An ultrasound beamformer using oversampling

Freeman, S.R.; Quick, M.K.; Morin, Marc; Anderson, R. C.; Desilets, C.S.; Linnenbrink, Thomas E.; O’Donnell, Matthew

doi:10.1109/ultsym.1997.663335

Cited by 17 publications

(12 citation statements)

References 1 publication

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“…The focusing code Q ik is a b-bit integer that indicates the number of master clock periods which must be advanced the sampling instant for focus i at element k from a nominal value ν. The range must be greater than the minimum given by (15), and the timing errors will be kept below half a master clock period at every focus. However, in practical situations, some common minimum range is chosen for all the steering angles and elements.…”

Section: The Static Progressive Correction Focusing Techniquementioning

confidence: 99%

“…This way, information density is increased to η = b/m bits per sample. Because ν increases with m, the minimum range R 0 increases as well (15). samples decreases as R 0 increases if the maximum range is kept constant.…”

Section: Application Of the Static Approachmentioning

confidence: 99%

“…More recently, single-bit delta-sigma (∆Σ) modulators have been proposed, offering several advantages, among them the possibility of integration of the A/D converters of several channels together with the digital beamforming circuits into a single chip [15], [16]. The high oversampling rate used (on the order of 32), allows one to extract bit sequences long enough to reconstruct the instantaneous analog value at the focusing points [17].…”

Section: Introductionmentioning

confidence: 99%

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The progressive focusing correction technique for ultrasound beamforming

Fritsch¹,

Parrilla²,

Ibanez³

et al. 2006

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Abstract-This work presents a novel method for digital ultrasound beamforming based on programmable table look-ups, in which vectors containing coded focusing information are efficiently stored, achieving an information density of a fraction of bit per acquired sample. Timing errors at the foci are within half the period of a master clock of arbitrarily high frequency to improve imaging quality with low resource requirements. The technique is applicable with conventional as well as with ∆Σ converters.The bit-width of the focusing code and the number of samples per focus can be defined to improve both memory size and F# with controlled timing errors. In the static mode, the number of samples per focus is fixed, and in the dynamic approach that figure grows progressively, taking advantage of the increasing depth of focus. Furthermore, the latter has the lowest memory requirements.The technique is well suited for research purposes as well as for real-world applications, offering a degree of freedom not available with other approaches. It allows, for example, modifying the sampling instants to phase aberration correction, beamforming in layered structures, etc. The described modular and scalable prototype has been built using low-cost field programmable gate arrays (FPGAs). Experimental measurements are in good agreement with the theoretically expected errors.

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Section: The Static Progressive Correction Focusing Techniquementioning

confidence: 99%

Section: Application Of the Static Approachmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The progressive focusing correction technique for ultrasound beamforming

Fritsch¹,

Parrilla²,

Ibanez³

et al. 2006

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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“…While the published literatures [10,11] deal with specific RF frequencies, a novel structure of ultrasonic receiver is proposed based on a programmable -ADC as shown in Fig. 1(b).…”

Section: Introductionmentioning

confidence: 99%

A 1.8 V CMOS fourth-order Gm-C bandpass sigma-delta modulator dedicated to front-end ultrasonic receivers

Qin

El‐Sankary

2006

Analog Integr Circ Sig Process

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A 4th order bandpass sigma-delta modulator for ultrasound applications is presented. By cascading two second-order identical Gm-C bandpass filters, a 4th-order modulator was designed with high power-efficiency, stability, tunability and programmability. The modulator is dedicated for application with intermediate frequency of 3 MHz and bandwidth of 200 kHz. Implemented in a standard 0.18 µm CMOS technology, the post-layout simulation of the modulator gives a dynamic range of 78 dB. Chip measurements are reported after successfully tuning the modulator to operate at four-time of its folded specifications. The final SNR achieves 58 dB at 0.75 MHz with 50 kHz bandwidth. The modulator consumes 2.5 mW from 1.8 V power supply. Moreover, a programming method is introduced and corresponding circuit is designed to change the central frequency of the modulator between 3 and 20 MHz for scanning different regions of the body. However the 200 kHz bandwidth limits the modulator only for Dobbler mode applications, the effective facilities of programmability are valuable property to expand this application to other wide band applications in future.

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“…Several techniques have been proposed to handle the dynamic focusing artifact problem suffered by SDBF, and they are discussed in the following sections. [17], [24], [28]. Three methods were proposed to correct the artifacts: insert-zero, divide-by-two, and compensated sigma-delta modulator.…”

Section: Sigma-delta Receive Beamformingmentioning

confidence: 99%

Efficient sigma-delta beamforming techniques for ultrasound imaging application

Cheong¹

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A-mode Amplitude mode Apodization The amplitude windowing of electrical pulses across the aperture in order to reduce side lobe level and prevent gating lobes. B-mode Brightness mode CE-SDBF Coded Excitation Sigma-Delta BeamFormer CIC filter Cascaded Integrator-Comb filter CNR Contrast-to-Noise Ratio: The ratio of the mean value difference between scatterers and cyst to the standard deviation of the scatterers.

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An ultrasound beamformer using oversampling

Cited by 17 publications

References 1 publication

The progressive focusing correction technique for ultrasound beamforming

The progressive focusing correction technique for ultrasound beamforming

A 1.8 V CMOS fourth-order Gm-C bandpass sigma-delta modulator dedicated to front-end ultrasonic receivers

Efficient sigma-delta beamforming techniques for ultrasound imaging application

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