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The goal of this work is to design high-resolution, high-contrast and robust MV adaptive beamforming algorithms, which are also implemented in real-time frame rate. Multi-operator optimization is introduced into MV adaptive beamforming in this work to propose a multi-operator MV adaptive beamforming algorithmic optimization framework. Based on the proposed algorithmic optimization framework, the algorithm optimization can be either conducted by activating a single optimization operator, or conducted by activating multiple optimization operators. The multi-operator MV (MOMV) adaptive beamforming algorithms are then derived from this framework. Moreover, in order to promote the real-time imaging capability of MOMV beamforming, a GPU-based parallel acceleration framework is proposed along with the algorithmic optimization framework by exploring the image-level coarse-grained parallelization and pixel-level fine-grained parallelization. GPU computing resource allocation strategy and memory access strategy are both explored to better design the acceleration framework. Comprehensive quantitative simulation evaluations and qualitative in vivo experiments of imaging performance are studied, and the results demonstrate that the proposed MOMV adaptive beamforming algorithms significantly improve the imaging performance as compared with other MV beamforming algorithms, which have high resolution, high contrast, good robustness, and real-time imaging capability with thousands of acceleration speedup. Furthermore, the MOMV beamforming algorithm without eigen-decomposition and projection optimization operator achieves much higher beamforming frame rate with little downgrade of image quality as compared with the MOMV beamforming algorithm with all optimization operators. [ABSTRACT FROM AUTHOR]

Medical ultrasound imaging stands out from other modalities in providing real-time diagnostic capability at an affordable price while being physically portable. This article explores the suitability of using GPUs as the primary signal and image processors for future medical ultrasound imaging systems. A case study on synthetic aperture (SA) imaging illustrates the promise of using high-performance GPUs in such systems. [ABSTRACT FROM PUBLISHER]

An atmospheric pressure needle plasma is generated with a hollowneedle-plate dielectric barrier discharge, and the plasma parameters are measured by optical emission spectroscopy. The length of the needle plasma reaches 3 cm with an argon flow rate in the range from 3.5 to 6.1 ml/min when the applied voltage is 7.2 kV. The spatial distribution of oxygen-atom spectral-line intensity indicates that there is a large concentration of excited oxygen atoms in the middle of the plasma. Gas temperature is estimated by simulating the spectrum of OH radical around 309 nm. The spatial distribution of gas temperature along the plasma is uniform. Gas temperature decreases with the increase in argon flow rate. Electron density determined by the Stark broadening of H\alpha is in the range from 5.8 \times 10^14 to 6.0 \times 10^14\ \cm^-3 when the electron temperature is 1–4 eV. The application of plasma in the modification of material surface is demonstrated. [ABSTRACT FROM PUBLISHER]