented while designing the vibration isolation system of the vibratory conveyer-separator. The system’s operational characteristics are determined, and the computer simulation of the springs stress-strain state is carried out. Practical value. The proposed design of the vibratory conveyer-separator can be implemented in various industries (machine-building, chemical, pharmaceutical, food-processing, construction, mining, metallurgy, textile industries etc.) for conveying different loose, bulky and piecewise products, and separating them into fractions of different sizes. Scopes of further investigations. While carrying out further investigations, it is necessary to analyse the influence of the proposed design of vibratory conveyer-separator on the foundation during its operation, and to consider the necessary of applying the additional fixation systems.

Utility of Coil-Assisted Retrograde Transvenous Obliteration II (CARTO-II) for the Treatment of Gastric Varices.

PurposeTo investigate the technical feasibility, safety and clinical outcomes of coil-assisted retrograde transvenous obliteration II (CARTO-II) for gastric varices (GV).Materials and MethodsThirty-six consecutive patients who had undergone CARTO-II between June 2016 and April 2018 were included in the study. In the CARTO procedure, coil embolization of the drainage vein is performed “before” injection of the sclerosant to replace the use of balloon catheter. In the CARTO-II procedure, coil embolization of the drainage vein was performed “after” injection of the sclerosant to prevent migration of the sclerosant. CARTO-II was performed with ethanolamine oleate iopamidol, and the balloon catheter was immediately removed after coil placement. Technical and clinical success rates, number of coils used, presence or absence of severe complications, timing of the procedure, and rate of GV recurrence after the procedure were analyzed retrospectively.ResultsIn all patients, GV sclerosis, coil placement and removal of the balloon catheter were successfully completed. The technical success rate was 100%. No patients experienced severe complications such as coil migration or pulmonary embolization. The mean number of metallic coils used per procedure was 3.36. Mean length of the procedure was 132.8 min. Contrast-enhanced computed tomography after CARTO-II confirmed complete variceal thrombosis in all cases. The recurrence rate of GV during follow-up was 2.8% (mean follow-up, 207 days).ConclusionCARTO-II was feasible and safe and could be performed relatively quickly. The number of coils used and the rate of GV recurrence were both low. CARTO-II may have an important role to play in the management of GV.