Shield Technology Research Articles

A magnetic shielding strategy for magnetic sensor in magnetic flux leakage testing

The magnetic flux leakage (MFL) signal is the leakage of magnetic field lines near the defect of the magnetized specimen, and its quality is critical to the nondestructive quantitative testing technology. The strategy of magnetic shielding (MS) technology is expected to enhance the MFL signal quality; however, the inconsistency between the existing experiments and simulation results limits the application of this technology. Here, we developed a finite element simulation method for the MS effect, which possesses the quantitative analysis ability to experimental results. Furthermore, the finite element simulations reveal the MS effect on MFL signals, and demonstrate the main influencing factors and the law that cause differences in the MS effect. The suitable size parameters of MS equipment and defect size of the tested specimen are the key factors affecting the MS effect. The theoretical analysis and conclusion in the paper can provide the reference for the MS equipment design in the MFL testing sensor.

Safety and Efficacy of Flow Diverter Therapy for Unruptured Intracranial Aneurysm Compared to Traditional Endovascular Strategy : A Multi-Center, Randomized, Open-Label Trial

Endovascular treatment of large, wide-necked intracranial aneurysms by coil embolization is often complicated by low rates of complete occlusion and high rates of recurrence. A flow diverter device has been shown to be safe and effective for the treatment of not only large and giant unruptured aneurysms, but small and medium aneurysms. However, in Korea, its use has only recently been approved for aneurysms <10 mm. This study aims to compare the safety and efficacy of flow diversion and coil embolization for the treatment of unruptured aneurysms ≥7 mm. The participants will include patients aged between 19 and 75 years to be treated for unruptured cerebral aneurysms ≥7 mm for the first time or for recurrent aneurysms after initial endovascular coil embolization. Participants assigned to a flow diversion cohort will be treated using any of the following devices : Pipeline Flex Embolization Device with Shield Technology (Medtronic, Minneapolis, MN, USA), Surpass Evolve (Stryker Neurovascular, Fremont, CA, USA), and FRED or FRED Jr. (MicroVention, Tustin, CA, USA). Participants assigned to a coil embolization cohort will undergo traditional endovascular coiling. The primary endpoint will be complete occlusion confirmed by cerebral angiography at 12 months after treatment. Secondary safety outcomes will evaluate periprocedural and post-procedural complications for up to 12 months. The trial will begin enrollment in 2022, and clinical data will be available after enrollment and follow-up. This article describes the aim and design of a multi-center, randomized, open-label trial to compare the safety and efficacy of flow diversion versus traditional endovascular treatment for unruptured cerebral aneurysms ≥7 mm.

Safety and Clinical Effectiveness of Pipeline Shield Device for Intracranial Aneurysms in an Australian Cohort (SCOPE‐AUS)

Background The Pipeline Flex Embolization Device (PED) with Shield Technology (PED‐Shield) is a third‐generation flow diverting stents with surface modification designed to reduce platelet adhesion and thrombogenicity. We report the long‐term safety and effectiveness of the PED‐Shield in the treatment of unruptured intracranial aneurysms in an Australian cohort. Methods SCOPE‐AUS (Safety and Clinical Effectiveness Of Pipeline Shield Embolization Device for Treatment of Intracranial Aneurysms in Australia) is a multicenter, single‐arm, retrospective study of patients with unruptured intracranial aneurysms treated with the PED‐Shield flow diverting stents at 3 high‐volume neurointervention centers in Australia between May 1, 2015, and June 30, 2018, evaluating safety and efficacy. The primary outcome was neurologic adverse event or neurologic‐related death at 1 year, and the secondary outcome was long‐term complete aneurysm occlusion. Results A total of 238 patients (mean age 55.8±11.0 years, 73.1% [174/238] female) and 278 aneurysms were treated via 247 procedures. Two (0.7%) aneurysms were retreated during the 18‐month follow‐up. Overall occlusion rates at 18 months or at last follow‐up imaging were 92.5% (233/252). There were 35 (14.7%) total primary end point events. The 12‐month neurologic morbidity and mortality rates were 3.8% (9/238) and 1.3% (3/238), respectively. For the subgroup of internal carotid artery aneurysms, mortality (0.7%) and morbidity (2.0%) rates were low, and the complete occlusion rate was 92.5% (147/155). Conclusions In this multicenter study, which includes a wide variety of both distal bifurcation and proximal unruptured intracranial aneurysms, the occlusion rates and safety outcomes of the PED‐Shield flow diverting stent demonstrate a high proportion of complete aneurysm occlusion, extremely low retreatment rates, and low complication rates.

Nanoparticle-Enhanced β-Phase Formation in Electroactive PVDF Composites: A Review of Systems for Applications in Energy Harvesting, EMI Shielding, and Membrane Technology

Nanoparticle-Enhanced β-Phase Formation in Electroactive PVDF Composites: A Review of Systems for Applications in Energy Harvesting, EMI Shielding, and Membrane Technology

Influence of rare-earth ions on the radiation protection ability of some optical glasses containing Bi2O3 and SiO2

ObjectiveThis study probed the gamma ray shielding functionality of some rare earth doped bismuth-silicate glasses (BS). The mass attenuation coefficient MAC of pure BS (BS-Pure) and those with 2.5 mol% of Bi2O3 substituted with CeO2 (BS-Ce), Nd2O3 (BS-Nd), Sm2O3 (BS-Sm), and Eu2O3 (BS-Eu) was estimated. MethodThe experimental values of glass density and molar volume were systematically used to evaluate the radiation shielding properties of the studied optical glasses. The MAC was computed for photon energies between 0.015 and 15 MeV by employing Monte Carlo simulation and Phy-X software. MAC values were then used to extract all the other related parameters. ResultsMAC computed via the two approached agrees well within 1.9%. MAC of the glasses fluctuates between 0.041 and 100.044 cm2g−1 for BS-Pure; 0.041 – 98.725 cm2g−1 for BS-Ce; 0.041 – 99.249 cm2g−1 for BS-Nd; 0.04 – 99.335 cm2g−1 for BS-Sm; and 0.041 – 99.061 cm2g−1 for BS-Eu. Also, the effective atomic number of the glasses were within the range of 38.707–81.874 for BS-Pure, 38.397–81.509 for BS-Ce, 38.377–81.366 for BS-Nd, 38.402–81.366 for BS-Sm and 38.414–81.368 for BS-Eu. ConclusionCompared to traditional photon shields such as concrete, RS-360 commercial glasses, recently investigated heavy glasses, polymer and rocks, the BS-X glasses displayed superior shielding potential. The BS-X glasses thus could function well in gamma radiation shielding technology.

Analysis and design of precise testing instrument chassis considering electromagnetic shielding

In this work, the issues regarding the mechanism and structural design of electromagnetic shielding technology are introduced. In accordance with the use requirements of precise testing instruments, the precautions in the chassis design with respect to electromagnetic shielding are determined. Moreover, the approach to improve the chassis through experiments is proposed, and the test shows that the improved chassis can meet the requirements of shielding.

Evaluating the Intrinsic Electromagnetic Field Generated by Neurons From Repetitive Motor Activities in Humans With a Non-contact Non-invasive Electromagnetic Helmet.

IntroductionThe actions of neurons are dependent on electrochemical signal pathways mediated by neurotransmitters and create measurable electrical charges. These charges have been found to be measurable through neuroimaging technologies and now through a novel non-contact non-invasive sensor without supercooling. Identifying whether this technology can be appropriately interpreted with synchronized motor well-defined activities in vivo may allow for further clinical applications.MethodsA non-contact, non-invasive helmet constructed and modified using shielding technology with proprietary magnetic field sensors was utilized to measure the brain’s electromagnetic field (EMF). Human volunteers donned helmets and were asked to perform repetitive tapping exercises in order to identify waves consistent with tapping from the left and right hemispheres. A gyroscope was utilized to ensure that measured waves were not from micro-movement but were from neuronal firing. Multiple individuals were tested to evaluate the reproducibility of tapping and commonalities between individualsResultsRight and left-sided tapping generated discernible wave changes from baseline measurements obtained by the helmet without a subject as well as differed from when the subject was at rest. Wave patterns varied from person to person but were overall similar in each subject individually. Shielding was necessary to identify signals but EMF was identified when shielding was transitioned from around the helmet to within the helmet design.ConclusionIt is possible to measure in-vivo electromagnetic fields generated by the human brain generated by stereotyped tasks in a non-contact non-invasive manner. These waves were reliably obtained within each individual with some variability in morphology from subject to subject however were similar in each subject. Signals varied based on activity and stereotyped motor activities were identified. A helmet using shielding technology within the helmet itself was able to effectively identify EMF signals. Future analysis may focus on translating these waves into functional mapping for clinical applications.

802 First United States Experience with Pipeline Flex with Shield Technology for Treatment of Intracranial Aneurysms

INTRODUCTION: Pipeline Flex with Shield technology (PED-Shield) is a third generation flow-diverter. A surface modification of the mesh with phosphorylcholine covalently bound to the metal struts aims to reduce thrombogenicity. In this study, we report the first United-States series of patients treated with the PED-Shield. METHODS: Information for the first 10 patients with intracranial aneurysms treated with PED-Shield was retrospectively collected. Patients were started on dual antiplatelet therapy (DAPT; 325 mg of aspirin and 75 mg of clopidogrel or 180 mg of ticagrelor) 7-days prior to intervention. After procedure, all patients were discharged on DAPT and planned to switch to aspirin alone at 6 months. RESULTS: Ten patients with 11 intracranial wide-necked aneurysms underwent treatment with PED-Shield between June 2021 and July 2021. The mean age of patients was 64.7 (45 - 86), and nine were female. All aneurysms were unruptured and located in the anterior-circulation. Mean maximum aneurysm diameter was 4.86mm, mean neck width was 3.05mm. Regarding morphology, all aneurysms were saccular except for one, which was fusiform. In one case, the device demonstrated insufficient distal opening, which was repaired with balloon angioplasty. There were no other technical issues or intraoperative complications. We observed no endoleak after deployment of the devices. There were two complications in the post-operative period: one patient had a groin hematoma, which was attributed to failure of the closure device and successfully managed with no clinical repercussions; one patient experienced an asymptomatic distal small intraparenchymal hematoma and trace subarachnoid hemorrhage on post-procedure non-contrast CT, which remained stable over several days. None of the patients experienced transient ischemic attacks or strokes. All patients were discharged in stable condition and unchanged functional status. CONCLUSIONS: In our initial experience with PED-Shield for the treatment of intracranial aneurysms, the device demonstrated excellent performance and no major complications. Further studies are needed to evaluate long term follow-up and safety of different antiplatelet regimens.

Effects of Composition on the Electromagnetic Wave Shielding/Absorption and Corrosion in Zn-Ni Alloy Thin Film

In the Fourth industrial age, there is increasing use of electronic devices with high frequency (GHz) operating circuits for radio wave transmission/reception. This can lead to electromagnetic noise, and malfunctions in nearby devices. Electromagnetic shielding technology has emerged as an important way of preventing device malfunctions due to noise, and interest in shielding materials for electromagnetic waves has also increased. To allow compact integration and light weight electronic devices, highly efficient, thin and multifunctional film materials are required. This study selected the Zn-Ni alloy, which has adequate corrosion resistance, to protect the metal parent material of electronic components. Various compositions of the alloy were deposited using magnetron sputtering. Phase formation and composition were confirmed through XRD and SEM and EDS. The surface resistance of the thin films was measured using the 4point probe method, to calculate the shielding rate of the thin films. The electromagnetic wave shielding/absorption rate then measured according to frequency and the results compared with the calculated values. Corrosion resistance was evaluated with a polarization test. The far field electromagnetic shielding/absorption rate increased as the Zn content increased, up to 52 dB in a film with 70 at% of Zn. Corrosion resistivity behavior was the opposite. However, the Ni5Zn21 phase formation, which occurred in films with lower Zn composition, helped to improve electromagnetic absorption in the near field as well as corrosion resistivity. Therefore, the optimum composition of the Zn-Ni films was provisionally determined to be around Ni: Zn = 43:57 for electronic devices using electromagnetic waves in the near field range.

Nuclear disarmament verification based on (n,γ) reaction using physical encryption technology

To reduce the risk of leaking confidential information in nuclear arms control, we propose a new arms control inspection concept based on neutron activation analysis, in conjunction with physical shielding technology to distort the energy and propagation path of the outgoing particles in the physical domain. The reliability and security of this authentication concept are demonstrated using Monte Carlo simulations. It turns out that the concept can readily identify isotope cheats and two typical geometric cheats without revealing sensitive information about the inspected items.

First U.S. Experience Using the Pipeline Flex Embolization Device with Shield Technology for Treatment of Intracranial Aneurysms

The Pipeline Flex Embolization Device with Shield technology (PED-Shield [Medtronic, Dublin, Ireland]) is a third-generation flow diverter. Surface modification of the mesh with phosphorylcholine covalently bound to the metal struts aims to reduce thrombogenicity. In the present study, we report the results from the first U.S. series of patients with intracranial aneurysms treated with the PED-Shield and a comprehensive systematic literature review. We retrospectively collected the patient demographics, aneurysm characteristics, procedural details, and periprocedural complications from our prospectively maintained endovascular database (April 2021 to July 2021). Our literature review encompassed 3 databases (PubMed, Embase, and MEDLINE). Ten patients with 11 anterior circulation unruptured wide-necked aneurysms (10 saccular, 1 fusiform) were included. The average patient age was 64.7 years (range, 45-86 years), and 9 were women. One device demonstrated insufficient distal opening. No other technical issues or intraprocedural complications had occurred. After the procedure, 1 patient had developed a groin hematoma and 1 had experienced a small intracranial hemorrhage, with no clinical repercussions. All patients were discharged with dual-antiplatelet therapy. In the review, we identified 15 studies. Most had been conducted in Europe and South America and 3 were U.S. case reports of compassionate use of the device. In our initial periprocedural experience with the PED-Shield for intracranial aneurysm treatment, the device demonstrated an excellent performance and no major complications. Further studies are required to evaluate the long-term follow-up results and the safety of different antiplatelet regimens.

Actively-shielded ultrahigh field MRI/NMR superconducting magnet design

Active shielding technology has been widely applied to the superconducting magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) magnets design, revealing excellent performance on the stray field control. For such a highly homogeneous field superconducting magnet design, an appropriate optimization strategy is essential to guarantee the magnetic field homogeneity in the central region and the expected 5 Gauss line range, especially for the ultrahigh field superconducting magnet. Based on the compensating field optimization method, an actively-shielded whole-body 14 T MRI magnet and an actively-shielded 1.3 GHz NMR magnet were presented, and detailed analyses were conducted to evaluate the feasibility of the designs. The developed magnet design method, coil pattern, wire arrangement, and stress/strain adjustment will be used to guide the corresponding project implementation.

Three-Dimensional Intraarterial Vaso Computed Tomography Depiction of Pipeline Flex with Shield Technology Flow Diverter Stent in Ruptured Blister Aneurysm of Supraclinoid Internal Carotid Artery

AbstractBlister aneurysms are intracranial arterial lesions originating at nonbranching sites of the dorsal supraclinoid internal carotid artery and basilar artery.1 Among different treatment options, the use of flow-diverting devices is gaining popularity and has the potential for becoming the standard of care.2 Radiological evaluation of flow diverter braid expansion and vessel wall apposition during procedure has become useful in preventing life-threatening complications. Incomplete coverage of an aneurysm neck, kinking, or incomplete expansion and malapposition of a stent carries a significant risk for thromboembolic events.3 4

Sending a spacecraft to interstellar comet 2I/Borisov

On 2019 August 30, a second interstellar object 2I/Borisov was discovered 2 years after the discovery of the first known interstellar object, 1I/’Oumuamua. Can we send a spacecraft to this object, using existing and near-term technologies? In this paper we assess the technical feasibility of a near-term mission to 2I/Borisov. We apply the Optimum Interplanetary Trajectory Software (OITS) tool to generate trajectories to 2I/Borisov. As results, we get the minimal ΔV trajectory with a launch date in 2018 July. For this trajectory, a Falcon Heavy launcher could have hauled an 8 ton spacecraft to 2I/Borisov. For a later launch date, results for a combined powered Jupiter flyby with a Solar Oberth maneuver are presented. For a launch in 2027, we could reach 2I/Borisov in 2052, using the Space Launch System (SLS), up-scaled Parker probe heat shield technology, and solid propulsion engines. Using a SLS a spacecraft with a mass of 765 kg could be sent to 2I/Borisov. A Falcon Heavy could deliver 202 kg to 2I/Borisov. Arrival times sooner than 2052 can potentially be achieved but with higher ΔV requirements and lower spacecraft payload masses. 2I/Borisov’s discovery shortly after the discovery of 1I/’Oumuamua implies that the next interstellar object might be discovered in the near future. The feasibility of a mission to both, 1I/’Oumuamua and 2I/Borisov using scaled versions of existing technologies indicates that missions to at least some future interstellar objects are feasible as well.

Double-Coil Dynamic Shielding Technology for Wireless Power Transmission in Electric Vehicles

During wireless charging, the transmission distance of electric vehicles varies, resulting in different levels of electromagnetic field leakage. An improved active shielding technology, the double-coil dynamic shielding technology, is proposed in this paper for wireless power transfer (WPT) systems with different transmission distances. Modeling, simulation, and experiments are performed for the WPT system with a double-coil dynamic shielding scheme and compared with other cases. The results show that the proposed double-coil dynamic shielding scheme is able to shield approximately 70% of the electromagnetic field leakage for WPT systems at different transmission distances. In addition, it essentially causes no degradation in transmission efficiency (only 3.1%). The effectiveness and feasibility of the proposed scheme are verified.

Reducing space radiation cancer risk with magnetic shielding

Interplanetary space radiation presents significant hazards to astronaut health and survival because it can cause both acute and chronic health effects including carcinogenesis. Mitigation of space radiation risks remains critical for enabling human missions beyond Earth orbit. Currently available options for space radiation shielding, such as water shielding, may not be sufficient at reducing space radiation dose and cancer risk to within current regulatory limits. Active magnetic shielding using superconductors has consistently been identified for further study due to its high potential benefit. In response, we have developed Monte Carlo models to determine the effectiveness of several of the latest magnetic shielding concepts, along with current passive shielding techniques, in terms of risk of exposure induced death. This was done for various Mars flyby mission profiles according to current space agency risk tolerance limits. Our study found that few shielding options were able to meet current risk tolerance limits without relying on astronauts of advanced age (>60 years). However, all of the magnetic shielding configurations provided substantial benefit in reducing space radiation cancer risk given high magnetic field strength (7 Tesla). With this information, space agencies can move towards engineering assessments of magnetic shielding technology and begin to advance the concept into a solution enabling interplanetary travel.

Single-session treatment of bilateral, tandem, internal carotid artery aneurysms with pipeline flex with shield technology

The treatment of intracranial aneurysms (IA) has been transformed by the development of flow-diversion (FD) devices. Initially, these revolutionary devices were conceived for giant and fusiform aneurysms located on the internal carotid artery (ICA). Technological improvements have expanded their indications. Distal middle cerebral, anterior cerebral artery aneurysms, or even posterior fossa aneurysms can now benefit from this technology. One other category of aneurysms that can be treated is multiple IA’s.&#x0D; Multiple IA’s are encountered in approximately one-quarter of patients presenting with subarachnoid haemorrhage. Endovascular management of such cases is complex, requiring different devices and treatment strategies to secure all lesions. FD’s can be successfully employed to reconstruct vessels, which harbour more than one aneurysm, especially multiple ICA lesions. Multiple aneurysms located on both ICA’s are generically known as tandem aneurysms.&#x0D; We present the case of a patient with tandem aneurysms located on both intracranial internal carotid arteries that we treated simultaneously with the Pipeline Flex with Shield Technology in one single session. To the best of our knowledge, this is the first case reported in the literature so far.

Study on the Electromagnetic Shielding of Accessory Device without Electromagnetic Shielding Technology in the Magnetic Resonance Room

Study on the Electromagnetic Shielding of Accessory Device without Electromagnetic Shielding Technology in the Magnetic Resonance Room

Transparent Electromagnetic Shielding Film Utilizing Imprinting-Based Micro Patterning Technology.

Utilization of methods involving component integration has accelerated, owing to the growth of the smart mobile industry. However, this integration leads to interference issues between the components, thereby elucidating the importance of the electromagnetic interference (EMI) shielding technology to solve such issues. EMI shielding technology has been previously implemented via the reflection or absorption of electromagnetic waves by using conductive materials. Nevertheless, to tackle the recent changes in the industry, a transparent and flexible EMI shielding technology is necessitated. In this study, a transparent and flexible EMI shielding material was fabricated by filling a conductive binder in a film comprising an intaglio pattern; this was achieved by using the ultraviolet (UV) imprinting technology to realize mass production. Subsequently, changes in the aperture ratio and shielding characteristics were analyzed according to the structure of the pattern. Based on this analysis, a square pattern was designed and a film with an intaglio pattern was developed through a UV imprinting process. Furthermore, it was confirmed that the transmittance, conductivity, and EMI shielding rate of the film were altered while changing the coating thickness of the conductive particles in the intaglio pattern. The final film prepared in this study exhibited characteristics that satisfied the required EMI shielding performance for electric and electronic applications, while achieving flexible structural stability and transparency.

Multilayered Graphene-Assisted Broadband Scattering Suppression through an Ultrathin and Ultralight Metasurface

Here, we present an ultralight multilayered graphene-based metasurface for suppressing specular reflection. With the help of a joint optimization method, dual low-reflection mechanisms including absorption and random diffusion are realized within the same structure, resulting in a remarkable decrease in the backward reflected energy in an ultrabroadband range of 7.5 to 43 GHz (a relative bandwidth of 140.6%). Experiments demonstrate that our design with a thickness of approximately 3.27 mm can maintain excellent antireflection performance over a wide angle range of 0 to 45° for both TE and TM waves. Additionally, as a result of adopting low-density substrates (polyethylene terephthalate and polymethylacrylimide foam) and multilayered graphene films, the proposed metasurface shows the advantage of ultralight weight, thus opening an avenue for a number of engineering applications such as electromagnetic shielding, information security, and electromagnetic compatibility technology. In addition, owing to the natural characteristics (corrosion resistance, bending resistance, etc.) of multilayered graphene films, the proposed metasurface shows enormous potential in some particular application scenarios with harsh conditions.