A method for analyzing waves in structures consisting of metal strips on dispersive media

The paper presents the theoretical and experimental study of synthetic transmit aperture (STA) method combined with Golay coded transmission for medical ultrasound imaging applications. The transmission of long waveforms characterized by a particular autocorrelation function allows to increase the total energy of the transmitted signal without increasing the peak pressure. It can also improve signalto-noise ratio and increase the visualization depth maintaining the ultrasound image resolution.In the work the 128-element linear transducer array with 0.3 mm pitch excited by the 8 and 16-bits Golay coded sequences as well as a one cycle at nominal frequencies 4 MHz were used. The comparison of 2D ultrasound images of the tissue mimicking phantoms is presented to demonstrate the benefits of coded transmission. The image reconstruction was performed using synthetic STA algorithm with transmit and receive signals correction based on a single element directivity function.

Section: Resultsmentioning

confidence: 99%

Golay Coded Sequences in Synthetic Aperture Imaging Systems

Trots¹,

Tasinkevych²,

Nowicki³

et al. 2011

“…The method developed earlier in electrostatics (Danicki, Tasinkevych, 2006;Tasinkevych, Danicki, 2005a) was adopted here. The finite baffle system was approximated by some multi-periodic structure with a certain large period and an approach similar to the one developed in our previous work (Tasinkevych, Danicki, 2010) was used to find a solution to the considered problem by means of the BIS-expansion method (Blotekja et al, 1973). The presented numerical examples show that the method yields all interesting characteristics of a linear transducer array for beamforming analysis.…”

Section: Discussionmentioning

confidence: 98%

Wave Generation by a Finite Baffle Array in Application to Beam-Forming Analysis

Tasinkevych¹

2010

Directional excitation of sound in an aperiodic finite baffle system is analyzed using a method developed earlier in electrostatics. The solution to the corresponding boundary value problem is obtained in the spatial-frequency domain. The acoustic pressure and normal particle velocity distribution in acoustic media can be easily computed by the inverse Fourier transform from their spatial spectra on the baffle plane. The presented method can be used for linear acoustic phased arrays modeling with finite element size and inter-element interactions taken into account. Some illustrative numerical examples presenting the far-field radiation pattern and wavebeam steering are given.

“…In the already developed electrostatic techniques, the Bloch components p n are expanded again using the method introduced by Blotekjoer, Ingebrigtsen, and Skeie (Blotekja et al, 1973), referred to as the BIS expansion method, into the finite series of Legendre polynomials P k (·) = P (0) k (·), which expansion, possessing crucial property to the considered boundary-value problem (Erdelyi et al, 1953):…”

Section: Application Of Electrostatic Methodsmentioning

confidence: 99%

Full-wave Analysis of Periodic Baffle System in Beamforming Applications

Tasinkevych¹,

Danicki²

2010

Mixed boundary-value problem for periodic baffles in acoustic medium is solved with help of the method developed earlier in electrostatics. The nice feature of the method is that the resulting matrices are relatively easy for computations and that the results satisfy exactly the energy conservation law. Illustrative numerical examples present the wave-beam steering (in the far-field) in a baffle system that may be considered as a model of one-dimensional ultrasonic transducer array.