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Artykuły w czasopismach na temat "HiFUN simulations"
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Yadav, Sumit Kumar, Souradip Paul i Mayanglambam Suheshkumar Singh. "Effect of HIFU-Induced Thermal Ablation in Numerical Breast Phantom". Photonics 10, nr 4 (9.04.2023): 425. http://dx.doi.org/10.3390/photonics10040425.
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Breast cancer is a leading cause of cancer-related deaths in women, and treatment involved invasive surgery such as lumpectomy. In the last decade, a non-invasive, non-contact high-intensity focused ultrasound (HIFU) therapy was developed for treatment with promising results. However, its success rate depends on patient selection, tissue heterogeneities, HIFU operational parameters, and even imaging techniques. In this emerging field, computer simulations can provide us with a much-needed platform to learn, test, and deduce results virtually before conducting experiments. In this study, we used three different classes of anatomically realistic numerical breast phantoms from clinical contrast-enhanced magnetic resonance imaging (MRI) data, including scattered-, heterogeneous-, and extremely dense-type breasts. Upon assigning the appropriate acoustic and optical parameters to the tissues within, we simulated HIFU propagation by using the k-Wave toolbox in MATLAB and compared the changes introduced in the three types of breasts. It was found that scattered-type breast was best-suited for HIFU therapy. Furthermore, we simulated light-beam propagation with the ValoMC toolbox in MATLAB after introducing the lesion to compare the distribution of the initial pressure generated via the photoacoustic effect. This simulation study will be of significant clinical impact, especially in the study and management of HIFU-based treatments, which are individual/tissue-selective in nature.
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Treweek, Benjamin C., Jacob H. Brody, Alper Erturk, S. H. Swift, Chandler Smith, Cameron A. McCormick, Timothy Walsh i Nathan W. Moore. "Large-scale simulation of high-intensity focused ultrasound with Sierra/SD". Journal of the Acoustical Society of America 153, nr 3_supplement (1.03.2023): A271. http://dx.doi.org/10.1121/10.0018815.
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High-frequency simulations of acoustic wave propagation are known to be computationally challenging, and the difficulty is compounded for large domains. For problems like high-intensity focused ultrasound (HIFU) with coupling between piezoelectric and acoustic media, both challenges are present. The larger domain sizes, higher-order elements, and greater levels of refinement necessary in such simulations result in millions of degrees of freedom, large system matrices, and substantial memory requirements, raising the need for parallel high-performance computing (HPC). Sierra/SD is a massively parallel HPC application developed for finite element method simulations in structural dynamics and acoustics. In this work, Sierra/SD is used to simulate an acoustic pulse from a piezoelectric transducer focused on an elastic scatterer in a fluid medium. Three-dimensional simulation results are presented for the acoustic field in the fluid and the stress field in the scatterer, and performance is compared between Sierra/SD and COMSOL Multiphysics for smaller geometries. Finally, to showcase the expanded analysis possibilities afforded by HPC for HIFU, an example is presented using a support vector machine to determine a decision boundary for maximum stress in the scatterer. [SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.]
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SUZUKI, Katsuyuki, Daiji Fujii i Hideomi OHTSUBO. "HIFU Simulation using Voxel Analysis". Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2003.15 (2003): 153–54. http://dx.doi.org/10.1299/jsmebio.2003.15.153.
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LEE, KANG IL, IMBO SIM, GWAN SUK KANG i MIN JOO CHOI. "NUMERICAL SIMULATION OF TEMPERATURE ELEVATION IN SOFT TISSUE BY HIGH INTENSITY FOCUSED ULTRASOUND". Modern Physics Letters B 22, nr 11 (10.05.2008): 803–7. http://dx.doi.org/10.1142/s0217984908015413.
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In focused ultrasound surgery, high intensity focused ultrasound (HIFU) can be used to destroy pathological tissue deep inside the body without any damage to the surrounding normal tissue. This noninvasive technique has been used to treat malignant tumors of the liver, prostate, kidney, and benign breast tumors via a percutaneous or transrectal approach without the need for general anaesthesia. In the present study, a finite element method was used for the simulation of temperature elevation in soft tissue by HIFU. First, the HIFU field was modeled using the Westervelt equation for the propagation of finite-amplitude sound in a thermoviscous fluid in order to account for the effects of diffraction, absorption, and nonlinearity. Second, the Pennes bioheat transfer equation was used to predict the temperature elevation in soft tissue by HIFU. In order to verify the numerical simulation, the simulated temperature elevation at the focus in a tissue-mimicking phantom was compared with the measurements, using a concave focused transducer with a focal length of 62.6 mm, a radius of 35.0 mm, and a center frequency of 1.1 MHz.
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Shan, Feng, Xiasheng Guo, Juan Tu, Jianchun Cheng i Dong Zhang. "Multi-relaxation-time lattice Boltzmann modeling of the acoustic field generated by focused transducer". International Journal of Modern Physics C 28, nr 03 (marzec 2017): 1750038. http://dx.doi.org/10.1142/s0129183117500383.
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The high-intensity focused ultrasound (HIFU) has become an attractive therapeutic tool for the noninvasive tumor treatment. The ultrasonic transducer is the key component in HIFU treatment to generate the HIFU energy. The dimension of focal region generated by the transducer is closely relevant to the safety of HIFU treatment. Therefore, it is essential to numerically investigate the focal region of the transducer. Although the conventional acoustic wave equations have been used successfully to describe the acoustic field, there still exist some inherent drawbacks. In this work, we presented an axisymmetric isothermal multi-relaxation-time lattice Boltzmann method (MRT-LBM) model with the Bouzidi–Firdaouss–Lallemand (BFL) boundary condition in cylindrical coordinate system. With this model, some preliminary simulations were firstly conducted to determine a reasonable value of the relaxation parameter. Then, the validity of the model was examined by comparing the results obtained with the LBM results with the Khokhlov–Zabolotskaya–Kuznetsov (KZK) equation and the Spheroidal beam equation (SBE) for the focused transducers with different aperture angles, respectively. In addition, the influences of the aperture angle on the focal region were investigated. The proposed model in this work will provide significant references for the parameter optimization of the focused transducer for applications in the HIFU treatment or other fields, and provide new insights into the conventional acoustic numerical simulations.
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Farbin, Grace. "A preliminary numerical investigation of convolutional neural network (CNN) techniques for filtering high-intensity focused ultrasound (HIFU) noise in images". Journal of the Acoustical Society of America 153, nr 3_supplement (1.03.2023): A350. http://dx.doi.org/10.1121/10.0019119.
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High-intensity focused ultrasound (HIFU) is a minimally invasive medical procedure that uses ultrasonic waves to ablate or heat tissue with the aim of treating tumors and tremors. Diagnostic ultrasound imaging is the primary mode of imaging during HIFU treatments due to its real-time capabilities. However, HIFU noise, produced from therapeutic ultrasound components, interfere with the diagnostic ultrasound components and cause difficulty in monitoring changes to tissue during treatment. In a multitude of HIFU treatments, deep learning has been used as a tool to detect coagulation, monitor temperature, and segment tumors. Convolutional neural network (CNN) models are a series of deep learning algorithms that can assign importance to aspects of an inputted image and differentiate one from the other. Based on previous methods of filtering, CNNs too can be trained to filter raw RF signals received by an ultrasound probe for subsequent real-time treatment feedback with HIFU. Here, we were able to present a preliminary investigation of a CNN approach for HIFU noise reduction. To do this, we used acoustic wave simulations from k-Wave, a time-domain, full-wave model for ultrasound wave propagation, in combination with the Deep Learning Toolbox from MATLAB. Subsequent analyses studied the performance of noise reduction via the proposed regression model.
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Tan, Qiaolai, Xiao Zou, Yajun Ding, Xinmin Zhao i Shengyou Qian. "The Influence of Dynamic Tissue Properties on HIFU Hyperthermia: A Numerical Simulation Study". Applied Sciences 8, nr 10 (16.10.2018): 1933. http://dx.doi.org/10.3390/app8101933.
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Accurate temperature and thermal dose prediction are crucial to high-intensity focused ultrasound (HIFU) hyperthermia, which has been used successfully for the non-invasive treatment of solid tumors. For the conventional method of prediction, the tissue properties are usually set as constants. However, the temperature rise induced by HIFU irradiation in tissues will cause changes in the tissue properties that in turn affect the acoustic and temperature field. Herein, an acoustic–thermal coupling model is presented to predict the temperature and thermal damage zone in tissue in terms of the Westervelt equation and Pennes bioheat transfer equation, and the individual influence of each dynamic tissue property and the joint effect of all of the dynamic tissue properties are studied. The simulation results show that the dynamic acoustic absorption coefficient has the greatest influence on the temperature and thermal damage zone among all of the individual dynamic tissue properties. In addition, compared with the conventional method, the dynamic acoustic absorption coefficient leads to a higher focal temperature and a larger thermal damage zone; on the contrary, the dynamic blood perfusion leads to a lower focal temperature and a smaller thermal damage zone. Moreover, the conventional method underestimates the focal temperature and the thermal damage zone, compared with the simulation that was performed using all of the dynamic tissue properties. The results of this study will be helpful to guide the doctors to develop more accurate clinical protocols for HIFU treatment planning.
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Zhao, Peng, Yuebing Wang, Shiqi Tong, Jie Tao i Yongjie Sheng. "The Effects of Energy on the Relationship between the Acoustic Focal Region and Biological Focal Region during Low-Power Cumulative HIFU Ablation". Applied Sciences 13, nr 7 (1.04.2023): 4492. http://dx.doi.org/10.3390/app13074492.
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The biological focal region (BFR) induced by a single high-intensity focused ultrasound (HIFU) exposure is considered to be the foundation of the ultrasound ablation of tumor lesions. The purpose of this study was to explore the relationship between the acoustic focal region (AFR) and the BFRs with different combinations of power and time in low-power cumulative HIFU treatment. The finite-difference time-domain (FDTD) method was used to simulate AFR and BFR during HIFU ablation. The acoustic fields, the temperature profiles, and the shapes of BFRs were calculated by the Westervelt equation, Pennes’ equation, and the equivalent thermal dose model. In order to verify the simulation rules, phantom and ex vivo bovine livers were exposed by HIFU with a different power and time. The results demonstrated that in the low-power cumulative HIFU treatment, when the lengths of BFRs and the length of AFR were approximately equal, the shape of the BFR induced by ‘high power × short time’ exposure was closer to that of AFR than the shape of the BFR induced by ‘low power × long time’ exposure, and the exposure energy required was significantly reduced. The analysis revealed the relationship between the BFR and the AFR with different acoustic power. This study provides a reference for doctors to determine power, time, and movement distance in clinical treatment.
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Daschner, Rosa, Holger Hewener, Wolfgang Bost, Steffen Weber, Steffen Tretbar i Marc Fournelle. "Ultrasound Thermometry for HIFU-Therapy". Current Directions in Biomedical Engineering 7, nr 2 (1.10.2021): 554–57. http://dx.doi.org/10.1515/cdbme-2021-2141.
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Abstract High-Intensity Focused Ultrasound (HIFU) is an alternative tumour therapy with the ability for non-invasive thermal ablation of tissue. For a safe application, the heat deposition needs to be monitored over time, which is currently done with Magnetic Resonance Imaging. Ultrasound (US) based monitoring is a promising alternative, as it is less expensive and allows the use of a single device for both therapy and monitoring. In this work, a method for spatial and temporal US thermometry has been investigated based on simulation studies and in-vitro measurements. The chosen approach is based on the approximately linear dependence between temperature and speed of sound (SoS) in tissue for a given temperature range. By tracking the speckles of successive B-images, the possibility of detecting local changes in SoS and therefore in temperature is given. A speckle tracking algorithm was implemented for 2D and 3D US thermometry using a spatial compounding method to reduce artifacts. The algorithm was experimentally validated in an agar-based phantom and in porcine tissue for temperature rises up to △ 8°C. We used a focusing single element US transducer as therapeutic probe, a linear (/matrix array) transducer with 128 (/32∙32) elements for imaging and thermocouples for validation and calibration. In all experiments, both computational and in-vitro, we succeeded in monitoring the thermal induced SoS changes over time. The in-vitro measurements were in good agreement with the simulation results and the thermocouple measurements (rms temperature difference = 0.53 °C, rms correlation coefficient = 0. 96).
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Wang, Haoyang, Yuchen Sun, Yuxin Wang, Ying Chen, Yun Ge, Jie Yuan i Paul Carson. "Temperature-Controlled Hyperthermia with Non-Invasive Temperature Monitoring through Speed of Sound Imaging". Applied Sciences 13, nr 12 (20.06.2023): 7317. http://dx.doi.org/10.3390/app13127317.
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Hyperthermia therapy (HT) is used to treat diseases through heating of high temperature usually in conjunction with some other medical therapeutics such as chemotherapy and radiotherapy. In this study, we propose a promising temperature-controlled hyperthermia method that uses high-intensity focused ultrasound (HIFU) for clinical tumor treatment combined with diagnostic ultrasound image guidance and non-invasive temperature monitoring through speed of sound (SOS) imaging. HIFU heating is realized by a ring ultrasound transducer array with 256 elements. In this study, tumors in the human thigh were set as heating targets. The inner structure information of thigh tissue is obtained by B-mode ultrasound imaging. Since the relationship between temperature and SOS in different human tissue is available, the temperature detection is converted to the SOS detection obtained by the full-wave inversion (FWI) method. Simulation results show that our model can achieve expected hyperthermia of constant temperature on tumor target with 0.2 °C maximum temperature fluctuation for 5 h. Through simulation, our proposed thermal therapy model achieves accurate temperature control of ±0.2 °C in human thigh tumors, which verifies the feasibility of the proposed temperature-controlled hyperthermia model. Furthermore, the temperature measurement can share the same ring ultrasound transducer array for HIFU heating and B-mode ultrasound imaging, which provides a guiding significance for clinical application.
Rozprawy doktorskie na temat "HiFUN simulations"
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Barnat, Nesrine. "Conception et validation d'une méthode non-invasive de traitement des varices par ultrasons focalisés de haute intensité". Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLET057.
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Cette thèse avait pour objectif le développement d’une méthode d’ablation thermique non-invasive des veines par ultrasons focalisés de haute intensité (HIFU). Elle a pour but de démontrer la preuve de concepts et permettre à terme le traitement des varices des membres inférieurs avec le dispositif de Theraclion.La possibilité d’occlure des vaisseaux de petits calibres a tout d’abord été investiguée. Deux procédures de traitement candidates ont été évaluées par simulations numériques puis in vivo sur des veines de lapin. L’analyse histologique a démontré l’efficacité des traitements, en particulier lorsque les vaisseaux étaient comprimés lors des tirs.Une nouvelle procédure d’ablation thermique a ensuite été conçue pour coaguler des veines de plus gros calibres, de diamètre plus proche des varices humaines. Des mesures de températures in vivo sur des veines de brebis lors de tirs HIFU ont permis d’estimer le pas de tir permettant d’obtenir une coagulation continue le long de la veine. Des essais en aigu sur des veines saphènes de brebis ont permis de quantifier les dommages thermiques et de valider l’efficacité immédiate de notre méthode de traitement. Enfin, une étude avec suivis distants jusqu’à 90 jours a été conduite chez la brebis afin d’étudier l’efficacité et la sécurité à long terme de notre méthode de traitement. L’analyse histologique des dommages thermiques a validé sur la brebis la performance et la sécurité de notre méthode d’ablation thermique. D’un point de vue histopathologique, les dommages engendrés par nos traitements HIFU se sont également révélés similaires à ceux observés après traitement par radiofréquence, une technique endovasculaire d’ablation thermique des varices.L’ensemble de ces travaux a permis à Theraclion d’obtenir l’autorisation de conduire un essai clinique sur 50 patients. Les résultats très positifs de cette étude ont conduit à l’obtention du marquage CE du dispositif HIFU pour cette indication thérapeutiqueA novel thermal approach to treat non-invasively incompetent veins with high-intensity focused ultrasound (HIFU) is presented in this thesis.The ability to occlude small veins was first investigated. Two different sonication procedures were evaluated by numerical simulations and tested in vivo on rabbit veins. The histologic examination of the treated veins demonstrated the efficacy of the treatments, especially when the vein was compressed during ultrasonic exposures.A new procedure was then designed in order to coagulate larger veins, closer to human vein diameters. Experimental temperature measurements at the vein wall during HIFU pulses were used as inputs to determine numerically the optimum spacing between the pulses in order to induce a continuous coagulation along the vein. Acute animal trials on sheep veins were conducted to quantify tissue damages following such treatments. Finally, chronic studies up to 90 days were conducted on sheep in order to evaluate the long-term safety and efficacy of our treatment procedure. The histological findings validated the performance and safety of our HIFU thermal method, in a sheep model. From a pathology standpoint, the HIFU lesions are similar to those observed after radiofrequency ablation (an endovenous thermal modality used for the treatment of varicose veins).The results presented in this thesis allowed Theraclion to get the authorization to conduct first-in-human clinical trials for varicose vein treatments. The results were very encouraging and led to the CE-marking of the HIFU system
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Bing, Fabrice. "Traitement des lésions osseuses par Ultrasons Focalisés de Haute Intensité : de la simulation aux applications cliniques". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD045/document.
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Après un état de l’art sur l’ablation des lésions osseuses, les expérimentations HIFU sur l’os présentées ont montré un échauffement périosté plus étendu avec un tir profond. Les tirs sur le ciment, dont le coefficient α a été mesuré, reproduisent les mêmes courbes thermiques. Une simulation a été réalisée avec 2 valeurs de α (4.7 et 9.9 dB/cm) : l’échauffement est moins important avec α=4.7. La simulation confirme certains résultats de la thermo-IRM : une élévation thermique maximale au niveau du périoste (zone focale) avec le tir superficiel, un échauffement latéral plus marqué avec le tir profond et une tendance à l’inertie thermique. A partir d’une analyse rétrospective des cas traités par imagerie mini-invasive, l’ablation HIFU semble possible pour 50% des ostéomes ostéoïdes et 35.7% des métastases. 35.9% de cas supplémentaires auraient pu être traités par HIFU si une protection des structures sensibles ou une consolidation étaient réalisées. A 1 MHz, l’interférence des aiguilles avec les US n’était visible qu’avec les aiguilles 13G. Si les aiguilles 18 à 22G interfèrent peu avec les US, un écran acoustique pourrait se former à la suite d’injection de liquideAfter a “state of art” on bone lesions ablation techniques, bone experimentations presented showed that deep focalisation allows the best lateral periosteal heating. On cement, from which the coefficient α was measured, the same thermic curves were observed. A simulation was done with two values of α (4.7 et 9.9 dB/cm). A higher heating at the periosteal focal point with superficial focalisation and a higher periosteal lateral heating with deep focalisation with a thermic inertia, were confirmed with simulation. Heating was higher with the high α value. A retrospective analysis of the bone lesions treated with minimally invasive treatment showed that 50% of osteoid osteomas and 35.7% of metastases were classified as suitable with MRgHIFU alone. 35.9% additional cases may have been treated with dissection or consolidation. At 1 MHz, US distortion due to the presence of needles in the US cone was observed only with the 13-gauge needle. However, if 18 to 22G needles may induce few distortion, an acoustic barrier may appear if the liquid injected flows in front of the US
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Grisey, Anthony. "Modélisation et optimisation de la déposition de chaleur pour les ablations thermiques par ultrasons focalisés". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLC008.
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L'objectif de ce manuscrit est de présenter mes travaux concernant la modélisation des ablations thermiques par ultrasons focalisés. La méthode de simulation du faisceau acoustique, fondée sur l'utilisation de la bibliothèque k-Wave, est appliquée à un cas concret de propagation des ultrasons à travers une couche de tissu superficiel. Des mesures à l'hydrophone réalisées dans différentes configurations sur des échantillons biologiques fournissent une validation en régime linéaire. A partir de ces résultats, l'influence des tissus superficiels sur la focalisation est évaluée en fonction de la géométrie du problème grâce à des simulations non linéaires.La modélisation thermique des traitements est ensuite discutée avec la volonté de réaliser des simulations thermiques réellement quantitatives. En particulier, un modèle équivalent de la déposition de chaleur en présence d'ébullition est proposé et validé grâce à l'utilisation de données expérimentales originales, diversifiées et peu coûteuses à acquérir.Finalement, un algorithme d'optimisation fondé sur le principe du maximum de Pontryagin est proposé afin d'optimiser la durée des traitements. L'approche étudiée consiste à optimiser la trajectoire du point focal pour maximiser l'efficacité de la déposition de chaleur. A travers une série d'exemples, les avantages et les limites de l'algorithme proposé sont discutésThis manuscript aims at discussing the complex issue of modeling high-intensity focused ultrasound thermal ablations. An acoustical simulation method, based on the use of the k-Wave library, is described and applied to the description of the interaction between the acoustic beam and the superficial tissue layers. It is validated in the linear domain based on hydrophone measurements realized in different configurations with biological samples. Nonlinear simulations are subsequently used to evaluate the influence of the tissue geometry on the beam focusing.The thermal modeling of the treatment is then discussed with intent to design a truly quantitative model. An equivalent model of the modified heat deposition pattern in presence of boiling is presented and validated based on the use of original, diverse and unexpensive data.Finally, an algorithm is proposed to optimize the focal spot trajectory in order to maximize the heat deposition efficiency, thus reducing treatment time. The advantages and the limits of the approach are discussed based on different examples
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Chen, Ben-Ting, i 陳北亭. "Numerical simulation of lesion formation and temperature distribution in HIFU ablation". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/12210831928497123194.
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博士中原大學
土木工程研究所
103
Abstract High-intensity focused ultrasound (HIFU) has become a potential alternative to conventional therapies for primary and metastatic tumors, especially for those patients who are not suitable candidates for surgical resection. Thorough understanding of HIFU characteristics is important both for the accurate prediction of ultrasound induced bioeffects in tissues and for the development of standards to ensure the safety and efficacy of treatments. In-vitro experiments and numerical simulations are useful for prototyping and optimizing the geometries of device designs. In addition, they also form the basis of treatment planning platforms that assist physicians in tailoring thermal therapy procedures and operating parameters. Polymerization of N-isopropylacrylamide (NIPAM) with acrylic acid (AAc) has been adopted to fabricate reusable tissue-mimicking hydrogel phantoms designed for the real-time visualization and examination of thermal lesion formation in ablation and hyperthermia therapies. The cloud point temperature of the NIPAM-based hydrogel phantoms can be adjusted by the concentration of AAc to represent the threshold temperature of pain (42 C) or tissue damage (52 C). The mechanical, thermal and acoustic properties of the developed phantoms are similar to those of human soft tissues. The ability of the phantoms to provide visualization of thermal lesions produced by either microwave or high-intensity focused ultrasound (HIFU) ablation was examined. By processing the optical images of the phantoms at different stages of the heating process, a thermal lesion can be considered formed (i.e., threshold temperature reached) when the grayscale value reaches the half-saturation point. Additionally, energy thresholds for inducing transient or permanent bubbles in the phantoms during HIFU ablation were also identified to shed light on the onset of cavitation or material damage. An integrated computational framework for modeling HIFU thermal ablation is proposed in this study. The temperature field was obtained by solving the bioheat transfer equation (BHTE) through the finite element method, while the lesion was considered as denatured material and modelled with the latent heat. An equivalent attenuation coefficient, which considers the temperature-dependent properties of the phantom and ultrasound diffraction due to bubbles, is proposed in the nonlinear thermal transient analysis. Moreover, a modified thermal dose formulation is also proposed to predict the lesion size, shape, and location. In-vitro thermal ablation experiments using HIFU under different electrical powers were carried out to validate this computational framework. Our numerical results demonstrated that temperature histories and lesion areas from the proposed model correlated well with those from in-vitro experiments. Finally, we develop a novel method for both temperature estimation and thermal mapping that uses ultrasound B-mode RF data. The proposed method is a hybrid that combines elements of physical and statistical models to achieve higher precision and resolution of temperature variations and distribution. We propose a dimensionless combined index (CI) that combines the echo shift differential and signal intensity difference with a weighting factor relative to the distance from the heat source. In vitro experiments were performed, verifying that the combined index has a strong linear relationship with temperature variation and can be used to effectively estimate temperature with an average relative error of less than 5%. This algorithm provides an alternative for imaging guidance-based techniques during thermal therapy, and could easily be integrated into existing ultrasound systems.
Części książek na temat "HiFUN simulations"
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Nakajima, Y., J. Uebayashi, Y. Tamura i Y. Matsumoto. "Large-scale simulation for HIFU treatment to brain". W Shock Waves, 863–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-85181-3_11.
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Lilkova, E., N. Ilieva, P. Petkov, E. Krachmarova, G. Nacheva i L. Litov. "Molecular Dynamics Simulations of His$$_6$$-FLAG-hIFN$$\gamma $$ Fusion Glycoproteins". W Advanced Computing in Industrial Mathematics, 256–67. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71616-5_23.
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Audigier, Chloé, Younsu Kim, Nicholas Ellens i Emad M. Boctor. "Physics-Based Simulation to Enable Ultrasound Monitoring of HIFU Ablation: An MRI Validation". W Medical Image Computing and Computer Assisted Intervention – MICCAI 2018, 89–97. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-00937-3_11.
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"Numerical Simulation of High Intensity Focused Ultrasound (HIFU) Using a Fully Compressible Multiscale Model". W Proceedings of the 10th International Symposium on Cavitation (CAV2018), 789–94. ASME Press, 2018. http://dx.doi.org/10.1115/1.861851_ch150.
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Arif, Tariq M., i Zhiming Ji. "A Fast Estimation Model for Angular Spectrum Based Focused Ultrasound Wave Simulation in Layered Tissue Media". W ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-11088.
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Abstract High-Intensity Focused Ultrasound (HIFU) is a popular non-invasive therapeutic tool and widely used in many clinical settings. The simulation models used for HIFU responses are computationally expensive and time-consuming. Among many numerical HIFU simulation methods, the Rayleigh-Sommerfeld approach is considered to be a reliable one. However, Rayleigh-Sommerfeld is suitable for homogeneous medium, and for a heterogeneous media, many approximations should be made in order to reduce the calculation time. In this study, we propose a fast methodology for estimating focused ultrasound pressure-temperature field responses through layered tissue media. A computationally efficient nonlinear angular spectrum-based method that can address the effects of varying attenuations, reflections and refractions from tissue layers is implemented to calculate reference datasets. From the simulation datasets, a profile function coupled with a GUI code is constructed for estimating the pressure-temperature response by using a Gaussian function and a Genetic Algorithm. The HIFU response model illustrated in this study can be advantageous and time-effective when multiple simulations are required on a similar complex patient model, and it can be used to guide and reduce the sets of simulations required for planning HIFU treatment.
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Okita, Kohei, Ryuta Narumi, Takashi Azuma, Shu Takagi i Yoichiro Matsumoto. "Modeling and Simulation of High-Intensity Focused Ultrasound Therapy for Breast Cancer". W ASME 2013 Conference on Frontiers in Medical Devices: Applications of Computer Modeling and Simulation. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fmd2013-16055.
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Therapeutic application of ultrasound is of interest for a tumor treatment, thrombolysis, drag delivery, blood-brain barrier opening and so on. High-intensity focused ultrasound (HIFU) therapy has been developed as the noninvasive treatment deep cancers in particular. Issues as the defocusing and distortion of ultrasound in the body and the long treatment time in current HIFU should be resolved quickly. Numerical simulation is required for the early development of the advance HIFU system.
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Chao, Yu-Tin, Ya-Lin Yu, Jia-Yush Yen, Che-Jung Hsu, Michael Kam, Shih Tang Liu, Ming-Chih Ho, Yung-Yaw Chen i Feng-Li Lian. "A Novel Design of High Intensity Focus Ultrasound (HIFU) for Enlarged Focus Area Application". W Modelling and Simulation. Calgary,AB,Canada: ACTAPRESS, 2013. http://dx.doi.org/10.2316/p.2013.802-036.
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Solovchuk, Maxim A., Tony W. H. Sheu i Marc Thiriet. "Investigation Into the Acoustic Streaming and Convective Cooling Phenomena During a High-Intensity Focused Ultrasound Thermal Ablation". W ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-19004.
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The present study is aimed at predicting liver tumor temperature increase during a high-intensity focused ultrasound (HIFU) thermal ablation using the proposed acoustics-heat-fluid coupling model. The linear Westervelt equation is adopted for modeling the incident finite-amplitude wave propagation. The nonlinear hemodynamic equations are also taken into account in the simulation domain that contains a hepatic tissue domain, where homogenization dominates perfusion, and a vascular domain, where blood convective cooling may be essential in determining the success of HIFU. We also consider the energy equation for the modeling thermal conduction heat transfer. Two heat sinks are dealt with to account for tissue perfusion and forced convection-induced cooling. The effect of acoustic streaming is also included in the current HIFU simulation study. Convective cooling in large blood vessel and acoustic streaming were shown to change the temperature near blood vessel. It was shown that the acoustic streaming effect can change the blood flow distribution in hepatic arterial branches and leads to mass flux redistribution. The effect of acoustic streaming can be used to control blood drug delivery. In the current work the realistic geometry for the blood vessel and liver was reconstructed using the MRI images. The presented results may be further used to construct a surgical planning platform for the non-invasive HIFU (High-Intensity Focal Ultrasound) tumor ablating (or cauterizing) therapy in real liver geometry on the basis of the MRI image.
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Magda Abbas, A., C. Constatin- Coussios i O. Robin Cleveland. "Patient Specific Simulation of HIFU Kidney Tumour Ablation". W 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2018. http://dx.doi.org/10.1109/embc.2018.8513647.
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Xiaorui, Chen, Zhang Xiaojing, Wang Shaolin i Jian Xiqi. "Simulation of the therapeutic region during HIFU therapy". W 2011 4th International Conference on Biomedical Engineering and Informatics (BMEI). IEEE, 2011. http://dx.doi.org/10.1109/bmei.2011.6098400.
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Soneson, Joshua E., i Emad S. Ebbini. "A User-Friendly Software Package for HIFU Simulation". W 8TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND. AIP, 2009. http://dx.doi.org/10.1063/1.3131405.
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Schaal, Christoph, i Vibhav Durgesh. "Investigation of the Scattering of Focused Ultrasonic Waves at Bones". W ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-87133.
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High-intensity focused ultrasound (HIFU) can be used for the ablation of tissue, such as in the case of prostate cancer. However, targeting tissue deeper inside the body remains challenging due to the increased attenuation and scattering of the ultrasonic waves. In this work, the partial and complete obstruction of the ultrasonic beam from a HIFU transducer at bones is investigated. Ultrasonic transmission and reflection under such conditions have scarcely been the focus of previous research. Thus, this work provides a reference based on numerical and experimental results. To this end, numerical simulations are conducted for various bone obstruction configurations. In addition, a diffraction-based shadowgraph technique is used for the ultrasound visualization in laboratory experiments. Imaging of focused ultrasonic waves is performed in water with no obstruction, varying partial obstruction, as well as with complete obstruction by bones phantoms. It is shown that there is reasonable agreement between the findings from experiments and simulations. While the field of view in experiments is limited, the entire pressure field in the area of interest can be investigated in numerical simulations. Overall, the results of this work provide a basis for future research in the field of therapeutic ultrasound.
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Ma, Jingsen, Xiaolong Deng, Chao-Tsung Hsiao i Georges L. Chahine. "Hybrid MPI-OpenMP Accelerated Euler-Lagrange Simulations of Microbubble Enhanced HIFU". W ASME 2021 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/fedsm2021-65815.
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Abstract Microbubble enhanced High Intensity Focused Ultrasound (HIFU) is of great interest to tissue ablation for solid tumor treatments such as in liver and brain cancers, in which contrast agents/microbubbles are injected into the targeted region to promote heating and reduce pre-focal tissue damage. A compressible Euler-Lagrange coupled model has been developed to accurately characterize the acoustic and thermal fields during this process. This employs a compressible Navier-Stokes solver for the ultrasound acoustic field and a discrete singularities model for bubble dynamics. To address the demanding computational cost in practical biological applications, a multi-level hybrid MPI-OpenMP parallelization scheme is developed to take advantage of both scalability of MPI and load balancing of OpenMP. At the first level, the Eulerian computational domain is divided into multiple subdomains and the bubbles are subdivided in groups based on which subdomain they fall into. At the next level, in each subdomain containing bubbles, multiple OpenMP threads are activated to speed up the bubble computations. More OpenMP threads are used inside each subdomain where the bubbles are clustered. By doing this, MPI load imbalance issue due to non-uniformity of bubble presence is compensated. The hybrid MPI-OpenMP Euler-Lagrange solver is used to conduct simulations and physical studies of bubble-enhanced HIFU problems containing a large number of microbubbles. The phenomenon of acoustic shadowing caused by the bubble cloud is then analyzed and discussed. Hybrid parallelization efficiency tests and demonstration of its advantages against using MPI alone are presented.
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Amin, Viren. "HIFU Therapy Planning Using Pre-treatment Imaging and Simulation". W THERAPEUTIC ULTRASOUND: 5th International Symposium on Therapeutic Ultrasound. AIP, 2006. http://dx.doi.org/10.1063/1.2205467.
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