Acácio José Zimbico

Dr. Acácio José Zimbico

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 August 2018 in BioMedical Engineering OnLine
Verified
Journal Article
Open access
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AZAcácio José Zimbico
Acácio José Zimbico
DGDiogo Watchel Granado
Diogo Watchel Granado
FSFabio Kurt Schneider
Fabio Kurt Schneider
JMJoaquim Miguel Maia
Joaquim Miguel Maia
AAAmauri Amorin Assef
Amauri Amorin Assef
ECEduardo Tavares Costa
Eduardo Tavares Costa
The eigenspace generalized sidelobe canceller (EGSC) beamformer combined with a signal-to-noise ratio (SNR) dependent coherence factor (CF) is suggested for coherent plane wave compounding (PW) imaging. Conventional CF based methods such as generalized CF and subarray CF can improve the image quality, however, they are not suitable for low SNR. On the other hand, the EGSC CF based approach can introduce improvements in image quality, however, in PW imaging is susceptible to suffer from degradation due to low SNR which leads to a poor image quality. To overcome this limitation, the SNR dependent CF method is suggested for application in such situations due to its ability to control the SNR levels. The Field II and the Verasonics ultrasound imaging system with a L11-4v array transducer with a contrast resolution phantom were used to capture the plane wave sequences of simulation and experimental data, respectively. The performance evaluation using full width at half maximum (FWHM), contrast (CR and CNR) and the speckle statistics by using the signal to noise ratio (SNR) complemented by the Rayleigh distribution analysis was performed. In order to evaluate the performance of the $$\text {EGSC}_{3}$$ (the SNR CF) beamformer, the comparison is done with particular importance to other CF-based approaches such as $$\text {EGSC}_{1}$$ (the generalized CF) and, $$\text {EGSC}_{2}$$ (the subarray CF) respectively. Taking DAS as reference, $$\text {EGSC}_3$$ showed 30.3 and 39.5% of improvement for $$\text {CR(dB)}$$ and $$\text {CNR}$$ , respectively, when using experimental data. The proposed method also slightly outperforms the $$\text {EGSC}_1$$ and $$\text {EGSC}_2$$ methods for $$\text {CR(dB)}$$ , $$\text {CNR}$$ , and speckle statistics assessment. The $$\text {EGSC}_3$$ is, therefore, suitable for CPWC by improving the spatial resolution and contrast while preserving the speckle pattern.

28 October 2018 in Sensors
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Journal Article
Open access
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NJNivaldo Theodoro Schiefler Jr.
Nivaldo Theodoro Schiefler Jr.
JMJoaquim Miguel Maia
Joaquim Miguel Maia
FFábio Schneider
Fábio Schneider
AZAcácio José Zimbico
Acácio José Zimbico
Amauri Amorin AssefAmauri Amorin Assef
Amauri Amorin Assef
ECEduardo T. Costa
Eduardo T. Costa
Ultrasonic imaging is one of the most important techniques to help medical diagnosis. However, obtaining high quality images requires the acquisition, processing, and storage of a large amount of data. In this work, we evaluated a new ultrasound imaging technique based on plane wave and sparse arrays to increase the scan rate and reduce the amount of data amount to be stored. The performance of the proposed method was tested using simulated echo data (from Field II) and phantom data acquired using a Verasonics system equipped with a L11-4v linear array transducer. The tests were done using 128 elements for transmission and 128, 65, 44, and 23 elements sparsely distributed for reception. The simulated data were compared with images obtained with the Delay and Sum (DAS) method and the experimental data were compared with those acquired from Verasonics. The obtained results using the Full Width at Half Maximum (FWHM) criteria at −6 dB showed that the images generated by the proposed method were similar in terms of resolutions (axial and lateral) and contrast to the simulated and the Verasonics commercial ones, indicating that the sparse reception proposed method is suitable for ultrasound imaging.

21 February 2025 in Sensors
Verified
Journal Article
Open access
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LNLarissa Comar Neves
Larissa Comar Neves
FRFelipe M. Ribas
Felipe M. Ribas
JMJoaquim Miguel Maia
Joaquim Miguel Maia
AZAcácio José Zimbico
Acácio José Zimbico
Amauri Amorin AssefAmauri Amorin Assef
Amauri Amorin Assef
ECEduardo T. Costa
Eduardo T. Costa
Medical ultrasound imaging using coherent plane-wave compounding (CPWC) for higher frame-rate applications has generated considerable interest in the research community. The adaptive Eigenspace Beamformer technique combined with a Generalized Sidelobe Canceler (GSC) provides noise and interference reduction in images, improving resolution and contrast compared to basic methods: Delay and Sum (DAS) and Minimum Variance (MV). Different filtering approaches are applied in ultrasound image processing to reduce speckle signals. This work introduces the combination of beamformer Eigenspace Based on Minimum Variance (ESBMV) associated with GSC (EGSC) and the Kuan (EGSCK), Lee (EGSCL), and Wiener (EGSCW) filters and their enhanced versions to obtain better quality of plane-wave ultrasound images. The EGSCK technique did not present significant improvements compared to other methods. However, the EGSC with enhanced Kuan (EGSCKe) showed a remarkable reduction in geometric distortion, i.e., 0.13 mm (35%) and 0.49 mm (67%) compared to the EGSC and DAS techniques, respectively. The EGSC with Enhanced Wiener (EGSCWe) showed the best improvements in contrast radio (CR) aspects, i.e., 74% compared to the DAS technique and 60% to the EGSC technique. Furthermore, our proposed method reduces geometric distortion, making it a good option for plane-wave ultrasound imaging.

30 May 2018
Verified
Book Chapter
Closed access
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AZAcácio José Zimbico
Acácio José Zimbico
DGDiogo W. Granado
Diogo W. Granado
FSFabio K. Schneider
Fabio K. Schneider
JMJoaquim Miguel Maia
Joaquim Miguel Maia
AAAmauri A. Assef
Amauri A. Assef
ECEduardo T. Costa
Eduardo T. Costa