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Number of results: 7
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Focused Ultrasound: Doing Damage so as to Heal

Mirosław Ząbek Paweł Obierzyński Adrian Drożdż
ACADEMIA. The magazine of the Polish Academy of Sciences | 2022 | No 3 (75) Turning Points | 60-63 | DOI: 10.24425/academiaPAS.2022.143999
Keywords focused ultrasound brain Gamma Knife MRI neurosurgery
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Abstract

Innovative treatments that actually involve damaging certain parts of the brain may represent some patients’ only chance for recovery.
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Authors and Affiliations

Mirosław Ząbek
1 2
Paweł Obierzyński
1 2
Adrian Drożdż
1 3
  1. Interventional Neurology Center (INC), Department of Neurosurgery, Bródno Mazovian Hospital in Warsaw
  2. Department of Neurosurgery, Medical Center for Post-Graduate Education (CMKP)
  3. Center for Biostructure Research, Medical University of Warsaw

Application of focusing systems to the protection of information during data transmission in the zone of direct radio visibility

Yelizaveta Vitulyova Kaisarali Kadyrzhan Aruzhan Kadyrzhan Ibragim Suleimenov
International Journal of Electronics and Telecommunications | 2024 | vol. 70 | No 3 | 699-705 | DOI: 10.24425/ijet.2024.149599
Keywords information security unmanned aerial vehicle electronic warfare line of sight focusing system
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Abstract

It is shown that focusing systems built on the basis of a system of radio receivers spaced apart in space and simulating the operation of a lens can be used to ensure the protection of information during data transmission in the direct radio visibility zone. The synthesis of the lens equivalent in this case is carried out by using a system of phase shifters that change the phase of the oscillations arriving at each of the receivers, so that the receiving system is tuned to a radio wave source located at a specific point in space. In this case, information protection is provided according to the “friend or foe” principle, and any commands coming from other areas of space, except for the point where the authorized operator is located, are ignored. The advantage of this approach is the ability to partially or completely abandon the use of cryptographic methods. It is shown that the proposed approach is of considerable interest for ensuring the stable operation of groups of unmanned aerial vehicles from the point of view of the possibility of intercepting control using electronic warfare methods.
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Authors and Affiliations

Yelizaveta Vitulyova
1
Kaisarali Kadyrzhan
1
Aruzhan Kadyrzhan
2
Ibragim Suleimenov
2
ORCID: ORCID
  1. Almaty University of Power Engineering and Telecommunications named after Gumarbek Daukeev
  2. National Engineering Academy of the Republic of Kazakhstan

Calculation for Acoustic Radiation Force from Rectangular Weakly Focusing Transducer Using the Ray Acoustic Model

Lili Yu Shuchang Qiao Wende Shou Junhua Li
Archives of Acoustics | 2022 | vol. 47 | No 1 | 81-88 | DOI: 10.24425/aoa.2022.140734
Keywords radiation force calculation ray acoustic model rectangular weakly focusing transducer far-field integration
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Abstract

Based on the ray acoustic model, a new relationship between the radiation force and the acoustic power is studied for a rectangular weakly focusing transducer. The effect of pressure reflection coefficient on this model is discussed. For a totally absorbing target, an approximate closed-form expression is also derived and the performance of this model is compared with that of the far-field integration model. The numerical results show that the agreement is excellent with these two models, which can be both used for correction of measured results, but the formula based on the ray acoustic model can be applied more widely in practice because of its simpler expression. The experimental results show further the effectiveness of the relationship between radiation force and acoustic power for rectangular weakly focusing transducer based on the ray acoustic model. The results presented in this paper are important for application of ultrasound transducers in therapy.
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Authors and Affiliations

Lili Yu
1
Shuchang Qiao
1
Wende Shou
2 3
Junhua Li
4
  1. Merchant Marine College, Shanghai Maritime University, Shanghai 201306, China
  2. School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
  3. Shanghai Institute of Ultrasound in Medicine, Shanghai 200233, China
  4. College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China

The Effect of Dynamic Beam Deflection and Focus Shift on the Acoustic Field Distribution Inside the Ultrasonic Ring Array

Wiktor Staszewski Tadeusz Gudra Krzysztof J. Opieliński
Archives of Acoustics | 2019 | vol. 44 | No 4 | 625-636 | DOI: 10.24425/aoa.2019.129721
Keywords ultrasonic ring array acoustic field distribution ultrasonic beam focusing ultrasound tomography
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Abstract

This paper presents the results of acoustic field distribution simulations for the 1024-element ultrasonic ring array intended for the diagnosis of female breast tissue with the use of ultrasound tomography. For the purpose of analysing data, all acoustic fields created by each elementary transducer were combined. The natural position of the focus inside the ultrasonic ring array was changed by altering activation time of individual transducers in sectors consisting of 32, 64, and 128 ultrasonic transducers. Manipulating the position of the focus inside the array will allow to concentrate the ultrasonic beam in a chosen location in the interior space of the ring array. The goal of this research is to receive the best possible quality of images of cross-sections of the female breast. The study also analysed the influence of the acoustic field distribution on the inclination of the beam. The results will enable to choose an optimal focus and an optimal number of activated transducers.

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Authors and Affiliations

Wiktor Staszewski
Tadeusz Gudra
Krzysztof J. Opieliński

Non-contact harmonic detection of ferromagnetic material defects based on SQGSR and OPLTF

Yizhen Zhao Xinhua Wang Yingchun Chen Haiyang Ju Yi Shuai
Metrology and Measurement Systems | 2021 | vol. 28 | No 1 | 55-72 | DOI: 10.24425/mms.2021.135992
Keywords harmonic detection ferromagnetic materials defects focusing vector array signal extraction algorithm
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Abstract

In order to find the defects in ferromagnetic materials, a non-contact harmonic detection method is proposed. According to the principle of frequency modulated carrier wave, a tunnel magneto resistance harmonic focusing vector array detector was designed which radiates lower and higher frequency electromagnetic waves through the coil array to the detection targets. We use bistable stochastic resonance to enhance the energy of collected weak target signal and apply quantum computation and a Sobol low deviation sequence to improve genetic algorithm performance. Then we use the orthogonal phase-locked loop to eliminate the intrinsic background excitation field and tensor calculations to fuse the vector array signal. The finite element model of array detector and the magnetic dipole harmonic numerical model were also established. The simulation results show that the target signal can be identified effectively, its focusing performance is improved by 2 times, and the average signal-to-noise ratio is improved by 9.6 times after the algorithm processing. For the experiments, we take Q235 steel pipeline as the object to realize the recognition of three defects. Compared with the traditional methods, the proposed method is more effective for ferromagnetic materials defects detection.
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Authors and Affiliations

Yizhen Zhao
1
Xinhua Wang
1
Yingchun Chen
1
Haiyang Ju
1
Yi Shuai
1
  1. Beijing University of Technology, College of Mechanical Engineering and Applied Electronics Technology, 100 Ping Le Yuan, Chaoyang District, Beijing 100124, China

Design and Verification of Sector Vortex Archimedean Spiral Phased Array Transducer for Improving Focus Acoustic Pressure

Xiaodan Lu Deping Zeng
Archives of Acoustics | 2024 | vol. 49 | No 1 | 73-81 | DOI: 10.24425/aoa.2024.148769
Keywords phased array transducer Archimedean spiral high-intensity focused ultrasound (HIFU) focal deflection
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Abstract

The emergence of high-intensity focused ultrasound applications brings great potential to establish noninvasive therapeutic treatment in place of conventional surgery. However, the development of ultrasonic technology also poses challenges to the design and manufacture of high-power ultrasound transducers with sufficient acoustic pressure. Here, the design of a sector vortex Archimedean spiral phased array transducer that is able to enhance focal acoustic pressure is proposed by maximizing the filling factor of the piezoelectric array. The transducer design was experimentally verified by hydrophone measurements and matched well with acoustic simulation studies. The focal deflection was shown to be feasible up to ±9 mm laterally and up to ±20 mm axially, where the effective focal acoustic pressure can be maintained above 50% and the level of the grating lobe below 30%. Furthermore, a homogeneous pressure distribution without secondary focus was observed in the pre-focal region of the transducer. The rational design of a high-intensity focused ultrasound transducer indicates promising development in the treatment of deep tissue thermal ablation for clinical applications.
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Authors and Affiliations

Xiaodan Lu
1
Deping Zeng
2
  1. State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering Chongqing Medical University Chongqing, China
  2. National Engineering Research Center of Ultrasound Medicine Chongqing, China

Intermetallic compound layer formation in indium-based micro-bump array fabrication technology for IR detectors

Paweł Kozłowski Agata Jasik Adam Łaszcz Krzysztof Czuba Krzysztof Chmielewski Krzysztof Zdunek
Opto-Electronics Review | 2024 | 32 | 1 | e148833 | DOI: 10.24425/opelre.2024.148833
Keywords indium micro-bump under bump metallization intermetallic alloy focused ion beam energy dispersive spectrometry
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Abstract

This work reports on the investigation of homogeneity of the inside of indium micro-bumps/ columns placed on Ti/Pt/Au under bump metallisation. This is very important for connection resistivity, long-time durability, and subsequent hybridisation process (e.g., die-bonding). Gold reacts with indium to form intermetallic alloys with different chemo-physical parameters than pure indium. The geometrical and structural parameters of intermetallic alloys were analysed based on transmission electron microscope images. Distribution of elements in the investigated samples was determined using the transmission electron micro-scope with energy dispersive spectroscopy method. A thickness of intermetallic alloy was 1.02 μm and 1.67 μm in non-annealed (A) and annealed (B) indium columns, respectively. The layered and column-like interior structure of alloys was observed for both samples, respectively, with twice bigger grains in sample B. The graded chemical composition of Au-In intermetallic alloy was detected for the non-annealed In columns in contrast to the constant composition of 40% of Au and 60% of In for the annealed sample B. The atomic distribution has a minor impact on the In column mechanical stability. A yield above 99% of an In column with a 25 µm diameter and a 11 µm height is possible for a uniform columnar structure of intermetallic alloy with a thickness of 1.67 μm.
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Authors and Affiliations

Paweł Kozłowski
1
ORCID: ORCID
Agata Jasik
1
ORCID: ORCID
Adam Łaszcz
1
ORCID: ORCID
Krzysztof Czuba
1
ORCID: ORCID
Krzysztof Chmielewski
1
ORCID: ORCID
Krzysztof Zdunek
2
ORCID: ORCID
  1.  Łukasiewicz Research Network – Institute of Microelectronics and Photonics, Al. Lotników 32/46, 02-668 Warsaw, Poland
  2. Warsaw University of Technology, Faculty of Materials Science and Engineering, ul. Wołoska 141, 02-507 Warsaw, Poland

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