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This article investigates the modeling and implementation of the load-independent operation for the push–pull Class E topology with coupled inductors. The analytical modeling is first presented and provides a new design methodology, which distantly improves the soft-switching performance, load regulation, and efficiency compared with the conventional inductor-coupled Class E topology. An LCC-S resonant Class E$ ^2$ converter, which combines the load-independent inductor-coupled inverter and active rectifier, is proposed for MHz-wireless power transfer (MHz-WPT) applications. The active inductor-coupled Class E rectifier maintains soft switching, constant voltage gain, and zero-phase-angle input at various loads. A three-winding magnetic structure is also proposed to improve the coupled inductors by enhanced self-inductance, which features more effective harmonic suppression with lower magnetic losses and volumes. By the proposed methodology and the improved magnetic structure, the converter features negligible harmonic contents and maintains soft switching with a constant voltage conversion ratio over the entire load range. A 6.78-MHz WPT prototype was built to verify the proposed methodology with detailed parameter design and hardware implementation. The prototype realizes load-independent zero-voltage switching and maintains an approximately constant voltage gain with +5/$-$4% variance from no-load to 320-W output power. The measured dc–dc efficiency reaches 89.3% at 210 W.

The Coronavirus Disease 2019 (COVID-19) has spread globally and caused serious damage. Chest X-ray images are widely used for COVID-19 diagnosis and the Artificial Intelligence method can increase efficiency and accuracy. In the Challenge of Chest XR COVID-19 detection in Ethics and Explainability for Responsible Data Science (EE-RDS) conference 2021, we proposed a method that combined Swin Transformer and Transformer in Transformer to classify chest X-ray images as three classes: COVID-19, Pneumonia, and Normal (healthy) and achieved 0.9475 accuracies on the test set.

This paper presents the analytical modeling of synchronous class E rectifiers with the load-independent operation, which achieves zero-phase-angle input impedance, soft-switching over the entire load range with a constant voltage gain. The optimal design of the synchronous class E rectifier is proposed to realize both of zero-voltage-switching turn-on and zero-current-switching turn-off at the expected output power. An LCC-S compensated MHz-WPT topology, which comprises the push-pull class E inverter and rectifier with the load-independent operation, is proposed to achieve the fully soft-switching and a nearly-constant voltage gain over the entire load range. The efficiency improvement of the compensation network is also investigated to provide a design methodology for the proposed topology. A 6.78-MHz WPT prototype, along with an alternative phase detector using an auxiliary coil to realize phase detection, is built to validate the analytical model and the proposed methodology. The system efficiency reaches 86.7 % at 214 watts output. The synchronous push-pull class E rectifier maintains soft-switching over the load range, and the rectification efficiency reaches 94.6 %.

This paper presents the circuit design and magnetic integration of push-pull class-E inverters for wireless power transfer (WPT) up to megahertz. The design criterion for achieving ZVS of a class-E inverter with coupled windings is derived mathematically. The approaches of magnetic integration for push-pull class-E inverters are analyzed and compared. Then, a new magnetic structure with hybrid magnetic materials is proposed to build the integrated inductors with either coupled windings or uncoupled windings. A 3 MHz WPT system is built to verify the analysis. The detailed comparison of the class-E inverters with magnetic integration is presented in terms of switch voltage, efficiency, harmonic currents and thermal distribution. In the optimized design example, the switches keep ZVS over the entire load range without using any closed-loop control. The system efficiency reaches 87.1% at 350 W output power.

Lei Pi,1,* Di Che,1,* Haifeng Long,2,3,* Zhenzhen Fang,4 Jiawen Li,1 Shuyi Lin,2 Yunfeng Liu,2 Meiai Li,2 Lijuan Bao,2 Wenli Li,2 Yuan Zhang,2 Qiulian Deng,2 Techang Liu,5 Li Zhang,5 Xiaoqiong Gu1,2 1Department of Clinical Biological Resource Bank, Guangzhou Institute of Pediatrics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China; 2Department of Clinical Laboratory, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China; 3Department of Clinical Laboratory, The First Clinical Medical College, Jinan University, Guangzhou, China; 4Program of Molecular Medicine, Guangzhou Women and Children’s Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; 5Department of Cardiology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China *These authors contributed equally to this work Introduction: Kawasaki disease is a kind of systemic vasculitis that mainly damages moderate and small-sized blood vessels, and is a leading cause of coronary artery lesions (CAL). Antiplatelet therapy is a routine component of Kawasaki disease treatment strategies. So it is important to evaluate the antiplatelet effect of aspirin because of the individual biological variability of antiplatelet effect of aspirin. The immature platelet fraction (IPF) has attracted particular attention as it may influence the antiplatelet effect of aspirin. This study investigated the prognostic factors for evaluating the degree of vasculitis and the effect of antiplatelet therapy in children with Kawasaki disease. Materials and methods: Blood samples were collected from 44 patients with Kawasaki disease before aspirin treatment and 7 to 10 days after treatment. The IPF counts, percentage of the IPF, and highly fluorescent IPF were detected by a Sysmex XE-5000 instrument. The levels of 11-dehydrothromboxane B2 (11-DH-TXB2), soluble