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EchoeScan's
area of engineering expertise is broad-based, incorporating
elements of ultrasound physics, real-time signal and image processing,
optimal
filtering, control theory, computer modeling, circuit theory, and
electronic design.
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TRANSMIT
TECHNIQUES
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We
have particular expertise in the development of arbitrary
waveform generators (AWG) for ultrasound excitation. This
also
includes use
of inverse filtering for broadening the bandwidth of
piezoelectric transducers. EchoeScan's innovative solution for transmit beamforming makes
the
benefits of AWGs available to midrange and entry-level
machines. To
learn about the the industry's first PWM
transmit beamformer IC, click here. |
RECEIVE
PROCESSING
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| Having in-depth
knowledge in various aspects of ultrasound front-end processing, we
have
proposed unique variable-gain,
low-noise charge
preamplifier as well as several novel architectures for both BJT and CMOS LNAs.
Our expertise also includes conceptual analysis of phase-insensitive
receive beamformer and Mathcad
modeling of a piezoelectric transducer connected via coaxial
cable.
Furthermore, EchoeScan has substantial experience in signal
conditioning for single antenna
intravascular MRI. |
DOPPLER
IMAGING
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| EchoeScan
has
a wide
range of experience in ultrasound Doppler applications, including data
acquisition, beamforming, wall filtering, and Doppler
shift estimation. |
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PROJECTS
EXAMPLES
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The
projects
listed below are representative examples of work completed by
EchoeScan. These projects have been
successfully
transferred to our clients for silicon implementation.
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The
TBF embodies a complete transmit channel driven by PWM waveforms
stored in a conventional sequence memory. PWM
signals controls the transmit pulse envelope (shape) by changing the
duty cycle of the carrier. The
circuitry allows high precision (beyond sampling rate) phase rotation
of the carrier. It also provides transmit apodization. Implementing
such an IC makes the benefits of digital transmit
beamformers available to midrange and entry-level machines since
it merely requires a modified programming of the sequence memory.
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| The TGC
circuit represents a low noise binary-coded
gain amplifier having its amplification factor progressively increased
during the penetration of the transmitted pulse into a patient’s body.
This allows enhancing both the system dynamic range and SNR. |
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The DBF
is a
segment of CW Doppler receive beamformer. It is aimed to receive a
plurality of RF signals, to
convert
the RF to an IF, to provide the relative phasing of the IF outputs
across the channels, and to sum the per-channel phase-shifted
outputs. The above operations are implemented within a frequency
range where the flatband noise sources are dominate even in MOS
structures. It allows to get a sufficient SNR without a high gain LNA,
i.e., using low-voltage process technologies.
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