Abstract
This paper presents a novel beamformer architecture for a low-cost receiver front-end, and investigates if the
image quality can be maintained. The system is oriented to the development of a hand-held wireless ultrasound
probe based on Synthetic Aperture Sequential Beamforming, and has the advantage of effectively reducing
circuit complexity and power dissipation. The array of transducers is divided into sub-apertures, in which the
signals from the single channels are aligned through a network of cascaded gradient delays, and summed in
the analog domain before A/D conversion. The delay values are quantized to simplify the shifting unit, and a
single A/D converter is needed for each sub-aperture yielding a compact, low-power architecture that can be
integrated in a single chip. A simulation study was performed using a 3.75 MHz convex array, and the point
spread function (PSF) for different configurations was evaluated in terms of lateral full-width-at-half-maximum
(FWHM) and −20 dB cystic resolution (CR). Several setups were simulated varying the sub-aperture size N and
the quantization step, and design constraints were obtained comparing the PSF to that of an ideal non-quantized
system. The PSF is shown for N = 32 with a quantization step of 12 ns. For this configuration, the FWHM is
degraded by 0.25% and the CR is 8.70% lower compared to the ideal situation. The results demonstrate that
the gradient beamformer provides an adequate image quality, and open the way to a fully-integrated chip for a
compact, low-cost, wireless ultrasound probe.
image quality can be maintained. The system is oriented to the development of a hand-held wireless ultrasound
probe based on Synthetic Aperture Sequential Beamforming, and has the advantage of effectively reducing
circuit complexity and power dissipation. The array of transducers is divided into sub-apertures, in which the
signals from the single channels are aligned through a network of cascaded gradient delays, and summed in
the analog domain before A/D conversion. The delay values are quantized to simplify the shifting unit, and a
single A/D converter is needed for each sub-aperture yielding a compact, low-power architecture that can be
integrated in a single chip. A simulation study was performed using a 3.75 MHz convex array, and the point
spread function (PSF) for different configurations was evaluated in terms of lateral full-width-at-half-maximum
(FWHM) and −20 dB cystic resolution (CR). Several setups were simulated varying the sub-aperture size N and
the quantization step, and design constraints were obtained comparing the PSF to that of an ideal non-quantized
system. The PSF is shown for N = 32 with a quantization step of 12 ns. For this configuration, the FWHM is
degraded by 0.25% and the CR is 8.70% lower compared to the ideal situation. The results demonstrate that
the gradient beamformer provides an adequate image quality, and open the way to a fully-integrated chip for a
compact, low-cost, wireless ultrasound probe.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of SPIE |
| Editors | Neb Duric, Brecht Heyde |
| Number of pages | 8 |
| Volume | 9790 |
| Publisher | SPIE - International Society for Optical Engineering |
| Publication date | 2016 |
| Article number | 979010 |
| DOIs | |
| Publication status | Published - 2016 |
| Event | SPIE Medical Imaging 2016 - Town & Country Resort and Convention Cente, San Diego, United States Duration: 27 Feb 2016 → 3 Mar 2016 https://spie.org/conferences-and-exhibitions/past-conferences-and-exhibitions/medical-imaging-2016 |
Conference
| Conference | SPIE Medical Imaging 2016 |
|---|---|
| Location | Town & Country Resort and Convention Cente |
| Country/Territory | United States |
| City | San Diego |
| Period | 27/02/2016 → 03/03/2016 |
| Internet address |
Keywords
- Analog beamformer
- Portable scanner
- Synthetic Aperture Sequential Beamforming
- Point-of-care ultrasound