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Your search keyword '"Song, Tai-kyong"' showing total 46 results
Start Over Author "Song, Tai-kyong" Publication Type Conference Materials
46 results on '"Song, Tai-kyong"'

39. New baseband pulse compression for chirp coded excitation.

Author

Yoon, Changhan, Wooyoul Lee, Jae Hee Song, Chang, Jin Ho, Song, Tai-kyong, and Yoo, Yangmo

Abstract

In ultrasound medical imaging, the signal-to-noise ratio (SNR) improvement can be achieved by utilizing the code excitation. To preserve the axial resolution, a pulse compression (PC) is performed by applying a matched filter based on the transmit code. However, the conventional PC method requires a few hundred filter coefficients when compressing elongated code (e.g., chirp) into a short pulse, yielding to considerably high computational complexity. In this paper, an efficient PC method of chirp coded excitation is proposed to lower the complexity burden. In the proposed method, the PC is conducted with the decimated complex baseband data instead of a beamformed radio-frequency (RF) data. Although compression is applied with the complex data, a total computational complexity is reduced by a factor of 4 L2 since L-fold decimation is performed to reduce both data and the number of filter coefficients. The proposed method was evaluated with the phantom study. For quantitative comparison, the −6dB axial resolution for 15 wire targets and the clutter-energy-to-total-energy ratios (CTRs) at a hypo-echoic region were measured. CTR were 27.6 dB and 27.4 dB for the conventional and proposed PC methods, respectively. These results indicate that the proposed method can maintain the performance of pulse compression of chirp coded excitation while substantially reducing computational complexity. [ABSTRACT FROM PUBLISHER]

Published
2013
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40. Image quality improvement based on inter-frame motion compensation for photoacoustic imaging: A preliminary study.

Author

Minjae Kim, Kang, Jeeun, Chang, Jin Ho, Song, Tai-Kyong, and Yoo, Yangmo

Abstract

Photoacoustic imaging (PAI) is capable of providing real-time anatomical and functional information of pathological changes. In PAI, the frame averaging (FA) technique is commonly used for enhancing signal-to-noise ratio (SNR) instead of increasing the power of a pulsed laser to avoid unwanted adverse effects. However, the FA technique suffers from motion artifacts due to the limited pulse repetition frequencies (PRFs) (e.g., 10–20 Hz) of a commonly-used Nd:Yag laser. In this paper, to improve the image quality of PAI, a new FA technique combined with inter-frame motion compensation (i.e., FA-IFMC) is proposed. The RF data acquisition was conducted with a commercial ultrasound imaging system (Ultrasonix Inc., Vancouver, BC, Canada) for the 0.9-mm diameter graphite lead-injected chicken breast. For the laser excitation, a Surelite Nd:YAG OPO system (Continuum Inc., Santa Clara, CA, USA) was used at the rate of 10 Hz and at the wavelength of 700nm with a bifurcated fiber bundle. From the phantom experiment, peak signal-to-noise ratio (PSNR) and the axial resolution were improved by 15.8 dB and 1.06 mm compared to the conventional FA method, respectively. These results indicate that the suggested FA-IFMC method can improve image quality of PAI by enhancing PSNR and axial resolution due to the lowerd blurring artifacts from motions. [ABSTRACT FROM PUBLISHER]

Published
2013
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