Bibliografie tematiche / Passive Acoustic Mapping,Passive Cavitation Imaging / Articoli di riviste

Articoli di riviste sul tema "Passive Acoustic Mapping,Passive Cavitation Imaging"

Segui questo link per vedere altri tipi di pubblicazioni sul tema: Passive Acoustic Mapping,Passive Cavitation Imaging.
Autore: Grafiati
Pubblicato: 1 giugno 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Passive Acoustic Mapping,Passive Cavitation Imaging".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.

1

Therre, Sarah, Wolfgang Bost, Holger Hewener, Steffen Tretbar e Marc Fournelle. "Passive Acoustic Mapping for ultrasound therapy monitoring". Current Directions in Biomedical Engineering 7, n. 2 (1 ottobre 2021): 437–40. http://dx.doi.org/10.1515/cdbme-2021-2111.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Abstract Passive Acoustic Mapping (PAM) is an ultrasoundbased imaging method developed for monitoring therapeutic ultrasound. By using diagnostic transducers to passively record the acoustic signals that are emitted by cavitation bubbles, the origin of the bubbles can be reconstructed and displayed as intensity maps. In this study, two matrix arrays with different aperture sizes were used for the volumetric reconstruction of simulated and experimental data. In a second step, the number of elements being used for the reconstruction was reduced by more than the factor of eight in order to assess the influence on the imaging quality. In the numerical part of the study, the image quality was greatly improved by increasing the aperture size, while a high number of elements used for the reconstruction merely offers minor improvements. The experimentally obtained results were able to confirm the numerical findings regarding the achievable reconstruction quality.
2

Wu, Qiang, Michael Gray, Cameron Smith, Luca Bau, Constantin Coussios e Eleanor P. Stride. "Correlating high-speed optical imaging and passive acoustic mapping of cavitation dynamics". Journal of the Acoustical Society of America 151, n. 4 (aprile 2022): A174. http://dx.doi.org/10.1121/10.0011017.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
The biological effects of acoustic cavitation are mediated by a range of phenomena associated with different types of bubble activity, e.g., micro-streaming, micro-jetting, and shockwave generation. The acoustic emissions generated by cavitation are also correlated to bubble dynamics. Hence, monitoring these emissions during ultrasound therapy is desirable, to maximise treatment safety and efficacy. The precise relationship between the spectral content of acoustic emissions and bubble dynamics is, however, less well understood. The aim of this study was to use simultaneous ultra-high-speed optical imaging (1–10 MHz) and passive acoustic mapping to characterise the behaviour of individual and clusters of microbubbles over a range of ultrasound exposures. As expected from the literature and numerical modelling, both the number of discrete harmonic components and amplitude of broadband content in the emissions increased with increasing amplitude of bubble oscillation. This suggests that passive acoustic mapping provides a useful indicator of spherical bubble behaviour. Frequently, however, complex bubble behaviour, such as fragmentation and coalescence was observed, which could produce substantially different effects in tissue compared with spherical bubble collapse. Future work will focus on determining whether these differences can be adequately captured in defining a future cavitation “dose” based on acoustic emissions for different applications.
3

Gray, Michael, e Kevin J. Haworth. "Advances in ultrasound imaging: Passive cavitation imaging/mapping". Journal of the Acoustical Society of America 149, n. 4 (aprile 2021): A91. http://dx.doi.org/10.1121/10.0004612.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Smith, Cameron, Luca Bau, Michael Gray e Constantin Coussios. "PAM, not spam: Towards quantitative, reproducible, and energy-preserving cavitation imaging". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A268. http://dx.doi.org/10.1121/10.0018809.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Since the development of the original passive acoustic mapping (PAM) algorithm for cavitation imaging in 2008, which employed a conventional beamformer adapted from seismology (time exposure acoustics), sequential algorithmic improvements have sought to enhance spatial resolution, reduce computation time and enable increasingly setup-independent reporting of cavitation activity. These enhancements have included the use of frequency-domain rather than time-domain implementations to improve computational efficiency, the introduction of the Robust Capon Beamformer to reduce artefacts, sub-aperture processing to further increase frame rate and the implementation of corrections for frequency-dependent attenuation and for array sensitivity and diffraction to account for probe- and depth-related variability. Once these corrections are taken into account, current PAM algorithms produce accurate estimates of cavitation source strength at a single location, but not in the surrounding region, leading to inaccurate estimates of the total cavitation energy over the treatment volume. We present an energy-preserving and computationally efficient PAM algorithm based on Lucy-Richardson deconvolution, that enables the calculation of a set-up independent Cavitational Radiated Energy Density (CRED) that ensures cavitation images accurately reflect the total energy of radiated acoustic emissions within the imaging domain.
5

Jones, Ryan M., Dallan McMahon, Lulu Deng, Meaghan O'Reilly e Kullervo Hynynen. "Passive acoustic mapping within the cranial vault during microbubble-mediated ultrasound brain therapy". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A314. http://dx.doi.org/10.1121/10.0018976.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Over the past 15 years, the use of passive sensor arrays combined with established beamforming algorithms to image acoustic activity during ultrasound therapies, so-called passive acoustic mapping (PAM), has been increasingly investigated for cavitation-based treatment monitoring and control purposes. Our group is interested in applications of microbubble-mediated ultrasound therapy in the brain, during which the skull bone presents unique challenges for both treatment delivery and acoustic emissions monitoring. We have demonstrated that skull-specific transcranial aberration correction methods can be applied during receive beamforming to augment PAM image quality through the skull bone, borrowing techniques developed originally for transmit beam focusing. Using custom clinical-prototype transmit/receive phased arrays, we have performed 3D microbubble imaging in vivo through ex vivo human skullcaps, and have exploited the resulting spatiotemporal cavitation information for real-time exposure level calibration and offline bioeffect distribution prediction. Ultrafast processing of acoustic emissions data can uncover cavitation dynamics hidden by conventional whole-burst temporal averaging, as well as inform temporal under-sampling strategies when millisecond-long tone bursts are applied. This talk will provide a historical overview of PAM for ultrasound therapy monitoring throughout the body, followed by a summary of recent progress made in mapping cavitation activity within the cranial vault during brain applications.
6

Gray, Michael, Christian Coviello, Miklos Gyongy, Erasmia Lyka, Catherine Paverd, Calum Crake, Delphine Elbes, Cameron Smith e Constantin Coussios. "Weight for it… adaptive beamformers in passive acoustic mapping for cavitation imaging". Journal of the Acoustical Society of America 148, n. 4 (ottobre 2020): 2449. http://dx.doi.org/10.1121/1.5146758.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Crake, Calum, Marie de Saint Victor, Joshua Owen, Christian Coviello, Jamie Collin, Constantin-C. Coussios e Eleanor Stride. "Passive acoustic mapping of magnetic microbubbles for cavitation enhancement and localization". Physics in Medicine and Biology 60, n. 2 (7 gennaio 2015): 785–806. http://dx.doi.org/10.1088/0031-9155/60/2/785.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
8

Li, Mucong, Daiwei Li, Yun Jing, Pei Zhong e Junjie Yao. "Real-time passive cavitation mapping with high spatial-temporal resolution". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A215—A216. http://dx.doi.org/10.1121/10.0016057.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Shock wave lithotripsy (SWL) and laser lithotripsy (LL) have been widely used for clinical treatment of kidney stones. Cavitation plays an important role in stone fragmentation in both SWL and LL, yet it may also contribute to renal tissue injury. It is therefore crucial to determine the spatiotemporal distributions of cavitation activities to maximize stone fragmentation while minimizing tissue injury. Passive cavitation mapping (PCM) has most practical applications in deep biological tissues and is most promising for clinical translation. We have developed a set of technologies for 2D/3D PCM that can be seamlessly integrated with ultrasound imaging and photoacoustic imaging. Our 2D/3D PCM has achieved a spatial resolution of hundreds of micrometers and a temporal resolution of several microseconds. We also developed a transient angular spectrum approach for PCM reconstruction, which is ten times faster than the traditional delay-and-sum method. Using the 2D/3D PCM system, we imaged shockwave- and laser-induced single cavitation bubbles in both free field and constricted space, as well as on large animal models. Collectively, our results have demonstrated the high reliability and spatial-temporal accuracy of the 2D/3D PCM approach, which paves the way for future in vivo applications and human studies during SWL and LL.
9

Yao, Junjie. "Real-time passive cavitation mapping with high spatial-temporal resolution". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A315. http://dx.doi.org/10.1121/10.0018980.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Shock wave lithotripsy (SWL) and laser lithotripsy (LL) have been widely used for clinical treatment of kidney stones. Cavitation plays an important role in stone fragmentation in both SWL and LL, yet it may also contribute to renal tissue injury. It is therefore crucial to determine the spatiotemporal distributions of cavitation activities to maximize stone fragmentation while minimizing tissue injury. Passive cavitation mapping (PCM) has most practical applications in deep biological tissues and is most promising for clinical translation. We have developed a set of technologies for 2D/3D PCM that can be seamlessly integrated with ultrasound imaging and photoacoustic imaging. Our 2D/3D PCM has achieved a spatial resolution of hundreds of micrometers and a temporal resolution of several microseconds. We also developed a transient angular spectrum approach for PCM reconstruction, which is ten times faster than the traditional delay-and-sum method. Using the 2D/3D PCM system, we imaged shockwave- and laser-induced single cavitation bubbles in both free field and constricted space, as well as on large animal models. Collectively, our results have demonstrated the high reliability and spatial-temporal accuracy of the 2D/3D PCM approach, which paves the way for future in vivo applications and human studies during SWL and LL.
10

Boulos, Paul, Franois Varray, Adrien Poizat, Alessandro Ramalli, Bruno Gilles, Jean-Christophe Bera e Christian Cachard. "Weighting the Passive Acoustic Mapping Technique With the Phase Coherence Factor for Passive Ultrasound Imaging of Ultrasound-Induced Cavitation". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 65, n. 12 (dicembre 2018): 2301–10. http://dx.doi.org/10.1109/tuffc.2018.2871983.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
11

Lu, Shukuan, Hong Hu, Xianbo Yu, Jiangying Long, Bowen Jing, Yujin Zong e Mingxi Wan. "Passive acoustic mapping of cavitation using eigenspace-based robust Capon beamformer in ultrasound therapy". Ultrasonics Sonochemistry 41 (marzo 2018): 670–79. http://dx.doi.org/10.1016/j.ultsonch.2017.10.017.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
12

Smith, Cameron A. B., e Constantin C. Coussios. "Spatiotemporal Assessment of the Cellular Safety of Cavitation-Based Therapies by Passive Acoustic Mapping". Ultrasound in Medicine & Biology 46, n. 5 (maggio 2020): 1235–43. http://dx.doi.org/10.1016/j.ultrasmedbio.2020.01.009.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
13

Song, Minho, Oleg A. Sapozhnikov, Yak-Nam Wang, Joo Ha Hwang e Tatiana D. Khokhlova. "Passive and Doppler-based assessment of cavitation activity induced by pulsed focused ultrasound". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A249—A250. http://dx.doi.org/10.1121/10.0016171.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Pulsed focused ultrasound (pFUS) exposures utilizing short, nonlinearly distorted pulses at low duty cycle have been shown to enhance drug and gene delivery to targeted tissue through inertial cavitation activity. Passive cavitation detection (PCD) and mapping of broadband emissions are current conventional methods to monitor and quantify cavitation but provide limited spatial resolution. Here, plane-wave Doppler imaging was used with PCD to quantify pFUS-induced cavitation in ex vivo bovine tissues and in vivo surgically exposed porcine liver, kidney, and pancreas. A 1.5 MHz FUS transducer (aperture 75 mm, F-number 0.75) was used to deliver 60 pulses (duration 1 ms, 0.1% duty cycle, focal pressure p+ = 70i–110 MPa, p− = 13–20 MPa). A coaxially mounted ATL P7-4 ultrasound imaging probe was used for PCD during the FUS pulse, and Doppler and B-mode sequences. Disrupted tissue areas were collected for histology and compared to Doppler power images. Maximum Doppler power was found to correlate to broadband noise level for each FUS pulse. The Doppler power map integrated over the exposure was observed to correlate spatially with tissue disruption area from histology, which thus represents a promising real-time metric for quantifying cavitation activity induced by pFUS exposures. [Work supported by NIH R01CA154451, R01EB025187, and R01EB23910.]
14

Lu, Shukuan, Aiwei Shi, Bowen Jing, Xuan Du e Mingxi Wan. "Real-time monitoring of controllable cavitation erosion in a vessel phantom with passive acoustic mapping". Ultrasonics Sonochemistry 39 (novembre 2017): 291–300. http://dx.doi.org/10.1016/j.ultsonch.2017.03.060.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
15

Coviello, Christian, James Kwan, Susan Graham, Rachel Myers, Apurva Shah, Penny Probert Smith, Robert Carlisle e Constantin Coussios. "Instigation and monitoring of inertial cavitation from nanoscale particles using a diagnostic imaging platform and passive acoustic mapping". Journal of the Acoustical Society of America 136, n. 4 (ottobre 2014): 2302. http://dx.doi.org/10.1121/1.4900329.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
16

Dunn-Lawless, Darcy, Joel Balkaran, Brian Lyons, Robert Carlisle, Constantin Coussios e Michael Gray. "Investigation of spatio-temporal inertial cavitation activity for optimization of needle-free ultrasound-enhanced vaccine delivery". Journal of the Acoustical Society of America 154, n. 4_supplement (1 ottobre 2023): A24. http://dx.doi.org/10.1121/10.0022670.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Ultrasound-induced cavitation is a promising mechanism for pain-free delivery of vaccines without needles. However, the relationships between cavitation energy and the various bioeffects involved in transdermal vaccination, including skin permeabilization, convective drug transport, reversible and irreversible sonoporation, and immune-stimulation, are not well understood. Previous transdermal ultrasound experiments have demonstrated inhomogeneous delivery across the exposed surface, which remains poorly understood. In this work, we first seek to fully characterize and quantify spatio-temporal cavitation activity across the skin surface, to identify a local cavitation dose that is optimal for all four key bioeffects. We have designed a new in vitro experimental setup that exposes several potential skin models to 265 kHz focused ultrasound, a new generation of protein-based cavitation nuclei (pCaNs), and a fluorescently labelled vaccine analogue, while simultaneously imaging cavitation activity parallel to the skin surface by Passive Acoustic Mapping (PAM). Subsequent staining and multi-photon microscopy of the skin models allows a direct comparison between the PAM-derived spatiotemporal inertial cavitation dose and locations where particular bioeffects were maximized. We will discuss the results of this investigation, how they relate to our recent in vivo study, and whether these findings enable enhancements of the spatial homogeneity and reproducibility of needle-free ultrasound vaccination.
17

Sharahi, Hossein J., Christopher N. Acconcia, Matthew Li, Anne Martel e Kullervo Hynynen. "A Convolutional Neural Network for Beamforming and Image Reconstruction in Passive Cavitation Imaging". Sensors 23, n. 21 (27 ottobre 2023): 8760. http://dx.doi.org/10.3390/s23218760.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Convolutional neural networks (CNNs), initially developed for image processing applications, have recently received significant attention within the field of medical ultrasound imaging. In this study, passive cavitation imaging/mapping (PCI/PAM), which is used to map cavitation sources based on the correlation of signals across an array of receivers, is evaluated. Traditional reconstruction techniques in PCI, such as delay-and-sum, yield high spatial resolution at the cost of a substantial computational time. This results from the resource-intensive process of determining sensor weights for individual pixels in these methodologies. Consequently, the use of conventional algorithms for image reconstruction does not meet the speed requirements that are essential for real-time monitoring. Here, we show that a three-dimensional (3D) convolutional network can learn the image reconstruction algorithm for a 16×16 element matrix probe with a receive frequency ranging from 256 kHz up to 1.0 MHz. The network was trained and evaluated using simulated data representing point sources, resulting in the successful reconstruction of volumetric images with high sensitivity, especially for single isolated sources (100% in the test set). As the number of simultaneous sources increased, the network’s ability to detect weaker intensity sources diminished, although it always correctly identified the main lobe. Notably, however, network inference was remarkably fast, completing the task in approximately 178 s for a dataset comprising 650 frames of 413 volume images with signal duration of 20μs. This processing speed is roughly thirty times faster than a parallelized implementation of the traditional time exposure acoustics algorithm on the same GPU device. This would open a new door for PCI application in the real-time monitoring of ultrasound ablation.
18

Lu, Shukuan, Xianbo Yu, Renyan Li, Yujin Zong e Mingxi Wan. "Passive cavitation mapping using dual apodization with cross-correlation in ultrasound therapy monitoring". Ultrasonics Sonochemistry 54 (giugno 2019): 18–31. http://dx.doi.org/10.1016/j.ultsonch.2019.02.020.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
19

Crake, Calum, Seán Finn, Laurent Marsac, Michael Gray, Robert Carlisle, Constantin Coussios e Christian Coviello. "Passive acoustic mapping and B-mode ultrasound imaging utilizing compressed sensing for real-time monitoring of cavitation-enhanced drug delivery". Journal of the Acoustical Society of America 143, n. 3 (marzo 2018): 1872. http://dx.doi.org/10.1121/1.5036143.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
20

Crake, Calum, Iason T. Papademetriou, Yongzhi Zhang, Natalia Vykhodtseva, Nathan J. McDannold e Tyrone M. Porter. "Simultaneous Passive Acoustic Mapping and Magnetic Resonance Thermometry for Monitoring of Cavitation-Enhanced Tumor Ablation in Rabbits Using Focused Ultrasound and Phase-Shift Nanoemulsions". Ultrasound in Medicine & Biology 44, n. 12 (dicembre 2018): 2609–24. http://dx.doi.org/10.1016/j.ultrasmedbio.2018.07.023.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
21

Shoar, Kya, Erasmia Lyka, Constantin Coussios e Robin Cleveland. "Passive acoustic mapping of cavitation during shock wave lithotripsy". Journal of the Acoustical Society of America 141, n. 5 (maggio 2017): 3673. http://dx.doi.org/10.1121/1.4987970.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
22

Keller, Sara, Gareth LuTheryn, Michael Gray, Eleanor P. Stride, Robin O. Cleveland e Constantin Coussios. "Spatio-temporal evaluation of anti-biofilm cavitation activity by passive acoustic mapping". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A247—A248. http://dx.doi.org/10.1121/10.0016162.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Bacterial biofilms present a major challenge to achieving effective antibiotic therapy, as these sessile communities of microbes confer protection to bacteria by decreasing antibiotic efficacy. Focused ultrasound can mechanically disrupt biofilms, offering a new ‘drug-free’ antibiotic paradigm. The goal of this work is to validate, quantify, and optimize the role of acoustic cavitation in the biofilm disruption process through spatiotemporal monitoring of cavitation activity. A clinical isolate strain of Staphylococcus aureus from native valve endocarditis was cultured for 72 hours within a flow channel to form a biofilm. A 1.1 MHz spherically focused transducer was used to expose the biofilm from below at a 45° angle. The in situ acoustic field was characterized with a fibre-optic hydrophone. A calibrated 5–11 MHz linear array was placed 25 mm above the biofilm in order to record acoustic emissions during biofilm disruption from which passive acoustic maps of cavitation could be derived. Biofilms were exposed to 4.5 MPa peak rarefactional pressure (derated), 10,000 cycles, at a 1 Hz PRF. Qualitative reduction of biofilms was assessed by live/dead staining with Syto 9/propidium iodide, which was correlated with cavitation activity observed in the passive acoustic maps.
23

Coviello, Christian, James Choi, Jamie Collin, Robert Carlisle, Miklos Gyongy e Constantin C. Coussios. "Passive acoustic mapping of stable and inertial cavitation during ultrasound therapy". Journal of the Acoustical Society of America 136, n. 4 (ottobre 2014): 2300. http://dx.doi.org/10.1121/1.4900321.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
24

Elliott, Jacob, Eric Rokni, Paul Trzcinski, Michael Krane, Jeff Harris e Julianna Simon. "Acoustic cavitation detection in biomedical and underwater systems". Journal of the Acoustical Society of America 154, n. 4_supplement (1 ottobre 2023): A192. http://dx.doi.org/10.1121/10.0023234.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
In the past decade, significant progress has been made in detecting and localizing cavitation for treatment monitoring in biomedical acoustics. Here, we compare passive cavitation imaging (PCI) and passive cavitation detection (PCD) during histotripsy in tissue-mimicking polyacrylamide (PA) hydrogels; PCI and bubble Doppler ultrasound are also used to evaluate flow-induced cavitation in a water tunnel. A Philips/ATL L7-4 transducer driven with a research ultrasound system was used for both PCI and Doppler imaging; a Sonic Concepts Y-107 transducer was used for PCD. PA hydrogels were treated with 1.5 MHz focused ultrasound (10-ms pulses with p + = 127 MPa/p− = 35 MPa repeated at 1-Hz for 60 s). In the 12-in. water tunnel, cavitation on a 1-in. diameter steel cylinder was imaged through a 0.5-inch-thick acrylic window while flow increased from 30–35 ft/s. High-speed cameras were also used in both experiments. In PA hydrogels, cavitation was observed with both PCI and PCD, although signal trends differed over the treatment. In the water tunnel, both PCI and Doppler ultrasound detected and localized cavitation events such as the horseshoe vortex, with measured amplitudes increasing with flow speed. These results show that cavitation imaging can be applied to multiple areas of acoustics. [Tissue work supported by NIHR01EB032860].
25

Jing, Yun, Mucong Li, Juanjuan Gu, Pei Zhong e Junjie Yao. "Time-resolved passive cavitation mapping using the transient angular spectrum approach". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A268. http://dx.doi.org/10.1121/10.0018806.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Passive cavitation mapping (PCM), which generates images using bubble acoustic emission signals, has been increasingly used for monitoring and guiding focused ultrasound surgery. This study investigates a transient angular spectrum (AS) approach for PCM. The working principle of this approach is to backpropagate the received signal to the domain of interest and reconstruct the spatial–temporal wavefield encoded with the bubble location and collapse time. The transient AS approach is validated using an in silico model, water bath, and in vivo experiments. It is found that the transient AS approach yields similar results to delay and sum, but is considerably faster. The results obtained by this study suggest that the transient AS approach is promising for fast and accurate PCM.
26

Farbin, Grace, Andrew Frizado e Meaghan O'Reilly. "An ex vivo experimental demonstration of passive acoustic mapping through the human spinal column". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A249. http://dx.doi.org/10.1121/10.0016170.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
The delivery of drugs to the central nervous system is grossly limited by the presence of the blood-brain and blood-spinal cord barriers. These barriers can be transiently permeabilized using low-intensity focused ultrasound combined with circulating microbubbles. The spectral content of acoustic emissions from cavitating microbubbles can be analyzed to control for and mitigate potential bioeffects. However, there is a large degree of uncertainty as to where these cavitation signals are originating. Passive beamforming of microbubble emissions recorded using multi-element arrays can enable spatial mapping of cavitation activity. Passive acoustic mapping (PAM) is challenging to implement in the presence of an intervening bone layer but has been successfully demonstrated through the skull. Here we present the first experimental demonstration of PAM through human vertebral bone. A tube containing flowing microbubbles was placed in the canal of ex vivo human thoracic vertebrae (stack of 3 vertebrae) and excited (250 kHz) through the right laminae. A 64-element large aperture 2D array was used to receive the harmonic emissions through the left laminae. Reconstructed maps successfully localized the cavitation activity to the spinal canal. Future work will examine effects of phase/amplitude correction, receiver number, and location of the cavitation relative to the vertebral anatomy.
27

Patel, Arpit, Scott J. Schoen e Costas D. Arvanitis. "Closed-Loop Spatial and Temporal Control of Cavitation Activity With Passive Acoustic Mapping". IEEE Transactions on Biomedical Engineering 66, n. 7 (luglio 2019): 2022–31. http://dx.doi.org/10.1109/tbme.2018.2882337.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
28

Konofagou, Elisa. "Real-time transcranial mapping in non-human primates and human subjects during opening of the blood-brain barrier". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A314. http://dx.doi.org/10.1121/10.0018977.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Opening of the blood-brain barrier (BBB) with focused ultrasound and microbubbles has been shown repeatedly in several preclinical disease models and clinical studies. Transcranial 2D mapping of the cavitation mechanism responsible for BBB opening is however challenging in primate brains due to the skull thickness. A real-time cavitation mapping system will be presented that can transcranially map the cavitation occurrence and dose in real time throughout the BBB opening procedure in Alzheimer’s disease (AD) adult and diffuse intrinsic pontine glioma (DIPG) pediatric patients. Passive acoustic mapping (PAM) with coherence factor (CF) correction is used to passively map the microbubble activity within the brain. Compared to passive cavitation detection (PCD), multi-element CF-PAM allows us to determine the exact location of the BBB opening without the need of contrast-enhanced MRI. An open-architecture ultrasound imager (Vantage, Verasonics, Redmond, WA) with a P4-2 (ATL, Philips) is used to provide the best tradeoff between transcranial propagation, spatial resolution and depth penetration. The system is first optimized in targeting the putamen during BBB opening in non-human primates followed by feasibility in the prefrontal cortex in AD and the pons in DIPG patients, achieving feedback rates of 2 Hz during the clinical procedures.
29

Bae, Sua, Antonios Pouliopoulos, Robin Ji, Keyu Liu, Sergio Jiménez-Gambín, Omid Yousefian, Danae Kokossis, Lawrence Honig e Elisa Konofagou. "Transcranial cavitation mapping of blood–brain barrier opening regions in Alzheimer’s disease patients using a neuronavigation-guided focused ultrasound system". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A315. http://dx.doi.org/10.1121/10.0018978.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
We present real-time cavitation monitoring and mapping in a clinical trial for blood-brain barrier (BBB) opening in Alzheimer’s disease (AD) patients using a neuronavigation-guided focused ultrasound (FUS) system. Six AD patients (N = 6, age = 68.5 ± 9.5) were sonicated at the right prefrontal lobe with a single-element FUS transducer (PNP = 0.2 MPa, fc = 0.25 MHz, pulse length = 10 ms, PRF = 2 Hz, duration = 2 min) with the microbubble administration (Definity). We performed passive cavitation detection (PCD) using a single-element hydrophone (N = 4), and passive acoustic mapping (PAM) with a 64-element phased array transducer (N = 2). Five patients showed successful BBB opening (volume = 654 ± 394 mm3) on day0, and closure on day3, confirmed by contrast-enhanced T1-weighted MRI, while one patient served as a negative BBB opening case due to the insufficient microbubble administration. Ultra-harmonic cavitation dose (CD) correlated with the opening volume (R2 = 0.66, N = 4), but harmonic and broadband CDs showed a relatively poor correlation (R2 = 0.06 and 0.33). Cavitation maps (N = 2) showed a spatial distribution of acoustic energy that roughly coincided with the respective BBB opening location. We thus demonstrated the successful BBB opening and cavitation monitoring with the neuronavigation-guided system that allowed for a cost-effective procedure compared to the MR-guided approaches. The PCD and PAM showed promising results for potentially predicting the BBB opening volume and location found in MRI.
30

Therre, Sarah, Marc Fournelle e Steffen Tretbar. "Optimization of 3D Passive Acoustic Mapping Image Metrics: Impact of Sensor Geometry and Beamforming Approach". Sensors 24, n. 6 (14 marzo 2024): 1868. http://dx.doi.org/10.3390/s24061868.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Three-dimensional passive acoustic mapping (PAM) with matrix arrays typically suffers from high demands on the receiving electronics and high computational load. In our study, we investigated, both numerically and experimentally, the influence of matrix array aperture size, element count, and beamforming approaches on defined image metrics. With a numerical Vokurka model, matrix array acquisitions of cavitation signals were simulated. In the experimental part, two 32 × 32 matrix arrays with different pitches and aperture sizes were used. After being reconstructed into 3D cavitation maps, defined metrics were calculated for a quantitative comparison of experimental and numerical data. The numerical results showed that the enlargement of the aperture from 5 to 40 mm resulted in an improvement of the full width at half maximum (FWHM) by factors of 6 and 13 (in lateral and axial dimension, respectively). A larger array sparsity influenced the point spread function (PSF) only slightly, while the grating lobe level (GLL) remained more than 12 dB below the main lobe. These results were successfully experimentally confirmed. To further reduce the GLL caused by array sparsity, we adapted a non-linear filter from optoacoustics for use in PAM. In combination with the delay, multiply, sum, and integrate (DMSAI) algorithm, the GLL was decreased by 20 dB for 64-element reconstructions, resulting in levels that were identical to the fully populated matrix reconstruction levels.
31

Smith, Cameron, e Constantin Coussios. "Defining a nuclei-independent unified cavitation dose for the spatiotemporal quantification of cavitation-mediated bioeffects by passive acoustic mapping". Journal of the Acoustical Society of America 146, n. 4 (ottobre 2019): 2991. http://dx.doi.org/10.1121/1.5137353.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
32

Grundy, Megan, Luca Bau, Claudia Hill, Catherine Paverd, Christophoros Mannaris, James Kwan, Calum Crake, Christian Coviello, Constantin Coussios e Robert Carlisle. "Improved therapeutic antibody delivery to xenograft tumors using cavitation nucleated by gas-entrapping nanoparticles". Nanomedicine 16, n. 1 (gennaio 2021): 37–50. http://dx.doi.org/10.2217/nnm-2020-0263.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Aims: Testing ultrasound-mediated cavitation for enhanced delivery of the therapeutic antibody cetuximab to tumors in a mouse model. Methods: Tumors with strong EGF receptor expression were grown bilaterally. Cetuximab was coadministered intravenously with cavitation nuclei, consisting of either the ultrasound contrast agent Sonovue or gas-stabilizing nanoscale SonoTran Particles. One of the two tumors was exposed to focused ultrasound. Passive acoustic mapping localized and monitored cavitation activity. Both tumors were then excised and cetuximab concentration was quantified. Results: Cavitation increased tumoral cetuximab concentration. When nucleated by Sonovue, a 2.1-fold increase (95% CI 1.3- to 3.4-fold) was measured, whereas SonoTran Particles gave a 3.6-fold increase (95% CI 2.3- to 5.8-fold). Conclusions: Ultrasound-mediated cavitation, especially when nucleated by nanoscale gas-entrapping particles, can noninvasively increase site-specific delivery of therapeutic antibodies to solid tumors.
33

Xu, Zhiyuan, Carissa Carlson, John Snell, Matt Eames, Arik Hananel, M. Beatriz Lopes, Prashant Raghavan et al. "Intracranial inertial cavitation threshold and thermal ablation lesion creation using MRI-guided 220-kHz focused ultrasound surgery: preclinical investigation". Journal of Neurosurgery 122, n. 1 (gennaio 2015): 152–61. http://dx.doi.org/10.3171/2014.9.jns14541.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
OBJECT In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. METHODS Ten female piglets that had undergone a craniectomy were sonicated using a 220-kHz transcranial MRgFUS system over an acoustic energy range of 5600–14,000 J. For each piglet, a long-duration sonication (40-second duration) was performed on the right thalamus, and a short sonication (20-second duration) was performed on the left thalamus. An acoustic power range of 140–300 W was used for long-duration sonications and 300–700 W for short-duration sonications. Signals collected by 2 passive cavitation detectors were stored in memory during each sonication, and any subsequent cavitation activity was integrated within the bandwidth of the detectors. Real-time 2D MR thermometry was performed during the sonications. T1-weighted, T2-weighted, gradient-recalled echo, and diffusion-weighted imaging MRI was performed after treatment to assess the lesions. The piglets were killed immediately after the last series of posttreatment MR images were obtained. Their brains were harvested, and histological examinations were then performed to further evaluate the lesions. RESULTS Two types of lesions were induced: thermal ablation lesions, as evidenced by an acute ischemic infarction on MRI and histology, and hemorrhagic lesions, associated with inertial cavitation. Passive cavitation signals exhibited 3 main patterns identified as follows: no cavitation, stable cavitation, and inertial cavitation. Low-power and longer sonications induced only thermal lesions, with a peak temperature threshold for lesioning of 53°C. Hemorrhagic lesions occurred only with high-power and shorter sonications. The sizes of the hemorrhages measured on macroscopic histological examinations correlated with the intensity of the cavitation activity (R2 = 0.74). The acoustic cavitation activity detected by the passive cavitation detectors exhibited a threshold of 0.09 V·Hz for the occurrence of hemorrhages. CONCLUSIONS This work demonstrates that 220-kHz ultrasound is capable of inducing a thermal lesion in the brain of living swines without hemorrhage. Although the same acoustic energy can induce either a hemorrhage or a thermal lesion, it seems that low-power, long-duration sonication is less likely to cause hemorrhage and may be safer. Although further study is needed to decrease the likelihood of ischemic infarction associated with the 220-kHz ultrasound, the threshold established in this work may allow for the detection and prevention of deleterious cavitations.
34

Frizado, Andrew, Grace Farbin e Meaghan O'Reilly. "Monitoring cavitation activity through bone: Passive acoustic mapping for monitoring ultrasound therapy in the central nervous system". Journal of the Acoustical Society of America 152, n. 4 (ottobre 2022): A244. http://dx.doi.org/10.1121/10.0016150.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
The blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) are major impediments to the pharmacological treatment of central nervous system disorders. Focused ultrasound in combination with intravenously administered microbubbles can transiently increase the permeability of the BBB and BSCB to enable passage of therapeutics from the blood pool to the brain and spinal cord tissues. Safely controlling these treatments relies on information such as the cavitation state (i.e., stable vs. inertial), and location. Passive acoustic mapping (PAM) is a beamforming approach that does not require absolute time of flight knowledge and is therefore well suited for monitoring ultrasound therapy where therapy pulses are long, ranging from several cycles to milliseconds in length. PAM applied with large receiver arrays can enable three-dimensional monitoring of cavitation activity through the bone for non-invasive treatment monitoring. This talk will discuss the application of PAM in brain and spinal cord and the challenges posed by the skull and vertebral bony geometry, with a focus on recent in silico and experimental work in transvertebral PAM.
35

Kim, Pilsu, Sua Bae, Jae Hee Song e Tai-kyong Song. "Comparison study of passive acoustic mapping and high-speed photography for monitoring in situ cavitation bubbles". Journal of the Acoustical Society of America 145, n. 6 (giugno 2019): EL604—EL610. http://dx.doi.org/10.1121/1.5113961.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
36

Crake, Calum, Paul Boulos, Maura Power, Edward Ellis, Florian Monnier, Alessandro Polcaro, Richard Kozick e Christian Coviello. "Passive acoustic mapping utilizing compressed-domain processing for real-time monitoring of cavitation-enhanced drug delivery". Journal of the Acoustical Society of America 148, n. 4 (ottobre 2020): 2449. http://dx.doi.org/10.1121/1.5146759.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
37

Frizado, Andrew Paul, e Meaghan Anne O'Reilly. "A numerical investigation of passive acoustic mapping for monitoring bubble-mediated focused ultrasound treatment of the spinal cord". Journal of the Acoustical Society of America 153, n. 4 (aprile 2023): 2271–84. http://dx.doi.org/10.1121/10.0017836.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Focused ultrasound (FUS) combined with intravenous microbubbles (MBs) has been shown to increase drug delivery to the spinal cord in animal models. Eventual clinical translation of such a technique in the sensitive spinal cord requires robust treatment monitoring to ensure efficacy, localization, safety, and provide key intraprocedural feedback. Here, the use of passive acoustic mapping (PAM) of MB emissions with a spine-specific detector array in the context of transvertebral FUS sonications is investigated in silico. Using computed tomography-derived human vertebral geometry, transvertebral detection of MBs is evaluated over varying source locations with and without phase and amplitude corrections (PACs). The impact of prefocal cavitation is studied by simulating concurrent cavitation events in the canal and pre-laminar region. Spatially sensitive application of phase and amplitude is used to balance signal strengths emanating from different axial depths in combination with multiple dynamic ranges to elicit multisource viewing. Collectively, the results of this study encourage the use of PAM in transvertebral FUS applications with PACs to not only localize sources originating in the spinal canal but also multiple sources of innate amplitude mismatches when corrective methods are applied.
38

Crake, Calum, Robert Carlisle, Joshua Owen, Sean Smart, Christian Coviello, Constantin Coussios e Eleanor P. Stride. "In vivo biodistribution of fluorescently tagged magnetic microbubbles for cavitation enhancement with real time passive acoustic mapping". Journal of the Acoustical Society of America 138, n. 3 (settembre 2015): 1845. http://dx.doi.org/10.1121/1.4933870.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
39

Crake, Calum, Joshua Owen, Sean Smart, Christian Coviello, Constantin-C. Coussios, Robert Carlisle e Eleanor Stride. "Enhancement and Passive Acoustic Mapping of Cavitation from Fluorescently Tagged Magnetic Resonance-Visible Magnetic Microbubbles In Vivo". Ultrasound in Medicine & Biology 42, n. 12 (dicembre 2016): 3022–36. http://dx.doi.org/10.1016/j.ultrasmedbio.2016.08.002.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
40

Lu, Shukuan, Renyan Li, Xianbo Yu, Diya Wang e Mingxi Wan. "Delay multiply and sum beamforming method applied to enhance linear‐array passive acoustic mapping of ultrasound cavitation". Medical Physics 46, n. 10 (10 agosto 2019): 4441–54. http://dx.doi.org/10.1002/mp.13714.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
41

Lin, Yi, Meaghan A. O’Reilly e Kullervo Hynynen. "A PVDF Receiver for Acoustic Monitoring of Microbubble-Mediated Ultrasound Brain Therapy". Sensors 23, n. 3 (26 gennaio 2023): 1369. http://dx.doi.org/10.3390/s23031369.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
The real-time monitoring of spectral characteristics of microbubble (MB) acoustic emissions permits the prediction of increases in blood–brain barrier (BBB) permeability and of tissue damage in MB-mediated focused ultrasound (FUS) brain therapy. Single-element passive cavitation detectors provide limited spatial information regarding MB activity, greatly affecting the performance of acoustic control. However, an array of receivers can be used to spatially map cavitation events and thus improve treatment control. The spectral content of the acoustic emissions provides additional information that can be correlated with the bio-effects, and wideband receivers can thus provide the most complete spectral information. Here, we develop a miniature polyvinylidene fluoride (PVDF thickness = 110 μm, active area = 1.2 mm2) broadband receiver for the acoustic monitoring of MBs. The receiver has superior sensitivity (2.36–3.87 V/MPa) to those of a commercial fibre-optic hydrophone in the low megahertz frequency range (0.51–5.4 MHz). The receiver also has a wide −6 dB acceptance angle (54 degrees at 1.1 MHz and 13 degrees at 5.4 MHz) and the ability to detect subharmonic and higher harmonic MB emissions in phantoms. The overall acoustic performance of this low-cost receiver indicates its suitability for the eventual use within an array for MB monitoring and mapping in preclinical studies.
42

Choi, James J., Robert C. Carlisle, Christian Coviello, Len Seymour e Constantin-C. Coussios. "Non-invasive and real-time passive acoustic mapping of ultrasound-mediated drug delivery". Physics in Medicine and Biology 59, n. 17 (7 agosto 2014): 4861–77. http://dx.doi.org/10.1088/0031-9155/59/17/4861.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
43

Gray, Michael D., e Constantin C. Coussios. "Compensation of array lens effects for improved co-registration of passive acoustic mapping and B-mode images for cavitation monitoring". Journal of the Acoustical Society of America 146, n. 1 (luglio 2019): EL78—EL84. http://dx.doi.org/10.1121/1.5118238.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
44

Coviello, Christian, Rachel Myers, Edward Jackson, Erasmia Lyka, Lauren Morris, Cliff Rowe, James J. Kwan, Robert Carlisle e Constantin Coussios. "Cavitation enhanced drug delivery in-vivo using combined B-mode guidance and real-time passive acoustic mapping: Challenges and results". Journal of the Acoustical Society of America 141, n. 5 (maggio 2017): 3491. http://dx.doi.org/10.1121/1.4987286.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
45

Jones, Ryan M., Meaghan A. O’Reilly e Kullervo Hynynen. "Transcranial passive acoustic mapping with hemispherical sparse arrays using CT-based skull-specific aberration corrections: a simulation study". Physics in Medicine and Biology 58, n. 14 (27 giugno 2013): 4981–5005. http://dx.doi.org/10.1088/0031-9155/58/14/4981.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
46

Jensen, C. R., R. O. Cleveland e C. C. Coussios. "Real-time temperature estimation and monitoring of HIFU ablation through a combined modeling and passive acoustic mapping approach". Physics in Medicine and Biology 58, n. 17 (6 agosto 2013): 5833–50. http://dx.doi.org/10.1088/0031-9155/58/17/5833.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
47

Xiang, Gaoming, Daiwei Li, Junqin Chen, Arpit Mishra, Georgy Sankin, Xuning Zhao, Yuqi Tang, Kevin Wang, Junjie Yao e Pei Zhong. "Dissimilar cavitation dynamics and damage patterns produced by parallel fiber alignment to the stone surface in holmium:yttrium aluminum garnet laser lithotripsy". Physics of Fluids 35, n. 3 (marzo 2023): 033303. http://dx.doi.org/10.1063/5.0139741.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Recent studies indicate that cavitation may play a vital role in laser lithotripsy. However, the underlying bubble dynamics and associated damage mechanisms are largely unknown. In this study, we use ultra-high-speed shadowgraph imaging, hydrophone measurements, three-dimensional passive cavitation mapping (3D-PCM), and phantom test to investigate the transient dynamics of vapor bubbles induced by a holmium:yttrium aluminum garnet laser and their correlation with solid damage. We vary the standoff distance ( SD) between the fiber tip and solid boundary under parallel fiber alignment and observe several distinctive features in bubble dynamics. First, long pulsed laser irradiation and solid boundary interaction create an elongated “pear-shaped” bubble that collapses asymmetrically and forms multiple jets in sequence. Second, unlike nanosecond laser-induced cavitation bubbles, jet impact on solid boundary generates negligible pressure transients and causes no direct damage. A non-circular toroidal bubble forms, particularly following the primary and secondary bubble collapses at SD = 1.0 and 3.0 mm, respectively. We observe three intensified bubble collapses with strong shock wave emissions: the intensified bubble collapse by shock wave, the ensuing reflected shock wave from the solid boundary, and self-intensified collapse of an inverted “triangle-shaped” or “horseshoe-shaped” bubble. Third, high-speed shadowgraph imaging and 3D-PCM confirm that the shock origins from the distinctive bubble collapse form either two discrete spots or a “smiling-face” shape. The spatial collapse pattern is consistent with the similar BegoStone surface damage, suggesting that the shockwave emissions during the intensified asymmetric collapse of the pear-shaped bubble are decisive for the solid damage.
48

Guyot, Alexandre, Marc Lennon, Nicolas Thomas, Simon Gueguen, Tristan Petit, Thierry Lorho, Serge Cassen e Laurence Hubert-Moy. "Airborne Hyperspectral Imaging for Submerged Archaeological Mapping in Shallow Water Environments". Remote Sensing 11, n. 19 (25 settembre 2019): 2237. http://dx.doi.org/10.3390/rs11192237.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
Nearshore areas around the world contain a wide variety of archeological structures, including prehistoric remains submerged by sea level rise during the Holocene glacial retreat. While natural processes, such as erosion, rising sea level, and exceptional climatic events have always threatened the integrity of this submerged cultural heritage, the importance of protecting them is becoming increasingly critical with the expanding effects of global climate change and human activities. Aerial archaeology, as a non-invasive technique, contributes greatly to documentation of archaeological remains. In an underwater context, the difficulty of crossing the water column to reach the bottom and its potential archaeological information usually requires active remote-sensing technologies such as airborne LiDAR bathymetry or ship-borne acoustic soundings. More recently, airborne hyperspectral passive sensors have shown potential for accessing water-bottom information in shallow water environments. While hyperspectral imagery has been assessed in terrestrial continental archaeological contexts, this study brings new perspectives for documenting submerged archaeological structures using airborne hyperspectral remote sensing. Airborne hyperspectral data were recorded in the Visible Near Infra-Red (VNIR) spectral range (400–1000 nm) over the submerged megalithic site of Er Lannic (Morbihan, France). The method used to process these data included (i) visualization of submerged anomalous features using a minimum noise fraction transform, (ii) automatic detection of these features using Isolation Forest and the Reed–Xiaoli detector and (iii) morphological and spectral analysis of archaeological structures from water-depth and water-bottom reflectance derived from the inversion of a radiative transfer model of the water column. The results, compared to archaeological reference data collected from in-situ archaeological surveys, showed for the first time the potential of airborne hyperspectral imagery for archaeological mapping in complex shallow water environments.
49

Febriawan, H. K., P. Helmholz e I. M. Parnum. "SUPPORT VECTOR MACHINE AND DECISION TREE BASED CLASSIFICATION OF SIDE-SCAN SONAR MOSAICS USING TEXTURAL FEATURES". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (4 giugno 2019): 27–34. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-27-2019.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
Abstract (sommario):
<p><strong>Abstract.</strong> The diversity and heterogeneity of coastal, estuarine and stream habitats has led to them becoming a prevalent topic for study. Woody ruins are areas of potential riverbed habitat, particularly for fish. Therefore, the mapping of those areas is of interest. However, due to the limited visibility in some river systems, satellites, airborne or other camera-based systems (passive systems) cannot be used. By contrast, sidescan sonar is a popular underwater acoustic imaging system that is capable of providing high- resolution monochromatic images of the seafloor and riverbeds. Although the study of sidescan sonar imaging using supervised classification has become a prominent research subject, the use of composite texture features in machine learning classification is still limited. This study describes an investigation of the use of texture analysis and feature extraction on side-scan sonar imagery in two supervised machine learning classifications: Support Vector Machine (SVM) and Decision Tree (DT). A combination of first- order texture and second-order texture is investigated to obtain the most appropriate texture features for the image classification. SVM, using linear and Gaussian kernels along with Decision Tree classifiers, was examined using selected texture features. The results of overall accuracy and kappa coefficient revealed that SVM using a linear kernel leads to a more promising result, with 77% overall accuracy and 0.62 kappa, than SVM using either a Gaussian kernel or Decision Tree (60% and 73% overall accuracy, and 0.39 and 0.59 kappa, respectively). However, this study has demonstrated that SVM using linear and Gaussian kernels as well as a Decision Tree makes it capable of being used in side-scan sonar image classification and riverbed habitat mapping.</p>
50

Gray, Michael D., Delphine Elbes, Catherine Paverd, Erasmia Lyka, Christian M. Coviello, Robin O. Cleveland e Constantin C. Coussios. "Dual Array Passive Acoustic Mapping for Cavitation Imaging with Enhanced 2-D Resolution". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2020, 1. http://dx.doi.org/10.1109/tuffc.2020.3019573.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri

Vai alla bibliografia