Pulse elongation and deconvolution filtering for medical ultrasonic imaging

Abstract

are associated with pulse compression methods Abstract --_ Range sidelobe artifacts which can be reduced with a new method composed of Pulse Elongation and Deconvolution (PED). Both approaches yield similar signal-to-noise ratio (SNR) improvements. The deconvolution is implemented as a stabilized inverse filter. The mean square error (MMSE) sense. An analytlcal excitation wave form is optimized in a minimum expression for the power spectrum of the optimal pulse is presented and several techniques t o numerically optimize the excitation pulse are shown. The effects of FED well as ultrasonic images.are demonstrated in computer simulations as

Influence of the ultrasound transducer bandwidth on selection of the complementary Golay bit code length

“…In this case deconvolving with the excitation waveform had several advantages; the excitation waveform was known because it was a part of the design and after the deconvolution with the excitation pulse, the resulted compressed echoes had similar waveform characteristics as those, which were obtained with a conventional system. The results presented in [9] demonstrated that the range resolution obtained during in vivo imaging of liver at 3 MHz was comparable to that of the conventional pulse-echo system. Similarly, in [10] the penetration depth (and hence S/N ratio) improvement in a real-time imaging system using pulse and the pseudo chirp sequence excitation was reported.…”

“…The improvement of the SNR gain in medical ultrasonic imaging was clearly demonstrated by Haider et al [9]. The gain was achieved by the elongation of the excitation pulse and employment of the deconvolution filter, which was implemented as a modified Wiener filter with the deconvolution kernel being the excitation waveform.…”

Inspection of drinks cans using non-contact electromagnetic acoustic transducers

“…Pulse compression is a technique that is used in a wide range of applications, including the ultrasonic testing of concrete (Chang & Lee, 2004) and in medical ultrasonic imaging (Haider, Lewin, & Thomenius, 1998;O'Donnell, 1992;Misaridis et al, 2000). There are many types of waveform that could be used to achieve pulse compression (Behar & Adam, 2004).…”

Barker coded excitation with linear frequency modulated carrier for ultrasonic imaging

“…However, the major problem associated with coded excitation is the range sidelobe artifacts [7][8][9][10]19]. In the Barker-13 coded excitation system, the peak sidelobe level (PSL) of matched filtered output is −22.3 dB below the mainlobe, which is not tolerated in medical ultrasound imaging.…”