Dr. Svetoslav Ivanov Nikolov Profile

Dr. Svetoslav Ivanov Nikolov

Fellow at BK Ultrasound

SPIE Involvement:

Conference Program Committee | Author

Proceedings Article | 1 April 2016 Paper

Volumetric synthetic aperture imaging with a piezoelectric 2D row-column probe

Hamed Bouzari, Mathias Engholm, Thomas Lehrmann Christiansen, Christopher Beers, Anders Lei, Matthias Bo Stuart, Svetoslav Ivanov Nikolov, Erik Vilain Thomsen, Jørgen Arendt Jensen

Proceedings Volume 9790, 97900Y (2016) https://doi.org/10.1117/12.2216074

KEYWORDS: Point spread functions, Transducers, Ultrasonography, Signal to noise ratio, Synthetic aperture imaging, 3D image processing, Spatial resolution, Prototyping, Scanners, Tissues, Apodization, Electrodes

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Proceedings Article | 17 March 2015 Paper

Synthetic aperture imaging using a semi-analytic model for the transmit beams

Jens Hansen, Svetoslav Nikolov

Proceedings Volume 9419, 94190K (2015) https://doi.org/10.1117/12.2081936

KEYWORDS: Synthetic aperture imaging, Transducers, Tissues, Image transmission, Ultrasonography, Spherical lenses, In vivo imaging, Computer simulations, Virtual point source, Binary data

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Proceedings Article | 17 March 2015 Paper

In vivo real-time volumetric synthetic aperture ultrasound imaging

Hamed Bouzari, Morten Rasmussen, Andreas Brandt, Matthias Stuart, Svetoslav Nikolov, Jørgen Jensen

Proceedings Volume 9419, 94190I (2015) https://doi.org/10.1117/12.2081631

KEYWORDS: Ultrasonography, In vivo imaging, Transducers, Synthetic aperture radar, Scanners, Imaging systems, Tissues, Acoustics, Temporal resolution, Signal to noise ratio

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Proceedings Article | 20 March 2014 Paper

Real-time GPU implementation of transverse oscillation vector velocity flow imaging

David Pierson Bradway, Michael Johannes Pihl, Andreas Krebs, Borislav Gueorguiev Tomov, Carsten Straso Kjær, Svetoslav Ivanov Nikolov, Jørgen Arendt Jensen

Proceedings Volume 9040, 90401Y (2014) https://doi.org/10.1117/12.2043582

KEYWORDS: Ultrasonography, Scanners, MATLAB, Visualization, Data acquisition, Signal processing, Data processing, Algorithm development, Quantization, Diagnostics

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Proceedings Article | 12 March 2010 Paper

Ultrasound image quality assessment: a framework for evaluation of clinical image quality

Martin Christian Hemmsen, Mads Møller Petersen, Svetoslav Ivanov Nikolov, Michael Backmann Nielsen, Jørgen Arendt Jensen

Proceedings Volume 7629, 76290C (2010) https://doi.org/10.1117/12.840664

KEYWORDS: Scanners, Image quality, Ultrasonography, Data acquisition, Image quality standards, Image processing, Diagnostics, Statistical analysis, Transducers, MATLAB

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Proceedings Article | 12 March 2007 Paper

Effective and versatile software beamformation toolbox

Jacob Kortbek, Svetoslav Nikolov, Jørgen Arendt Jensen

Proceedings Volume 6513, 651319 (2007) https://doi.org/10.1117/12.702996

KEYWORDS: Apodization, Phased arrays, Transducers, Ultrasonography, MATLAB, C++, Signal processing, Image processing, Image quality, Wave propagation

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Delay-and-sum array beamforming is an essential part of signal processing in ultrasound imaging. Although the principles are simple, there are many implementation details to consider for obtaining a reliable and computational efficient beamforming. Different methods for calculation of time-delays are used for different waveforms. Various inter-sample interpolation schemes such as FIR-filtering, polynomial, and spline interpolation can be chosen. Apodization can be any preferred window function of fixed size applied on the channel signals or it can be dynamic with an expanding and contracting aperture to obtain a preferred constant F-number. An effective and versatile software toolbox for off-line beamformation designed to address all of these issues has been developed. It is capable of exploiting parallelization of computations on a Linux cluster and is written in C++ with a MATLAB(MathWorks Inc.) interface. It is an aid to support simulations and experimental investigation of 3D imaging, synthetic aperture imaging, and directional flow estimation. A number of parameters are necessary to fully define the spatial beamforming and some parameters are optional. All spatial specifications are given in 3D space such as the physical positions of the transducer elements during transmit and receive and the positions of the points to beamform. The points of focus are defined as a collection of lines each having an origin, a direction, a distance between points and a length. The transducer, the points to beamform, and the apodization are defined as individual objects and a combination of these define the actual beamforming. Once the beamforming is defined, the time-delays and apodization values for every combination of transmit elements, receive elements and focus points can be calculated and stored in lookup-tables (LUT). Parametric beamforming can also be applied where calculations are done by demand, thus, reducing the storage demand dramatically. On a standard PC with a Pentium 4, 2.66 GHz processor running Linux the toolbox can beamform 100,000 points in lines of various directions in 20 seconds using a transducer of 128 elements, dynamic apodization and 3rd order polynomial interpolation. This is a decrease in computation time of at least a factor of 15 compared to an implementation directly in MATLAB of a similar beamformer.

Proceedings Article | 16 March 2006 Paper

Recursive delay calculation unit for parametric beamformer

Svetoslav Nikolov, Jørgen Jensen, Borislav Tomov

Proceedings Volume 6147, 61470D (2006) https://doi.org/10.1117/12.653573

KEYWORDS: Phased arrays, Field programmable gate arrays, Point spread functions, Transducers, Clocks, Imaging arrays, Synthetic aperture imaging, Error analysis, Image quality, Image transmission

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Proceedings Article | 28 April 2004 Paper

A novel velocity estimator using multiple frequency carriers

Zhuo Zhang, Andreas Jakobsson, Svetoslav Nikolov, Jonathon Chambers

Proceedings Volume 5373, (2004) https://doi.org/10.1117/12.534512

KEYWORDS: Blood, Ultrasonography, Signal to noise ratio, Transducers, Doppler effect, Blood circulation, Speckle, Monte Carlo methods, Scanners, Tissues

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Proceedings Article | 11 April 2002 Paper

Virtual ultrasound sources in high-resolution ultrasound imaging

Svetoslav Nikolov, Joergen Jensen

Proceedings Volume 4687, (2002) https://doi.org/10.1117/12.462178

KEYWORDS: Transducers, Wavefronts, Point spread functions, Ultrasonography, Image resolution, Imaging arrays, Virtual reality, Spherical lenses, Signal to noise ratio, Wave propagation

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Proceedings Article | 11 April 2002 Paper

Comparison between different encoding schemes for synthetic aperture imaging

Svetoslav Nikolov, Joergen Jensen

Proceedings Volume 4687, (2002) https://doi.org/10.1117/12.462151

KEYWORDS: Computer programming, Signal to noise ratio, Ultrasonography, Image resolution, In vivo imaging, Fermium, Frequency modulation, Chemical elements, Image quality, Transducers

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Showing 5 of 10 publications

Conference Committee Involvement (11)